repo
stringlengths 2
152
⌀ | file
stringlengths 15
239
| code
stringlengths 0
58.4M
| file_length
int64 0
58.4M
| avg_line_length
float64 0
1.81M
| max_line_length
int64 0
12.7M
| extension_type
stringclasses 364
values |
|---|---|---|---|---|---|---|
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/manifold/tests/test_mds.py | import numpy as np
from numpy.testing import assert_array_almost_equal
from sklearn.manifold import mds
from sklearn.utils.testing import assert_raises
def test_smacof():
# test metric smacof using the data of "Modern Multidimensional Scaling",
# Borg & Groenen, p 154
sim = np.array([[0, 5, 3, 4],
[5, 0, 2, 2],
[3, 2, 0, 1],
[4, 2, 1, 0]])
Z = np.array([[-.266, -.539],
[.451, .252],
[.016, -.238],
[-.200, .524]])
X, _ = mds.smacof(sim, init=Z, n_components=2, max_iter=1, n_init=1)
X_true = np.array([[-1.415, -2.471],
[1.633, 1.107],
[.249, -.067],
[-.468, 1.431]])
assert_array_almost_equal(X, X_true, decimal=3)
def test_smacof_error():
# Not symmetric similarity matrix:
sim = np.array([[0, 5, 9, 4],
[5, 0, 2, 2],
[3, 2, 0, 1],
[4, 2, 1, 0]])
assert_raises(ValueError, mds.smacof, sim)
# Not squared similarity matrix:
sim = np.array([[0, 5, 9, 4],
[5, 0, 2, 2],
[4, 2, 1, 0]])
assert_raises(ValueError, mds.smacof, sim)
# init not None and not correct format:
sim = np.array([[0, 5, 3, 4],
[5, 0, 2, 2],
[3, 2, 0, 1],
[4, 2, 1, 0]])
Z = np.array([[-.266, -.539],
[.016, -.238],
[-.200, .524]])
assert_raises(ValueError, mds.smacof, sim, init=Z, n_init=1)
def test_MDS():
sim = np.array([[0, 5, 3, 4],
[5, 0, 2, 2],
[3, 2, 0, 1],
[4, 2, 1, 0]])
mds_clf = mds.MDS(metric=False, n_jobs=3, dissimilarity="precomputed")
mds_clf.fit(sim)
| 1,873 | 29.225806 | 77 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/manifold/tests/test_spectral_embedding.py | import numpy as np
from numpy.testing import assert_array_almost_equal
from numpy.testing import assert_array_equal
from scipy import sparse
from scipy.linalg import eigh
from sklearn.manifold.spectral_embedding_ import SpectralEmbedding
from sklearn.manifold.spectral_embedding_ import _graph_is_connected
from sklearn.manifold.spectral_embedding_ import _graph_connected_component
from sklearn.manifold import spectral_embedding
from sklearn.metrics.pairwise import rbf_kernel
from sklearn.metrics import normalized_mutual_info_score
from sklearn.cluster import KMeans
from sklearn.datasets.samples_generator import make_blobs
from sklearn.utils.extmath import _deterministic_vector_sign_flip
from sklearn.utils.testing import assert_true, assert_equal, assert_raises
from sklearn.utils.testing import SkipTest
# non centered, sparse centers to check the
centers = np.array([
[0.0, 5.0, 0.0, 0.0, 0.0],
[0.0, 0.0, 4.0, 0.0, 0.0],
[1.0, 0.0, 0.0, 5.0, 1.0],
])
n_samples = 1000
n_clusters, n_features = centers.shape
S, true_labels = make_blobs(n_samples=n_samples, centers=centers,
cluster_std=1., random_state=42)
def _check_with_col_sign_flipping(A, B, tol=0.0):
""" Check array A and B are equal with possible sign flipping on
each columns"""
sign = True
for column_idx in range(A.shape[1]):
sign = sign and ((((A[:, column_idx] -
B[:, column_idx]) ** 2).mean() <= tol ** 2) or
(((A[:, column_idx] +
B[:, column_idx]) ** 2).mean() <= tol ** 2))
if not sign:
return False
return True
def test_sparse_graph_connected_component():
rng = np.random.RandomState(42)
n_samples = 300
boundaries = [0, 42, 121, 200, n_samples]
p = rng.permutation(n_samples)
connections = []
for start, stop in zip(boundaries[:-1], boundaries[1:]):
group = p[start:stop]
# Connect all elements within the group at least once via an
# arbitrary path that spans the group.
for i in range(len(group) - 1):
connections.append((group[i], group[i + 1]))
# Add some more random connections within the group
min_idx, max_idx = 0, len(group) - 1
n_random_connections = 1000
source = rng.randint(min_idx, max_idx, size=n_random_connections)
target = rng.randint(min_idx, max_idx, size=n_random_connections)
connections.extend(zip(group[source], group[target]))
# Build a symmetric affinity matrix
row_idx, column_idx = tuple(np.array(connections).T)
data = rng.uniform(.1, 42, size=len(connections))
affinity = sparse.coo_matrix((data, (row_idx, column_idx)))
affinity = 0.5 * (affinity + affinity.T)
for start, stop in zip(boundaries[:-1], boundaries[1:]):
component_1 = _graph_connected_component(affinity, p[start])
component_size = stop - start
assert_equal(component_1.sum(), component_size)
# We should retrieve the same component mask by starting by both ends
# of the group
component_2 = _graph_connected_component(affinity, p[stop - 1])
assert_equal(component_2.sum(), component_size)
assert_array_equal(component_1, component_2)
def test_spectral_embedding_two_components(seed=36):
# Test spectral embedding with two components
random_state = np.random.RandomState(seed)
n_sample = 100
affinity = np.zeros(shape=[n_sample * 2, n_sample * 2])
# first component
affinity[0:n_sample,
0:n_sample] = np.abs(random_state.randn(n_sample, n_sample)) + 2
# second component
affinity[n_sample::,
n_sample::] = np.abs(random_state.randn(n_sample, n_sample)) + 2
# Test of internal _graph_connected_component before connection
component = _graph_connected_component(affinity, 0)
assert_true(component[:n_sample].all())
assert_true(not component[n_sample:].any())
component = _graph_connected_component(affinity, -1)
assert_true(not component[:n_sample].any())
assert_true(component[n_sample:].all())
# connection
affinity[0, n_sample + 1] = 1
affinity[n_sample + 1, 0] = 1
affinity.flat[::2 * n_sample + 1] = 0
affinity = 0.5 * (affinity + affinity.T)
true_label = np.zeros(shape=2 * n_sample)
true_label[0:n_sample] = 1
se_precomp = SpectralEmbedding(n_components=1, affinity="precomputed",
random_state=np.random.RandomState(seed))
embedded_coordinate = se_precomp.fit_transform(affinity)
# Some numpy versions are touchy with types
embedded_coordinate = \
se_precomp.fit_transform(affinity.astype(np.float32))
# thresholding on the first components using 0.
label_ = np.array(embedded_coordinate.ravel() < 0, dtype="float")
assert_equal(normalized_mutual_info_score(true_label, label_), 1.0)
def test_spectral_embedding_precomputed_affinity(seed=36):
# Test spectral embedding with precomputed kernel
gamma = 1.0
se_precomp = SpectralEmbedding(n_components=2, affinity="precomputed",
random_state=np.random.RandomState(seed))
se_rbf = SpectralEmbedding(n_components=2, affinity="rbf",
gamma=gamma,
random_state=np.random.RandomState(seed))
embed_precomp = se_precomp.fit_transform(rbf_kernel(S, gamma=gamma))
embed_rbf = se_rbf.fit_transform(S)
assert_array_almost_equal(
se_precomp.affinity_matrix_, se_rbf.affinity_matrix_)
assert_true(_check_with_col_sign_flipping(embed_precomp, embed_rbf, 0.05))
def test_spectral_embedding_callable_affinity(seed=36):
# Test spectral embedding with callable affinity
gamma = 0.9
kern = rbf_kernel(S, gamma=gamma)
se_callable = SpectralEmbedding(n_components=2,
affinity=(
lambda x: rbf_kernel(x, gamma=gamma)),
gamma=gamma,
random_state=np.random.RandomState(seed))
se_rbf = SpectralEmbedding(n_components=2, affinity="rbf",
gamma=gamma,
random_state=np.random.RandomState(seed))
embed_rbf = se_rbf.fit_transform(S)
embed_callable = se_callable.fit_transform(S)
assert_array_almost_equal(
se_callable.affinity_matrix_, se_rbf.affinity_matrix_)
assert_array_almost_equal(kern, se_rbf.affinity_matrix_)
assert_true(
_check_with_col_sign_flipping(embed_rbf, embed_callable, 0.05))
def test_spectral_embedding_amg_solver(seed=36):
# Test spectral embedding with amg solver
try:
from pyamg import smoothed_aggregation_solver # noqa
except ImportError:
raise SkipTest("pyamg not available.")
se_amg = SpectralEmbedding(n_components=2, affinity="nearest_neighbors",
eigen_solver="amg", n_neighbors=5,
random_state=np.random.RandomState(seed))
se_arpack = SpectralEmbedding(n_components=2, affinity="nearest_neighbors",
eigen_solver="arpack", n_neighbors=5,
random_state=np.random.RandomState(seed))
embed_amg = se_amg.fit_transform(S)
embed_arpack = se_arpack.fit_transform(S)
assert_true(_check_with_col_sign_flipping(embed_amg, embed_arpack, 0.05))
def test_pipeline_spectral_clustering(seed=36):
# Test using pipeline to do spectral clustering
random_state = np.random.RandomState(seed)
se_rbf = SpectralEmbedding(n_components=n_clusters,
affinity="rbf",
random_state=random_state)
se_knn = SpectralEmbedding(n_components=n_clusters,
affinity="nearest_neighbors",
n_neighbors=5,
random_state=random_state)
for se in [se_rbf, se_knn]:
km = KMeans(n_clusters=n_clusters, random_state=random_state)
km.fit(se.fit_transform(S))
assert_array_almost_equal(
normalized_mutual_info_score(
km.labels_,
true_labels), 1.0, 2)
def test_spectral_embedding_unknown_eigensolver(seed=36):
# Test that SpectralClustering fails with an unknown eigensolver
se = SpectralEmbedding(n_components=1, affinity="precomputed",
random_state=np.random.RandomState(seed),
eigen_solver="<unknown>")
assert_raises(ValueError, se.fit, S)
def test_spectral_embedding_unknown_affinity(seed=36):
# Test that SpectralClustering fails with an unknown affinity type
se = SpectralEmbedding(n_components=1, affinity="<unknown>",
random_state=np.random.RandomState(seed))
assert_raises(ValueError, se.fit, S)
def test_connectivity(seed=36):
# Test that graph connectivity test works as expected
graph = np.array([[1, 0, 0, 0, 0],
[0, 1, 1, 0, 0],
[0, 1, 1, 1, 0],
[0, 0, 1, 1, 1],
[0, 0, 0, 1, 1]])
assert_equal(_graph_is_connected(graph), False)
assert_equal(_graph_is_connected(sparse.csr_matrix(graph)), False)
assert_equal(_graph_is_connected(sparse.csc_matrix(graph)), False)
graph = np.array([[1, 1, 0, 0, 0],
[1, 1, 1, 0, 0],
[0, 1, 1, 1, 0],
[0, 0, 1, 1, 1],
[0, 0, 0, 1, 1]])
assert_equal(_graph_is_connected(graph), True)
assert_equal(_graph_is_connected(sparse.csr_matrix(graph)), True)
assert_equal(_graph_is_connected(sparse.csc_matrix(graph)), True)
def test_spectral_embedding_deterministic():
# Test that Spectral Embedding is deterministic
random_state = np.random.RandomState(36)
data = random_state.randn(10, 30)
sims = rbf_kernel(data)
embedding_1 = spectral_embedding(sims)
embedding_2 = spectral_embedding(sims)
assert_array_almost_equal(embedding_1, embedding_2)
def test_spectral_embedding_unnormalized():
# Test that spectral_embedding is also processing unnormalized laplacian
# correctly
random_state = np.random.RandomState(36)
data = random_state.randn(10, 30)
sims = rbf_kernel(data)
n_components = 8
embedding_1 = spectral_embedding(sims,
norm_laplacian=False,
n_components=n_components,
drop_first=False)
# Verify using manual computation with dense eigh
laplacian, dd = sparse.csgraph.laplacian(sims, normed=False,
return_diag=True)
_, diffusion_map = eigh(laplacian)
embedding_2 = diffusion_map.T[:n_components] * dd
embedding_2 = _deterministic_vector_sign_flip(embedding_2).T
assert_array_almost_equal(embedding_1, embedding_2)
| 11,104 | 41.064394 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/manifold/tests/test_isomap.py | from itertools import product
import numpy as np
from numpy.testing import (assert_almost_equal, assert_array_almost_equal,
assert_equal)
from sklearn import datasets
from sklearn import manifold
from sklearn import neighbors
from sklearn import pipeline
from sklearn import preprocessing
from sklearn.utils.testing import assert_less
eigen_solvers = ['auto', 'dense', 'arpack']
path_methods = ['auto', 'FW', 'D']
def test_isomap_simple_grid():
# Isomap should preserve distances when all neighbors are used
N_per_side = 5
Npts = N_per_side ** 2
n_neighbors = Npts - 1
# grid of equidistant points in 2D, n_components = n_dim
X = np.array(list(product(range(N_per_side), repeat=2)))
# distances from each point to all others
G = neighbors.kneighbors_graph(X, n_neighbors,
mode='distance').toarray()
for eigen_solver in eigen_solvers:
for path_method in path_methods:
clf = manifold.Isomap(n_neighbors=n_neighbors, n_components=2,
eigen_solver=eigen_solver,
path_method=path_method)
clf.fit(X)
G_iso = neighbors.kneighbors_graph(clf.embedding_,
n_neighbors,
mode='distance').toarray()
assert_array_almost_equal(G, G_iso)
def test_isomap_reconstruction_error():
# Same setup as in test_isomap_simple_grid, with an added dimension
N_per_side = 5
Npts = N_per_side ** 2
n_neighbors = Npts - 1
# grid of equidistant points in 2D, n_components = n_dim
X = np.array(list(product(range(N_per_side), repeat=2)))
# add noise in a third dimension
rng = np.random.RandomState(0)
noise = 0.1 * rng.randn(Npts, 1)
X = np.concatenate((X, noise), 1)
# compute input kernel
G = neighbors.kneighbors_graph(X, n_neighbors,
mode='distance').toarray()
centerer = preprocessing.KernelCenterer()
K = centerer.fit_transform(-0.5 * G ** 2)
for eigen_solver in eigen_solvers:
for path_method in path_methods:
clf = manifold.Isomap(n_neighbors=n_neighbors, n_components=2,
eigen_solver=eigen_solver,
path_method=path_method)
clf.fit(X)
# compute output kernel
G_iso = neighbors.kneighbors_graph(clf.embedding_,
n_neighbors,
mode='distance').toarray()
K_iso = centerer.fit_transform(-0.5 * G_iso ** 2)
# make sure error agrees
reconstruction_error = np.linalg.norm(K - K_iso) / Npts
assert_almost_equal(reconstruction_error,
clf.reconstruction_error())
def test_transform():
n_samples = 200
n_components = 10
noise_scale = 0.01
# Create S-curve dataset
X, y = datasets.samples_generator.make_s_curve(n_samples, random_state=0)
# Compute isomap embedding
iso = manifold.Isomap(n_components, 2)
X_iso = iso.fit_transform(X)
# Re-embed a noisy version of the points
rng = np.random.RandomState(0)
noise = noise_scale * rng.randn(*X.shape)
X_iso2 = iso.transform(X + noise)
# Make sure the rms error on re-embedding is comparable to noise_scale
assert_less(np.sqrt(np.mean((X_iso - X_iso2) ** 2)), 2 * noise_scale)
def test_pipeline():
# check that Isomap works fine as a transformer in a Pipeline
# only checks that no error is raised.
# TODO check that it actually does something useful
X, y = datasets.make_blobs(random_state=0)
clf = pipeline.Pipeline(
[('isomap', manifold.Isomap()),
('clf', neighbors.KNeighborsClassifier())])
clf.fit(X, y)
assert_less(.9, clf.score(X, y))
def test_isomap_clone_bug():
# regression test for bug reported in #6062
model = manifold.Isomap()
for n_neighbors in [10, 15, 20]:
model.set_params(n_neighbors=n_neighbors)
model.fit(np.random.rand(50, 2))
assert_equal(model.nbrs_.n_neighbors,
n_neighbors)
| 4,301 | 33.416 | 77 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/manifold/tests/test_locally_linear.py | from itertools import product
import numpy as np
from numpy.testing import assert_almost_equal, assert_array_almost_equal
from scipy import linalg
from sklearn import neighbors, manifold
from sklearn.manifold.locally_linear import barycenter_kneighbors_graph
from sklearn.utils.testing import assert_less
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.testing import assert_raise_message
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_true
eigen_solvers = ['dense', 'arpack']
# ----------------------------------------------------------------------
# Test utility routines
def test_barycenter_kneighbors_graph():
X = np.array([[0, 1], [1.01, 1.], [2, 0]])
A = barycenter_kneighbors_graph(X, 1)
assert_array_almost_equal(
A.toarray(),
[[0., 1., 0.],
[1., 0., 0.],
[0., 1., 0.]])
A = barycenter_kneighbors_graph(X, 2)
# check that columns sum to one
assert_array_almost_equal(np.sum(A.toarray(), 1), np.ones(3))
pred = np.dot(A.toarray(), X)
assert_less(linalg.norm(pred - X) / X.shape[0], 1)
# ----------------------------------------------------------------------
# Test LLE by computing the reconstruction error on some manifolds.
def test_lle_simple_grid():
# note: ARPACK is numerically unstable, so this test will fail for
# some random seeds. We choose 2 because the tests pass.
rng = np.random.RandomState(2)
# grid of equidistant points in 2D, n_components = n_dim
X = np.array(list(product(range(5), repeat=2)))
X = X + 1e-10 * rng.uniform(size=X.shape)
n_components = 2
clf = manifold.LocallyLinearEmbedding(n_neighbors=5,
n_components=n_components,
random_state=rng)
tol = 0.1
N = barycenter_kneighbors_graph(X, clf.n_neighbors).toarray()
reconstruction_error = linalg.norm(np.dot(N, X) - X, 'fro')
assert_less(reconstruction_error, tol)
for solver in eigen_solvers:
clf.set_params(eigen_solver=solver)
clf.fit(X)
assert_true(clf.embedding_.shape[1] == n_components)
reconstruction_error = linalg.norm(
np.dot(N, clf.embedding_) - clf.embedding_, 'fro') ** 2
assert_less(reconstruction_error, tol)
assert_almost_equal(clf.reconstruction_error_,
reconstruction_error, decimal=1)
# re-embed a noisy version of X using the transform method
noise = rng.randn(*X.shape) / 100
X_reembedded = clf.transform(X + noise)
assert_less(linalg.norm(X_reembedded - clf.embedding_), tol)
def test_lle_manifold():
rng = np.random.RandomState(0)
# similar test on a slightly more complex manifold
X = np.array(list(product(np.arange(18), repeat=2)))
X = np.c_[X, X[:, 0] ** 2 / 18]
X = X + 1e-10 * rng.uniform(size=X.shape)
n_components = 2
for method in ["standard", "hessian", "modified", "ltsa"]:
clf = manifold.LocallyLinearEmbedding(n_neighbors=6,
n_components=n_components,
method=method, random_state=0)
tol = 1.5 if method == "standard" else 3
N = barycenter_kneighbors_graph(X, clf.n_neighbors).toarray()
reconstruction_error = linalg.norm(np.dot(N, X) - X)
assert_less(reconstruction_error, tol)
for solver in eigen_solvers:
clf.set_params(eigen_solver=solver)
clf.fit(X)
assert_true(clf.embedding_.shape[1] == n_components)
reconstruction_error = linalg.norm(
np.dot(N, clf.embedding_) - clf.embedding_, 'fro') ** 2
details = ("solver: %s, method: %s" % (solver, method))
assert_less(reconstruction_error, tol, msg=details)
assert_less(np.abs(clf.reconstruction_error_ -
reconstruction_error),
tol * reconstruction_error, msg=details)
# Test the error raised when parameter passed to lle is invalid
def test_lle_init_parameters():
X = np.random.rand(5, 3)
clf = manifold.LocallyLinearEmbedding(eigen_solver="error")
msg = "unrecognized eigen_solver 'error'"
assert_raise_message(ValueError, msg, clf.fit, X)
clf = manifold.LocallyLinearEmbedding(method="error")
msg = "unrecognized method 'error'"
assert_raise_message(ValueError, msg, clf.fit, X)
def test_pipeline():
# check that LocallyLinearEmbedding works fine as a Pipeline
# only checks that no error is raised.
# TODO check that it actually does something useful
from sklearn import pipeline, datasets
X, y = datasets.make_blobs(random_state=0)
clf = pipeline.Pipeline(
[('filter', manifold.LocallyLinearEmbedding(random_state=0)),
('clf', neighbors.KNeighborsClassifier())])
clf.fit(X, y)
assert_less(.9, clf.score(X, y))
# Test the error raised when the weight matrix is singular
def test_singular_matrix():
M = np.ones((10, 3))
f = ignore_warnings
assert_raises(ValueError, f(manifold.locally_linear_embedding),
M, 2, 1, method='standard', eigen_solver='arpack')
# regression test for #6033
def test_integer_input():
rand = np.random.RandomState(0)
X = rand.randint(0, 100, size=(20, 3))
for method in ["standard", "hessian", "modified", "ltsa"]:
clf = manifold.LocallyLinearEmbedding(method=method, n_neighbors=10)
clf.fit(X) # this previously raised a TypeError
| 5,600 | 37.102041 | 76 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/manifold/tests/__init__.py | 0 | 0 | 0 | py |
|
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/semi_supervised/label_propagation.py | # coding=utf8
"""
Label propagation in the context of this module refers to a set of
semi-supervised classification algorithms. At a high level, these algorithms
work by forming a fully-connected graph between all points given and solving
for the steady-state distribution of labels at each point.
These algorithms perform very well in practice. The cost of running can be very
expensive, at approximately O(N^3) where N is the number of (labeled and
unlabeled) points. The theory (why they perform so well) is motivated by
intuitions from random walk algorithms and geometric relationships in the data.
For more information see the references below.
Model Features
--------------
Label clamping:
The algorithm tries to learn distributions of labels over the dataset given
label assignments over an initial subset. In one variant, the algorithm does
not allow for any errors in the initial assignment (hard-clamping) while
in another variant, the algorithm allows for some wiggle room for the initial
assignments, allowing them to change by a fraction alpha in each iteration
(soft-clamping).
Kernel:
A function which projects a vector into some higher dimensional space. This
implementation supports RBF and KNN kernels. Using the RBF kernel generates
a dense matrix of size O(N^2). KNN kernel will generate a sparse matrix of
size O(k*N) which will run much faster. See the documentation for SVMs for
more info on kernels.
Examples
--------
>>> from sklearn import datasets
>>> from sklearn.semi_supervised import LabelPropagation
>>> label_prop_model = LabelPropagation()
>>> iris = datasets.load_iris()
>>> rng = np.random.RandomState(42)
>>> random_unlabeled_points = rng.rand(len(iris.target)) < 0.3
>>> labels = np.copy(iris.target)
>>> labels[random_unlabeled_points] = -1
>>> label_prop_model.fit(iris.data, labels)
... # doctest: +NORMALIZE_WHITESPACE +ELLIPSIS
LabelPropagation(...)
Notes
-----
References:
[1] Yoshua Bengio, Olivier Delalleau, Nicolas Le Roux. In Semi-Supervised
Learning (2006), pp. 193-216
[2] Olivier Delalleau, Yoshua Bengio, Nicolas Le Roux. Efficient
Non-Parametric Function Induction in Semi-Supervised Learning. AISTAT 2005
"""
# Authors: Clay Woolam <[email protected]>
# Utkarsh Upadhyay <[email protected]>
# License: BSD
from abc import ABCMeta, abstractmethod
import warnings
import numpy as np
from scipy import sparse
from ..base import BaseEstimator, ClassifierMixin
from ..externals import six
from ..metrics.pairwise import rbf_kernel
from ..neighbors.unsupervised import NearestNeighbors
from ..utils.extmath import safe_sparse_dot
from ..utils.multiclass import check_classification_targets
from ..utils.validation import check_X_y, check_is_fitted, check_array
from ..exceptions import ConvergenceWarning
class BaseLabelPropagation(six.with_metaclass(ABCMeta, BaseEstimator,
ClassifierMixin)):
"""Base class for label propagation module.
Parameters
----------
kernel : {'knn', 'rbf', callable}
String identifier for kernel function to use or the kernel function
itself. Only 'rbf' and 'knn' strings are valid inputs. The function
passed should take two inputs, each of shape [n_samples, n_features],
and return a [n_samples, n_samples] shaped weight matrix
gamma : float
Parameter for rbf kernel
n_neighbors : integer > 0
Parameter for knn kernel
alpha : float
Clamping factor
max_iter : integer
Change maximum number of iterations allowed
tol : float
Convergence tolerance: threshold to consider the system at steady
state
n_jobs : int, optional (default = 1)
The number of parallel jobs to run.
If ``-1``, then the number of jobs is set to the number of CPU cores.
"""
def __init__(self, kernel='rbf', gamma=20, n_neighbors=7,
alpha=1, max_iter=30, tol=1e-3, n_jobs=1):
self.max_iter = max_iter
self.tol = tol
# kernel parameters
self.kernel = kernel
self.gamma = gamma
self.n_neighbors = n_neighbors
# clamping factor
self.alpha = alpha
self.n_jobs = n_jobs
def _get_kernel(self, X, y=None):
if self.kernel == "rbf":
if y is None:
return rbf_kernel(X, X, gamma=self.gamma)
else:
return rbf_kernel(X, y, gamma=self.gamma)
elif self.kernel == "knn":
if self.nn_fit is None:
self.nn_fit = NearestNeighbors(self.n_neighbors,
n_jobs=self.n_jobs).fit(X)
if y is None:
return self.nn_fit.kneighbors_graph(self.nn_fit._fit_X,
self.n_neighbors,
mode='connectivity')
else:
return self.nn_fit.kneighbors(y, return_distance=False)
elif callable(self.kernel):
if y is None:
return self.kernel(X, X)
else:
return self.kernel(X, y)
else:
raise ValueError("%s is not a valid kernel. Only rbf and knn"
" or an explicit function "
" are supported at this time." % self.kernel)
@abstractmethod
def _build_graph(self):
raise NotImplementedError("Graph construction must be implemented"
" to fit a label propagation model.")
def predict(self, X):
"""Performs inductive inference across the model.
Parameters
----------
X : array_like, shape = [n_samples, n_features]
Returns
-------
y : array_like, shape = [n_samples]
Predictions for input data
"""
probas = self.predict_proba(X)
return self.classes_[np.argmax(probas, axis=1)].ravel()
def predict_proba(self, X):
"""Predict probability for each possible outcome.
Compute the probability estimates for each single sample in X
and each possible outcome seen during training (categorical
distribution).
Parameters
----------
X : array_like, shape = [n_samples, n_features]
Returns
-------
probabilities : array, shape = [n_samples, n_classes]
Normalized probability distributions across
class labels
"""
check_is_fitted(self, 'X_')
X_2d = check_array(X, accept_sparse=['csc', 'csr', 'coo', 'dok',
'bsr', 'lil', 'dia'])
weight_matrices = self._get_kernel(self.X_, X_2d)
if self.kernel == 'knn':
probabilities = []
for weight_matrix in weight_matrices:
ine = np.sum(self.label_distributions_[weight_matrix], axis=0)
probabilities.append(ine)
probabilities = np.array(probabilities)
else:
weight_matrices = weight_matrices.T
probabilities = np.dot(weight_matrices, self.label_distributions_)
normalizer = np.atleast_2d(np.sum(probabilities, axis=1)).T
probabilities /= normalizer
return probabilities
def fit(self, X, y):
"""Fit a semi-supervised label propagation model based
All the input data is provided matrix X (labeled and unlabeled)
and corresponding label matrix y with a dedicated marker value for
unlabeled samples.
Parameters
----------
X : array-like, shape = [n_samples, n_features]
A {n_samples by n_samples} size matrix will be created from this
y : array_like, shape = [n_samples]
n_labeled_samples (unlabeled points are marked as -1)
All unlabeled samples will be transductively assigned labels
Returns
-------
self : returns an instance of self.
"""
X, y = check_X_y(X, y)
self.X_ = X
check_classification_targets(y)
# actual graph construction (implementations should override this)
graph_matrix = self._build_graph()
# label construction
# construct a categorical distribution for classification only
classes = np.unique(y)
classes = (classes[classes != -1])
self.classes_ = classes
n_samples, n_classes = len(y), len(classes)
alpha = self.alpha
if self._variant == 'spreading' and \
(alpha is None or alpha <= 0.0 or alpha >= 1.0):
raise ValueError('alpha=%s is invalid: it must be inside '
'the open interval (0, 1)' % alpha)
y = np.asarray(y)
unlabeled = y == -1
# initialize distributions
self.label_distributions_ = np.zeros((n_samples, n_classes))
for label in classes:
self.label_distributions_[y == label, classes == label] = 1
y_static = np.copy(self.label_distributions_)
if self._variant == 'propagation':
# LabelPropagation
y_static[unlabeled] = 0
else:
# LabelSpreading
y_static *= 1 - alpha
l_previous = np.zeros((self.X_.shape[0], n_classes))
unlabeled = unlabeled[:, np.newaxis]
if sparse.isspmatrix(graph_matrix):
graph_matrix = graph_matrix.tocsr()
for self.n_iter_ in range(self.max_iter):
if np.abs(self.label_distributions_ - l_previous).sum() < self.tol:
break
l_previous = self.label_distributions_
self.label_distributions_ = safe_sparse_dot(
graph_matrix, self.label_distributions_)
if self._variant == 'propagation':
normalizer = np.sum(
self.label_distributions_, axis=1)[:, np.newaxis]
self.label_distributions_ /= normalizer
self.label_distributions_ = np.where(unlabeled,
self.label_distributions_,
y_static)
else:
# clamp
self.label_distributions_ = np.multiply(
alpha, self.label_distributions_) + y_static
else:
warnings.warn(
'max_iter=%d was reached without convergence.' % self.max_iter,
category=ConvergenceWarning
)
self.n_iter_ += 1
normalizer = np.sum(self.label_distributions_, axis=1)[:, np.newaxis]
self.label_distributions_ /= normalizer
# set the transduction item
transduction = self.classes_[np.argmax(self.label_distributions_,
axis=1)]
self.transduction_ = transduction.ravel()
return self
class LabelPropagation(BaseLabelPropagation):
"""Label Propagation classifier
Read more in the :ref:`User Guide <label_propagation>`.
Parameters
----------
kernel : {'knn', 'rbf', callable}
String identifier for kernel function to use or the kernel function
itself. Only 'rbf' and 'knn' strings are valid inputs. The function
passed should take two inputs, each of shape [n_samples, n_features],
and return a [n_samples, n_samples] shaped weight matrix.
gamma : float
Parameter for rbf kernel
n_neighbors : integer > 0
Parameter for knn kernel
alpha : float
Clamping factor.
.. deprecated:: 0.19
This parameter will be removed in 0.21.
'alpha' is fixed to zero in 'LabelPropagation'.
max_iter : integer
Change maximum number of iterations allowed
tol : float
Convergence tolerance: threshold to consider the system at steady
state
n_jobs : int, optional (default = 1)
The number of parallel jobs to run.
If ``-1``, then the number of jobs is set to the number of CPU cores.
Attributes
----------
X_ : array, shape = [n_samples, n_features]
Input array.
classes_ : array, shape = [n_classes]
The distinct labels used in classifying instances.
label_distributions_ : array, shape = [n_samples, n_classes]
Categorical distribution for each item.
transduction_ : array, shape = [n_samples]
Label assigned to each item via the transduction.
n_iter_ : int
Number of iterations run.
Examples
--------
>>> from sklearn import datasets
>>> from sklearn.semi_supervised import LabelPropagation
>>> label_prop_model = LabelPropagation()
>>> iris = datasets.load_iris()
>>> rng = np.random.RandomState(42)
>>> random_unlabeled_points = rng.rand(len(iris.target)) < 0.3
>>> labels = np.copy(iris.target)
>>> labels[random_unlabeled_points] = -1
>>> label_prop_model.fit(iris.data, labels)
... # doctest: +NORMALIZE_WHITESPACE +ELLIPSIS
LabelPropagation(...)
References
----------
Xiaojin Zhu and Zoubin Ghahramani. Learning from labeled and unlabeled data
with label propagation. Technical Report CMU-CALD-02-107, Carnegie Mellon
University, 2002 http://pages.cs.wisc.edu/~jerryzhu/pub/CMU-CALD-02-107.pdf
See Also
--------
LabelSpreading : Alternate label propagation strategy more robust to noise
"""
_variant = 'propagation'
def __init__(self, kernel='rbf', gamma=20, n_neighbors=7,
alpha=None, max_iter=1000, tol=1e-3, n_jobs=1):
super(LabelPropagation, self).__init__(
kernel=kernel, gamma=gamma, n_neighbors=n_neighbors, alpha=alpha,
max_iter=max_iter, tol=tol, n_jobs=n_jobs)
def _build_graph(self):
"""Matrix representing a fully connected graph between each sample
This basic implementation creates a non-stochastic affinity matrix, so
class distributions will exceed 1 (normalization may be desired).
"""
if self.kernel == 'knn':
self.nn_fit = None
affinity_matrix = self._get_kernel(self.X_)
normalizer = affinity_matrix.sum(axis=0)
if sparse.isspmatrix(affinity_matrix):
affinity_matrix.data /= np.diag(np.array(normalizer))
else:
affinity_matrix /= normalizer[:, np.newaxis]
return affinity_matrix
def fit(self, X, y):
if self.alpha is not None:
warnings.warn(
"alpha is deprecated since 0.19 and will be removed in 0.21.",
DeprecationWarning
)
self.alpha = None
return super(LabelPropagation, self).fit(X, y)
class LabelSpreading(BaseLabelPropagation):
"""LabelSpreading model for semi-supervised learning
This model is similar to the basic Label Propagation algorithm,
but uses affinity matrix based on the normalized graph Laplacian
and soft clamping across the labels.
Read more in the :ref:`User Guide <label_propagation>`.
Parameters
----------
kernel : {'knn', 'rbf', callable}
String identifier for kernel function to use or the kernel function
itself. Only 'rbf' and 'knn' strings are valid inputs. The function
passed should take two inputs, each of shape [n_samples, n_features],
and return a [n_samples, n_samples] shaped weight matrix
gamma : float
parameter for rbf kernel
n_neighbors : integer > 0
parameter for knn kernel
alpha : float
Clamping factor. A value in [0, 1] that specifies the relative amount
that an instance should adopt the information from its neighbors as
opposed to its initial label.
alpha=0 means keeping the initial label information; alpha=1 means
replacing all initial information.
max_iter : integer
maximum number of iterations allowed
tol : float
Convergence tolerance: threshold to consider the system at steady
state
n_jobs : int, optional (default = 1)
The number of parallel jobs to run.
If ``-1``, then the number of jobs is set to the number of CPU cores.
Attributes
----------
X_ : array, shape = [n_samples, n_features]
Input array.
classes_ : array, shape = [n_classes]
The distinct labels used in classifying instances.
label_distributions_ : array, shape = [n_samples, n_classes]
Categorical distribution for each item.
transduction_ : array, shape = [n_samples]
Label assigned to each item via the transduction.
n_iter_ : int
Number of iterations run.
Examples
--------
>>> from sklearn import datasets
>>> from sklearn.semi_supervised import LabelSpreading
>>> label_prop_model = LabelSpreading()
>>> iris = datasets.load_iris()
>>> rng = np.random.RandomState(42)
>>> random_unlabeled_points = rng.rand(len(iris.target)) < 0.3
>>> labels = np.copy(iris.target)
>>> labels[random_unlabeled_points] = -1
>>> label_prop_model.fit(iris.data, labels)
... # doctest: +NORMALIZE_WHITESPACE +ELLIPSIS
LabelSpreading(...)
References
----------
Dengyong Zhou, Olivier Bousquet, Thomas Navin Lal, Jason Weston,
Bernhard Schoelkopf. Learning with local and global consistency (2004)
http://citeseer.ist.psu.edu/viewdoc/summary?doi=10.1.1.115.3219
See Also
--------
LabelPropagation : Unregularized graph based semi-supervised learning
"""
_variant = 'spreading'
def __init__(self, kernel='rbf', gamma=20, n_neighbors=7, alpha=0.2,
max_iter=30, tol=1e-3, n_jobs=1):
# this one has different base parameters
super(LabelSpreading, self).__init__(kernel=kernel, gamma=gamma,
n_neighbors=n_neighbors,
alpha=alpha, max_iter=max_iter,
tol=tol,
n_jobs=n_jobs)
def _build_graph(self):
"""Graph matrix for Label Spreading computes the graph laplacian"""
# compute affinity matrix (or gram matrix)
if self.kernel == 'knn':
self.nn_fit = None
n_samples = self.X_.shape[0]
affinity_matrix = self._get_kernel(self.X_)
laplacian = sparse.csgraph.laplacian(affinity_matrix, normed=True)
laplacian = -laplacian
if sparse.isspmatrix(laplacian):
diag_mask = (laplacian.row == laplacian.col)
laplacian.data[diag_mask] = 0.0
else:
laplacian.flat[::n_samples + 1] = 0.0 # set diag to 0.0
return laplacian
| 18,811 | 34.832381 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/semi_supervised/__init__.py | """
The :mod:`sklearn.semi_supervised` module implements semi-supervised learning
algorithms. These algorithms utilized small amounts of labeled data and large
amounts of unlabeled data for classification tasks. This module includes Label
Propagation.
"""
from .label_propagation import LabelPropagation, LabelSpreading
__all__ = ['LabelPropagation', 'LabelSpreading']
| 371 | 32.818182 | 78 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/semi_supervised/tests/test_label_propagation.py | """ test the label propagation module """
import numpy as np
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_no_warnings
from sklearn.semi_supervised import label_propagation
from sklearn.metrics.pairwise import rbf_kernel
from sklearn.datasets import make_classification
from sklearn.exceptions import ConvergenceWarning
from numpy.testing import assert_array_almost_equal
from numpy.testing import assert_array_equal
ESTIMATORS = [
(label_propagation.LabelPropagation, {'kernel': 'rbf'}),
(label_propagation.LabelPropagation, {'kernel': 'knn', 'n_neighbors': 2}),
(label_propagation.LabelPropagation, {
'kernel': lambda x, y: rbf_kernel(x, y, gamma=20)
}),
(label_propagation.LabelSpreading, {'kernel': 'rbf'}),
(label_propagation.LabelSpreading, {'kernel': 'knn', 'n_neighbors': 2}),
(label_propagation.LabelSpreading, {
'kernel': lambda x, y: rbf_kernel(x, y, gamma=20)
}),
]
def test_fit_transduction():
samples = [[1., 0.], [0., 2.], [1., 3.]]
labels = [0, 1, -1]
for estimator, parameters in ESTIMATORS:
clf = estimator(**parameters).fit(samples, labels)
assert_equal(clf.transduction_[2], 1)
def test_distribution():
samples = [[1., 0.], [0., 1.], [1., 1.]]
labels = [0, 1, -1]
for estimator, parameters in ESTIMATORS:
clf = estimator(**parameters).fit(samples, labels)
if parameters['kernel'] == 'knn':
continue # unstable test; changes in k-NN ordering break it
assert_array_almost_equal(clf.predict_proba([[1., 0.0]]),
np.array([[1., 0.]]), 2)
else:
assert_array_almost_equal(np.asarray(clf.label_distributions_[2]),
np.array([.5, .5]), 2)
def test_predict():
samples = [[1., 0.], [0., 2.], [1., 3.]]
labels = [0, 1, -1]
for estimator, parameters in ESTIMATORS:
clf = estimator(**parameters).fit(samples, labels)
assert_array_equal(clf.predict([[0.5, 2.5]]), np.array([1]))
def test_predict_proba():
samples = [[1., 0.], [0., 1.], [1., 2.5]]
labels = [0, 1, -1]
for estimator, parameters in ESTIMATORS:
clf = estimator(**parameters).fit(samples, labels)
assert_array_almost_equal(clf.predict_proba([[1., 1.]]),
np.array([[0.5, 0.5]]))
def test_alpha_deprecation():
X, y = make_classification(n_samples=100)
y[::3] = -1
lp_default = label_propagation.LabelPropagation(kernel='rbf', gamma=0.1)
lp_default_y = lp_default.fit(X, y).transduction_
lp_0 = label_propagation.LabelPropagation(alpha=0, kernel='rbf', gamma=0.1)
lp_0_y = assert_warns(DeprecationWarning, lp_0.fit, X, y).transduction_
assert_array_equal(lp_default_y, lp_0_y)
def test_label_spreading_closed_form():
n_classes = 2
X, y = make_classification(n_classes=n_classes, n_samples=200,
random_state=0)
y[::3] = -1
clf = label_propagation.LabelSpreading().fit(X, y)
# adopting notation from Zhou et al (2004):
S = clf._build_graph()
Y = np.zeros((len(y), n_classes + 1))
Y[np.arange(len(y)), y] = 1
Y = Y[:, :-1]
for alpha in [0.1, 0.3, 0.5, 0.7, 0.9]:
expected = np.dot(np.linalg.inv(np.eye(len(S)) - alpha * S), Y)
expected /= expected.sum(axis=1)[:, np.newaxis]
clf = label_propagation.LabelSpreading(max_iter=10000, alpha=alpha)
clf.fit(X, y)
assert_array_almost_equal(expected, clf.label_distributions_, 4)
def test_label_propagation_closed_form():
n_classes = 2
X, y = make_classification(n_classes=n_classes, n_samples=200,
random_state=0)
y[::3] = -1
Y = np.zeros((len(y), n_classes + 1))
Y[np.arange(len(y)), y] = 1
unlabelled_idx = Y[:, (-1,)].nonzero()[0]
labelled_idx = (Y[:, (-1,)] == 0).nonzero()[0]
clf = label_propagation.LabelPropagation(max_iter=10000,
gamma=0.1)
clf.fit(X, y)
# adopting notation from Zhu et al 2002
T_bar = clf._build_graph()
Tuu = T_bar[np.meshgrid(unlabelled_idx, unlabelled_idx, indexing='ij')]
Tul = T_bar[np.meshgrid(unlabelled_idx, labelled_idx, indexing='ij')]
Y = Y[:, :-1]
Y_l = Y[labelled_idx, :]
Y_u = np.dot(np.dot(np.linalg.inv(np.eye(Tuu.shape[0]) - Tuu), Tul), Y_l)
expected = Y.copy()
expected[unlabelled_idx, :] = Y_u
expected /= expected.sum(axis=1)[:, np.newaxis]
assert_array_almost_equal(expected, clf.label_distributions_, 4)
def test_valid_alpha():
n_classes = 2
X, y = make_classification(n_classes=n_classes, n_samples=200,
random_state=0)
for alpha in [-0.1, 0, 1, 1.1, None]:
assert_raises(ValueError,
lambda **kwargs:
label_propagation.LabelSpreading(**kwargs).fit(X, y),
alpha=alpha)
def test_convergence_speed():
# This is a non-regression test for #5774
X = np.array([[1., 0.], [0., 1.], [1., 2.5]])
y = np.array([0, 1, -1])
mdl = label_propagation.LabelSpreading(kernel='rbf', max_iter=5000)
mdl.fit(X, y)
# this should converge quickly:
assert mdl.n_iter_ < 10
assert_array_equal(mdl.predict(X), [0, 1, 1])
def test_convergence_warning():
# This is a non-regression test for #5774
X = np.array([[1., 0.], [0., 1.], [1., 2.5]])
y = np.array([0, 1, -1])
mdl = label_propagation.LabelSpreading(kernel='rbf', max_iter=1)
assert_warns(ConvergenceWarning, mdl.fit, X, y)
assert_equal(mdl.n_iter_, mdl.max_iter)
mdl = label_propagation.LabelPropagation(kernel='rbf', max_iter=1)
assert_warns(ConvergenceWarning, mdl.fit, X, y)
assert_equal(mdl.n_iter_, mdl.max_iter)
mdl = label_propagation.LabelSpreading(kernel='rbf', max_iter=500)
assert_no_warnings(mdl.fit, X, y)
mdl = label_propagation.LabelPropagation(kernel='rbf', max_iter=500)
assert_no_warnings(mdl.fit, X, y)
| 6,187 | 35.615385 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/semi_supervised/tests/__init__.py | 0 | 0 | 0 | py |
|
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/_build_utils/__init__.py | """
Utilities useful during the build.
"""
# author: Andy Mueller, Gael Varoquaux
# license: BSD
from __future__ import division, print_function, absolute_import
import os
from distutils.version import LooseVersion
from numpy.distutils.system_info import get_info
DEFAULT_ROOT = 'sklearn'
CYTHON_MIN_VERSION = '0.23'
def get_blas_info():
def atlas_not_found(blas_info_):
def_macros = blas_info.get('define_macros', [])
for x in def_macros:
if x[0] == "NO_ATLAS_INFO":
# if x[1] != 1 we should have lapack
# how do we do that now?
return True
if x[0] == "ATLAS_INFO":
if "None" in x[1]:
# this one turned up on FreeBSD
return True
return False
blas_info = get_info('blas_opt', 0)
if (not blas_info) or atlas_not_found(blas_info):
cblas_libs = ['cblas']
blas_info.pop('libraries', None)
else:
cblas_libs = blas_info.pop('libraries', [])
return cblas_libs, blas_info
def build_from_c_and_cpp_files(extensions):
"""Modify the extensions to build from the .c and .cpp files.
This is useful for releases, this way cython is not required to
run python setup.py install.
"""
for extension in extensions:
sources = []
for sfile in extension.sources:
path, ext = os.path.splitext(sfile)
if ext in ('.pyx', '.py'):
if extension.language == 'c++':
ext = '.cpp'
else:
ext = '.c'
sfile = path + ext
sources.append(sfile)
extension.sources = sources
def maybe_cythonize_extensions(top_path, config):
"""Tweaks for building extensions between release and development mode."""
is_release = os.path.exists(os.path.join(top_path, 'PKG-INFO'))
if is_release:
build_from_c_and_cpp_files(config.ext_modules)
else:
message = ('Please install cython with a version >= {0} in order '
'to build a scikit-learn development version.').format(
CYTHON_MIN_VERSION)
try:
import Cython
if LooseVersion(Cython.__version__) < CYTHON_MIN_VERSION:
message += ' Your version of Cython was {0}.'.format(
Cython.__version__)
raise ValueError(message)
from Cython.Build import cythonize
except ImportError as exc:
exc.args += (message,)
raise
config.ext_modules = cythonize(config.ext_modules)
| 2,644 | 30.117647 | 78 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/model_selection/_validation.py | """
The :mod:`sklearn.model_selection._validation` module includes classes and
functions to validate the model.
"""
# Author: Alexandre Gramfort <[email protected]>
# Gael Varoquaux <[email protected]>
# Olivier Grisel <[email protected]>
# Raghav RV <[email protected]>
# License: BSD 3 clause
from __future__ import print_function
from __future__ import division
import warnings
import numbers
import time
import numpy as np
import scipy.sparse as sp
from ..base import is_classifier, clone
from ..utils import indexable, check_random_state, safe_indexing
from ..utils.deprecation import DeprecationDict
from ..utils.validation import _is_arraylike, _num_samples
from ..utils.metaestimators import _safe_split
from ..externals.joblib import Parallel, delayed, logger
from ..externals.six.moves import zip
from ..metrics.scorer import check_scoring, _check_multimetric_scoring
from ..exceptions import FitFailedWarning
from ._split import check_cv
from ..preprocessing import LabelEncoder
__all__ = ['cross_validate', 'cross_val_score', 'cross_val_predict',
'permutation_test_score', 'learning_curve', 'validation_curve']
def cross_validate(estimator, X, y=None, groups=None, scoring=None, cv=None,
n_jobs=1, verbose=0, fit_params=None,
pre_dispatch='2*n_jobs', return_train_score="warn"):
"""Evaluate metric(s) by cross-validation and also record fit/score times.
Read more in the :ref:`User Guide <multimetric_cross_validation>`.
Parameters
----------
estimator : estimator object implementing 'fit'
The object to use to fit the data.
X : array-like
The data to fit. Can be for example a list, or an array.
y : array-like, optional, default: None
The target variable to try to predict in the case of
supervised learning.
groups : array-like, with shape (n_samples,), optional
Group labels for the samples used while splitting the dataset into
train/test set.
scoring : string, callable, list/tuple, dict or None, default: None
A single string (see :ref:`scoring_parameter`) or a callable
(see :ref:`scoring`) to evaluate the predictions on the test set.
For evaluating multiple metrics, either give a list of (unique) strings
or a dict with names as keys and callables as values.
NOTE that when using custom scorers, each scorer should return a single
value. Metric functions returning a list/array of values can be wrapped
into multiple scorers that return one value each.
See :ref:`multimetric_grid_search` for an example.
If None, the estimator's default scorer (if available) is used.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross validation,
- integer, to specify the number of folds in a `(Stratified)KFold`,
- An object to be used as a cross-validation generator.
- An iterable yielding train, test splits.
For integer/None inputs, if the estimator is a classifier and ``y`` is
either binary or multiclass, :class:`StratifiedKFold` is used. In all
other cases, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
n_jobs : integer, optional
The number of CPUs to use to do the computation. -1 means
'all CPUs'.
verbose : integer, optional
The verbosity level.
fit_params : dict, optional
Parameters to pass to the fit method of the estimator.
pre_dispatch : int, or string, optional
Controls the number of jobs that get dispatched during parallel
execution. Reducing this number can be useful to avoid an
explosion of memory consumption when more jobs get dispatched
than CPUs can process. This parameter can be:
- None, in which case all the jobs are immediately
created and spawned. Use this for lightweight and
fast-running jobs, to avoid delays due to on-demand
spawning of the jobs
- An int, giving the exact number of total jobs that are
spawned
- A string, giving an expression as a function of n_jobs,
as in '2*n_jobs'
return_train_score : boolean, optional
Whether to include train scores.
Current default is ``'warn'``, which behaves as ``True`` in addition
to raising a warning when a training score is looked up.
That default will be changed to ``False`` in 0.21.
Computing training scores is used to get insights on how different
parameter settings impact the overfitting/underfitting trade-off.
However computing the scores on the training set can be computationally
expensive and is not strictly required to select the parameters that
yield the best generalization performance.
Returns
-------
scores : dict of float arrays of shape=(n_splits,)
Array of scores of the estimator for each run of the cross validation.
A dict of arrays containing the score/time arrays for each scorer is
returned. The possible keys for this ``dict`` are:
``test_score``
The score array for test scores on each cv split.
``train_score``
The score array for train scores on each cv split.
This is available only if ``return_train_score`` parameter
is ``True``.
``fit_time``
The time for fitting the estimator on the train
set for each cv split.
``score_time``
The time for scoring the estimator on the test set for each
cv split. (Note time for scoring on the train set is not
included even if ``return_train_score`` is set to ``True``
Examples
--------
>>> from sklearn import datasets, linear_model
>>> from sklearn.model_selection import cross_validate
>>> from sklearn.metrics.scorer import make_scorer
>>> from sklearn.metrics import confusion_matrix
>>> from sklearn.svm import LinearSVC
>>> diabetes = datasets.load_diabetes()
>>> X = diabetes.data[:150]
>>> y = diabetes.target[:150]
>>> lasso = linear_model.Lasso()
Single metric evaluation using ``cross_validate``
>>> cv_results = cross_validate(lasso, X, y, return_train_score=False)
>>> sorted(cv_results.keys()) # doctest: +ELLIPSIS
['fit_time', 'score_time', 'test_score']
>>> cv_results['test_score'] # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
array([ 0.33..., 0.08..., 0.03...])
Multiple metric evaluation using ``cross_validate``
(please refer the ``scoring`` parameter doc for more information)
>>> scores = cross_validate(lasso, X, y,
... scoring=('r2', 'neg_mean_squared_error'))
>>> print(scores['test_neg_mean_squared_error']) # doctest: +ELLIPSIS
[-3635.5... -3573.3... -6114.7...]
>>> print(scores['train_r2']) # doctest: +ELLIPSIS
[ 0.28... 0.39... 0.22...]
See Also
---------
:func:`sklearn.model_selection.cross_val_score`:
Run cross-validation for single metric evaluation.
:func:`sklearn.metrics.make_scorer`:
Make a scorer from a performance metric or loss function.
"""
X, y, groups = indexable(X, y, groups)
cv = check_cv(cv, y, classifier=is_classifier(estimator))
scorers, _ = _check_multimetric_scoring(estimator, scoring=scoring)
# We clone the estimator to make sure that all the folds are
# independent, and that it is pickle-able.
parallel = Parallel(n_jobs=n_jobs, verbose=verbose,
pre_dispatch=pre_dispatch)
scores = parallel(
delayed(_fit_and_score)(
clone(estimator), X, y, scorers, train, test, verbose, None,
fit_params, return_train_score=return_train_score,
return_times=True)
for train, test in cv.split(X, y, groups))
if return_train_score:
train_scores, test_scores, fit_times, score_times = zip(*scores)
train_scores = _aggregate_score_dicts(train_scores)
else:
test_scores, fit_times, score_times = zip(*scores)
test_scores = _aggregate_score_dicts(test_scores)
# TODO: replace by a dict in 0.21
ret = DeprecationDict() if return_train_score == 'warn' else {}
ret['fit_time'] = np.array(fit_times)
ret['score_time'] = np.array(score_times)
for name in scorers:
ret['test_%s' % name] = np.array(test_scores[name])
if return_train_score:
key = 'train_%s' % name
ret[key] = np.array(train_scores[name])
if return_train_score == 'warn':
message = (
'You are accessing a training score ({!r}), '
'which will not be available by default '
'any more in 0.21. If you need training scores, '
'please set return_train_score=True').format(key)
# warn on key access
ret.add_warning(key, message, FutureWarning)
return ret
def cross_val_score(estimator, X, y=None, groups=None, scoring=None, cv=None,
n_jobs=1, verbose=0, fit_params=None,
pre_dispatch='2*n_jobs'):
"""Evaluate a score by cross-validation
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
estimator : estimator object implementing 'fit'
The object to use to fit the data.
X : array-like
The data to fit. Can be for example a list, or an array.
y : array-like, optional, default: None
The target variable to try to predict in the case of
supervised learning.
groups : array-like, with shape (n_samples,), optional
Group labels for the samples used while splitting the dataset into
train/test set.
scoring : string, callable or None, optional, default: None
A string (see model evaluation documentation) or
a scorer callable object / function with signature
``scorer(estimator, X, y)``.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross validation,
- integer, to specify the number of folds in a `(Stratified)KFold`,
- An object to be used as a cross-validation generator.
- An iterable yielding train, test splits.
For integer/None inputs, if the estimator is a classifier and ``y`` is
either binary or multiclass, :class:`StratifiedKFold` is used. In all
other cases, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
n_jobs : integer, optional
The number of CPUs to use to do the computation. -1 means
'all CPUs'.
verbose : integer, optional
The verbosity level.
fit_params : dict, optional
Parameters to pass to the fit method of the estimator.
pre_dispatch : int, or string, optional
Controls the number of jobs that get dispatched during parallel
execution. Reducing this number can be useful to avoid an
explosion of memory consumption when more jobs get dispatched
than CPUs can process. This parameter can be:
- None, in which case all the jobs are immediately
created and spawned. Use this for lightweight and
fast-running jobs, to avoid delays due to on-demand
spawning of the jobs
- An int, giving the exact number of total jobs that are
spawned
- A string, giving an expression as a function of n_jobs,
as in '2*n_jobs'
Returns
-------
scores : array of float, shape=(len(list(cv)),)
Array of scores of the estimator for each run of the cross validation.
Examples
--------
>>> from sklearn import datasets, linear_model
>>> from sklearn.model_selection import cross_val_score
>>> diabetes = datasets.load_diabetes()
>>> X = diabetes.data[:150]
>>> y = diabetes.target[:150]
>>> lasso = linear_model.Lasso()
>>> print(cross_val_score(lasso, X, y)) # doctest: +ELLIPSIS
[ 0.33150734 0.08022311 0.03531764]
See Also
---------
:func:`sklearn.model_selection.cross_validate`:
To run cross-validation on multiple metrics and also to return
train scores, fit times and score times.
:func:`sklearn.metrics.make_scorer`:
Make a scorer from a performance metric or loss function.
"""
# To ensure multimetric format is not supported
scorer = check_scoring(estimator, scoring=scoring)
cv_results = cross_validate(estimator=estimator, X=X, y=y, groups=groups,
scoring={'score': scorer}, cv=cv,
return_train_score=False,
n_jobs=n_jobs, verbose=verbose,
fit_params=fit_params,
pre_dispatch=pre_dispatch)
return cv_results['test_score']
def _fit_and_score(estimator, X, y, scorer, train, test, verbose,
parameters, fit_params, return_train_score=False,
return_parameters=False, return_n_test_samples=False,
return_times=False, error_score='raise'):
"""Fit estimator and compute scores for a given dataset split.
Parameters
----------
estimator : estimator object implementing 'fit'
The object to use to fit the data.
X : array-like of shape at least 2D
The data to fit.
y : array-like, optional, default: None
The target variable to try to predict in the case of
supervised learning.
scorer : A single callable or dict mapping scorer name to the callable
If it is a single callable, the return value for ``train_scores`` and
``test_scores`` is a single float.
For a dict, it should be one mapping the scorer name to the scorer
callable object / function.
The callable object / fn should have signature
``scorer(estimator, X, y)``.
train : array-like, shape (n_train_samples,)
Indices of training samples.
test : array-like, shape (n_test_samples,)
Indices of test samples.
verbose : integer
The verbosity level.
error_score : 'raise' (default) or numeric
Value to assign to the score if an error occurs in estimator fitting.
If set to 'raise', the error is raised. If a numeric value is given,
FitFailedWarning is raised. This parameter does not affect the refit
step, which will always raise the error.
parameters : dict or None
Parameters to be set on the estimator.
fit_params : dict or None
Parameters that will be passed to ``estimator.fit``.
return_train_score : boolean, optional, default: False
Compute and return score on training set.
return_parameters : boolean, optional, default: False
Return parameters that has been used for the estimator.
return_n_test_samples : boolean, optional, default: False
Whether to return the ``n_test_samples``
return_times : boolean, optional, default: False
Whether to return the fit/score times.
Returns
-------
train_scores : dict of scorer name -> float, optional
Score on training set (for all the scorers),
returned only if `return_train_score` is `True`.
test_scores : dict of scorer name -> float, optional
Score on testing set (for all the scorers).
n_test_samples : int
Number of test samples.
fit_time : float
Time spent for fitting in seconds.
score_time : float
Time spent for scoring in seconds.
parameters : dict or None, optional
The parameters that have been evaluated.
"""
if verbose > 1:
if parameters is None:
msg = ''
else:
msg = '%s' % (', '.join('%s=%s' % (k, v)
for k, v in parameters.items()))
print("[CV] %s %s" % (msg, (64 - len(msg)) * '.'))
# Adjust length of sample weights
fit_params = fit_params if fit_params is not None else {}
fit_params = dict([(k, _index_param_value(X, v, train))
for k, v in fit_params.items()])
test_scores = {}
train_scores = {}
if parameters is not None:
estimator.set_params(**parameters)
start_time = time.time()
X_train, y_train = _safe_split(estimator, X, y, train)
X_test, y_test = _safe_split(estimator, X, y, test, train)
is_multimetric = not callable(scorer)
n_scorers = len(scorer.keys()) if is_multimetric else 1
try:
if y_train is None:
estimator.fit(X_train, **fit_params)
else:
estimator.fit(X_train, y_train, **fit_params)
except Exception as e:
# Note fit time as time until error
fit_time = time.time() - start_time
score_time = 0.0
if error_score == 'raise':
raise
elif isinstance(error_score, numbers.Number):
if is_multimetric:
test_scores = dict(zip(scorer.keys(),
[error_score, ] * n_scorers))
if return_train_score:
train_scores = dict(zip(scorer.keys(),
[error_score, ] * n_scorers))
else:
test_scores = error_score
if return_train_score:
train_scores = error_score
warnings.warn("Classifier fit failed. The score on this train-test"
" partition for these parameters will be set to %f. "
"Details: \n%r" % (error_score, e), FitFailedWarning)
else:
raise ValueError("error_score must be the string 'raise' or a"
" numeric value. (Hint: if using 'raise', please"
" make sure that it has been spelled correctly.)")
else:
fit_time = time.time() - start_time
# _score will return dict if is_multimetric is True
test_scores = _score(estimator, X_test, y_test, scorer, is_multimetric)
score_time = time.time() - start_time - fit_time
if return_train_score:
train_scores = _score(estimator, X_train, y_train, scorer,
is_multimetric)
if verbose > 2:
if is_multimetric:
for scorer_name, score in test_scores.items():
msg += ", %s=%s" % (scorer_name, score)
else:
msg += ", score=%s" % test_scores
if verbose > 1:
total_time = score_time + fit_time
end_msg = "%s, total=%s" % (msg, logger.short_format_time(total_time))
print("[CV] %s %s" % ((64 - len(end_msg)) * '.', end_msg))
ret = [train_scores, test_scores] if return_train_score else [test_scores]
if return_n_test_samples:
ret.append(_num_samples(X_test))
if return_times:
ret.extend([fit_time, score_time])
if return_parameters:
ret.append(parameters)
return ret
def _score(estimator, X_test, y_test, scorer, is_multimetric=False):
"""Compute the score(s) of an estimator on a given test set.
Will return a single float if is_multimetric is False and a dict of floats,
if is_multimetric is True
"""
if is_multimetric:
return _multimetric_score(estimator, X_test, y_test, scorer)
else:
if y_test is None:
score = scorer(estimator, X_test)
else:
score = scorer(estimator, X_test, y_test)
if hasattr(score, 'item'):
try:
# e.g. unwrap memmapped scalars
score = score.item()
except ValueError:
# non-scalar?
pass
if not isinstance(score, numbers.Number):
raise ValueError("scoring must return a number, got %s (%s) "
"instead. (scorer=%r)"
% (str(score), type(score), scorer))
return score
def _multimetric_score(estimator, X_test, y_test, scorers):
"""Return a dict of score for multimetric scoring"""
scores = {}
for name, scorer in scorers.items():
if y_test is None:
score = scorer(estimator, X_test)
else:
score = scorer(estimator, X_test, y_test)
if hasattr(score, 'item'):
try:
# e.g. unwrap memmapped scalars
score = score.item()
except ValueError:
# non-scalar?
pass
scores[name] = score
if not isinstance(score, numbers.Number):
raise ValueError("scoring must return a number, got %s (%s) "
"instead. (scorer=%s)"
% (str(score), type(score), name))
return scores
def cross_val_predict(estimator, X, y=None, groups=None, cv=None, n_jobs=1,
verbose=0, fit_params=None, pre_dispatch='2*n_jobs',
method='predict'):
"""Generate cross-validated estimates for each input data point
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
estimator : estimator object implementing 'fit' and 'predict'
The object to use to fit the data.
X : array-like
The data to fit. Can be, for example a list, or an array at least 2d.
y : array-like, optional, default: None
The target variable to try to predict in the case of
supervised learning.
groups : array-like, with shape (n_samples,), optional
Group labels for the samples used while splitting the dataset into
train/test set.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross validation,
- integer, to specify the number of folds in a `(Stratified)KFold`,
- An object to be used as a cross-validation generator.
- An iterable yielding train, test splits.
For integer/None inputs, if the estimator is a classifier and ``y`` is
either binary or multiclass, :class:`StratifiedKFold` is used. In all
other cases, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
n_jobs : integer, optional
The number of CPUs to use to do the computation. -1 means
'all CPUs'.
verbose : integer, optional
The verbosity level.
fit_params : dict, optional
Parameters to pass to the fit method of the estimator.
pre_dispatch : int, or string, optional
Controls the number of jobs that get dispatched during parallel
execution. Reducing this number can be useful to avoid an
explosion of memory consumption when more jobs get dispatched
than CPUs can process. This parameter can be:
- None, in which case all the jobs are immediately
created and spawned. Use this for lightweight and
fast-running jobs, to avoid delays due to on-demand
spawning of the jobs
- An int, giving the exact number of total jobs that are
spawned
- A string, giving an expression as a function of n_jobs,
as in '2*n_jobs'
method : string, optional, default: 'predict'
Invokes the passed method name of the passed estimator. For
method='predict_proba', the columns correspond to the classes
in sorted order.
Returns
-------
predictions : ndarray
This is the result of calling ``method``
Notes
-----
In the case that one or more classes are absent in a training portion, a
default score needs to be assigned to all instances for that class if
``method`` produces columns per class, as in {'decision_function',
'predict_proba', 'predict_log_proba'}. For ``predict_proba`` this value is
0. In order to ensure finite output, we approximate negative infinity by
the minimum finite float value for the dtype in other cases.
Examples
--------
>>> from sklearn import datasets, linear_model
>>> from sklearn.model_selection import cross_val_predict
>>> diabetes = datasets.load_diabetes()
>>> X = diabetes.data[:150]
>>> y = diabetes.target[:150]
>>> lasso = linear_model.Lasso()
>>> y_pred = cross_val_predict(lasso, X, y)
"""
X, y, groups = indexable(X, y, groups)
cv = check_cv(cv, y, classifier=is_classifier(estimator))
if method in ['decision_function', 'predict_proba', 'predict_log_proba']:
le = LabelEncoder()
y = le.fit_transform(y)
# We clone the estimator to make sure that all the folds are
# independent, and that it is pickle-able.
parallel = Parallel(n_jobs=n_jobs, verbose=verbose,
pre_dispatch=pre_dispatch)
prediction_blocks = parallel(delayed(_fit_and_predict)(
clone(estimator), X, y, train, test, verbose, fit_params, method)
for train, test in cv.split(X, y, groups))
# Concatenate the predictions
predictions = [pred_block_i for pred_block_i, _ in prediction_blocks]
test_indices = np.concatenate([indices_i
for _, indices_i in prediction_blocks])
if not _check_is_permutation(test_indices, _num_samples(X)):
raise ValueError('cross_val_predict only works for partitions')
inv_test_indices = np.empty(len(test_indices), dtype=int)
inv_test_indices[test_indices] = np.arange(len(test_indices))
# Check for sparse predictions
if sp.issparse(predictions[0]):
predictions = sp.vstack(predictions, format=predictions[0].format)
else:
predictions = np.concatenate(predictions)
return predictions[inv_test_indices]
def _fit_and_predict(estimator, X, y, train, test, verbose, fit_params,
method):
"""Fit estimator and predict values for a given dataset split.
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
estimator : estimator object implementing 'fit' and 'predict'
The object to use to fit the data.
X : array-like of shape at least 2D
The data to fit.
y : array-like, optional, default: None
The target variable to try to predict in the case of
supervised learning.
train : array-like, shape (n_train_samples,)
Indices of training samples.
test : array-like, shape (n_test_samples,)
Indices of test samples.
verbose : integer
The verbosity level.
fit_params : dict or None
Parameters that will be passed to ``estimator.fit``.
method : string
Invokes the passed method name of the passed estimator.
Returns
-------
predictions : sequence
Result of calling 'estimator.method'
test : array-like
This is the value of the test parameter
"""
# Adjust length of sample weights
fit_params = fit_params if fit_params is not None else {}
fit_params = dict([(k, _index_param_value(X, v, train))
for k, v in fit_params.items()])
X_train, y_train = _safe_split(estimator, X, y, train)
X_test, _ = _safe_split(estimator, X, y, test, train)
if y_train is None:
estimator.fit(X_train, **fit_params)
else:
estimator.fit(X_train, y_train, **fit_params)
func = getattr(estimator, method)
predictions = func(X_test)
if method in ['decision_function', 'predict_proba', 'predict_log_proba']:
n_classes = len(set(y))
if n_classes != len(estimator.classes_):
recommendation = (
'To fix this, use a cross-validation '
'technique resulting in properly '
'stratified folds')
warnings.warn('Number of classes in training fold ({}) does '
'not match total number of classes ({}). '
'Results may not be appropriate for your use case. '
'{}'.format(len(estimator.classes_),
n_classes, recommendation),
RuntimeWarning)
if method == 'decision_function':
if (predictions.ndim == 2 and
predictions.shape[1] != len(estimator.classes_)):
# This handles the case when the shape of predictions
# does not match the number of classes used to train
# it with. This case is found when sklearn.svm.SVC is
# set to `decision_function_shape='ovo'`.
raise ValueError('Output shape {} of {} does not match '
'number of classes ({}) in fold. '
'Irregular decision_function outputs '
'are not currently supported by '
'cross_val_predict'.format(
predictions.shape, method,
len(estimator.classes_),
recommendation))
if len(estimator.classes_) <= 2:
# In this special case, `predictions` contains a 1D array.
raise ValueError('Only {} class/es in training fold, this '
'is not supported for decision_function '
'with imbalanced folds. {}'.format(
len(estimator.classes_),
recommendation))
float_min = np.finfo(predictions.dtype).min
default_values = {'decision_function': float_min,
'predict_log_proba': float_min,
'predict_proba': 0}
predictions_for_all_classes = np.full((_num_samples(predictions),
n_classes),
default_values[method])
predictions_for_all_classes[:, estimator.classes_] = predictions
predictions = predictions_for_all_classes
return predictions, test
def _check_is_permutation(indices, n_samples):
"""Check whether indices is a reordering of the array np.arange(n_samples)
Parameters
----------
indices : ndarray
integer array to test
n_samples : int
number of expected elements
Returns
-------
is_partition : bool
True iff sorted(indices) is np.arange(n)
"""
if len(indices) != n_samples:
return False
hit = np.zeros(n_samples, dtype=bool)
hit[indices] = True
if not np.all(hit):
return False
return True
def _index_param_value(X, v, indices):
"""Private helper function for parameter value indexing."""
if not _is_arraylike(v) or _num_samples(v) != _num_samples(X):
# pass through: skip indexing
return v
if sp.issparse(v):
v = v.tocsr()
return safe_indexing(v, indices)
def permutation_test_score(estimator, X, y, groups=None, cv=None,
n_permutations=100, n_jobs=1, random_state=0,
verbose=0, scoring=None):
"""Evaluate the significance of a cross-validated score with permutations
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
estimator : estimator object implementing 'fit'
The object to use to fit the data.
X : array-like of shape at least 2D
The data to fit.
y : array-like
The target variable to try to predict in the case of
supervised learning.
groups : array-like, with shape (n_samples,), optional
Labels to constrain permutation within groups, i.e. ``y`` values
are permuted among samples with the same group identifier.
When not specified, ``y`` values are permuted among all samples.
When a grouped cross-validator is used, the group labels are
also passed on to the ``split`` method of the cross-validator. The
cross-validator uses them for grouping the samples while splitting
the dataset into train/test set.
scoring : string, callable or None, optional, default: None
A single string (see :ref:`scoring_parameter`) or a callable
(see :ref:`scoring`) to evaluate the predictions on the test set.
If None the estimator's default scorer, if available, is used.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross validation,
- integer, to specify the number of folds in a `(Stratified)KFold`,
- An object to be used as a cross-validation generator.
- An iterable yielding train, test splits.
For integer/None inputs, if the estimator is a classifier and ``y`` is
either binary or multiclass, :class:`StratifiedKFold` is used. In all
other cases, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
n_permutations : integer, optional
Number of times to permute ``y``.
n_jobs : integer, optional
The number of CPUs to use to do the computation. -1 means
'all CPUs'.
random_state : int, RandomState instance or None, optional (default=0)
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
verbose : integer, optional
The verbosity level.
Returns
-------
score : float
The true score without permuting targets.
permutation_scores : array, shape (n_permutations,)
The scores obtained for each permutations.
pvalue : float
The p-value, which approximates the probability that the score would
be obtained by chance. This is calculated as:
`(C + 1) / (n_permutations + 1)`
Where C is the number of permutations whose score >= the true score.
The best possible p-value is 1/(n_permutations + 1), the worst is 1.0.
Notes
-----
This function implements Test 1 in:
Ojala and Garriga. Permutation Tests for Studying Classifier
Performance. The Journal of Machine Learning Research (2010)
vol. 11
"""
X, y, groups = indexable(X, y, groups)
cv = check_cv(cv, y, classifier=is_classifier(estimator))
scorer = check_scoring(estimator, scoring=scoring)
random_state = check_random_state(random_state)
# We clone the estimator to make sure that all the folds are
# independent, and that it is pickle-able.
score = _permutation_test_score(clone(estimator), X, y, groups, cv, scorer)
permutation_scores = Parallel(n_jobs=n_jobs, verbose=verbose)(
delayed(_permutation_test_score)(
clone(estimator), X, _shuffle(y, groups, random_state),
groups, cv, scorer)
for _ in range(n_permutations))
permutation_scores = np.array(permutation_scores)
pvalue = (np.sum(permutation_scores >= score) + 1.0) / (n_permutations + 1)
return score, permutation_scores, pvalue
permutation_test_score.__test__ = False # to avoid a pb with nosetests
def _permutation_test_score(estimator, X, y, groups, cv, scorer):
"""Auxiliary function for permutation_test_score"""
avg_score = []
for train, test in cv.split(X, y, groups):
X_train, y_train = _safe_split(estimator, X, y, train)
X_test, y_test = _safe_split(estimator, X, y, test, train)
estimator.fit(X_train, y_train)
avg_score.append(scorer(estimator, X_test, y_test))
return np.mean(avg_score)
def _shuffle(y, groups, random_state):
"""Return a shuffled copy of y eventually shuffle among same groups."""
if groups is None:
indices = random_state.permutation(len(y))
else:
indices = np.arange(len(groups))
for group in np.unique(groups):
this_mask = (groups == group)
indices[this_mask] = random_state.permutation(indices[this_mask])
return safe_indexing(y, indices)
def learning_curve(estimator, X, y, groups=None,
train_sizes=np.linspace(0.1, 1.0, 5), cv=None, scoring=None,
exploit_incremental_learning=False, n_jobs=1,
pre_dispatch="all", verbose=0, shuffle=False,
random_state=None):
"""Learning curve.
Determines cross-validated training and test scores for different training
set sizes.
A cross-validation generator splits the whole dataset k times in training
and test data. Subsets of the training set with varying sizes will be used
to train the estimator and a score for each training subset size and the
test set will be computed. Afterwards, the scores will be averaged over
all k runs for each training subset size.
Read more in the :ref:`User Guide <learning_curve>`.
Parameters
----------
estimator : object type that implements the "fit" and "predict" methods
An object of that type which is cloned for each validation.
X : array-like, shape (n_samples, n_features)
Training vector, where n_samples is the number of samples and
n_features is the number of features.
y : array-like, shape (n_samples) or (n_samples, n_features), optional
Target relative to X for classification or regression;
None for unsupervised learning.
groups : array-like, with shape (n_samples,), optional
Group labels for the samples used while splitting the dataset into
train/test set.
train_sizes : array-like, shape (n_ticks,), dtype float or int
Relative or absolute numbers of training examples that will be used to
generate the learning curve. If the dtype is float, it is regarded as a
fraction of the maximum size of the training set (that is determined
by the selected validation method), i.e. it has to be within (0, 1].
Otherwise it is interpreted as absolute sizes of the training sets.
Note that for classification the number of samples usually have to
be big enough to contain at least one sample from each class.
(default: np.linspace(0.1, 1.0, 5))
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross validation,
- integer, to specify the number of folds in a `(Stratified)KFold`,
- An object to be used as a cross-validation generator.
- An iterable yielding train, test splits.
For integer/None inputs, if the estimator is a classifier and ``y`` is
either binary or multiclass, :class:`StratifiedKFold` is used. In all
other cases, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
scoring : string, callable or None, optional, default: None
A string (see model evaluation documentation) or
a scorer callable object / function with signature
``scorer(estimator, X, y)``.
exploit_incremental_learning : boolean, optional, default: False
If the estimator supports incremental learning, this will be
used to speed up fitting for different training set sizes.
n_jobs : integer, optional
Number of jobs to run in parallel (default 1).
pre_dispatch : integer or string, optional
Number of predispatched jobs for parallel execution (default is
all). The option can reduce the allocated memory. The string can
be an expression like '2*n_jobs'.
verbose : integer, optional
Controls the verbosity: the higher, the more messages.
shuffle : boolean, optional
Whether to shuffle training data before taking prefixes of it
based on``train_sizes``.
random_state : int, RandomState instance or None, optional (default=None)
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`. Used when ``shuffle`` is True.
Returns
-------
train_sizes_abs : array, shape = (n_unique_ticks,), dtype int
Numbers of training examples that has been used to generate the
learning curve. Note that the number of ticks might be less
than n_ticks because duplicate entries will be removed.
train_scores : array, shape (n_ticks, n_cv_folds)
Scores on training sets.
test_scores : array, shape (n_ticks, n_cv_folds)
Scores on test set.
Notes
-----
See :ref:`examples/model_selection/plot_learning_curve.py
<sphx_glr_auto_examples_model_selection_plot_learning_curve.py>`
"""
if exploit_incremental_learning and not hasattr(estimator, "partial_fit"):
raise ValueError("An estimator must support the partial_fit interface "
"to exploit incremental learning")
X, y, groups = indexable(X, y, groups)
cv = check_cv(cv, y, classifier=is_classifier(estimator))
# Store it as list as we will be iterating over the list multiple times
cv_iter = list(cv.split(X, y, groups))
scorer = check_scoring(estimator, scoring=scoring)
n_max_training_samples = len(cv_iter[0][0])
# Because the lengths of folds can be significantly different, it is
# not guaranteed that we use all of the available training data when we
# use the first 'n_max_training_samples' samples.
train_sizes_abs = _translate_train_sizes(train_sizes,
n_max_training_samples)
n_unique_ticks = train_sizes_abs.shape[0]
if verbose > 0:
print("[learning_curve] Training set sizes: " + str(train_sizes_abs))
parallel = Parallel(n_jobs=n_jobs, pre_dispatch=pre_dispatch,
verbose=verbose)
if shuffle:
rng = check_random_state(random_state)
cv_iter = ((rng.permutation(train), test) for train, test in cv_iter)
if exploit_incremental_learning:
classes = np.unique(y) if is_classifier(estimator) else None
out = parallel(delayed(_incremental_fit_estimator)(
clone(estimator), X, y, classes, train, test, train_sizes_abs,
scorer, verbose) for train, test in cv_iter)
else:
train_test_proportions = []
for train, test in cv_iter:
for n_train_samples in train_sizes_abs:
train_test_proportions.append((train[:n_train_samples], test))
out = parallel(delayed(_fit_and_score)(
clone(estimator), X, y, scorer, train, test,
verbose, parameters=None, fit_params=None, return_train_score=True)
for train, test in train_test_proportions)
out = np.array(out)
n_cv_folds = out.shape[0] // n_unique_ticks
out = out.reshape(n_cv_folds, n_unique_ticks, 2)
out = np.asarray(out).transpose((2, 1, 0))
return train_sizes_abs, out[0], out[1]
def _translate_train_sizes(train_sizes, n_max_training_samples):
"""Determine absolute sizes of training subsets and validate 'train_sizes'.
Examples:
_translate_train_sizes([0.5, 1.0], 10) -> [5, 10]
_translate_train_sizes([5, 10], 10) -> [5, 10]
Parameters
----------
train_sizes : array-like, shape (n_ticks,), dtype float or int
Numbers of training examples that will be used to generate the
learning curve. If the dtype is float, it is regarded as a
fraction of 'n_max_training_samples', i.e. it has to be within (0, 1].
n_max_training_samples : int
Maximum number of training samples (upper bound of 'train_sizes').
Returns
-------
train_sizes_abs : array, shape (n_unique_ticks,), dtype int
Numbers of training examples that will be used to generate the
learning curve. Note that the number of ticks might be less
than n_ticks because duplicate entries will be removed.
"""
train_sizes_abs = np.asarray(train_sizes)
n_ticks = train_sizes_abs.shape[0]
n_min_required_samples = np.min(train_sizes_abs)
n_max_required_samples = np.max(train_sizes_abs)
if np.issubdtype(train_sizes_abs.dtype, np.floating):
if n_min_required_samples <= 0.0 or n_max_required_samples > 1.0:
raise ValueError("train_sizes has been interpreted as fractions "
"of the maximum number of training samples and "
"must be within (0, 1], but is within [%f, %f]."
% (n_min_required_samples,
n_max_required_samples))
train_sizes_abs = (train_sizes_abs * n_max_training_samples).astype(
dtype=np.int, copy=False)
train_sizes_abs = np.clip(train_sizes_abs, 1,
n_max_training_samples)
else:
if (n_min_required_samples <= 0 or
n_max_required_samples > n_max_training_samples):
raise ValueError("train_sizes has been interpreted as absolute "
"numbers of training samples and must be within "
"(0, %d], but is within [%d, %d]."
% (n_max_training_samples,
n_min_required_samples,
n_max_required_samples))
train_sizes_abs = np.unique(train_sizes_abs)
if n_ticks > train_sizes_abs.shape[0]:
warnings.warn("Removed duplicate entries from 'train_sizes'. Number "
"of ticks will be less than the size of "
"'train_sizes' %d instead of %d)."
% (train_sizes_abs.shape[0], n_ticks), RuntimeWarning)
return train_sizes_abs
def _incremental_fit_estimator(estimator, X, y, classes, train, test,
train_sizes, scorer, verbose):
"""Train estimator on training subsets incrementally and compute scores."""
train_scores, test_scores = [], []
partitions = zip(train_sizes, np.split(train, train_sizes)[:-1])
for n_train_samples, partial_train in partitions:
train_subset = train[:n_train_samples]
X_train, y_train = _safe_split(estimator, X, y, train_subset)
X_partial_train, y_partial_train = _safe_split(estimator, X, y,
partial_train)
X_test, y_test = _safe_split(estimator, X, y, test, train_subset)
if y_partial_train is None:
estimator.partial_fit(X_partial_train, classes=classes)
else:
estimator.partial_fit(X_partial_train, y_partial_train,
classes=classes)
train_scores.append(_score(estimator, X_train, y_train, scorer))
test_scores.append(_score(estimator, X_test, y_test, scorer))
return np.array((train_scores, test_scores)).T
def validation_curve(estimator, X, y, param_name, param_range, groups=None,
cv=None, scoring=None, n_jobs=1, pre_dispatch="all",
verbose=0):
"""Validation curve.
Determine training and test scores for varying parameter values.
Compute scores for an estimator with different values of a specified
parameter. This is similar to grid search with one parameter. However, this
will also compute training scores and is merely a utility for plotting the
results.
Read more in the :ref:`User Guide <learning_curve>`.
Parameters
----------
estimator : object type that implements the "fit" and "predict" methods
An object of that type which is cloned for each validation.
X : array-like, shape (n_samples, n_features)
Training vector, where n_samples is the number of samples and
n_features is the number of features.
y : array-like, shape (n_samples) or (n_samples, n_features), optional
Target relative to X for classification or regression;
None for unsupervised learning.
param_name : string
Name of the parameter that will be varied.
param_range : array-like, shape (n_values,)
The values of the parameter that will be evaluated.
groups : array-like, with shape (n_samples,), optional
Group labels for the samples used while splitting the dataset into
train/test set.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross validation,
- integer, to specify the number of folds in a `(Stratified)KFold`,
- An object to be used as a cross-validation generator.
- An iterable yielding train, test splits.
For integer/None inputs, if the estimator is a classifier and ``y`` is
either binary or multiclass, :class:`StratifiedKFold` is used. In all
other cases, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
scoring : string, callable or None, optional, default: None
A string (see model evaluation documentation) or
a scorer callable object / function with signature
``scorer(estimator, X, y)``.
n_jobs : integer, optional
Number of jobs to run in parallel (default 1).
pre_dispatch : integer or string, optional
Number of predispatched jobs for parallel execution (default is
all). The option can reduce the allocated memory. The string can
be an expression like '2*n_jobs'.
verbose : integer, optional
Controls the verbosity: the higher, the more messages.
Returns
-------
train_scores : array, shape (n_ticks, n_cv_folds)
Scores on training sets.
test_scores : array, shape (n_ticks, n_cv_folds)
Scores on test set.
Notes
-----
See :ref:`sphx_glr_auto_examples_model_selection_plot_validation_curve.py`
"""
X, y, groups = indexable(X, y, groups)
cv = check_cv(cv, y, classifier=is_classifier(estimator))
scorer = check_scoring(estimator, scoring=scoring)
parallel = Parallel(n_jobs=n_jobs, pre_dispatch=pre_dispatch,
verbose=verbose)
out = parallel(delayed(_fit_and_score)(
clone(estimator), X, y, scorer, train, test, verbose,
parameters={param_name: v}, fit_params=None, return_train_score=True)
# NOTE do not change order of iteration to allow one time cv splitters
for train, test in cv.split(X, y, groups) for v in param_range)
out = np.asarray(out)
n_params = len(param_range)
n_cv_folds = out.shape[0] // n_params
out = out.reshape(n_cv_folds, n_params, 2).transpose((2, 1, 0))
return out[0], out[1]
def _aggregate_score_dicts(scores):
"""Aggregate the list of dict to dict of np ndarray
The aggregated output of _fit_and_score will be a list of dict
of form [{'prec': 0.1, 'acc':1.0}, {'prec': 0.1, 'acc':1.0}, ...]
Convert it to a dict of array {'prec': np.array([0.1 ...]), ...}
Parameters
----------
scores : list of dict
List of dicts of the scores for all scorers. This is a flat list,
assumed originally to be of row major order.
Example
-------
>>> scores = [{'a': 1, 'b':10}, {'a': 2, 'b':2}, {'a': 3, 'b':3},
... {'a': 10, 'b': 10}] # doctest: +SKIP
>>> _aggregate_score_dicts(scores) # doctest: +SKIP
{'a': array([1, 2, 3, 10]),
'b': array([10, 2, 3, 10])}
"""
out = {}
for key in scores[0]:
out[key] = np.asarray([score[key] for score in scores])
return out
| 53,401 | 38.645137 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/model_selection/_search.py | """
The :mod:`sklearn.model_selection._search` includes utilities to fine-tune the
parameters of an estimator.
"""
from __future__ import print_function
from __future__ import division
# Author: Alexandre Gramfort <[email protected]>,
# Gael Varoquaux <[email protected]>
# Andreas Mueller <[email protected]>
# Olivier Grisel <[email protected]>
# Raghav RV <[email protected]>
# License: BSD 3 clause
from abc import ABCMeta, abstractmethod
from collections import Mapping, namedtuple, defaultdict, Sequence
from functools import partial, reduce
from itertools import product
import operator
import warnings
import numpy as np
from scipy.stats import rankdata
from ..base import BaseEstimator, is_classifier, clone
from ..base import MetaEstimatorMixin
from ._split import check_cv
from ._validation import _fit_and_score
from ._validation import _aggregate_score_dicts
from ..exceptions import NotFittedError
from ..externals.joblib import Parallel, delayed
from ..externals import six
from ..utils import check_random_state
from ..utils.fixes import sp_version
from ..utils.fixes import MaskedArray
from ..utils.random import sample_without_replacement
from ..utils.validation import indexable, check_is_fitted
from ..utils.metaestimators import if_delegate_has_method
from ..utils.deprecation import DeprecationDict
from ..metrics.scorer import _check_multimetric_scoring
from ..metrics.scorer import check_scoring
__all__ = ['GridSearchCV', 'ParameterGrid', 'fit_grid_point',
'ParameterSampler', 'RandomizedSearchCV']
class ParameterGrid(object):
"""Grid of parameters with a discrete number of values for each.
Can be used to iterate over parameter value combinations with the
Python built-in function iter.
Read more in the :ref:`User Guide <search>`.
Parameters
----------
param_grid : dict of string to sequence, or sequence of such
The parameter grid to explore, as a dictionary mapping estimator
parameters to sequences of allowed values.
An empty dict signifies default parameters.
A sequence of dicts signifies a sequence of grids to search, and is
useful to avoid exploring parameter combinations that make no sense
or have no effect. See the examples below.
Examples
--------
>>> from sklearn.model_selection import ParameterGrid
>>> param_grid = {'a': [1, 2], 'b': [True, False]}
>>> list(ParameterGrid(param_grid)) == (
... [{'a': 1, 'b': True}, {'a': 1, 'b': False},
... {'a': 2, 'b': True}, {'a': 2, 'b': False}])
True
>>> grid = [{'kernel': ['linear']}, {'kernel': ['rbf'], 'gamma': [1, 10]}]
>>> list(ParameterGrid(grid)) == [{'kernel': 'linear'},
... {'kernel': 'rbf', 'gamma': 1},
... {'kernel': 'rbf', 'gamma': 10}]
True
>>> ParameterGrid(grid)[1] == {'kernel': 'rbf', 'gamma': 1}
True
See also
--------
:class:`GridSearchCV`:
Uses :class:`ParameterGrid` to perform a full parallelized parameter
search.
"""
def __init__(self, param_grid):
if isinstance(param_grid, Mapping):
# wrap dictionary in a singleton list to support either dict
# or list of dicts
param_grid = [param_grid]
self.param_grid = param_grid
def __iter__(self):
"""Iterate over the points in the grid.
Returns
-------
params : iterator over dict of string to any
Yields dictionaries mapping each estimator parameter to one of its
allowed values.
"""
for p in self.param_grid:
# Always sort the keys of a dictionary, for reproducibility
items = sorted(p.items())
if not items:
yield {}
else:
keys, values = zip(*items)
for v in product(*values):
params = dict(zip(keys, v))
yield params
def __len__(self):
"""Number of points on the grid."""
# Product function that can handle iterables (np.product can't).
product = partial(reduce, operator.mul)
return sum(product(len(v) for v in p.values()) if p else 1
for p in self.param_grid)
def __getitem__(self, ind):
"""Get the parameters that would be ``ind``th in iteration
Parameters
----------
ind : int
The iteration index
Returns
-------
params : dict of string to any
Equal to list(self)[ind]
"""
# This is used to make discrete sampling without replacement memory
# efficient.
for sub_grid in self.param_grid:
# XXX: could memoize information used here
if not sub_grid:
if ind == 0:
return {}
else:
ind -= 1
continue
# Reverse so most frequent cycling parameter comes first
keys, values_lists = zip(*sorted(sub_grid.items())[::-1])
sizes = [len(v_list) for v_list in values_lists]
total = np.product(sizes)
if ind >= total:
# Try the next grid
ind -= total
else:
out = {}
for key, v_list, n in zip(keys, values_lists, sizes):
ind, offset = divmod(ind, n)
out[key] = v_list[offset]
return out
raise IndexError('ParameterGrid index out of range')
class ParameterSampler(object):
"""Generator on parameters sampled from given distributions.
Non-deterministic iterable over random candidate combinations for hyper-
parameter search. If all parameters are presented as a list,
sampling without replacement is performed. If at least one parameter
is given as a distribution, sampling with replacement is used.
It is highly recommended to use continuous distributions for continuous
parameters.
Note that before SciPy 0.16, the ``scipy.stats.distributions`` do not
accept a custom RNG instance and always use the singleton RNG from
``numpy.random``. Hence setting ``random_state`` will not guarantee a
deterministic iteration whenever ``scipy.stats`` distributions are used to
define the parameter search space. Deterministic behavior is however
guaranteed from SciPy 0.16 onwards.
Read more in the :ref:`User Guide <search>`.
Parameters
----------
param_distributions : dict
Dictionary where the keys are parameters and values
are distributions from which a parameter is to be sampled.
Distributions either have to provide a ``rvs`` function
to sample from them, or can be given as a list of values,
where a uniform distribution is assumed.
n_iter : integer
Number of parameter settings that are produced.
random_state : int, RandomState instance or None, optional (default=None)
Pseudo random number generator state used for random uniform sampling
from lists of possible values instead of scipy.stats distributions.
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
Returns
-------
params : dict of string to any
**Yields** dictionaries mapping each estimator parameter to
as sampled value.
Examples
--------
>>> from sklearn.model_selection import ParameterSampler
>>> from scipy.stats.distributions import expon
>>> import numpy as np
>>> np.random.seed(0)
>>> param_grid = {'a':[1, 2], 'b': expon()}
>>> param_list = list(ParameterSampler(param_grid, n_iter=4))
>>> rounded_list = [dict((k, round(v, 6)) for (k, v) in d.items())
... for d in param_list]
>>> rounded_list == [{'b': 0.89856, 'a': 1},
... {'b': 0.923223, 'a': 1},
... {'b': 1.878964, 'a': 2},
... {'b': 1.038159, 'a': 2}]
True
"""
def __init__(self, param_distributions, n_iter, random_state=None):
self.param_distributions = param_distributions
self.n_iter = n_iter
self.random_state = random_state
def __iter__(self):
# check if all distributions are given as lists
# in this case we want to sample without replacement
all_lists = np.all([not hasattr(v, "rvs")
for v in self.param_distributions.values()])
rnd = check_random_state(self.random_state)
if all_lists:
# look up sampled parameter settings in parameter grid
param_grid = ParameterGrid(self.param_distributions)
grid_size = len(param_grid)
if grid_size < self.n_iter:
raise ValueError(
"The total space of parameters %d is smaller "
"than n_iter=%d. For exhaustive searches, use "
"GridSearchCV." % (grid_size, self.n_iter))
for i in sample_without_replacement(grid_size, self.n_iter,
random_state=rnd):
yield param_grid[i]
else:
# Always sort the keys of a dictionary, for reproducibility
items = sorted(self.param_distributions.items())
for _ in six.moves.range(self.n_iter):
params = dict()
for k, v in items:
if hasattr(v, "rvs"):
if sp_version < (0, 16):
params[k] = v.rvs()
else:
params[k] = v.rvs(random_state=rnd)
else:
params[k] = v[rnd.randint(len(v))]
yield params
def __len__(self):
"""Number of points that will be sampled."""
return self.n_iter
def fit_grid_point(X, y, estimator, parameters, train, test, scorer,
verbose, error_score='raise', **fit_params):
"""Run fit on one set of parameters.
Parameters
----------
X : array-like, sparse matrix or list
Input data.
y : array-like or None
Targets for input data.
estimator : estimator object
A object of that type is instantiated for each grid point.
This is assumed to implement the scikit-learn estimator interface.
Either estimator needs to provide a ``score`` function,
or ``scoring`` must be passed.
parameters : dict
Parameters to be set on estimator for this grid point.
train : ndarray, dtype int or bool
Boolean mask or indices for training set.
test : ndarray, dtype int or bool
Boolean mask or indices for test set.
scorer : callable or None
The scorer callable object / function must have its signature as
``scorer(estimator, X, y)``.
If ``None`` the estimator's default scorer is used.
verbose : int
Verbosity level.
**fit_params : kwargs
Additional parameter passed to the fit function of the estimator.
error_score : 'raise' (default) or numeric
Value to assign to the score if an error occurs in estimator fitting.
If set to 'raise', the error is raised. If a numeric value is given,
FitFailedWarning is raised. This parameter does not affect the refit
step, which will always raise the error.
Returns
-------
score : float
Score of this parameter setting on given training / test split.
parameters : dict
The parameters that have been evaluated.
n_samples_test : int
Number of test samples in this split.
"""
# NOTE we are not using the return value as the scorer by itself should be
# validated before. We use check_scoring only to reject multimetric scorer
check_scoring(estimator, scorer)
scores, n_samples_test = _fit_and_score(estimator, X, y,
scorer, train,
test, verbose, parameters,
fit_params=fit_params,
return_n_test_samples=True,
error_score=error_score)
return scores, parameters, n_samples_test
def _check_param_grid(param_grid):
if hasattr(param_grid, 'items'):
param_grid = [param_grid]
for p in param_grid:
for name, v in p.items():
if isinstance(v, np.ndarray) and v.ndim > 1:
raise ValueError("Parameter array should be one-dimensional.")
if (isinstance(v, six.string_types) or
not isinstance(v, (np.ndarray, Sequence))):
raise ValueError("Parameter values for parameter ({0}) need "
"to be a sequence(but not a string) or"
" np.ndarray.".format(name))
if len(v) == 0:
raise ValueError("Parameter values for parameter ({0}) need "
"to be a non-empty sequence.".format(name))
# XXX Remove in 0.20
class _CVScoreTuple (namedtuple('_CVScoreTuple',
('parameters',
'mean_validation_score',
'cv_validation_scores'))):
# A raw namedtuple is very memory efficient as it packs the attributes
# in a struct to get rid of the __dict__ of attributes in particular it
# does not copy the string for the keys on each instance.
# By deriving a namedtuple class just to introduce the __repr__ method we
# would also reintroduce the __dict__ on the instance. By telling the
# Python interpreter that this subclass uses static __slots__ instead of
# dynamic attributes. Furthermore we don't need any additional slot in the
# subclass so we set __slots__ to the empty tuple.
__slots__ = ()
def __repr__(self):
"""Simple custom repr to summarize the main info"""
return "mean: {0:.5f}, std: {1:.5f}, params: {2}".format(
self.mean_validation_score,
np.std(self.cv_validation_scores),
self.parameters)
class BaseSearchCV(six.with_metaclass(ABCMeta, BaseEstimator,
MetaEstimatorMixin)):
"""Base class for hyper parameter search with cross-validation."""
@abstractmethod
def __init__(self, estimator, scoring=None,
fit_params=None, n_jobs=1, iid=True,
refit=True, cv=None, verbose=0, pre_dispatch='2*n_jobs',
error_score='raise', return_train_score=True):
self.scoring = scoring
self.estimator = estimator
self.n_jobs = n_jobs
self.fit_params = fit_params
self.iid = iid
self.refit = refit
self.cv = cv
self.verbose = verbose
self.pre_dispatch = pre_dispatch
self.error_score = error_score
self.return_train_score = return_train_score
@property
def _estimator_type(self):
return self.estimator._estimator_type
def score(self, X, y=None):
"""Returns the score on the given data, if the estimator has been refit.
This uses the score defined by ``scoring`` where provided, and the
``best_estimator_.score`` method otherwise.
Parameters
----------
X : array-like, shape = [n_samples, n_features]
Input data, where n_samples is the number of samples and
n_features is the number of features.
y : array-like, shape = [n_samples] or [n_samples, n_output], optional
Target relative to X for classification or regression;
None for unsupervised learning.
Returns
-------
score : float
"""
self._check_is_fitted('score')
if self.scorer_ is None:
raise ValueError("No score function explicitly defined, "
"and the estimator doesn't provide one %s"
% self.best_estimator_)
score = self.scorer_[self.refit] if self.multimetric_ else self.scorer_
return score(self.best_estimator_, X, y)
def _check_is_fitted(self, method_name):
if not self.refit:
raise NotFittedError('This %s instance was initialized '
'with refit=False. %s is '
'available only after refitting on the best '
'parameters. You can refit an estimator '
'manually using the ``best_parameters_`` '
'attribute'
% (type(self).__name__, method_name))
else:
check_is_fitted(self, 'best_estimator_')
@if_delegate_has_method(delegate=('best_estimator_', 'estimator'))
def predict(self, X):
"""Call predict on the estimator with the best found parameters.
Only available if ``refit=True`` and the underlying estimator supports
``predict``.
Parameters
-----------
X : indexable, length n_samples
Must fulfill the input assumptions of the
underlying estimator.
"""
self._check_is_fitted('predict')
return self.best_estimator_.predict(X)
@if_delegate_has_method(delegate=('best_estimator_', 'estimator'))
def predict_proba(self, X):
"""Call predict_proba on the estimator with the best found parameters.
Only available if ``refit=True`` and the underlying estimator supports
``predict_proba``.
Parameters
-----------
X : indexable, length n_samples
Must fulfill the input assumptions of the
underlying estimator.
"""
self._check_is_fitted('predict_proba')
return self.best_estimator_.predict_proba(X)
@if_delegate_has_method(delegate=('best_estimator_', 'estimator'))
def predict_log_proba(self, X):
"""Call predict_log_proba on the estimator with the best found parameters.
Only available if ``refit=True`` and the underlying estimator supports
``predict_log_proba``.
Parameters
-----------
X : indexable, length n_samples
Must fulfill the input assumptions of the
underlying estimator.
"""
self._check_is_fitted('predict_log_proba')
return self.best_estimator_.predict_log_proba(X)
@if_delegate_has_method(delegate=('best_estimator_', 'estimator'))
def decision_function(self, X):
"""Call decision_function on the estimator with the best found parameters.
Only available if ``refit=True`` and the underlying estimator supports
``decision_function``.
Parameters
-----------
X : indexable, length n_samples
Must fulfill the input assumptions of the
underlying estimator.
"""
self._check_is_fitted('decision_function')
return self.best_estimator_.decision_function(X)
@if_delegate_has_method(delegate=('best_estimator_', 'estimator'))
def transform(self, X):
"""Call transform on the estimator with the best found parameters.
Only available if the underlying estimator supports ``transform`` and
``refit=True``.
Parameters
-----------
X : indexable, length n_samples
Must fulfill the input assumptions of the
underlying estimator.
"""
self._check_is_fitted('transform')
return self.best_estimator_.transform(X)
@if_delegate_has_method(delegate=('best_estimator_', 'estimator'))
def inverse_transform(self, Xt):
"""Call inverse_transform on the estimator with the best found params.
Only available if the underlying estimator implements
``inverse_transform`` and ``refit=True``.
Parameters
-----------
Xt : indexable, length n_samples
Must fulfill the input assumptions of the
underlying estimator.
"""
self._check_is_fitted('inverse_transform')
return self.best_estimator_.inverse_transform(Xt)
@property
def classes_(self):
self._check_is_fitted("classes_")
return self.best_estimator_.classes_
def fit(self, X, y=None, groups=None, **fit_params):
"""Run fit with all sets of parameters.
Parameters
----------
X : array-like, shape = [n_samples, n_features]
Training vector, where n_samples is the number of samples and
n_features is the number of features.
y : array-like, shape = [n_samples] or [n_samples, n_output], optional
Target relative to X for classification or regression;
None for unsupervised learning.
groups : array-like, with shape (n_samples,), optional
Group labels for the samples used while splitting the dataset into
train/test set.
**fit_params : dict of string -> object
Parameters passed to the ``fit`` method of the estimator
"""
if self.fit_params is not None:
warnings.warn('"fit_params" as a constructor argument was '
'deprecated in version 0.19 and will be removed '
'in version 0.21. Pass fit parameters to the '
'"fit" method instead.', DeprecationWarning)
if fit_params:
warnings.warn('Ignoring fit_params passed as a constructor '
'argument in favor of keyword arguments to '
'the "fit" method.', RuntimeWarning)
else:
fit_params = self.fit_params
estimator = self.estimator
cv = check_cv(self.cv, y, classifier=is_classifier(estimator))
scorers, self.multimetric_ = _check_multimetric_scoring(
self.estimator, scoring=self.scoring)
if self.multimetric_:
if self.refit is not False and (
not isinstance(self.refit, six.string_types) or
# This will work for both dict / list (tuple)
self.refit not in scorers):
raise ValueError("For multi-metric scoring, the parameter "
"refit must be set to a scorer key "
"to refit an estimator with the best "
"parameter setting on the whole data and "
"make the best_* attributes "
"available for that metric. If this is not "
"needed, refit should be set to False "
"explicitly. %r was passed." % self.refit)
else:
refit_metric = self.refit
else:
refit_metric = 'score'
X, y, groups = indexable(X, y, groups)
n_splits = cv.get_n_splits(X, y, groups)
# Regenerate parameter iterable for each fit
candidate_params = list(self._get_param_iterator())
n_candidates = len(candidate_params)
if self.verbose > 0:
print("Fitting {0} folds for each of {1} candidates, totalling"
" {2} fits".format(n_splits, n_candidates,
n_candidates * n_splits))
base_estimator = clone(self.estimator)
pre_dispatch = self.pre_dispatch
out = Parallel(
n_jobs=self.n_jobs, verbose=self.verbose,
pre_dispatch=pre_dispatch
)(delayed(_fit_and_score)(clone(base_estimator), X, y, scorers, train,
test, self.verbose, parameters,
fit_params=fit_params,
return_train_score=self.return_train_score,
return_n_test_samples=True,
return_times=True, return_parameters=False,
error_score=self.error_score)
for parameters, (train, test) in product(candidate_params,
cv.split(X, y, groups)))
# if one choose to see train score, "out" will contain train score info
if self.return_train_score:
(train_score_dicts, test_score_dicts, test_sample_counts, fit_time,
score_time) = zip(*out)
else:
(test_score_dicts, test_sample_counts, fit_time,
score_time) = zip(*out)
# test_score_dicts and train_score dicts are lists of dictionaries and
# we make them into dict of lists
test_scores = _aggregate_score_dicts(test_score_dicts)
if self.return_train_score:
train_scores = _aggregate_score_dicts(train_score_dicts)
# TODO: replace by a dict in 0.21
results = (DeprecationDict() if self.return_train_score == 'warn'
else {})
def _store(key_name, array, weights=None, splits=False, rank=False):
"""A small helper to store the scores/times to the cv_results_"""
# When iterated first by splits, then by parameters
# We want `array` to have `n_candidates` rows and `n_splits` cols.
array = np.array(array, dtype=np.float64).reshape(n_candidates,
n_splits)
if splits:
for split_i in range(n_splits):
# Uses closure to alter the results
results["split%d_%s"
% (split_i, key_name)] = array[:, split_i]
array_means = np.average(array, axis=1, weights=weights)
results['mean_%s' % key_name] = array_means
# Weighted std is not directly available in numpy
array_stds = np.sqrt(np.average((array -
array_means[:, np.newaxis]) ** 2,
axis=1, weights=weights))
results['std_%s' % key_name] = array_stds
if rank:
results["rank_%s" % key_name] = np.asarray(
rankdata(-array_means, method='min'), dtype=np.int32)
_store('fit_time', fit_time)
_store('score_time', score_time)
# Use one MaskedArray and mask all the places where the param is not
# applicable for that candidate. Use defaultdict as each candidate may
# not contain all the params
param_results = defaultdict(partial(MaskedArray,
np.empty(n_candidates,),
mask=True,
dtype=object))
for cand_i, params in enumerate(candidate_params):
for name, value in params.items():
# An all masked empty array gets created for the key
# `"param_%s" % name` at the first occurence of `name`.
# Setting the value at an index also unmasks that index
param_results["param_%s" % name][cand_i] = value
results.update(param_results)
# Store a list of param dicts at the key 'params'
results['params'] = candidate_params
# NOTE test_sample counts (weights) remain the same for all candidates
test_sample_counts = np.array(test_sample_counts[:n_splits],
dtype=np.int)
for scorer_name in scorers.keys():
# Computed the (weighted) mean and std for test scores alone
_store('test_%s' % scorer_name, test_scores[scorer_name],
splits=True, rank=True,
weights=test_sample_counts if self.iid else None)
if self.return_train_score:
prev_keys = set(results.keys())
_store('train_%s' % scorer_name, train_scores[scorer_name],
splits=True)
if self.return_train_score == 'warn':
for key in set(results.keys()) - prev_keys:
message = (
'You are accessing a training score ({!r}), '
'which will not be available by default '
'any more in 0.21. If you need training scores, '
'please set return_train_score=True').format(key)
# warn on key access
results.add_warning(key, message, FutureWarning)
# For multi-metric evaluation, store the best_index_, best_params_ and
# best_score_ iff refit is one of the scorer names
# In single metric evaluation, refit_metric is "score"
if self.refit or not self.multimetric_:
self.best_index_ = results["rank_test_%s" % refit_metric].argmin()
self.best_params_ = candidate_params[self.best_index_]
self.best_score_ = results["mean_test_%s" % refit_metric][
self.best_index_]
if self.refit:
self.best_estimator_ = clone(base_estimator).set_params(
**self.best_params_)
if y is not None:
self.best_estimator_.fit(X, y, **fit_params)
else:
self.best_estimator_.fit(X, **fit_params)
# Store the only scorer not as a dict for single metric evaluation
self.scorer_ = scorers if self.multimetric_ else scorers['score']
self.cv_results_ = results
self.n_splits_ = n_splits
return self
@property
def grid_scores_(self):
check_is_fitted(self, 'cv_results_')
if self.multimetric_:
raise AttributeError("grid_scores_ attribute is not available for"
" multi-metric evaluation.")
warnings.warn(
"The grid_scores_ attribute was deprecated in version 0.18"
" in favor of the more elaborate cv_results_ attribute."
" The grid_scores_ attribute will not be available from 0.20",
DeprecationWarning)
grid_scores = list()
for i, (params, mean, std) in enumerate(zip(
self.cv_results_['params'],
self.cv_results_['mean_test_score'],
self.cv_results_['std_test_score'])):
scores = np.array(list(self.cv_results_['split%d_test_score'
% s][i]
for s in range(self.n_splits_)),
dtype=np.float64)
grid_scores.append(_CVScoreTuple(params, mean, scores))
return grid_scores
class GridSearchCV(BaseSearchCV):
"""Exhaustive search over specified parameter values for an estimator.
Important members are fit, predict.
GridSearchCV implements a "fit" and a "score" method.
It also implements "predict", "predict_proba", "decision_function",
"transform" and "inverse_transform" if they are implemented in the
estimator used.
The parameters of the estimator used to apply these methods are optimized
by cross-validated grid-search over a parameter grid.
Read more in the :ref:`User Guide <grid_search>`.
Parameters
----------
estimator : estimator object.
This is assumed to implement the scikit-learn estimator interface.
Either estimator needs to provide a ``score`` function,
or ``scoring`` must be passed.
param_grid : dict or list of dictionaries
Dictionary with parameters names (string) as keys and lists of
parameter settings to try as values, or a list of such
dictionaries, in which case the grids spanned by each dictionary
in the list are explored. This enables searching over any sequence
of parameter settings.
scoring : string, callable, list/tuple, dict or None, default: None
A single string (see :ref:`scoring_parameter`) or a callable
(see :ref:`scoring`) to evaluate the predictions on the test set.
For evaluating multiple metrics, either give a list of (unique) strings
or a dict with names as keys and callables as values.
NOTE that when using custom scorers, each scorer should return a single
value. Metric functions returning a list/array of values can be wrapped
into multiple scorers that return one value each.
See :ref:`multimetric_grid_search` for an example.
If None, the estimator's default scorer (if available) is used.
fit_params : dict, optional
Parameters to pass to the fit method.
.. deprecated:: 0.19
``fit_params`` as a constructor argument was deprecated in version
0.19 and will be removed in version 0.21. Pass fit parameters to
the ``fit`` method instead.
n_jobs : int, default=1
Number of jobs to run in parallel.
pre_dispatch : int, or string, optional
Controls the number of jobs that get dispatched during parallel
execution. Reducing this number can be useful to avoid an
explosion of memory consumption when more jobs get dispatched
than CPUs can process. This parameter can be:
- None, in which case all the jobs are immediately
created and spawned. Use this for lightweight and
fast-running jobs, to avoid delays due to on-demand
spawning of the jobs
- An int, giving the exact number of total jobs that are
spawned
- A string, giving an expression as a function of n_jobs,
as in '2*n_jobs'
iid : boolean, default=True
If True, the data is assumed to be identically distributed across
the folds, and the loss minimized is the total loss per sample,
and not the mean loss across the folds.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross validation,
- integer, to specify the number of folds in a `(Stratified)KFold`,
- An object to be used as a cross-validation generator.
- An iterable yielding train, test splits.
For integer/None inputs, if the estimator is a classifier and ``y`` is
either binary or multiclass, :class:`StratifiedKFold` is used. In all
other cases, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
refit : boolean, or string, default=True
Refit an estimator using the best found parameters on the whole
dataset.
For multiple metric evaluation, this needs to be a string denoting the
scorer is used to find the best parameters for refitting the estimator
at the end.
The refitted estimator is made available at the ``best_estimator_``
attribute and permits using ``predict`` directly on this
``GridSearchCV`` instance.
Also for multiple metric evaluation, the attributes ``best_index_``,
``best_score_`` and ``best_parameters_`` will only be available if
``refit`` is set and all of them will be determined w.r.t this specific
scorer.
See ``scoring`` parameter to know more about multiple metric
evaluation.
verbose : integer
Controls the verbosity: the higher, the more messages.
error_score : 'raise' (default) or numeric
Value to assign to the score if an error occurs in estimator fitting.
If set to 'raise', the error is raised. If a numeric value is given,
FitFailedWarning is raised. This parameter does not affect the refit
step, which will always raise the error.
return_train_score : boolean, optional
If ``False``, the ``cv_results_`` attribute will not include training
scores.
Current default is ``'warn'``, which behaves as ``True`` in addition
to raising a warning when a training score is looked up.
That default will be changed to ``False`` in 0.21.
Computing training scores is used to get insights on how different
parameter settings impact the overfitting/underfitting trade-off.
However computing the scores on the training set can be computationally
expensive and is not strictly required to select the parameters that
yield the best generalization performance.
Examples
--------
>>> from sklearn import svm, datasets
>>> from sklearn.model_selection import GridSearchCV
>>> iris = datasets.load_iris()
>>> parameters = {'kernel':('linear', 'rbf'), 'C':[1, 10]}
>>> svc = svm.SVC()
>>> clf = GridSearchCV(svc, parameters)
>>> clf.fit(iris.data, iris.target)
... # doctest: +NORMALIZE_WHITESPACE +ELLIPSIS
GridSearchCV(cv=None, error_score=...,
estimator=SVC(C=1.0, cache_size=..., class_weight=..., coef0=...,
decision_function_shape='ovr', degree=..., gamma=...,
kernel='rbf', max_iter=-1, probability=False,
random_state=None, shrinking=True, tol=...,
verbose=False),
fit_params=None, iid=..., n_jobs=1,
param_grid=..., pre_dispatch=..., refit=..., return_train_score=...,
scoring=..., verbose=...)
>>> sorted(clf.cv_results_.keys())
... # doctest: +NORMALIZE_WHITESPACE +ELLIPSIS
['mean_fit_time', 'mean_score_time', 'mean_test_score',...
'mean_train_score', 'param_C', 'param_kernel', 'params',...
'rank_test_score', 'split0_test_score',...
'split0_train_score', 'split1_test_score', 'split1_train_score',...
'split2_test_score', 'split2_train_score',...
'std_fit_time', 'std_score_time', 'std_test_score', 'std_train_score'...]
Attributes
----------
cv_results_ : dict of numpy (masked) ndarrays
A dict with keys as column headers and values as columns, that can be
imported into a pandas ``DataFrame``.
For instance the below given table
+------------+-----------+------------+-----------------+---+---------+
|param_kernel|param_gamma|param_degree|split0_test_score|...|rank_t...|
+============+===========+============+=================+===+=========+
| 'poly' | -- | 2 | 0.8 |...| 2 |
+------------+-----------+------------+-----------------+---+---------+
| 'poly' | -- | 3 | 0.7 |...| 4 |
+------------+-----------+------------+-----------------+---+---------+
| 'rbf' | 0.1 | -- | 0.8 |...| 3 |
+------------+-----------+------------+-----------------+---+---------+
| 'rbf' | 0.2 | -- | 0.9 |...| 1 |
+------------+-----------+------------+-----------------+---+---------+
will be represented by a ``cv_results_`` dict of::
{
'param_kernel': masked_array(data = ['poly', 'poly', 'rbf', 'rbf'],
mask = [False False False False]...)
'param_gamma': masked_array(data = [-- -- 0.1 0.2],
mask = [ True True False False]...),
'param_degree': masked_array(data = [2.0 3.0 -- --],
mask = [False False True True]...),
'split0_test_score' : [0.8, 0.7, 0.8, 0.9],
'split1_test_score' : [0.82, 0.5, 0.7, 0.78],
'mean_test_score' : [0.81, 0.60, 0.75, 0.82],
'std_test_score' : [0.02, 0.01, 0.03, 0.03],
'rank_test_score' : [2, 4, 3, 1],
'split0_train_score' : [0.8, 0.9, 0.7],
'split1_train_score' : [0.82, 0.5, 0.7],
'mean_train_score' : [0.81, 0.7, 0.7],
'std_train_score' : [0.03, 0.03, 0.04],
'mean_fit_time' : [0.73, 0.63, 0.43, 0.49],
'std_fit_time' : [0.01, 0.02, 0.01, 0.01],
'mean_score_time' : [0.007, 0.06, 0.04, 0.04],
'std_score_time' : [0.001, 0.002, 0.003, 0.005],
'params' : [{'kernel': 'poly', 'degree': 2}, ...],
}
NOTE
The key ``'params'`` is used to store a list of parameter
settings dicts for all the parameter candidates.
The ``mean_fit_time``, ``std_fit_time``, ``mean_score_time`` and
``std_score_time`` are all in seconds.
For multi-metric evaluation, the scores for all the scorers are
available in the ``cv_results_`` dict at the keys ending with that
scorer's name (``'_<scorer_name>'``) instead of ``'_score'`` shown
above. ('split0_test_precision', 'mean_train_precision' etc.)
best_estimator_ : estimator or dict
Estimator that was chosen by the search, i.e. estimator
which gave highest score (or smallest loss if specified)
on the left out data. Not available if ``refit=False``.
See ``refit`` parameter for more information on allowed values.
best_score_ : float
Mean cross-validated score of the best_estimator
For multi-metric evaluation, this is present only if ``refit`` is
specified.
best_params_ : dict
Parameter setting that gave the best results on the hold out data.
For multi-metric evaluation, this is present only if ``refit`` is
specified.
best_index_ : int
The index (of the ``cv_results_`` arrays) which corresponds to the best
candidate parameter setting.
The dict at ``search.cv_results_['params'][search.best_index_]`` gives
the parameter setting for the best model, that gives the highest
mean score (``search.best_score_``).
For multi-metric evaluation, this is present only if ``refit`` is
specified.
scorer_ : function or a dict
Scorer function used on the held out data to choose the best
parameters for the model.
For multi-metric evaluation, this attribute holds the validated
``scoring`` dict which maps the scorer key to the scorer callable.
n_splits_ : int
The number of cross-validation splits (folds/iterations).
Notes
------
The parameters selected are those that maximize the score of the left out
data, unless an explicit score is passed in which case it is used instead.
If `n_jobs` was set to a value higher than one, the data is copied for each
point in the grid (and not `n_jobs` times). This is done for efficiency
reasons if individual jobs take very little time, but may raise errors if
the dataset is large and not enough memory is available. A workaround in
this case is to set `pre_dispatch`. Then, the memory is copied only
`pre_dispatch` many times. A reasonable value for `pre_dispatch` is `2 *
n_jobs`.
See Also
---------
:class:`ParameterGrid`:
generates all the combinations of a hyperparameter grid.
:func:`sklearn.model_selection.train_test_split`:
utility function to split the data into a development set usable
for fitting a GridSearchCV instance and an evaluation set for
its final evaluation.
:func:`sklearn.metrics.make_scorer`:
Make a scorer from a performance metric or loss function.
"""
def __init__(self, estimator, param_grid, scoring=None, fit_params=None,
n_jobs=1, iid=True, refit=True, cv=None, verbose=0,
pre_dispatch='2*n_jobs', error_score='raise',
return_train_score="warn"):
super(GridSearchCV, self).__init__(
estimator=estimator, scoring=scoring, fit_params=fit_params,
n_jobs=n_jobs, iid=iid, refit=refit, cv=cv, verbose=verbose,
pre_dispatch=pre_dispatch, error_score=error_score,
return_train_score=return_train_score)
self.param_grid = param_grid
_check_param_grid(param_grid)
def _get_param_iterator(self):
"""Return ParameterGrid instance for the given param_grid"""
return ParameterGrid(self.param_grid)
class RandomizedSearchCV(BaseSearchCV):
"""Randomized search on hyper parameters.
RandomizedSearchCV implements a "fit" and a "score" method.
It also implements "predict", "predict_proba", "decision_function",
"transform" and "inverse_transform" if they are implemented in the
estimator used.
The parameters of the estimator used to apply these methods are optimized
by cross-validated search over parameter settings.
In contrast to GridSearchCV, not all parameter values are tried out, but
rather a fixed number of parameter settings is sampled from the specified
distributions. The number of parameter settings that are tried is
given by n_iter.
If all parameters are presented as a list,
sampling without replacement is performed. If at least one parameter
is given as a distribution, sampling with replacement is used.
It is highly recommended to use continuous distributions for continuous
parameters.
Read more in the :ref:`User Guide <randomized_parameter_search>`.
Parameters
----------
estimator : estimator object.
A object of that type is instantiated for each grid point.
This is assumed to implement the scikit-learn estimator interface.
Either estimator needs to provide a ``score`` function,
or ``scoring`` must be passed.
param_distributions : dict
Dictionary with parameters names (string) as keys and distributions
or lists of parameters to try. Distributions must provide a ``rvs``
method for sampling (such as those from scipy.stats.distributions).
If a list is given, it is sampled uniformly.
n_iter : int, default=10
Number of parameter settings that are sampled. n_iter trades
off runtime vs quality of the solution.
scoring : string, callable, list/tuple, dict or None, default: None
A single string (see :ref:`scoring_parameter`) or a callable
(see :ref:`scoring`) to evaluate the predictions on the test set.
For evaluating multiple metrics, either give a list of (unique) strings
or a dict with names as keys and callables as values.
NOTE that when using custom scorers, each scorer should return a single
value. Metric functions returning a list/array of values can be wrapped
into multiple scorers that return one value each.
See :ref:`multimetric_grid_search` for an example.
If None, the estimator's default scorer (if available) is used.
fit_params : dict, optional
Parameters to pass to the fit method.
.. deprecated:: 0.19
``fit_params`` as a constructor argument was deprecated in version
0.19 and will be removed in version 0.21. Pass fit parameters to
the ``fit`` method instead.
n_jobs : int, default=1
Number of jobs to run in parallel.
pre_dispatch : int, or string, optional
Controls the number of jobs that get dispatched during parallel
execution. Reducing this number can be useful to avoid an
explosion of memory consumption when more jobs get dispatched
than CPUs can process. This parameter can be:
- None, in which case all the jobs are immediately
created and spawned. Use this for lightweight and
fast-running jobs, to avoid delays due to on-demand
spawning of the jobs
- An int, giving the exact number of total jobs that are
spawned
- A string, giving an expression as a function of n_jobs,
as in '2*n_jobs'
iid : boolean, default=True
If True, the data is assumed to be identically distributed across
the folds, and the loss minimized is the total loss per sample,
and not the mean loss across the folds.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross validation,
- integer, to specify the number of folds in a `(Stratified)KFold`,
- An object to be used as a cross-validation generator.
- An iterable yielding train, test splits.
For integer/None inputs, if the estimator is a classifier and ``y`` is
either binary or multiclass, :class:`StratifiedKFold` is used. In all
other cases, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
refit : boolean, or string default=True
Refit an estimator using the best found parameters on the whole
dataset.
For multiple metric evaluation, this needs to be a string denoting the
scorer that would be used to find the best parameters for refitting
the estimator at the end.
The refitted estimator is made available at the ``best_estimator_``
attribute and permits using ``predict`` directly on this
``RandomizedSearchCV`` instance.
Also for multiple metric evaluation, the attributes ``best_index_``,
``best_score_`` and ``best_parameters_`` will only be available if
``refit`` is set and all of them will be determined w.r.t this specific
scorer.
See ``scoring`` parameter to know more about multiple metric
evaluation.
verbose : integer
Controls the verbosity: the higher, the more messages.
random_state : int, RandomState instance or None, optional, default=None
Pseudo random number generator state used for random uniform sampling
from lists of possible values instead of scipy.stats distributions.
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
error_score : 'raise' (default) or numeric
Value to assign to the score if an error occurs in estimator fitting.
If set to 'raise', the error is raised. If a numeric value is given,
FitFailedWarning is raised. This parameter does not affect the refit
step, which will always raise the error.
return_train_score : boolean, optional
If ``False``, the ``cv_results_`` attribute will not include training
scores.
Current default is ``'warn'``, which behaves as ``True`` in addition
to raising a warning when a training score is looked up.
That default will be changed to ``False`` in 0.21.
Computing training scores is used to get insights on how different
parameter settings impact the overfitting/underfitting trade-off.
However computing the scores on the training set can be computationally
expensive and is not strictly required to select the parameters that
yield the best generalization performance.
Attributes
----------
cv_results_ : dict of numpy (masked) ndarrays
A dict with keys as column headers and values as columns, that can be
imported into a pandas ``DataFrame``.
For instance the below given table
+--------------+-------------+-------------------+---+---------------+
| param_kernel | param_gamma | split0_test_score |...|rank_test_score|
+==============+=============+===================+===+===============+
| 'rbf' | 0.1 | 0.8 |...| 2 |
+--------------+-------------+-------------------+---+---------------+
| 'rbf' | 0.2 | 0.9 |...| 1 |
+--------------+-------------+-------------------+---+---------------+
| 'rbf' | 0.3 | 0.7 |...| 1 |
+--------------+-------------+-------------------+---+---------------+
will be represented by a ``cv_results_`` dict of::
{
'param_kernel' : masked_array(data = ['rbf', 'rbf', 'rbf'],
mask = False),
'param_gamma' : masked_array(data = [0.1 0.2 0.3], mask = False),
'split0_test_score' : [0.8, 0.9, 0.7],
'split1_test_score' : [0.82, 0.5, 0.7],
'mean_test_score' : [0.81, 0.7, 0.7],
'std_test_score' : [0.02, 0.2, 0.],
'rank_test_score' : [3, 1, 1],
'split0_train_score' : [0.8, 0.9, 0.7],
'split1_train_score' : [0.82, 0.5, 0.7],
'mean_train_score' : [0.81, 0.7, 0.7],
'std_train_score' : [0.03, 0.03, 0.04],
'mean_fit_time' : [0.73, 0.63, 0.43, 0.49],
'std_fit_time' : [0.01, 0.02, 0.01, 0.01],
'mean_score_time' : [0.007, 0.06, 0.04, 0.04],
'std_score_time' : [0.001, 0.002, 0.003, 0.005],
'params' : [{'kernel' : 'rbf', 'gamma' : 0.1}, ...],
}
NOTE
The key ``'params'`` is used to store a list of parameter
settings dicts for all the parameter candidates.
The ``mean_fit_time``, ``std_fit_time``, ``mean_score_time`` and
``std_score_time`` are all in seconds.
For multi-metric evaluation, the scores for all the scorers are
available in the ``cv_results_`` dict at the keys ending with that
scorer's name (``'_<scorer_name>'``) instead of ``'_score'`` shown
above. ('split0_test_precision', 'mean_train_precision' etc.)
best_estimator_ : estimator or dict
Estimator that was chosen by the search, i.e. estimator
which gave highest score (or smallest loss if specified)
on the left out data. Not available if ``refit=False``.
For multi-metric evaluation, this attribute is present only if
``refit`` is specified.
See ``refit`` parameter for more information on allowed values.
best_score_ : float
Mean cross-validated score of the best_estimator.
For multi-metric evaluation, this is not available if ``refit`` is
``False``. See ``refit`` parameter for more information.
best_params_ : dict
Parameter setting that gave the best results on the hold out data.
For multi-metric evaluation, this is not available if ``refit`` is
``False``. See ``refit`` parameter for more information.
best_index_ : int
The index (of the ``cv_results_`` arrays) which corresponds to the best
candidate parameter setting.
The dict at ``search.cv_results_['params'][search.best_index_]`` gives
the parameter setting for the best model, that gives the highest
mean score (``search.best_score_``).
For multi-metric evaluation, this is not available if ``refit`` is
``False``. See ``refit`` parameter for more information.
scorer_ : function or a dict
Scorer function used on the held out data to choose the best
parameters for the model.
For multi-metric evaluation, this attribute holds the validated
``scoring`` dict which maps the scorer key to the scorer callable.
n_splits_ : int
The number of cross-validation splits (folds/iterations).
Notes
-----
The parameters selected are those that maximize the score of the held-out
data, according to the scoring parameter.
If `n_jobs` was set to a value higher than one, the data is copied for each
parameter setting(and not `n_jobs` times). This is done for efficiency
reasons if individual jobs take very little time, but may raise errors if
the dataset is large and not enough memory is available. A workaround in
this case is to set `pre_dispatch`. Then, the memory is copied only
`pre_dispatch` many times. A reasonable value for `pre_dispatch` is `2 *
n_jobs`.
See Also
--------
:class:`GridSearchCV`:
Does exhaustive search over a grid of parameters.
:class:`ParameterSampler`:
A generator over parameter settins, constructed from
param_distributions.
"""
def __init__(self, estimator, param_distributions, n_iter=10, scoring=None,
fit_params=None, n_jobs=1, iid=True, refit=True, cv=None,
verbose=0, pre_dispatch='2*n_jobs', random_state=None,
error_score='raise', return_train_score="warn"):
self.param_distributions = param_distributions
self.n_iter = n_iter
self.random_state = random_state
super(RandomizedSearchCV, self).__init__(
estimator=estimator, scoring=scoring, fit_params=fit_params,
n_jobs=n_jobs, iid=iid, refit=refit, cv=cv, verbose=verbose,
pre_dispatch=pre_dispatch, error_score=error_score,
return_train_score=return_train_score)
def _get_param_iterator(self):
"""Return ParameterSampler instance for the given distributions"""
return ParameterSampler(
self.param_distributions, self.n_iter,
random_state=self.random_state)
| 58,290 | 41.331881 | 82 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/model_selection/_split.py | """
The :mod:`sklearn.model_selection._split` module includes classes and
functions to split the data based on a preset strategy.
"""
# Author: Alexandre Gramfort <[email protected]>,
# Gael Varoquaux <[email protected]>,
# Olivier Grisel <[email protected]>
# Raghav RV <[email protected]>
# License: BSD 3 clause
from __future__ import print_function
from __future__ import division
import warnings
from itertools import chain, combinations
from collections import Iterable
from math import ceil, floor
import numbers
from abc import ABCMeta, abstractmethod
import numpy as np
from ..utils import indexable, check_random_state, safe_indexing
from ..utils.validation import _num_samples, column_or_1d
from ..utils.validation import check_array
from ..utils.multiclass import type_of_target
from ..externals.six import with_metaclass
from ..externals.six.moves import zip
from ..utils.fixes import signature, comb
from ..base import _pprint
__all__ = ['BaseCrossValidator',
'KFold',
'GroupKFold',
'LeaveOneGroupOut',
'LeaveOneOut',
'LeavePGroupsOut',
'LeavePOut',
'RepeatedStratifiedKFold',
'RepeatedKFold',
'ShuffleSplit',
'GroupShuffleSplit',
'StratifiedKFold',
'StratifiedShuffleSplit',
'PredefinedSplit',
'train_test_split',
'check_cv']
class BaseCrossValidator(with_metaclass(ABCMeta)):
"""Base class for all cross-validators
Implementations must define `_iter_test_masks` or `_iter_test_indices`.
"""
def __init__(self):
# We need this for the build_repr to work properly in py2.7
# see #6304
pass
def split(self, X, y=None, groups=None):
"""Generate indices to split data into training and test set.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Training data, where n_samples is the number of samples
and n_features is the number of features.
y : array-like, of length n_samples
The target variable for supervised learning problems.
groups : array-like, with shape (n_samples,), optional
Group labels for the samples used while splitting the dataset into
train/test set.
Returns
-------
train : ndarray
The training set indices for that split.
test : ndarray
The testing set indices for that split.
Notes
-----
Randomized CV splitters may return different results for each call of
split. You can make the results identical by setting ``random_state``
to an integer.
"""
X, y, groups = indexable(X, y, groups)
indices = np.arange(_num_samples(X))
for test_index in self._iter_test_masks(X, y, groups):
train_index = indices[np.logical_not(test_index)]
test_index = indices[test_index]
yield train_index, test_index
# Since subclasses must implement either _iter_test_masks or
# _iter_test_indices, neither can be abstract.
def _iter_test_masks(self, X=None, y=None, groups=None):
"""Generates boolean masks corresponding to test sets.
By default, delegates to _iter_test_indices(X, y, groups)
"""
for test_index in self._iter_test_indices(X, y, groups):
test_mask = np.zeros(_num_samples(X), dtype=np.bool)
test_mask[test_index] = True
yield test_mask
def _iter_test_indices(self, X=None, y=None, groups=None):
"""Generates integer indices corresponding to test sets."""
raise NotImplementedError
@abstractmethod
def get_n_splits(self, X=None, y=None, groups=None):
"""Returns the number of splitting iterations in the cross-validator"""
def __repr__(self):
return _build_repr(self)
class LeaveOneOut(BaseCrossValidator):
"""Leave-One-Out cross-validator
Provides train/test indices to split data in train/test sets. Each
sample is used once as a test set (singleton) while the remaining
samples form the training set.
Note: ``LeaveOneOut()`` is equivalent to ``KFold(n_splits=n)`` and
``LeavePOut(p=1)`` where ``n`` is the number of samples.
Due to the high number of test sets (which is the same as the
number of samples) this cross-validation method can be very costly.
For large datasets one should favor :class:`KFold`, :class:`ShuffleSplit`
or :class:`StratifiedKFold`.
Read more in the :ref:`User Guide <cross_validation>`.
Examples
--------
>>> from sklearn.model_selection import LeaveOneOut
>>> X = np.array([[1, 2], [3, 4]])
>>> y = np.array([1, 2])
>>> loo = LeaveOneOut()
>>> loo.get_n_splits(X)
2
>>> print(loo)
LeaveOneOut()
>>> for train_index, test_index in loo.split(X):
... print("TRAIN:", train_index, "TEST:", test_index)
... X_train, X_test = X[train_index], X[test_index]
... y_train, y_test = y[train_index], y[test_index]
... print(X_train, X_test, y_train, y_test)
TRAIN: [1] TEST: [0]
[[3 4]] [[1 2]] [2] [1]
TRAIN: [0] TEST: [1]
[[1 2]] [[3 4]] [1] [2]
See also
--------
LeaveOneGroupOut
For splitting the data according to explicit, domain-specific
stratification of the dataset.
GroupKFold: K-fold iterator variant with non-overlapping groups.
"""
def _iter_test_indices(self, X, y=None, groups=None):
return range(_num_samples(X))
def get_n_splits(self, X, y=None, groups=None):
"""Returns the number of splitting iterations in the cross-validator
Parameters
----------
X : array-like, shape (n_samples, n_features)
Training data, where n_samples is the number of samples
and n_features is the number of features.
y : object
Always ignored, exists for compatibility.
groups : object
Always ignored, exists for compatibility.
Returns
-------
n_splits : int
Returns the number of splitting iterations in the cross-validator.
"""
if X is None:
raise ValueError("The 'X' parameter should not be None.")
return _num_samples(X)
class LeavePOut(BaseCrossValidator):
"""Leave-P-Out cross-validator
Provides train/test indices to split data in train/test sets. This results
in testing on all distinct samples of size p, while the remaining n - p
samples form the training set in each iteration.
Note: ``LeavePOut(p)`` is NOT equivalent to
``KFold(n_splits=n_samples // p)`` which creates non-overlapping test sets.
Due to the high number of iterations which grows combinatorically with the
number of samples this cross-validation method can be very costly. For
large datasets one should favor :class:`KFold`, :class:`StratifiedKFold`
or :class:`ShuffleSplit`.
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
p : int
Size of the test sets.
Examples
--------
>>> from sklearn.model_selection import LeavePOut
>>> X = np.array([[1, 2], [3, 4], [5, 6], [7, 8]])
>>> y = np.array([1, 2, 3, 4])
>>> lpo = LeavePOut(2)
>>> lpo.get_n_splits(X)
6
>>> print(lpo)
LeavePOut(p=2)
>>> for train_index, test_index in lpo.split(X):
... print("TRAIN:", train_index, "TEST:", test_index)
... X_train, X_test = X[train_index], X[test_index]
... y_train, y_test = y[train_index], y[test_index]
TRAIN: [2 3] TEST: [0 1]
TRAIN: [1 3] TEST: [0 2]
TRAIN: [1 2] TEST: [0 3]
TRAIN: [0 3] TEST: [1 2]
TRAIN: [0 2] TEST: [1 3]
TRAIN: [0 1] TEST: [2 3]
"""
def __init__(self, p):
self.p = p
def _iter_test_indices(self, X, y=None, groups=None):
for combination in combinations(range(_num_samples(X)), self.p):
yield np.array(combination)
def get_n_splits(self, X, y=None, groups=None):
"""Returns the number of splitting iterations in the cross-validator
Parameters
----------
X : array-like, shape (n_samples, n_features)
Training data, where n_samples is the number of samples
and n_features is the number of features.
y : object
Always ignored, exists for compatibility.
groups : object
Always ignored, exists for compatibility.
"""
if X is None:
raise ValueError("The 'X' parameter should not be None.")
return int(comb(_num_samples(X), self.p, exact=True))
class _BaseKFold(with_metaclass(ABCMeta, BaseCrossValidator)):
"""Base class for KFold, GroupKFold, and StratifiedKFold"""
@abstractmethod
def __init__(self, n_splits, shuffle, random_state):
if not isinstance(n_splits, numbers.Integral):
raise ValueError('The number of folds must be of Integral type. '
'%s of type %s was passed.'
% (n_splits, type(n_splits)))
n_splits = int(n_splits)
if n_splits <= 1:
raise ValueError(
"k-fold cross-validation requires at least one"
" train/test split by setting n_splits=2 or more,"
" got n_splits={0}.".format(n_splits))
if not isinstance(shuffle, bool):
raise TypeError("shuffle must be True or False;"
" got {0}".format(shuffle))
self.n_splits = n_splits
self.shuffle = shuffle
self.random_state = random_state
def split(self, X, y=None, groups=None):
"""Generate indices to split data into training and test set.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Training data, where n_samples is the number of samples
and n_features is the number of features.
y : array-like, shape (n_samples,)
The target variable for supervised learning problems.
groups : array-like, with shape (n_samples,), optional
Group labels for the samples used while splitting the dataset into
train/test set.
Returns
-------
train : ndarray
The training set indices for that split.
test : ndarray
The testing set indices for that split.
Notes
-----
Randomized CV splitters may return different results for each call of
split. You can make the results identical by setting ``random_state``
to an integer.
"""
X, y, groups = indexable(X, y, groups)
n_samples = _num_samples(X)
if self.n_splits > n_samples:
raise ValueError(
("Cannot have number of splits n_splits={0} greater"
" than the number of samples: {1}.").format(self.n_splits,
n_samples))
for train, test in super(_BaseKFold, self).split(X, y, groups):
yield train, test
def get_n_splits(self, X=None, y=None, groups=None):
"""Returns the number of splitting iterations in the cross-validator
Parameters
----------
X : object
Always ignored, exists for compatibility.
y : object
Always ignored, exists for compatibility.
groups : object
Always ignored, exists for compatibility.
Returns
-------
n_splits : int
Returns the number of splitting iterations in the cross-validator.
"""
return self.n_splits
class KFold(_BaseKFold):
"""K-Folds cross-validator
Provides train/test indices to split data in train/test sets. Split
dataset into k consecutive folds (without shuffling by default).
Each fold is then used once as a validation while the k - 1 remaining
folds form the training set.
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
n_splits : int, default=3
Number of folds. Must be at least 2.
shuffle : boolean, optional
Whether to shuffle the data before splitting into batches.
random_state : int, RandomState instance or None, optional, default=None
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`. Used when ``shuffle`` == True.
Examples
--------
>>> from sklearn.model_selection import KFold
>>> X = np.array([[1, 2], [3, 4], [1, 2], [3, 4]])
>>> y = np.array([1, 2, 3, 4])
>>> kf = KFold(n_splits=2)
>>> kf.get_n_splits(X)
2
>>> print(kf) # doctest: +NORMALIZE_WHITESPACE
KFold(n_splits=2, random_state=None, shuffle=False)
>>> for train_index, test_index in kf.split(X):
... print("TRAIN:", train_index, "TEST:", test_index)
... X_train, X_test = X[train_index], X[test_index]
... y_train, y_test = y[train_index], y[test_index]
TRAIN: [2 3] TEST: [0 1]
TRAIN: [0 1] TEST: [2 3]
Notes
-----
The first ``n_samples % n_splits`` folds have size
``n_samples // n_splits + 1``, other folds have size
``n_samples // n_splits``, where ``n_samples`` is the number of samples.
See also
--------
StratifiedKFold
Takes group information into account to avoid building folds with
imbalanced class distributions (for binary or multiclass
classification tasks).
GroupKFold: K-fold iterator variant with non-overlapping groups.
RepeatedKFold: Repeats K-Fold n times.
"""
def __init__(self, n_splits=3, shuffle=False,
random_state=None):
super(KFold, self).__init__(n_splits, shuffle, random_state)
def _iter_test_indices(self, X, y=None, groups=None):
n_samples = _num_samples(X)
indices = np.arange(n_samples)
if self.shuffle:
check_random_state(self.random_state).shuffle(indices)
n_splits = self.n_splits
fold_sizes = (n_samples // n_splits) * np.ones(n_splits, dtype=np.int)
fold_sizes[:n_samples % n_splits] += 1
current = 0
for fold_size in fold_sizes:
start, stop = current, current + fold_size
yield indices[start:stop]
current = stop
class GroupKFold(_BaseKFold):
"""K-fold iterator variant with non-overlapping groups.
The same group will not appear in two different folds (the number of
distinct groups has to be at least equal to the number of folds).
The folds are approximately balanced in the sense that the number of
distinct groups is approximately the same in each fold.
Parameters
----------
n_splits : int, default=3
Number of folds. Must be at least 2.
Examples
--------
>>> from sklearn.model_selection import GroupKFold
>>> X = np.array([[1, 2], [3, 4], [5, 6], [7, 8]])
>>> y = np.array([1, 2, 3, 4])
>>> groups = np.array([0, 0, 2, 2])
>>> group_kfold = GroupKFold(n_splits=2)
>>> group_kfold.get_n_splits(X, y, groups)
2
>>> print(group_kfold)
GroupKFold(n_splits=2)
>>> for train_index, test_index in group_kfold.split(X, y, groups):
... print("TRAIN:", train_index, "TEST:", test_index)
... X_train, X_test = X[train_index], X[test_index]
... y_train, y_test = y[train_index], y[test_index]
... print(X_train, X_test, y_train, y_test)
...
TRAIN: [0 1] TEST: [2 3]
[[1 2]
[3 4]] [[5 6]
[7 8]] [1 2] [3 4]
TRAIN: [2 3] TEST: [0 1]
[[5 6]
[7 8]] [[1 2]
[3 4]] [3 4] [1 2]
See also
--------
LeaveOneGroupOut
For splitting the data according to explicit domain-specific
stratification of the dataset.
"""
def __init__(self, n_splits=3):
super(GroupKFold, self).__init__(n_splits, shuffle=False,
random_state=None)
def _iter_test_indices(self, X, y, groups):
if groups is None:
raise ValueError("The 'groups' parameter should not be None.")
groups = check_array(groups, ensure_2d=False, dtype=None)
unique_groups, groups = np.unique(groups, return_inverse=True)
n_groups = len(unique_groups)
if self.n_splits > n_groups:
raise ValueError("Cannot have number of splits n_splits=%d greater"
" than the number of groups: %d."
% (self.n_splits, n_groups))
# Weight groups by their number of occurrences
n_samples_per_group = np.bincount(groups)
# Distribute the most frequent groups first
indices = np.argsort(n_samples_per_group)[::-1]
n_samples_per_group = n_samples_per_group[indices]
# Total weight of each fold
n_samples_per_fold = np.zeros(self.n_splits)
# Mapping from group index to fold index
group_to_fold = np.zeros(len(unique_groups))
# Distribute samples by adding the largest weight to the lightest fold
for group_index, weight in enumerate(n_samples_per_group):
lightest_fold = np.argmin(n_samples_per_fold)
n_samples_per_fold[lightest_fold] += weight
group_to_fold[indices[group_index]] = lightest_fold
indices = group_to_fold[groups]
for f in range(self.n_splits):
yield np.where(indices == f)[0]
class StratifiedKFold(_BaseKFold):
"""Stratified K-Folds cross-validator
Provides train/test indices to split data in train/test sets.
This cross-validation object is a variation of KFold that returns
stratified folds. The folds are made by preserving the percentage of
samples for each class.
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
n_splits : int, default=3
Number of folds. Must be at least 2.
shuffle : boolean, optional
Whether to shuffle each stratification of the data before splitting
into batches.
random_state : int, RandomState instance or None, optional, default=None
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`. Used when ``shuffle`` == True.
Examples
--------
>>> from sklearn.model_selection import StratifiedKFold
>>> X = np.array([[1, 2], [3, 4], [1, 2], [3, 4]])
>>> y = np.array([0, 0, 1, 1])
>>> skf = StratifiedKFold(n_splits=2)
>>> skf.get_n_splits(X, y)
2
>>> print(skf) # doctest: +NORMALIZE_WHITESPACE
StratifiedKFold(n_splits=2, random_state=None, shuffle=False)
>>> for train_index, test_index in skf.split(X, y):
... print("TRAIN:", train_index, "TEST:", test_index)
... X_train, X_test = X[train_index], X[test_index]
... y_train, y_test = y[train_index], y[test_index]
TRAIN: [1 3] TEST: [0 2]
TRAIN: [0 2] TEST: [1 3]
Notes
-----
All the folds have size ``trunc(n_samples / n_splits)``, the last one has
the complementary.
See also
--------
RepeatedStratifiedKFold: Repeats Stratified K-Fold n times.
"""
def __init__(self, n_splits=3, shuffle=False, random_state=None):
super(StratifiedKFold, self).__init__(n_splits, shuffle, random_state)
def _make_test_folds(self, X, y=None):
rng = self.random_state
y = np.asarray(y)
type_of_target_y = type_of_target(y)
allowed_target_types = ('binary', 'multiclass')
if type_of_target_y not in allowed_target_types:
raise ValueError(
'Supported target types are: {}. Got {!r} instead.'.format(
allowed_target_types, type_of_target_y))
y = column_or_1d(y)
n_samples = y.shape[0]
unique_y, y_inversed = np.unique(y, return_inverse=True)
y_counts = np.bincount(y_inversed)
min_groups = np.min(y_counts)
if np.all(self.n_splits > y_counts):
raise ValueError("n_splits=%d cannot be greater than the"
" number of members in each class."
% (self.n_splits))
if self.n_splits > min_groups:
warnings.warn(("The least populated class in y has only %d"
" members, which is too few. The minimum"
" number of members in any class cannot"
" be less than n_splits=%d."
% (min_groups, self.n_splits)), Warning)
# pre-assign each sample to a test fold index using individual KFold
# splitting strategies for each class so as to respect the balance of
# classes
# NOTE: Passing the data corresponding to ith class say X[y==class_i]
# will break when the data is not 100% stratifiable for all classes.
# So we pass np.zeroes(max(c, n_splits)) as data to the KFold
per_cls_cvs = [
KFold(self.n_splits, shuffle=self.shuffle,
random_state=rng).split(np.zeros(max(count, self.n_splits)))
for count in y_counts]
test_folds = np.zeros(n_samples, dtype=np.int)
for test_fold_indices, per_cls_splits in enumerate(zip(*per_cls_cvs)):
for cls, (_, test_split) in zip(unique_y, per_cls_splits):
cls_test_folds = test_folds[y == cls]
# the test split can be too big because we used
# KFold(...).split(X[:max(c, n_splits)]) when data is not 100%
# stratifiable for all the classes
# (we use a warning instead of raising an exception)
# If this is the case, let's trim it:
test_split = test_split[test_split < len(cls_test_folds)]
cls_test_folds[test_split] = test_fold_indices
test_folds[y == cls] = cls_test_folds
return test_folds
def _iter_test_masks(self, X, y=None, groups=None):
test_folds = self._make_test_folds(X, y)
for i in range(self.n_splits):
yield test_folds == i
def split(self, X, y, groups=None):
"""Generate indices to split data into training and test set.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Training data, where n_samples is the number of samples
and n_features is the number of features.
Note that providing ``y`` is sufficient to generate the splits and
hence ``np.zeros(n_samples)`` may be used as a placeholder for
``X`` instead of actual training data.
y : array-like, shape (n_samples,)
The target variable for supervised learning problems.
Stratification is done based on the y labels.
groups : object
Always ignored, exists for compatibility.
Returns
-------
train : ndarray
The training set indices for that split.
test : ndarray
The testing set indices for that split.
Notes
-----
Randomized CV splitters may return different results for each call of
split. You can make the results identical by setting ``random_state``
to an integer.
"""
y = check_array(y, ensure_2d=False, dtype=None)
return super(StratifiedKFold, self).split(X, y, groups)
class TimeSeriesSplit(_BaseKFold):
"""Time Series cross-validator
Provides train/test indices to split time series data samples
that are observed at fixed time intervals, in train/test sets.
In each split, test indices must be higher than before, and thus shuffling
in cross validator is inappropriate.
This cross-validation object is a variation of :class:`KFold`.
In the kth split, it returns first k folds as train set and the
(k+1)th fold as test set.
Note that unlike standard cross-validation methods, successive
training sets are supersets of those that come before them.
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
n_splits : int, default=3
Number of splits. Must be at least 1.
max_train_size : int, optional
Maximum size for a single training set.
Examples
--------
>>> from sklearn.model_selection import TimeSeriesSplit
>>> X = np.array([[1, 2], [3, 4], [1, 2], [3, 4]])
>>> y = np.array([1, 2, 3, 4])
>>> tscv = TimeSeriesSplit(n_splits=3)
>>> print(tscv) # doctest: +NORMALIZE_WHITESPACE
TimeSeriesSplit(max_train_size=None, n_splits=3)
>>> for train_index, test_index in tscv.split(X):
... print("TRAIN:", train_index, "TEST:", test_index)
... X_train, X_test = X[train_index], X[test_index]
... y_train, y_test = y[train_index], y[test_index]
TRAIN: [0] TEST: [1]
TRAIN: [0 1] TEST: [2]
TRAIN: [0 1 2] TEST: [3]
Notes
-----
The training set has size ``i * n_samples // (n_splits + 1)
+ n_samples % (n_splits + 1)`` in the ``i``th split,
with a test set of size ``n_samples//(n_splits + 1)``,
where ``n_samples`` is the number of samples.
"""
def __init__(self, n_splits=3, max_train_size=None):
super(TimeSeriesSplit, self).__init__(n_splits,
shuffle=False,
random_state=None)
self.max_train_size = max_train_size
def split(self, X, y=None, groups=None):
"""Generate indices to split data into training and test set.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Training data, where n_samples is the number of samples
and n_features is the number of features.
y : array-like, shape (n_samples,)
Always ignored, exists for compatibility.
groups : array-like, with shape (n_samples,), optional
Always ignored, exists for compatibility.
Returns
-------
train : ndarray
The training set indices for that split.
test : ndarray
The testing set indices for that split.
Notes
-----
Randomized CV splitters may return different results for each call of
split. You can make the results identical by setting ``random_state``
to an integer.
"""
X, y, groups = indexable(X, y, groups)
n_samples = _num_samples(X)
n_splits = self.n_splits
n_folds = n_splits + 1
if n_folds > n_samples:
raise ValueError(
("Cannot have number of folds ={0} greater"
" than the number of samples: {1}.").format(n_folds,
n_samples))
indices = np.arange(n_samples)
test_size = (n_samples // n_folds)
test_starts = range(test_size + n_samples % n_folds,
n_samples, test_size)
for test_start in test_starts:
if self.max_train_size and self.max_train_size < test_start:
yield (indices[test_start - self.max_train_size:test_start],
indices[test_start:test_start + test_size])
else:
yield (indices[:test_start],
indices[test_start:test_start + test_size])
class LeaveOneGroupOut(BaseCrossValidator):
"""Leave One Group Out cross-validator
Provides train/test indices to split data according to a third-party
provided group. This group information can be used to encode arbitrary
domain specific stratifications of the samples as integers.
For instance the groups could be the year of collection of the samples
and thus allow for cross-validation against time-based splits.
Read more in the :ref:`User Guide <cross_validation>`.
Examples
--------
>>> from sklearn.model_selection import LeaveOneGroupOut
>>> X = np.array([[1, 2], [3, 4], [5, 6], [7, 8]])
>>> y = np.array([1, 2, 1, 2])
>>> groups = np.array([1, 1, 2, 2])
>>> logo = LeaveOneGroupOut()
>>> logo.get_n_splits(X, y, groups)
2
>>> logo.get_n_splits(groups=groups) # 'groups' is always required
2
>>> print(logo)
LeaveOneGroupOut()
>>> for train_index, test_index in logo.split(X, y, groups):
... print("TRAIN:", train_index, "TEST:", test_index)
... X_train, X_test = X[train_index], X[test_index]
... y_train, y_test = y[train_index], y[test_index]
... print(X_train, X_test, y_train, y_test)
TRAIN: [2 3] TEST: [0 1]
[[5 6]
[7 8]] [[1 2]
[3 4]] [1 2] [1 2]
TRAIN: [0 1] TEST: [2 3]
[[1 2]
[3 4]] [[5 6]
[7 8]] [1 2] [1 2]
"""
def _iter_test_masks(self, X, y, groups):
if groups is None:
raise ValueError("The 'groups' parameter should not be None.")
# We make a copy of groups to avoid side-effects during iteration
groups = check_array(groups, copy=True, ensure_2d=False, dtype=None)
unique_groups = np.unique(groups)
if len(unique_groups) <= 1:
raise ValueError(
"The groups parameter contains fewer than 2 unique groups "
"(%s). LeaveOneGroupOut expects at least 2." % unique_groups)
for i in unique_groups:
yield groups == i
def get_n_splits(self, X=None, y=None, groups=None):
"""Returns the number of splitting iterations in the cross-validator
Parameters
----------
X : object, optional
Always ignored, exists for compatibility.
y : object, optional
Always ignored, exists for compatibility.
groups : array-like, with shape (n_samples,), optional
Group labels for the samples used while splitting the dataset into
train/test set. This 'groups' parameter must always be specified to
calculate the number of splits, though the other parameters can be
omitted.
Returns
-------
n_splits : int
Returns the number of splitting iterations in the cross-validator.
"""
if groups is None:
raise ValueError("The 'groups' parameter should not be None.")
groups = check_array(groups, ensure_2d=False, dtype=None)
return len(np.unique(groups))
class LeavePGroupsOut(BaseCrossValidator):
"""Leave P Group(s) Out cross-validator
Provides train/test indices to split data according to a third-party
provided group. This group information can be used to encode arbitrary
domain specific stratifications of the samples as integers.
For instance the groups could be the year of collection of the samples
and thus allow for cross-validation against time-based splits.
The difference between LeavePGroupsOut and LeaveOneGroupOut is that
the former builds the test sets with all the samples assigned to
``p`` different values of the groups while the latter uses samples
all assigned the same groups.
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
n_groups : int
Number of groups (``p``) to leave out in the test split.
Examples
--------
>>> from sklearn.model_selection import LeavePGroupsOut
>>> X = np.array([[1, 2], [3, 4], [5, 6]])
>>> y = np.array([1, 2, 1])
>>> groups = np.array([1, 2, 3])
>>> lpgo = LeavePGroupsOut(n_groups=2)
>>> lpgo.get_n_splits(X, y, groups)
3
>>> lpgo.get_n_splits(groups=groups) # 'groups' is always required
3
>>> print(lpgo)
LeavePGroupsOut(n_groups=2)
>>> for train_index, test_index in lpgo.split(X, y, groups):
... print("TRAIN:", train_index, "TEST:", test_index)
... X_train, X_test = X[train_index], X[test_index]
... y_train, y_test = y[train_index], y[test_index]
... print(X_train, X_test, y_train, y_test)
TRAIN: [2] TEST: [0 1]
[[5 6]] [[1 2]
[3 4]] [1] [1 2]
TRAIN: [1] TEST: [0 2]
[[3 4]] [[1 2]
[5 6]] [2] [1 1]
TRAIN: [0] TEST: [1 2]
[[1 2]] [[3 4]
[5 6]] [1] [2 1]
See also
--------
GroupKFold: K-fold iterator variant with non-overlapping groups.
"""
def __init__(self, n_groups):
self.n_groups = n_groups
def _iter_test_masks(self, X, y, groups):
if groups is None:
raise ValueError("The 'groups' parameter should not be None.")
groups = check_array(groups, copy=True, ensure_2d=False, dtype=None)
unique_groups = np.unique(groups)
if self.n_groups >= len(unique_groups):
raise ValueError(
"The groups parameter contains fewer than (or equal to) "
"n_groups (%d) numbers of unique groups (%s). LeavePGroupsOut "
"expects that at least n_groups + 1 (%d) unique groups be "
"present" % (self.n_groups, unique_groups, self.n_groups + 1))
combi = combinations(range(len(unique_groups)), self.n_groups)
for indices in combi:
test_index = np.zeros(_num_samples(X), dtype=np.bool)
for l in unique_groups[np.array(indices)]:
test_index[groups == l] = True
yield test_index
def get_n_splits(self, X=None, y=None, groups=None):
"""Returns the number of splitting iterations in the cross-validator
Parameters
----------
X : object, optional
Always ignored, exists for compatibility.
y : object, optional
Always ignored, exists for compatibility.
groups : array-like, with shape (n_samples,), optional
Group labels for the samples used while splitting the dataset into
train/test set. This 'groups' parameter must always be specified to
calculate the number of splits, though the other parameters can be
omitted.
Returns
-------
n_splits : int
Returns the number of splitting iterations in the cross-validator.
"""
if groups is None:
raise ValueError("The 'groups' parameter should not be None.")
groups = check_array(groups, ensure_2d=False, dtype=None)
return int(comb(len(np.unique(groups)), self.n_groups, exact=True))
class _RepeatedSplits(with_metaclass(ABCMeta)):
"""Repeated splits for an arbitrary randomized CV splitter.
Repeats splits for cross-validators n times with different randomization
in each repetition.
Parameters
----------
cv : callable
Cross-validator class.
n_repeats : int, default=10
Number of times cross-validator needs to be repeated.
random_state : int, RandomState instance or None, optional, default=None
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
**cvargs : additional params
Constructor parameters for cv. Must not contain random_state
and shuffle.
"""
def __init__(self, cv, n_repeats=10, random_state=None, **cvargs):
if not isinstance(n_repeats, (np.integer, numbers.Integral)):
raise ValueError("Number of repetitions must be of Integral type.")
if n_repeats <= 0:
raise ValueError("Number of repetitions must be greater than 0.")
if any(key in cvargs for key in ('random_state', 'shuffle')):
raise ValueError(
"cvargs must not contain random_state or shuffle.")
self.cv = cv
self.n_repeats = n_repeats
self.random_state = random_state
self.cvargs = cvargs
def split(self, X, y=None, groups=None):
"""Generates indices to split data into training and test set.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Training data, where n_samples is the number of samples
and n_features is the number of features.
y : array-like, of length n_samples
The target variable for supervised learning problems.
groups : array-like, with shape (n_samples,), optional
Group labels for the samples used while splitting the dataset into
train/test set.
Returns
-------
train : ndarray
The training set indices for that split.
test : ndarray
The testing set indices for that split.
"""
n_repeats = self.n_repeats
rng = check_random_state(self.random_state)
for idx in range(n_repeats):
cv = self.cv(random_state=rng, shuffle=True,
**self.cvargs)
for train_index, test_index in cv.split(X, y, groups):
yield train_index, test_index
def get_n_splits(self, X=None, y=None, groups=None):
"""Returns the number of splitting iterations in the cross-validator
Parameters
----------
X : object
Always ignored, exists for compatibility.
``np.zeros(n_samples)`` may be used as a placeholder.
y : object
Always ignored, exists for compatibility.
``np.zeros(n_samples)`` may be used as a placeholder.
groups : array-like, with shape (n_samples,), optional
Group labels for the samples used while splitting the dataset into
train/test set.
Returns
-------
n_splits : int
Returns the number of splitting iterations in the cross-validator.
"""
rng = check_random_state(self.random_state)
cv = self.cv(random_state=rng, shuffle=True,
**self.cvargs)
return cv.get_n_splits(X, y, groups) * self.n_repeats
class RepeatedKFold(_RepeatedSplits):
"""Repeated K-Fold cross validator.
Repeats K-Fold n times with different randomization in each repetition.
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
n_splits : int, default=5
Number of folds. Must be at least 2.
n_repeats : int, default=10
Number of times cross-validator needs to be repeated.
random_state : int, RandomState instance or None, optional, default=None
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
Examples
--------
>>> from sklearn.model_selection import RepeatedKFold
>>> X = np.array([[1, 2], [3, 4], [1, 2], [3, 4]])
>>> y = np.array([0, 0, 1, 1])
>>> rkf = RepeatedKFold(n_splits=2, n_repeats=2, random_state=2652124)
>>> for train_index, test_index in rkf.split(X):
... print("TRAIN:", train_index, "TEST:", test_index)
... X_train, X_test = X[train_index], X[test_index]
... y_train, y_test = y[train_index], y[test_index]
...
TRAIN: [0 1] TEST: [2 3]
TRAIN: [2 3] TEST: [0 1]
TRAIN: [1 2] TEST: [0 3]
TRAIN: [0 3] TEST: [1 2]
See also
--------
RepeatedStratifiedKFold: Repeates Stratified K-Fold n times.
"""
def __init__(self, n_splits=5, n_repeats=10, random_state=None):
super(RepeatedKFold, self).__init__(
KFold, n_repeats, random_state, n_splits=n_splits)
class RepeatedStratifiedKFold(_RepeatedSplits):
"""Repeated Stratified K-Fold cross validator.
Repeats Stratified K-Fold n times with different randomization in each
repetition.
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
n_splits : int, default=5
Number of folds. Must be at least 2.
n_repeats : int, default=10
Number of times cross-validator needs to be repeated.
random_state : None, int or RandomState, default=None
Random state to be used to generate random state for each
repetition.
Examples
--------
>>> from sklearn.model_selection import RepeatedStratifiedKFold
>>> X = np.array([[1, 2], [3, 4], [1, 2], [3, 4]])
>>> y = np.array([0, 0, 1, 1])
>>> rskf = RepeatedStratifiedKFold(n_splits=2, n_repeats=2,
... random_state=36851234)
>>> for train_index, test_index in rskf.split(X, y):
... print("TRAIN:", train_index, "TEST:", test_index)
... X_train, X_test = X[train_index], X[test_index]
... y_train, y_test = y[train_index], y[test_index]
...
TRAIN: [1 2] TEST: [0 3]
TRAIN: [0 3] TEST: [1 2]
TRAIN: [1 3] TEST: [0 2]
TRAIN: [0 2] TEST: [1 3]
See also
--------
RepeatedKFold: Repeats K-Fold n times.
"""
def __init__(self, n_splits=5, n_repeats=10, random_state=None):
super(RepeatedStratifiedKFold, self).__init__(
StratifiedKFold, n_repeats, random_state, n_splits=n_splits)
class BaseShuffleSplit(with_metaclass(ABCMeta)):
"""Base class for ShuffleSplit and StratifiedShuffleSplit"""
def __init__(self, n_splits=10, test_size="default", train_size=None,
random_state=None):
_validate_shuffle_split_init(test_size, train_size)
self.n_splits = n_splits
self.test_size = test_size
self.train_size = train_size
self.random_state = random_state
def split(self, X, y=None, groups=None):
"""Generate indices to split data into training and test set.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Training data, where n_samples is the number of samples
and n_features is the number of features.
y : array-like, shape (n_samples,)
The target variable for supervised learning problems.
groups : array-like, with shape (n_samples,), optional
Group labels for the samples used while splitting the dataset into
train/test set.
Returns
-------
train : ndarray
The training set indices for that split.
test : ndarray
The testing set indices for that split.
Notes
-----
Randomized CV splitters may return different results for each call of
split. You can make the results identical by setting ``random_state``
to an integer.
"""
X, y, groups = indexable(X, y, groups)
for train, test in self._iter_indices(X, y, groups):
yield train, test
@abstractmethod
def _iter_indices(self, X, y=None, groups=None):
"""Generate (train, test) indices"""
def get_n_splits(self, X=None, y=None, groups=None):
"""Returns the number of splitting iterations in the cross-validator
Parameters
----------
X : object
Always ignored, exists for compatibility.
y : object
Always ignored, exists for compatibility.
groups : object
Always ignored, exists for compatibility.
Returns
-------
n_splits : int
Returns the number of splitting iterations in the cross-validator.
"""
return self.n_splits
def __repr__(self):
return _build_repr(self)
class ShuffleSplit(BaseShuffleSplit):
"""Random permutation cross-validator
Yields indices to split data into training and test sets.
Note: contrary to other cross-validation strategies, random splits
do not guarantee that all folds will be different, although this is
still very likely for sizeable datasets.
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
n_splits : int, default 10
Number of re-shuffling & splitting iterations.
test_size : float, int, None, default=0.1
If float, should be between 0.0 and 1.0 and represent the proportion
of the dataset to include in the test split. If int, represents the
absolute number of test samples. If None, the value is set to the
complement of the train size. By default (the is parameter
unspecified), the value is set to 0.1.
The default will change in version 0.21. It will remain 0.1 only
if ``train_size`` is unspecified, otherwise it will complement
the specified ``train_size``.
train_size : float, int, or None, default=None
If float, should be between 0.0 and 1.0 and represent the
proportion of the dataset to include in the train split. If
int, represents the absolute number of train samples. If None,
the value is automatically set to the complement of the test size.
random_state : int, RandomState instance or None, optional (default=None)
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
Examples
--------
>>> from sklearn.model_selection import ShuffleSplit
>>> X = np.array([[1, 2], [3, 4], [5, 6], [7, 8]])
>>> y = np.array([1, 2, 1, 2])
>>> rs = ShuffleSplit(n_splits=3, test_size=.25, random_state=0)
>>> rs.get_n_splits(X)
3
>>> print(rs)
ShuffleSplit(n_splits=3, random_state=0, test_size=0.25, train_size=None)
>>> for train_index, test_index in rs.split(X):
... print("TRAIN:", train_index, "TEST:", test_index)
... # doctest: +ELLIPSIS
TRAIN: [3 1 0] TEST: [2]
TRAIN: [2 1 3] TEST: [0]
TRAIN: [0 2 1] TEST: [3]
>>> rs = ShuffleSplit(n_splits=3, train_size=0.5, test_size=.25,
... random_state=0)
>>> for train_index, test_index in rs.split(X):
... print("TRAIN:", train_index, "TEST:", test_index)
... # doctest: +ELLIPSIS
TRAIN: [3 1] TEST: [2]
TRAIN: [2 1] TEST: [0]
TRAIN: [0 2] TEST: [3]
"""
def _iter_indices(self, X, y=None, groups=None):
n_samples = _num_samples(X)
n_train, n_test = _validate_shuffle_split(n_samples,
self.test_size,
self.train_size)
rng = check_random_state(self.random_state)
for i in range(self.n_splits):
# random partition
permutation = rng.permutation(n_samples)
ind_test = permutation[:n_test]
ind_train = permutation[n_test:(n_test + n_train)]
yield ind_train, ind_test
class GroupShuffleSplit(ShuffleSplit):
'''Shuffle-Group(s)-Out cross-validation iterator
Provides randomized train/test indices to split data according to a
third-party provided group. This group information can be used to encode
arbitrary domain specific stratifications of the samples as integers.
For instance the groups could be the year of collection of the samples
and thus allow for cross-validation against time-based splits.
The difference between LeavePGroupsOut and GroupShuffleSplit is that
the former generates splits using all subsets of size ``p`` unique groups,
whereas GroupShuffleSplit generates a user-determined number of random
test splits, each with a user-determined fraction of unique groups.
For example, a less computationally intensive alternative to
``LeavePGroupsOut(p=10)`` would be
``GroupShuffleSplit(test_size=10, n_splits=100)``.
Note: The parameters ``test_size`` and ``train_size`` refer to groups, and
not to samples, as in ShuffleSplit.
Parameters
----------
n_splits : int (default 5)
Number of re-shuffling & splitting iterations.
test_size : float, int, None, optional
If float, should be between 0.0 and 1.0 and represent the proportion
of the dataset to include in the test split. If int, represents the
absolute number of test samples. If None, the value is set to the
complement of the train size. By default, the value is set to 0.2.
The default will change in version 0.21. It will remain 0.2 only
if ``train_size`` is unspecified, otherwise it will complement
the specified ``train_size``.
train_size : float, int, or None, default is None
If float, should be between 0.0 and 1.0 and represent the
proportion of the groups to include in the train split. If
int, represents the absolute number of train groups. If None,
the value is automatically set to the complement of the test size.
random_state : int, RandomState instance or None, optional (default=None)
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
'''
def __init__(self, n_splits=5, test_size="default", train_size=None,
random_state=None):
if test_size == "default":
if train_size is not None:
warnings.warn("From version 0.21, test_size will always "
"complement train_size unless both "
"are specified.",
FutureWarning)
test_size = 0.2
super(GroupShuffleSplit, self).__init__(
n_splits=n_splits,
test_size=test_size,
train_size=train_size,
random_state=random_state)
def _iter_indices(self, X, y, groups):
if groups is None:
raise ValueError("The 'groups' parameter should not be None.")
groups = check_array(groups, ensure_2d=False, dtype=None)
classes, group_indices = np.unique(groups, return_inverse=True)
for group_train, group_test in super(
GroupShuffleSplit, self)._iter_indices(X=classes):
# these are the indices of classes in the partition
# invert them into data indices
train = np.flatnonzero(np.in1d(group_indices, group_train))
test = np.flatnonzero(np.in1d(group_indices, group_test))
yield train, test
def _approximate_mode(class_counts, n_draws, rng):
"""Computes approximate mode of multivariate hypergeometric.
This is an approximation to the mode of the multivariate
hypergeometric given by class_counts and n_draws.
It shouldn't be off by more than one.
It is the mostly likely outcome of drawing n_draws many
samples from the population given by class_counts.
Parameters
----------
class_counts : ndarray of int
Population per class.
n_draws : int
Number of draws (samples to draw) from the overall population.
rng : random state
Used to break ties.
Returns
-------
sampled_classes : ndarray of int
Number of samples drawn from each class.
np.sum(sampled_classes) == n_draws
Examples
--------
>>> from sklearn.model_selection._split import _approximate_mode
>>> _approximate_mode(class_counts=np.array([4, 2]), n_draws=3, rng=0)
array([2, 1])
>>> _approximate_mode(class_counts=np.array([5, 2]), n_draws=4, rng=0)
array([3, 1])
>>> _approximate_mode(class_counts=np.array([2, 2, 2, 1]),
... n_draws=2, rng=0)
array([0, 1, 1, 0])
>>> _approximate_mode(class_counts=np.array([2, 2, 2, 1]),
... n_draws=2, rng=42)
array([1, 1, 0, 0])
"""
rng = check_random_state(rng)
# this computes a bad approximation to the mode of the
# multivariate hypergeometric given by class_counts and n_draws
continuous = n_draws * class_counts / class_counts.sum()
# floored means we don't overshoot n_samples, but probably undershoot
floored = np.floor(continuous)
# we add samples according to how much "left over" probability
# they had, until we arrive at n_samples
need_to_add = int(n_draws - floored.sum())
if need_to_add > 0:
remainder = continuous - floored
values = np.sort(np.unique(remainder))[::-1]
# add according to remainder, but break ties
# randomly to avoid biases
for value in values:
inds, = np.where(remainder == value)
# if we need_to_add less than what's in inds
# we draw randomly from them.
# if we need to add more, we add them all and
# go to the next value
add_now = min(len(inds), need_to_add)
inds = rng.choice(inds, size=add_now, replace=False)
floored[inds] += 1
need_to_add -= add_now
if need_to_add == 0:
break
return floored.astype(np.int)
class StratifiedShuffleSplit(BaseShuffleSplit):
"""Stratified ShuffleSplit cross-validator
Provides train/test indices to split data in train/test sets.
This cross-validation object is a merge of StratifiedKFold and
ShuffleSplit, which returns stratified randomized folds. The folds
are made by preserving the percentage of samples for each class.
Note: like the ShuffleSplit strategy, stratified random splits
do not guarantee that all folds will be different, although this is
still very likely for sizeable datasets.
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
n_splits : int, default 10
Number of re-shuffling & splitting iterations.
test_size : float, int, None, optional
If float, should be between 0.0 and 1.0 and represent the proportion
of the dataset to include in the test split. If int, represents the
absolute number of test samples. If None, the value is set to the
complement of the train size. By default, the value is set to 0.1.
The default will change in version 0.21. It will remain 0.1 only
if ``train_size`` is unspecified, otherwise it will complement
the specified ``train_size``.
train_size : float, int, or None, default is None
If float, should be between 0.0 and 1.0 and represent the
proportion of the dataset to include in the train split. If
int, represents the absolute number of train samples. If None,
the value is automatically set to the complement of the test size.
random_state : int, RandomState instance or None, optional (default=None)
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
Examples
--------
>>> from sklearn.model_selection import StratifiedShuffleSplit
>>> X = np.array([[1, 2], [3, 4], [1, 2], [3, 4]])
>>> y = np.array([0, 0, 1, 1])
>>> sss = StratifiedShuffleSplit(n_splits=3, test_size=0.5, random_state=0)
>>> sss.get_n_splits(X, y)
3
>>> print(sss) # doctest: +ELLIPSIS
StratifiedShuffleSplit(n_splits=3, random_state=0, ...)
>>> for train_index, test_index in sss.split(X, y):
... print("TRAIN:", train_index, "TEST:", test_index)
... X_train, X_test = X[train_index], X[test_index]
... y_train, y_test = y[train_index], y[test_index]
TRAIN: [1 2] TEST: [3 0]
TRAIN: [0 2] TEST: [1 3]
TRAIN: [0 2] TEST: [3 1]
"""
def __init__(self, n_splits=10, test_size="default", train_size=None,
random_state=None):
super(StratifiedShuffleSplit, self).__init__(
n_splits, test_size, train_size, random_state)
def _iter_indices(self, X, y, groups=None):
n_samples = _num_samples(X)
y = check_array(y, ensure_2d=False, dtype=None)
n_train, n_test = _validate_shuffle_split(n_samples, self.test_size,
self.train_size)
if y.ndim == 2:
# for multi-label y, map each distinct row to a string repr
# using join because str(row) uses an ellipsis if len(row) > 1000
y = np.array([' '.join(row.astype('str')) for row in y])
classes, y_indices = np.unique(y, return_inverse=True)
n_classes = classes.shape[0]
class_counts = np.bincount(y_indices)
if np.min(class_counts) < 2:
raise ValueError("The least populated class in y has only 1"
" member, which is too few. The minimum"
" number of groups for any class cannot"
" be less than 2.")
if n_train < n_classes:
raise ValueError('The train_size = %d should be greater or '
'equal to the number of classes = %d' %
(n_train, n_classes))
if n_test < n_classes:
raise ValueError('The test_size = %d should be greater or '
'equal to the number of classes = %d' %
(n_test, n_classes))
# Find the sorted list of instances for each class:
# (np.unique above performs a sort, so code is O(n logn) already)
class_indices = np.split(np.argsort(y_indices, kind='mergesort'),
np.cumsum(class_counts)[:-1])
rng = check_random_state(self.random_state)
for _ in range(self.n_splits):
# if there are ties in the class-counts, we want
# to make sure to break them anew in each iteration
n_i = _approximate_mode(class_counts, n_train, rng)
class_counts_remaining = class_counts - n_i
t_i = _approximate_mode(class_counts_remaining, n_test, rng)
train = []
test = []
for i in range(n_classes):
permutation = rng.permutation(class_counts[i])
perm_indices_class_i = class_indices[i].take(permutation,
mode='clip')
train.extend(perm_indices_class_i[:n_i[i]])
test.extend(perm_indices_class_i[n_i[i]:n_i[i] + t_i[i]])
train = rng.permutation(train)
test = rng.permutation(test)
yield train, test
def split(self, X, y, groups=None):
"""Generate indices to split data into training and test set.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Training data, where n_samples is the number of samples
and n_features is the number of features.
Note that providing ``y`` is sufficient to generate the splits and
hence ``np.zeros(n_samples)`` may be used as a placeholder for
``X`` instead of actual training data.
y : array-like, shape (n_samples,)
The target variable for supervised learning problems.
Stratification is done based on the y labels.
groups : object
Always ignored, exists for compatibility.
Returns
-------
train : ndarray
The training set indices for that split.
test : ndarray
The testing set indices for that split.
Notes
-----
Randomized CV splitters may return different results for each call of
split. You can make the results identical by setting ``random_state``
to an integer.
"""
y = check_array(y, ensure_2d=False, dtype=None)
return super(StratifiedShuffleSplit, self).split(X, y, groups)
def _validate_shuffle_split_init(test_size, train_size):
"""Validation helper to check the test_size and train_size at init
NOTE This does not take into account the number of samples which is known
only at split
"""
if test_size == "default":
if train_size is not None:
warnings.warn("From version 0.21, test_size will always "
"complement train_size unless both "
"are specified.",
FutureWarning)
test_size = 0.1
if test_size is None and train_size is None:
raise ValueError('test_size and train_size can not both be None')
if test_size is not None:
if np.asarray(test_size).dtype.kind == 'f':
if test_size >= 1.:
raise ValueError(
'test_size=%f should be smaller '
'than 1.0 or be an integer' % test_size)
elif np.asarray(test_size).dtype.kind != 'i':
# int values are checked during split based on the input
raise ValueError("Invalid value for test_size: %r" % test_size)
if train_size is not None:
if np.asarray(train_size).dtype.kind == 'f':
if train_size >= 1.:
raise ValueError("train_size=%f should be smaller "
"than 1.0 or be an integer" % train_size)
elif (np.asarray(test_size).dtype.kind == 'f' and
(train_size + test_size) > 1.):
raise ValueError('The sum of test_size and train_size = %f, '
'should be smaller than 1.0. Reduce '
'test_size and/or train_size.' %
(train_size + test_size))
elif np.asarray(train_size).dtype.kind != 'i':
# int values are checked during split based on the input
raise ValueError("Invalid value for train_size: %r" % train_size)
def _validate_shuffle_split(n_samples, test_size, train_size):
"""
Validation helper to check if the test/test sizes are meaningful wrt to the
size of the data (n_samples)
"""
if (test_size is not None and
np.asarray(test_size).dtype.kind == 'i' and
test_size >= n_samples):
raise ValueError('test_size=%d should be smaller than the number of '
'samples %d' % (test_size, n_samples))
if (train_size is not None and
np.asarray(train_size).dtype.kind == 'i' and
train_size >= n_samples):
raise ValueError("train_size=%d should be smaller than the number of"
" samples %d" % (train_size, n_samples))
if test_size == "default":
test_size = 0.1
if np.asarray(test_size).dtype.kind == 'f':
n_test = ceil(test_size * n_samples)
elif np.asarray(test_size).dtype.kind == 'i':
n_test = float(test_size)
if train_size is None:
n_train = n_samples - n_test
elif np.asarray(train_size).dtype.kind == 'f':
n_train = floor(train_size * n_samples)
else:
n_train = float(train_size)
if test_size is None:
n_test = n_samples - n_train
if n_train + n_test > n_samples:
raise ValueError('The sum of train_size and test_size = %d, '
'should be smaller than the number of '
'samples %d. Reduce test_size and/or '
'train_size.' % (n_train + n_test, n_samples))
return int(n_train), int(n_test)
class PredefinedSplit(BaseCrossValidator):
"""Predefined split cross-validator
Provides train/test indices to split data into train/test sets using a
predefined scheme specified by the user with the ``test_fold`` parameter.
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
test_fold : array-like, shape (n_samples,)
The entry ``test_fold[i]`` represents the index of the test set that
sample ``i`` belongs to. It is possible to exclude sample ``i`` from
any test set (i.e. include sample ``i`` in every training set) by
setting ``test_fold[i]`` equal to -1.
Examples
--------
>>> from sklearn.model_selection import PredefinedSplit
>>> X = np.array([[1, 2], [3, 4], [1, 2], [3, 4]])
>>> y = np.array([0, 0, 1, 1])
>>> test_fold = [0, 1, -1, 1]
>>> ps = PredefinedSplit(test_fold)
>>> ps.get_n_splits()
2
>>> print(ps) # doctest: +NORMALIZE_WHITESPACE +ELLIPSIS
PredefinedSplit(test_fold=array([ 0, 1, -1, 1]))
>>> for train_index, test_index in ps.split():
... print("TRAIN:", train_index, "TEST:", test_index)
... X_train, X_test = X[train_index], X[test_index]
... y_train, y_test = y[train_index], y[test_index]
TRAIN: [1 2 3] TEST: [0]
TRAIN: [0 2] TEST: [1 3]
"""
def __init__(self, test_fold):
self.test_fold = np.array(test_fold, dtype=np.int)
self.test_fold = column_or_1d(self.test_fold)
self.unique_folds = np.unique(self.test_fold)
self.unique_folds = self.unique_folds[self.unique_folds != -1]
def split(self, X=None, y=None, groups=None):
"""Generate indices to split data into training and test set.
Parameters
----------
X : object
Always ignored, exists for compatibility.
y : object
Always ignored, exists for compatibility.
groups : object
Always ignored, exists for compatibility.
Returns
-------
train : ndarray
The training set indices for that split.
test : ndarray
The testing set indices for that split.
"""
ind = np.arange(len(self.test_fold))
for test_index in self._iter_test_masks():
train_index = ind[np.logical_not(test_index)]
test_index = ind[test_index]
yield train_index, test_index
def _iter_test_masks(self):
"""Generates boolean masks corresponding to test sets."""
for f in self.unique_folds:
test_index = np.where(self.test_fold == f)[0]
test_mask = np.zeros(len(self.test_fold), dtype=np.bool)
test_mask[test_index] = True
yield test_mask
def get_n_splits(self, X=None, y=None, groups=None):
"""Returns the number of splitting iterations in the cross-validator
Parameters
----------
X : object
Always ignored, exists for compatibility.
y : object
Always ignored, exists for compatibility.
groups : object
Always ignored, exists for compatibility.
Returns
-------
n_splits : int
Returns the number of splitting iterations in the cross-validator.
"""
return len(self.unique_folds)
class _CVIterableWrapper(BaseCrossValidator):
"""Wrapper class for old style cv objects and iterables."""
def __init__(self, cv):
self.cv = list(cv)
def get_n_splits(self, X=None, y=None, groups=None):
"""Returns the number of splitting iterations in the cross-validator
Parameters
----------
X : object
Always ignored, exists for compatibility.
y : object
Always ignored, exists for compatibility.
groups : object
Always ignored, exists for compatibility.
Returns
-------
n_splits : int
Returns the number of splitting iterations in the cross-validator.
"""
return len(self.cv)
def split(self, X=None, y=None, groups=None):
"""Generate indices to split data into training and test set.
Parameters
----------
X : object
Always ignored, exists for compatibility.
y : object
Always ignored, exists for compatibility.
groups : object
Always ignored, exists for compatibility.
Returns
-------
train : ndarray
The training set indices for that split.
test : ndarray
The testing set indices for that split.
"""
for train, test in self.cv:
yield train, test
def check_cv(cv=3, y=None, classifier=False):
"""Input checker utility for building a cross-validator
Parameters
----------
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross-validation,
- integer, to specify the number of folds.
- An object to be used as a cross-validation generator.
- An iterable yielding train/test splits.
For integer/None inputs, if classifier is True and ``y`` is either
binary or multiclass, :class:`StratifiedKFold` is used. In all other
cases, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
y : array-like, optional
The target variable for supervised learning problems.
classifier : boolean, optional, default False
Whether the task is a classification task, in which case
stratified KFold will be used.
Returns
-------
checked_cv : a cross-validator instance.
The return value is a cross-validator which generates the train/test
splits via the ``split`` method.
"""
if cv is None:
cv = 3
if isinstance(cv, numbers.Integral):
if (classifier and (y is not None) and
(type_of_target(y) in ('binary', 'multiclass'))):
return StratifiedKFold(cv)
else:
return KFold(cv)
if not hasattr(cv, 'split') or isinstance(cv, str):
if not isinstance(cv, Iterable) or isinstance(cv, str):
raise ValueError("Expected cv as an integer, cross-validation "
"object (from sklearn.model_selection) "
"or an iterable. Got %s." % cv)
return _CVIterableWrapper(cv)
return cv # New style cv objects are passed without any modification
def train_test_split(*arrays, **options):
"""Split arrays or matrices into random train and test subsets
Quick utility that wraps input validation and
``next(ShuffleSplit().split(X, y))`` and application to input data
into a single call for splitting (and optionally subsampling) data in a
oneliner.
Read more in the :ref:`User Guide <cross_validation>`.
Parameters
----------
*arrays : sequence of indexables with same length / shape[0]
Allowed inputs are lists, numpy arrays, scipy-sparse
matrices or pandas dataframes.
test_size : float, int, None, optional
If float, should be between 0.0 and 1.0 and represent the proportion
of the dataset to include in the test split. If int, represents the
absolute number of test samples. If None, the value is set to the
complement of the train size. By default, the value is set to 0.25.
The default will change in version 0.21. It will remain 0.25 only
if ``train_size`` is unspecified, otherwise it will complement
the specified ``train_size``.
train_size : float, int, or None, default None
If float, should be between 0.0 and 1.0 and represent the
proportion of the dataset to include in the train split. If
int, represents the absolute number of train samples. If None,
the value is automatically set to the complement of the test size.
random_state : int, RandomState instance or None, optional (default=None)
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
shuffle : boolean, optional (default=True)
Whether or not to shuffle the data before splitting. If shuffle=False
then stratify must be None.
stratify : array-like or None (default is None)
If not None, data is split in a stratified fashion, using this as
the class labels.
Returns
-------
splitting : list, length=2 * len(arrays)
List containing train-test split of inputs.
.. versionadded:: 0.16
If the input is sparse, the output will be a
``scipy.sparse.csr_matrix``. Else, output type is the same as the
input type.
Examples
--------
>>> import numpy as np
>>> from sklearn.model_selection import train_test_split
>>> X, y = np.arange(10).reshape((5, 2)), range(5)
>>> X
array([[0, 1],
[2, 3],
[4, 5],
[6, 7],
[8, 9]])
>>> list(y)
[0, 1, 2, 3, 4]
>>> X_train, X_test, y_train, y_test = train_test_split(
... X, y, test_size=0.33, random_state=42)
...
>>> X_train
array([[4, 5],
[0, 1],
[6, 7]])
>>> y_train
[2, 0, 3]
>>> X_test
array([[2, 3],
[8, 9]])
>>> y_test
[1, 4]
>>> train_test_split(y, shuffle=False)
[[0, 1, 2], [3, 4]]
"""
n_arrays = len(arrays)
if n_arrays == 0:
raise ValueError("At least one array required as input")
test_size = options.pop('test_size', 'default')
train_size = options.pop('train_size', None)
random_state = options.pop('random_state', None)
stratify = options.pop('stratify', None)
shuffle = options.pop('shuffle', True)
if options:
raise TypeError("Invalid parameters passed: %s" % str(options))
if test_size == 'default':
test_size = None
if train_size is not None:
warnings.warn("From version 0.21, test_size will always "
"complement train_size unless both "
"are specified.",
FutureWarning)
if test_size is None and train_size is None:
test_size = 0.25
arrays = indexable(*arrays)
if shuffle is False:
if stratify is not None:
raise ValueError(
"Stratified train/test split is not implemented for "
"shuffle=False")
n_samples = _num_samples(arrays[0])
n_train, n_test = _validate_shuffle_split(n_samples, test_size,
train_size)
train = np.arange(n_train)
test = np.arange(n_train, n_train + n_test)
else:
if stratify is not None:
CVClass = StratifiedShuffleSplit
else:
CVClass = ShuffleSplit
cv = CVClass(test_size=test_size,
train_size=train_size,
random_state=random_state)
train, test = next(cv.split(X=arrays[0], y=stratify))
return list(chain.from_iterable((safe_indexing(a, train),
safe_indexing(a, test)) for a in arrays))
train_test_split.__test__ = False # to avoid a pb with nosetests
def _build_repr(self):
# XXX This is copied from BaseEstimator's get_params
cls = self.__class__
init = getattr(cls.__init__, 'deprecated_original', cls.__init__)
# Ignore varargs, kw and default values and pop self
init_signature = signature(init)
# Consider the constructor parameters excluding 'self'
if init is object.__init__:
args = []
else:
args = sorted([p.name for p in init_signature.parameters.values()
if p.name != 'self' and p.kind != p.VAR_KEYWORD])
class_name = self.__class__.__name__
params = dict()
for key in args:
# We need deprecation warnings to always be on in order to
# catch deprecated param values.
# This is set in utils/__init__.py but it gets overwritten
# when running under python3 somehow.
warnings.simplefilter("always", DeprecationWarning)
try:
with warnings.catch_warnings(record=True) as w:
value = getattr(self, key, None)
if len(w) and w[0].category == DeprecationWarning:
# if the parameter is deprecated, don't show it
continue
finally:
warnings.filters.pop(0)
params[key] = value
return '%s(%s)' % (class_name, _pprint(params, offset=len(class_name)))
| 77,125 | 35.796756 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/model_selection/__init__.py | from ._split import BaseCrossValidator
from ._split import KFold
from ._split import GroupKFold
from ._split import StratifiedKFold
from ._split import TimeSeriesSplit
from ._split import LeaveOneGroupOut
from ._split import LeaveOneOut
from ._split import LeavePGroupsOut
from ._split import LeavePOut
from ._split import RepeatedKFold
from ._split import RepeatedStratifiedKFold
from ._split import ShuffleSplit
from ._split import GroupShuffleSplit
from ._split import StratifiedShuffleSplit
from ._split import PredefinedSplit
from ._split import train_test_split
from ._split import check_cv
from ._validation import cross_val_score
from ._validation import cross_val_predict
from ._validation import cross_validate
from ._validation import learning_curve
from ._validation import permutation_test_score
from ._validation import validation_curve
from ._search import GridSearchCV
from ._search import RandomizedSearchCV
from ._search import ParameterGrid
from ._search import ParameterSampler
from ._search import fit_grid_point
__all__ = ('BaseCrossValidator',
'GridSearchCV',
'TimeSeriesSplit',
'KFold',
'GroupKFold',
'GroupShuffleSplit',
'LeaveOneGroupOut',
'LeaveOneOut',
'LeavePGroupsOut',
'LeavePOut',
'RepeatedKFold',
'RepeatedStratifiedKFold',
'ParameterGrid',
'ParameterSampler',
'PredefinedSplit',
'RandomizedSearchCV',
'ShuffleSplit',
'StratifiedKFold',
'StratifiedShuffleSplit',
'check_cv',
'cross_val_predict',
'cross_val_score',
'cross_validate',
'fit_grid_point',
'learning_curve',
'permutation_test_score',
'train_test_split',
'validation_curve')
| 1,868 | 30.15 | 47 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/model_selection/tests/test_split.py | """Test the split module"""
from __future__ import division
import warnings
import numpy as np
from scipy.sparse import coo_matrix, csc_matrix, csr_matrix
from scipy import stats
from itertools import combinations
from itertools import combinations_with_replacement
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import assert_false
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_raises_regexp
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_greater_equal
from sklearn.utils.testing import assert_not_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_warns_message
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import assert_raise_message
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.validation import _num_samples
from sklearn.utils.mocking import MockDataFrame
from sklearn.model_selection import cross_val_score
from sklearn.model_selection import KFold
from sklearn.model_selection import StratifiedKFold
from sklearn.model_selection import GroupKFold
from sklearn.model_selection import TimeSeriesSplit
from sklearn.model_selection import LeaveOneOut
from sklearn.model_selection import LeaveOneGroupOut
from sklearn.model_selection import LeavePOut
from sklearn.model_selection import LeavePGroupsOut
from sklearn.model_selection import ShuffleSplit
from sklearn.model_selection import GroupShuffleSplit
from sklearn.model_selection import StratifiedShuffleSplit
from sklearn.model_selection import PredefinedSplit
from sklearn.model_selection import check_cv
from sklearn.model_selection import train_test_split
from sklearn.model_selection import GridSearchCV
from sklearn.model_selection import RepeatedKFold
from sklearn.model_selection import RepeatedStratifiedKFold
from sklearn.linear_model import Ridge
from sklearn.model_selection._split import _validate_shuffle_split
from sklearn.model_selection._split import _CVIterableWrapper
from sklearn.model_selection._split import _build_repr
from sklearn.datasets import load_digits
from sklearn.datasets import make_classification
from sklearn.externals import six
from sklearn.externals.six.moves import zip
from sklearn.utils.fixes import comb
from sklearn.svm import SVC
X = np.ones(10)
y = np.arange(10) // 2
P_sparse = coo_matrix(np.eye(5))
test_groups = (
np.array([1, 1, 1, 1, 2, 2, 2, 3, 3, 3, 3, 3]),
np.array([0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3]),
np.array([0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2]),
np.array([1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4]),
[1, 1, 1, 1, 2, 2, 2, 3, 3, 3, 3, 3],
['1', '1', '1', '1', '2', '2', '2', '3', '3', '3', '3', '3'])
digits = load_digits()
class MockClassifier(object):
"""Dummy classifier to test the cross-validation"""
def __init__(self, a=0, allow_nd=False):
self.a = a
self.allow_nd = allow_nd
def fit(self, X, Y=None, sample_weight=None, class_prior=None,
sparse_sample_weight=None, sparse_param=None, dummy_int=None,
dummy_str=None, dummy_obj=None, callback=None):
"""The dummy arguments are to test that this fit function can
accept non-array arguments through cross-validation, such as:
- int
- str (this is actually array-like)
- object
- function
"""
self.dummy_int = dummy_int
self.dummy_str = dummy_str
self.dummy_obj = dummy_obj
if callback is not None:
callback(self)
if self.allow_nd:
X = X.reshape(len(X), -1)
if X.ndim >= 3 and not self.allow_nd:
raise ValueError('X cannot be d')
if sample_weight is not None:
assert_true(sample_weight.shape[0] == X.shape[0],
'MockClassifier extra fit_param sample_weight.shape[0]'
' is {0}, should be {1}'.format(sample_weight.shape[0],
X.shape[0]))
if class_prior is not None:
assert_true(class_prior.shape[0] == len(np.unique(y)),
'MockClassifier extra fit_param class_prior.shape[0]'
' is {0}, should be {1}'.format(class_prior.shape[0],
len(np.unique(y))))
if sparse_sample_weight is not None:
fmt = ('MockClassifier extra fit_param sparse_sample_weight'
'.shape[0] is {0}, should be {1}')
assert_true(sparse_sample_weight.shape[0] == X.shape[0],
fmt.format(sparse_sample_weight.shape[0], X.shape[0]))
if sparse_param is not None:
fmt = ('MockClassifier extra fit_param sparse_param.shape '
'is ({0}, {1}), should be ({2}, {3})')
assert_true(sparse_param.shape == P_sparse.shape,
fmt.format(sparse_param.shape[0],
sparse_param.shape[1],
P_sparse.shape[0], P_sparse.shape[1]))
return self
def predict(self, T):
if self.allow_nd:
T = T.reshape(len(T), -1)
return T[:, 0]
def score(self, X=None, Y=None):
return 1. / (1 + np.abs(self.a))
def get_params(self, deep=False):
return {'a': self.a, 'allow_nd': self.allow_nd}
@ignore_warnings
def test_cross_validator_with_default_params():
n_samples = 4
n_unique_groups = 4
n_splits = 2
p = 2
n_shuffle_splits = 10 # (the default value)
X = np.array([[1, 2], [3, 4], [5, 6], [7, 8]])
X_1d = np.array([1, 2, 3, 4])
y = np.array([1, 1, 2, 2])
groups = np.array([1, 2, 3, 4])
loo = LeaveOneOut()
lpo = LeavePOut(p)
kf = KFold(n_splits)
skf = StratifiedKFold(n_splits)
lolo = LeaveOneGroupOut()
lopo = LeavePGroupsOut(p)
ss = ShuffleSplit(random_state=0)
ps = PredefinedSplit([1, 1, 2, 2]) # n_splits = np of unique folds = 2
loo_repr = "LeaveOneOut()"
lpo_repr = "LeavePOut(p=2)"
kf_repr = "KFold(n_splits=2, random_state=None, shuffle=False)"
skf_repr = "StratifiedKFold(n_splits=2, random_state=None, shuffle=False)"
lolo_repr = "LeaveOneGroupOut()"
lopo_repr = "LeavePGroupsOut(n_groups=2)"
ss_repr = ("ShuffleSplit(n_splits=10, random_state=0, "
"test_size='default',\n train_size=None)")
ps_repr = "PredefinedSplit(test_fold=array([1, 1, 2, 2]))"
n_splits_expected = [n_samples, comb(n_samples, p), n_splits, n_splits,
n_unique_groups, comb(n_unique_groups, p),
n_shuffle_splits, 2]
for i, (cv, cv_repr) in enumerate(zip(
[loo, lpo, kf, skf, lolo, lopo, ss, ps],
[loo_repr, lpo_repr, kf_repr, skf_repr, lolo_repr, lopo_repr,
ss_repr, ps_repr])):
# Test if get_n_splits works correctly
assert_equal(n_splits_expected[i], cv.get_n_splits(X, y, groups))
# Test if the cross-validator works as expected even if
# the data is 1d
np.testing.assert_equal(list(cv.split(X, y, groups)),
list(cv.split(X_1d, y, groups)))
# Test that train, test indices returned are integers
for train, test in cv.split(X, y, groups):
assert_equal(np.asarray(train).dtype.kind, 'i')
assert_equal(np.asarray(train).dtype.kind, 'i')
# Test if the repr works without any errors
assert_equal(cv_repr, repr(cv))
# ValueError for get_n_splits methods
msg = "The 'X' parameter should not be None."
assert_raise_message(ValueError, msg,
loo.get_n_splits, None, y, groups)
assert_raise_message(ValueError, msg,
lpo.get_n_splits, None, y, groups)
def test_2d_y():
# smoke test for 2d y and multi-label
n_samples = 30
rng = np.random.RandomState(1)
X = rng.randint(0, 3, size=(n_samples, 2))
y = rng.randint(0, 3, size=(n_samples,))
y_2d = y.reshape(-1, 1)
y_multilabel = rng.randint(0, 2, size=(n_samples, 3))
groups = rng.randint(0, 3, size=(n_samples,))
splitters = [LeaveOneOut(), LeavePOut(p=2), KFold(), StratifiedKFold(),
RepeatedKFold(), RepeatedStratifiedKFold(),
ShuffleSplit(), StratifiedShuffleSplit(test_size=.5),
GroupShuffleSplit(), LeaveOneGroupOut(),
LeavePGroupsOut(n_groups=2), GroupKFold(), TimeSeriesSplit(),
PredefinedSplit(test_fold=groups)]
for splitter in splitters:
list(splitter.split(X, y, groups))
list(splitter.split(X, y_2d, groups))
try:
list(splitter.split(X, y_multilabel, groups))
except ValueError as e:
allowed_target_types = ('binary', 'multiclass')
msg = "Supported target types are: {}. Got 'multilabel".format(
allowed_target_types)
assert msg in str(e)
def check_valid_split(train, test, n_samples=None):
# Use python sets to get more informative assertion failure messages
train, test = set(train), set(test)
# Train and test split should not overlap
assert_equal(train.intersection(test), set())
if n_samples is not None:
# Check that the union of train an test split cover all the indices
assert_equal(train.union(test), set(range(n_samples)))
def check_cv_coverage(cv, X, y, groups, expected_n_splits=None):
n_samples = _num_samples(X)
# Check that a all the samples appear at least once in a test fold
if expected_n_splits is not None:
assert_equal(cv.get_n_splits(X, y, groups), expected_n_splits)
else:
expected_n_splits = cv.get_n_splits(X, y, groups)
collected_test_samples = set()
iterations = 0
for train, test in cv.split(X, y, groups):
check_valid_split(train, test, n_samples=n_samples)
iterations += 1
collected_test_samples.update(test)
# Check that the accumulated test samples cover the whole dataset
assert_equal(iterations, expected_n_splits)
if n_samples is not None:
assert_equal(collected_test_samples, set(range(n_samples)))
def test_kfold_valueerrors():
X1 = np.array([[1, 2], [3, 4], [5, 6]])
X2 = np.array([[1, 2], [3, 4], [5, 6], [7, 8], [9, 10]])
# Check that errors are raised if there is not enough samples
(ValueError, next, KFold(4).split(X1))
# Check that a warning is raised if the least populated class has too few
# members.
y = np.array([3, 3, -1, -1, 3])
skf_3 = StratifiedKFold(3)
assert_warns_message(Warning, "The least populated class",
next, skf_3.split(X2, y))
# Check that despite the warning the folds are still computed even
# though all the classes are not necessarily represented at on each
# side of the split at each split
with warnings.catch_warnings():
warnings.simplefilter("ignore")
check_cv_coverage(skf_3, X2, y, groups=None, expected_n_splits=3)
# Check that errors are raised if all n_groups for individual
# classes are less than n_splits.
y = np.array([3, 3, -1, -1, 2])
assert_raises(ValueError, next, skf_3.split(X2, y))
# Error when number of folds is <= 1
assert_raises(ValueError, KFold, 0)
assert_raises(ValueError, KFold, 1)
error_string = ("k-fold cross-validation requires at least one"
" train/test split")
assert_raise_message(ValueError, error_string,
StratifiedKFold, 0)
assert_raise_message(ValueError, error_string,
StratifiedKFold, 1)
# When n_splits is not integer:
assert_raises(ValueError, KFold, 1.5)
assert_raises(ValueError, KFold, 2.0)
assert_raises(ValueError, StratifiedKFold, 1.5)
assert_raises(ValueError, StratifiedKFold, 2.0)
# When shuffle is not a bool:
assert_raises(TypeError, KFold, n_splits=4, shuffle=None)
def test_kfold_indices():
# Check all indices are returned in the test folds
X1 = np.ones(18)
kf = KFold(3)
check_cv_coverage(kf, X1, y=None, groups=None, expected_n_splits=3)
# Check all indices are returned in the test folds even when equal-sized
# folds are not possible
X2 = np.ones(17)
kf = KFold(3)
check_cv_coverage(kf, X2, y=None, groups=None, expected_n_splits=3)
# Check if get_n_splits returns the number of folds
assert_equal(5, KFold(5).get_n_splits(X2))
def test_kfold_no_shuffle():
# Manually check that KFold preserves the data ordering on toy datasets
X2 = [[1, 2], [3, 4], [5, 6], [7, 8], [9, 10]]
splits = KFold(2).split(X2[:-1])
train, test = next(splits)
assert_array_equal(test, [0, 1])
assert_array_equal(train, [2, 3])
train, test = next(splits)
assert_array_equal(test, [2, 3])
assert_array_equal(train, [0, 1])
splits = KFold(2).split(X2)
train, test = next(splits)
assert_array_equal(test, [0, 1, 2])
assert_array_equal(train, [3, 4])
train, test = next(splits)
assert_array_equal(test, [3, 4])
assert_array_equal(train, [0, 1, 2])
def test_stratified_kfold_no_shuffle():
# Manually check that StratifiedKFold preserves the data ordering as much
# as possible on toy datasets in order to avoid hiding sample dependencies
# when possible
X, y = np.ones(4), [1, 1, 0, 0]
splits = StratifiedKFold(2).split(X, y)
train, test = next(splits)
assert_array_equal(test, [0, 2])
assert_array_equal(train, [1, 3])
train, test = next(splits)
assert_array_equal(test, [1, 3])
assert_array_equal(train, [0, 2])
X, y = np.ones(7), [1, 1, 1, 0, 0, 0, 0]
splits = StratifiedKFold(2).split(X, y)
train, test = next(splits)
assert_array_equal(test, [0, 1, 3, 4])
assert_array_equal(train, [2, 5, 6])
train, test = next(splits)
assert_array_equal(test, [2, 5, 6])
assert_array_equal(train, [0, 1, 3, 4])
# Check if get_n_splits returns the number of folds
assert_equal(5, StratifiedKFold(5).get_n_splits(X, y))
# Make sure string labels are also supported
X = np.ones(7)
y1 = ['1', '1', '1', '0', '0', '0', '0']
y2 = [1, 1, 1, 0, 0, 0, 0]
np.testing.assert_equal(
list(StratifiedKFold(2).split(X, y1)),
list(StratifiedKFold(2).split(X, y2)))
def test_stratified_kfold_ratios():
# Check that stratified kfold preserves class ratios in individual splits
# Repeat with shuffling turned off and on
n_samples = 1000
X = np.ones(n_samples)
y = np.array([4] * int(0.10 * n_samples) +
[0] * int(0.89 * n_samples) +
[1] * int(0.01 * n_samples))
for shuffle in (False, True):
for train, test in StratifiedKFold(5, shuffle=shuffle).split(X, y):
assert_almost_equal(np.sum(y[train] == 4) / len(train), 0.10, 2)
assert_almost_equal(np.sum(y[train] == 0) / len(train), 0.89, 2)
assert_almost_equal(np.sum(y[train] == 1) / len(train), 0.01, 2)
assert_almost_equal(np.sum(y[test] == 4) / len(test), 0.10, 2)
assert_almost_equal(np.sum(y[test] == 0) / len(test), 0.89, 2)
assert_almost_equal(np.sum(y[test] == 1) / len(test), 0.01, 2)
def test_kfold_balance():
# Check that KFold returns folds with balanced sizes
for i in range(11, 17):
kf = KFold(5).split(X=np.ones(i))
sizes = []
for _, test in kf:
sizes.append(len(test))
assert_true((np.max(sizes) - np.min(sizes)) <= 1)
assert_equal(np.sum(sizes), i)
def test_stratifiedkfold_balance():
# Check that KFold returns folds with balanced sizes (only when
# stratification is possible)
# Repeat with shuffling turned off and on
X = np.ones(17)
y = [0] * 3 + [1] * 14
for shuffle in (True, False):
cv = StratifiedKFold(3, shuffle=shuffle)
for i in range(11, 17):
skf = cv.split(X[:i], y[:i])
sizes = []
for _, test in skf:
sizes.append(len(test))
assert_true((np.max(sizes) - np.min(sizes)) <= 1)
assert_equal(np.sum(sizes), i)
def test_shuffle_kfold():
# Check the indices are shuffled properly
kf = KFold(3)
kf2 = KFold(3, shuffle=True, random_state=0)
kf3 = KFold(3, shuffle=True, random_state=1)
X = np.ones(300)
all_folds = np.zeros(300)
for (tr1, te1), (tr2, te2), (tr3, te3) in zip(
kf.split(X), kf2.split(X), kf3.split(X)):
for tr_a, tr_b in combinations((tr1, tr2, tr3), 2):
# Assert that there is no complete overlap
assert_not_equal(len(np.intersect1d(tr_a, tr_b)), len(tr1))
# Set all test indices in successive iterations of kf2 to 1
all_folds[te2] = 1
# Check that all indices are returned in the different test folds
assert_equal(sum(all_folds), 300)
def test_shuffle_kfold_stratifiedkfold_reproducibility():
# Check that when the shuffle is True multiple split calls produce the
# same split when random_state is set
X = np.ones(15) # Divisible by 3
y = [0] * 7 + [1] * 8
X2 = np.ones(16) # Not divisible by 3
y2 = [0] * 8 + [1] * 8
kf = KFold(3, shuffle=True, random_state=0)
skf = StratifiedKFold(3, shuffle=True, random_state=0)
for cv in (kf, skf):
np.testing.assert_equal(list(cv.split(X, y)), list(cv.split(X, y)))
np.testing.assert_equal(list(cv.split(X2, y2)), list(cv.split(X2, y2)))
kf = KFold(3, shuffle=True)
skf = StratifiedKFold(3, shuffle=True)
for cv in (kf, skf):
for data in zip((X, X2), (y, y2)):
# Test if the two splits are different
# numpy's assert_equal properly compares nested lists
try:
np.testing.assert_array_equal(list(cv.split(*data)),
list(cv.split(*data)))
except AssertionError:
pass
else:
raise AssertionError("The splits for data, %s, are same even "
"when random state is not set" % data)
def test_shuffle_stratifiedkfold():
# Check that shuffling is happening when requested, and for proper
# sample coverage
X_40 = np.ones(40)
y = [0] * 20 + [1] * 20
kf0 = StratifiedKFold(5, shuffle=True, random_state=0)
kf1 = StratifiedKFold(5, shuffle=True, random_state=1)
for (_, test0), (_, test1) in zip(kf0.split(X_40, y),
kf1.split(X_40, y)):
assert_not_equal(set(test0), set(test1))
check_cv_coverage(kf0, X_40, y, groups=None, expected_n_splits=5)
def test_kfold_can_detect_dependent_samples_on_digits(): # see #2372
# The digits samples are dependent: they are apparently grouped by authors
# although we don't have any information on the groups segment locations
# for this data. We can highlight this fact by computing k-fold cross-
# validation with and without shuffling: we observe that the shuffling case
# wrongly makes the IID assumption and is therefore too optimistic: it
# estimates a much higher accuracy (around 0.93) than that the non
# shuffling variant (around 0.81).
X, y = digits.data[:600], digits.target[:600]
model = SVC(C=10, gamma=0.005)
n_splits = 3
cv = KFold(n_splits=n_splits, shuffle=False)
mean_score = cross_val_score(model, X, y, cv=cv).mean()
assert_greater(0.92, mean_score)
assert_greater(mean_score, 0.80)
# Shuffling the data artificially breaks the dependency and hides the
# overfitting of the model with regards to the writing style of the authors
# by yielding a seriously overestimated score:
cv = KFold(n_splits, shuffle=True, random_state=0)
mean_score = cross_val_score(model, X, y, cv=cv).mean()
assert_greater(mean_score, 0.92)
cv = KFold(n_splits, shuffle=True, random_state=1)
mean_score = cross_val_score(model, X, y, cv=cv).mean()
assert_greater(mean_score, 0.92)
# Similarly, StratifiedKFold should try to shuffle the data as little
# as possible (while respecting the balanced class constraints)
# and thus be able to detect the dependency by not overestimating
# the CV score either. As the digits dataset is approximately balanced
# the estimated mean score is close to the score measured with
# non-shuffled KFold
cv = StratifiedKFold(n_splits)
mean_score = cross_val_score(model, X, y, cv=cv).mean()
assert_greater(0.93, mean_score)
assert_greater(mean_score, 0.80)
def test_shuffle_split():
ss1 = ShuffleSplit(test_size=0.2, random_state=0).split(X)
ss2 = ShuffleSplit(test_size=2, random_state=0).split(X)
ss3 = ShuffleSplit(test_size=np.int32(2), random_state=0).split(X)
for typ in six.integer_types:
ss4 = ShuffleSplit(test_size=typ(2), random_state=0).split(X)
for t1, t2, t3, t4 in zip(ss1, ss2, ss3, ss4):
assert_array_equal(t1[0], t2[0])
assert_array_equal(t2[0], t3[0])
assert_array_equal(t3[0], t4[0])
assert_array_equal(t1[1], t2[1])
assert_array_equal(t2[1], t3[1])
assert_array_equal(t3[1], t4[1])
@ignore_warnings
def test_stratified_shuffle_split_init():
X = np.arange(7)
y = np.asarray([0, 1, 1, 1, 2, 2, 2])
# Check that error is raised if there is a class with only one sample
assert_raises(ValueError, next,
StratifiedShuffleSplit(3, 0.2).split(X, y))
# Check that error is raised if the test set size is smaller than n_classes
assert_raises(ValueError, next, StratifiedShuffleSplit(3, 2).split(X, y))
# Check that error is raised if the train set size is smaller than
# n_classes
assert_raises(ValueError, next,
StratifiedShuffleSplit(3, 3, 2).split(X, y))
X = np.arange(9)
y = np.asarray([0, 0, 0, 1, 1, 1, 2, 2, 2])
# Check that errors are raised if there is not enough samples
assert_raises(ValueError, StratifiedShuffleSplit, 3, 0.5, 0.6)
assert_raises(ValueError, next,
StratifiedShuffleSplit(3, 8, 0.6).split(X, y))
assert_raises(ValueError, next,
StratifiedShuffleSplit(3, 0.6, 8).split(X, y))
# Train size or test size too small
assert_raises(ValueError, next,
StratifiedShuffleSplit(train_size=2).split(X, y))
assert_raises(ValueError, next,
StratifiedShuffleSplit(test_size=2).split(X, y))
def test_stratified_shuffle_split_respects_test_size():
y = np.array([0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2])
test_size = 5
train_size = 10
sss = StratifiedShuffleSplit(6, test_size=test_size, train_size=train_size,
random_state=0).split(np.ones(len(y)), y)
for train, test in sss:
assert_equal(len(train), train_size)
assert_equal(len(test), test_size)
def test_stratified_shuffle_split_iter():
ys = [np.array([1, 1, 1, 1, 2, 2, 2, 3, 3, 3, 3, 3]),
np.array([0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3]),
np.array([0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2] * 2),
np.array([1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4]),
np.array([-1] * 800 + [1] * 50),
np.concatenate([[i] * (100 + i) for i in range(11)]),
[1, 1, 1, 1, 2, 2, 2, 3, 3, 3, 3, 3],
['1', '1', '1', '1', '2', '2', '2', '3', '3', '3', '3', '3'],
]
for y in ys:
sss = StratifiedShuffleSplit(6, test_size=0.33,
random_state=0).split(np.ones(len(y)), y)
y = np.asanyarray(y) # To make it indexable for y[train]
# this is how test-size is computed internally
# in _validate_shuffle_split
test_size = np.ceil(0.33 * len(y))
train_size = len(y) - test_size
for train, test in sss:
assert_array_equal(np.unique(y[train]), np.unique(y[test]))
# Checks if folds keep classes proportions
p_train = (np.bincount(np.unique(y[train],
return_inverse=True)[1]) /
float(len(y[train])))
p_test = (np.bincount(np.unique(y[test],
return_inverse=True)[1]) /
float(len(y[test])))
assert_array_almost_equal(p_train, p_test, 1)
assert_equal(len(train) + len(test), y.size)
assert_equal(len(train), train_size)
assert_equal(len(test), test_size)
assert_array_equal(np.lib.arraysetops.intersect1d(train, test), [])
def test_stratified_shuffle_split_even():
# Test the StratifiedShuffleSplit, indices are drawn with a
# equal chance
n_folds = 5
n_splits = 1000
def assert_counts_are_ok(idx_counts, p):
# Here we test that the distribution of the counts
# per index is close enough to a binomial
threshold = 0.05 / n_splits
bf = stats.binom(n_splits, p)
for count in idx_counts:
prob = bf.pmf(count)
assert_true(prob > threshold,
"An index is not drawn with chance corresponding "
"to even draws")
for n_samples in (6, 22):
groups = np.array((n_samples // 2) * [0, 1])
splits = StratifiedShuffleSplit(n_splits=n_splits,
test_size=1. / n_folds,
random_state=0)
train_counts = [0] * n_samples
test_counts = [0] * n_samples
n_splits_actual = 0
for train, test in splits.split(X=np.ones(n_samples), y=groups):
n_splits_actual += 1
for counter, ids in [(train_counts, train), (test_counts, test)]:
for id in ids:
counter[id] += 1
assert_equal(n_splits_actual, n_splits)
n_train, n_test = _validate_shuffle_split(
n_samples, test_size=1. / n_folds, train_size=1. - (1. / n_folds))
assert_equal(len(train), n_train)
assert_equal(len(test), n_test)
assert_equal(len(set(train).intersection(test)), 0)
group_counts = np.unique(groups)
assert_equal(splits.test_size, 1.0 / n_folds)
assert_equal(n_train + n_test, len(groups))
assert_equal(len(group_counts), 2)
ex_test_p = float(n_test) / n_samples
ex_train_p = float(n_train) / n_samples
assert_counts_are_ok(train_counts, ex_train_p)
assert_counts_are_ok(test_counts, ex_test_p)
def test_stratified_shuffle_split_overlap_train_test_bug():
# See https://github.com/scikit-learn/scikit-learn/issues/6121 for
# the original bug report
y = [0, 1, 2, 3] * 3 + [4, 5] * 5
X = np.ones_like(y)
sss = StratifiedShuffleSplit(n_splits=1,
test_size=0.5, random_state=0)
train, test = next(sss.split(X=X, y=y))
# no overlap
assert_array_equal(np.intersect1d(train, test), [])
# complete partition
assert_array_equal(np.union1d(train, test), np.arange(len(y)))
def test_stratified_shuffle_split_multilabel():
# fix for issue 9037
for y in [np.array([[0, 1], [1, 0], [1, 0], [0, 1]]),
np.array([[0, 1], [1, 1], [1, 1], [0, 1]])]:
X = np.ones_like(y)
sss = StratifiedShuffleSplit(n_splits=1, test_size=0.5, random_state=0)
train, test = next(sss.split(X=X, y=y))
y_train = y[train]
y_test = y[test]
# no overlap
assert_array_equal(np.intersect1d(train, test), [])
# complete partition
assert_array_equal(np.union1d(train, test), np.arange(len(y)))
# correct stratification of entire rows
# (by design, here y[:, 0] uniquely determines the entire row of y)
expected_ratio = np.mean(y[:, 0])
assert_equal(expected_ratio, np.mean(y_train[:, 0]))
assert_equal(expected_ratio, np.mean(y_test[:, 0]))
def test_stratified_shuffle_split_multilabel_many_labels():
# fix in PR #9922: for multilabel data with > 1000 labels, str(row)
# truncates with an ellipsis for elements in positions 4 through
# len(row) - 4, so labels were not being correctly split using the powerset
# method for transforming a multilabel problem to a multiclass one; this
# test checks that this problem is fixed.
row_with_many_zeros = [1, 0, 1] + [0] * 1000 + [1, 0, 1]
row_with_many_ones = [1, 0, 1] + [1] * 1000 + [1, 0, 1]
y = np.array([row_with_many_zeros] * 10 + [row_with_many_ones] * 100)
X = np.ones_like(y)
sss = StratifiedShuffleSplit(n_splits=1, test_size=0.5, random_state=0)
train, test = next(sss.split(X=X, y=y))
y_train = y[train]
y_test = y[test]
# correct stratification of entire rows
# (by design, here y[:, 4] uniquely determines the entire row of y)
expected_ratio = np.mean(y[:, 4])
assert_equal(expected_ratio, np.mean(y_train[:, 4]))
assert_equal(expected_ratio, np.mean(y_test[:, 4]))
def test_predefinedsplit_with_kfold_split():
# Check that PredefinedSplit can reproduce a split generated by Kfold.
folds = -1 * np.ones(10)
kf_train = []
kf_test = []
for i, (train_ind, test_ind) in enumerate(KFold(5, shuffle=True).split(X)):
kf_train.append(train_ind)
kf_test.append(test_ind)
folds[test_ind] = i
ps_train = []
ps_test = []
ps = PredefinedSplit(folds)
# n_splits is simply the no of unique folds
assert_equal(len(np.unique(folds)), ps.get_n_splits())
for train_ind, test_ind in ps.split():
ps_train.append(train_ind)
ps_test.append(test_ind)
assert_array_equal(ps_train, kf_train)
assert_array_equal(ps_test, kf_test)
def test_group_shuffle_split():
for groups_i in test_groups:
X = y = np.ones(len(groups_i))
n_splits = 6
test_size = 1. / 3
slo = GroupShuffleSplit(n_splits, test_size=test_size, random_state=0)
# Make sure the repr works
repr(slo)
# Test that the length is correct
assert_equal(slo.get_n_splits(X, y, groups=groups_i), n_splits)
l_unique = np.unique(groups_i)
l = np.asarray(groups_i)
for train, test in slo.split(X, y, groups=groups_i):
# First test: no train group is in the test set and vice versa
l_train_unique = np.unique(l[train])
l_test_unique = np.unique(l[test])
assert_false(np.any(np.in1d(l[train], l_test_unique)))
assert_false(np.any(np.in1d(l[test], l_train_unique)))
# Second test: train and test add up to all the data
assert_equal(l[train].size + l[test].size, l.size)
# Third test: train and test are disjoint
assert_array_equal(np.intersect1d(train, test), [])
# Fourth test:
# unique train and test groups are correct, +- 1 for rounding error
assert_true(abs(len(l_test_unique) -
round(test_size * len(l_unique))) <= 1)
assert_true(abs(len(l_train_unique) -
round((1.0 - test_size) * len(l_unique))) <= 1)
def test_leave_one_p_group_out():
logo = LeaveOneGroupOut()
lpgo_1 = LeavePGroupsOut(n_groups=1)
lpgo_2 = LeavePGroupsOut(n_groups=2)
# Make sure the repr works
assert_equal(repr(logo), 'LeaveOneGroupOut()')
assert_equal(repr(lpgo_1), 'LeavePGroupsOut(n_groups=1)')
assert_equal(repr(lpgo_2), 'LeavePGroupsOut(n_groups=2)')
assert_equal(repr(LeavePGroupsOut(n_groups=3)),
'LeavePGroupsOut(n_groups=3)')
for j, (cv, p_groups_out) in enumerate(((logo, 1), (lpgo_1, 1),
(lpgo_2, 2))):
for i, groups_i in enumerate(test_groups):
n_groups = len(np.unique(groups_i))
n_splits = (n_groups if p_groups_out == 1
else n_groups * (n_groups - 1) / 2)
X = y = np.ones(len(groups_i))
# Test that the length is correct
assert_equal(cv.get_n_splits(X, y, groups=groups_i), n_splits)
groups_arr = np.asarray(groups_i)
# Split using the original list / array / list of string groups_i
for train, test in cv.split(X, y, groups=groups_i):
# First test: no train group is in the test set and vice versa
assert_array_equal(np.intersect1d(groups_arr[train],
groups_arr[test]).tolist(),
[])
# Second test: train and test add up to all the data
assert_equal(len(train) + len(test), len(groups_i))
# Third test:
# The number of groups in test must be equal to p_groups_out
assert_true(np.unique(groups_arr[test]).shape[0], p_groups_out)
# check get_n_splits() with dummy parameters
assert_equal(logo.get_n_splits(None, None, ['a', 'b', 'c', 'b', 'c']), 3)
assert_equal(logo.get_n_splits(groups=[1.0, 1.1, 1.0, 1.2]), 3)
assert_equal(lpgo_2.get_n_splits(None, None, np.arange(4)), 6)
assert_equal(lpgo_1.get_n_splits(groups=np.arange(4)), 4)
# raise ValueError if a `groups` parameter is illegal
with assert_raises(ValueError):
logo.get_n_splits(None, None, [0.0, np.nan, 0.0])
with assert_raises(ValueError):
lpgo_2.get_n_splits(None, None, [0.0, np.inf, 0.0])
msg = "The 'groups' parameter should not be None."
assert_raise_message(ValueError, msg,
logo.get_n_splits, None, None, None)
assert_raise_message(ValueError, msg,
lpgo_1.get_n_splits, None, None, None)
def test_leave_group_out_changing_groups():
# Check that LeaveOneGroupOut and LeavePGroupsOut work normally if
# the groups variable is changed before calling split
groups = np.array([0, 1, 2, 1, 1, 2, 0, 0])
X = np.ones(len(groups))
groups_changing = np.array(groups, copy=True)
lolo = LeaveOneGroupOut().split(X, groups=groups)
lolo_changing = LeaveOneGroupOut().split(X, groups=groups)
lplo = LeavePGroupsOut(n_groups=2).split(X, groups=groups)
lplo_changing = LeavePGroupsOut(n_groups=2).split(X, groups=groups)
groups_changing[:] = 0
for llo, llo_changing in [(lolo, lolo_changing), (lplo, lplo_changing)]:
for (train, test), (train_chan, test_chan) in zip(llo, llo_changing):
assert_array_equal(train, train_chan)
assert_array_equal(test, test_chan)
# n_splits = no of 2 (p) group combinations of the unique groups = 3C2 = 3
assert_equal(
3, LeavePGroupsOut(n_groups=2).get_n_splits(X, y=X,
groups=groups))
# n_splits = no of unique groups (C(uniq_lbls, 1) = n_unique_groups)
assert_equal(3, LeaveOneGroupOut().get_n_splits(X, y=X,
groups=groups))
def test_leave_one_p_group_out_error_on_fewer_number_of_groups():
X = y = groups = np.ones(0)
assert_raise_message(ValueError, "Found array with 0 sample(s)", next,
LeaveOneGroupOut().split(X, y, groups))
X = y = groups = np.ones(1)
msg = ("The groups parameter contains fewer than 2 unique groups ({}). "
"LeaveOneGroupOut expects at least 2.").format(groups)
assert_raise_message(ValueError, msg, next,
LeaveOneGroupOut().split(X, y, groups))
X = y = groups = np.ones(1)
msg = ("The groups parameter contains fewer than (or equal to) n_groups "
"(3) numbers of unique groups ({}). LeavePGroupsOut expects "
"that at least n_groups + 1 (4) unique groups "
"be present").format(groups)
assert_raise_message(ValueError, msg, next,
LeavePGroupsOut(n_groups=3).split(X, y, groups))
X = y = groups = np.arange(3)
msg = ("The groups parameter contains fewer than (or equal to) n_groups "
"(3) numbers of unique groups ({}). LeavePGroupsOut expects "
"that at least n_groups + 1 (4) unique groups "
"be present").format(groups)
assert_raise_message(ValueError, msg, next,
LeavePGroupsOut(n_groups=3).split(X, y, groups))
@ignore_warnings
def test_repeated_cv_value_errors():
# n_repeats is not integer or <= 0
for cv in (RepeatedKFold, RepeatedStratifiedKFold):
assert_raises(ValueError, cv, n_repeats=0)
assert_raises(ValueError, cv, n_repeats=1.5)
def test_repeated_kfold_determinstic_split():
X = [[1, 2], [3, 4], [5, 6], [7, 8], [9, 10]]
random_state = 258173307
rkf = RepeatedKFold(
n_splits=2,
n_repeats=2,
random_state=random_state)
# split should produce same and deterministic splits on
# each call
for _ in range(3):
splits = rkf.split(X)
train, test = next(splits)
assert_array_equal(train, [2, 4])
assert_array_equal(test, [0, 1, 3])
train, test = next(splits)
assert_array_equal(train, [0, 1, 3])
assert_array_equal(test, [2, 4])
train, test = next(splits)
assert_array_equal(train, [0, 1])
assert_array_equal(test, [2, 3, 4])
train, test = next(splits)
assert_array_equal(train, [2, 3, 4])
assert_array_equal(test, [0, 1])
assert_raises(StopIteration, next, splits)
def test_get_n_splits_for_repeated_kfold():
n_splits = 3
n_repeats = 4
rkf = RepeatedKFold(n_splits, n_repeats)
expected_n_splits = n_splits * n_repeats
assert_equal(expected_n_splits, rkf.get_n_splits())
def test_get_n_splits_for_repeated_stratified_kfold():
n_splits = 3
n_repeats = 4
rskf = RepeatedStratifiedKFold(n_splits, n_repeats)
expected_n_splits = n_splits * n_repeats
assert_equal(expected_n_splits, rskf.get_n_splits())
def test_repeated_stratified_kfold_determinstic_split():
X = [[1, 2], [3, 4], [5, 6], [7, 8], [9, 10]]
y = [1, 1, 1, 0, 0]
random_state = 1944695409
rskf = RepeatedStratifiedKFold(
n_splits=2,
n_repeats=2,
random_state=random_state)
# split should produce same and deterministic splits on
# each call
for _ in range(3):
splits = rskf.split(X, y)
train, test = next(splits)
assert_array_equal(train, [1, 4])
assert_array_equal(test, [0, 2, 3])
train, test = next(splits)
assert_array_equal(train, [0, 2, 3])
assert_array_equal(test, [1, 4])
train, test = next(splits)
assert_array_equal(train, [2, 3])
assert_array_equal(test, [0, 1, 4])
train, test = next(splits)
assert_array_equal(train, [0, 1, 4])
assert_array_equal(test, [2, 3])
assert_raises(StopIteration, next, splits)
def test_train_test_split_errors():
assert_raises(ValueError, train_test_split)
assert_raises(ValueError, train_test_split, range(3), train_size=1.1)
assert_raises(ValueError, train_test_split, range(3), test_size=0.6,
train_size=0.6)
assert_raises(ValueError, train_test_split, range(3),
test_size=np.float32(0.6), train_size=np.float32(0.6))
assert_raises(ValueError, train_test_split, range(3),
test_size="wrong_type")
assert_raises(ValueError, train_test_split, range(3), test_size=2,
train_size=4)
assert_raises(TypeError, train_test_split, range(3),
some_argument=1.1)
assert_raises(ValueError, train_test_split, range(3), range(42))
assert_raises(ValueError, train_test_split, range(10),
shuffle=False, stratify=True)
def test_train_test_split():
X = np.arange(100).reshape((10, 10))
X_s = coo_matrix(X)
y = np.arange(10)
# simple test
split = train_test_split(X, y, test_size=None, train_size=.5)
X_train, X_test, y_train, y_test = split
assert_equal(len(y_test), len(y_train))
# test correspondence of X and y
assert_array_equal(X_train[:, 0], y_train * 10)
assert_array_equal(X_test[:, 0], y_test * 10)
# don't convert lists to anything else by default
split = train_test_split(X, X_s, y.tolist())
X_train, X_test, X_s_train, X_s_test, y_train, y_test = split
assert_true(isinstance(y_train, list))
assert_true(isinstance(y_test, list))
# allow nd-arrays
X_4d = np.arange(10 * 5 * 3 * 2).reshape(10, 5, 3, 2)
y_3d = np.arange(10 * 7 * 11).reshape(10, 7, 11)
split = train_test_split(X_4d, y_3d)
assert_equal(split[0].shape, (7, 5, 3, 2))
assert_equal(split[1].shape, (3, 5, 3, 2))
assert_equal(split[2].shape, (7, 7, 11))
assert_equal(split[3].shape, (3, 7, 11))
# test stratification option
y = np.array([1, 1, 1, 1, 2, 2, 2, 2])
for test_size, exp_test_size in zip([2, 4, 0.25, 0.5, 0.75],
[2, 4, 2, 4, 6]):
train, test = train_test_split(y, test_size=test_size,
stratify=y,
random_state=0)
assert_equal(len(test), exp_test_size)
assert_equal(len(test) + len(train), len(y))
# check the 1:1 ratio of ones and twos in the data is preserved
assert_equal(np.sum(train == 1), np.sum(train == 2))
# test unshuffled split
y = np.arange(10)
for test_size in [2, 0.2]:
train, test = train_test_split(y, shuffle=False, test_size=test_size)
assert_array_equal(test, [8, 9])
assert_array_equal(train, [0, 1, 2, 3, 4, 5, 6, 7])
@ignore_warnings
def train_test_split_pandas():
# check train_test_split doesn't destroy pandas dataframe
types = [MockDataFrame]
try:
from pandas import DataFrame
types.append(DataFrame)
except ImportError:
pass
for InputFeatureType in types:
# X dataframe
X_df = InputFeatureType(X)
X_train, X_test = train_test_split(X_df)
assert_true(isinstance(X_train, InputFeatureType))
assert_true(isinstance(X_test, InputFeatureType))
def train_test_split_sparse():
# check that train_test_split converts scipy sparse matrices
# to csr, as stated in the documentation
X = np.arange(100).reshape((10, 10))
sparse_types = [csr_matrix, csc_matrix, coo_matrix]
for InputFeatureType in sparse_types:
X_s = InputFeatureType(X)
X_train, X_test = train_test_split(X_s)
assert_true(isinstance(X_train, csr_matrix))
assert_true(isinstance(X_test, csr_matrix))
def train_test_split_mock_pandas():
# X mock dataframe
X_df = MockDataFrame(X)
X_train, X_test = train_test_split(X_df)
assert_true(isinstance(X_train, MockDataFrame))
assert_true(isinstance(X_test, MockDataFrame))
X_train_arr, X_test_arr = train_test_split(X_df)
def train_test_split_list_input():
# Check that when y is a list / list of string labels, it works.
X = np.ones(7)
y1 = ['1'] * 4 + ['0'] * 3
y2 = np.hstack((np.ones(4), np.zeros(3)))
y3 = y2.tolist()
for stratify in (True, False):
X_train1, X_test1, y_train1, y_test1 = train_test_split(
X, y1, stratify=y1 if stratify else None, random_state=0)
X_train2, X_test2, y_train2, y_test2 = train_test_split(
X, y2, stratify=y2 if stratify else None, random_state=0)
X_train3, X_test3, y_train3, y_test3 = train_test_split(
X, y3, stratify=y3 if stratify else None, random_state=0)
np.testing.assert_equal(X_train1, X_train2)
np.testing.assert_equal(y_train2, y_train3)
np.testing.assert_equal(X_test1, X_test3)
np.testing.assert_equal(y_test3, y_test2)
@ignore_warnings
def test_shufflesplit_errors():
# When the {test|train}_size is a float/invalid, error is raised at init
assert_raises(ValueError, ShuffleSplit, test_size=None, train_size=None)
assert_raises(ValueError, ShuffleSplit, test_size=2.0)
assert_raises(ValueError, ShuffleSplit, test_size=1.0)
assert_raises(ValueError, ShuffleSplit, test_size=0.1, train_size=0.95)
assert_raises(ValueError, ShuffleSplit, train_size=1j)
# When the {test|train}_size is an int, validation is based on the input X
# and happens at split(...)
assert_raises(ValueError, next, ShuffleSplit(test_size=11).split(X))
assert_raises(ValueError, next, ShuffleSplit(test_size=10).split(X))
assert_raises(ValueError, next, ShuffleSplit(test_size=8,
train_size=3).split(X))
def test_shufflesplit_reproducible():
# Check that iterating twice on the ShuffleSplit gives the same
# sequence of train-test when the random_state is given
ss = ShuffleSplit(random_state=21)
assert_array_equal(list(a for a, b in ss.split(X)),
list(a for a, b in ss.split(X)))
def test_stratifiedshufflesplit_list_input():
# Check that when y is a list / list of string labels, it works.
sss = StratifiedShuffleSplit(test_size=2, random_state=42)
X = np.ones(7)
y1 = ['1'] * 4 + ['0'] * 3
y2 = np.hstack((np.ones(4), np.zeros(3)))
y3 = y2.tolist()
np.testing.assert_equal(list(sss.split(X, y1)),
list(sss.split(X, y2)))
np.testing.assert_equal(list(sss.split(X, y3)),
list(sss.split(X, y2)))
def test_train_test_split_allow_nans():
# Check that train_test_split allows input data with NaNs
X = np.arange(200, dtype=np.float64).reshape(10, -1)
X[2, :] = np.nan
y = np.repeat([0, 1], X.shape[0] / 2)
train_test_split(X, y, test_size=0.2, random_state=42)
def test_check_cv():
X = np.ones(9)
cv = check_cv(3, classifier=False)
# Use numpy.testing.assert_equal which recursively compares
# lists of lists
np.testing.assert_equal(list(KFold(3).split(X)), list(cv.split(X)))
y_binary = np.array([0, 1, 0, 1, 0, 0, 1, 1, 1])
cv = check_cv(3, y_binary, classifier=True)
np.testing.assert_equal(list(StratifiedKFold(3).split(X, y_binary)),
list(cv.split(X, y_binary)))
y_multiclass = np.array([0, 1, 0, 1, 2, 1, 2, 0, 2])
cv = check_cv(3, y_multiclass, classifier=True)
np.testing.assert_equal(list(StratifiedKFold(3).split(X, y_multiclass)),
list(cv.split(X, y_multiclass)))
# also works with 2d multiclass
y_multiclass_2d = y_multiclass.reshape(-1, 1)
cv = check_cv(3, y_multiclass_2d, classifier=True)
np.testing.assert_equal(list(StratifiedKFold(3).split(X, y_multiclass_2d)),
list(cv.split(X, y_multiclass_2d)))
assert_false(np.all(
next(StratifiedKFold(3).split(X, y_multiclass_2d))[0] ==
next(KFold(3).split(X, y_multiclass_2d))[0]))
X = np.ones(5)
y_multilabel = np.array([[0, 0, 0, 0], [0, 1, 1, 0], [0, 0, 0, 1],
[1, 1, 0, 1], [0, 0, 1, 0]])
cv = check_cv(3, y_multilabel, classifier=True)
np.testing.assert_equal(list(KFold(3).split(X)), list(cv.split(X)))
y_multioutput = np.array([[1, 2], [0, 3], [0, 0], [3, 1], [2, 0]])
cv = check_cv(3, y_multioutput, classifier=True)
np.testing.assert_equal(list(KFold(3).split(X)), list(cv.split(X)))
# Check if the old style classes are wrapped to have a split method
X = np.ones(9)
y_multiclass = np.array([0, 1, 0, 1, 2, 1, 2, 0, 2])
cv1 = check_cv(3, y_multiclass, classifier=True)
with warnings.catch_warnings(record=True):
from sklearn.cross_validation import StratifiedKFold as OldSKF
cv2 = check_cv(OldSKF(y_multiclass, n_folds=3))
np.testing.assert_equal(list(cv1.split(X, y_multiclass)),
list(cv2.split()))
assert_raises(ValueError, check_cv, cv="lolo")
def test_cv_iterable_wrapper():
y_multiclass = np.array([0, 1, 0, 1, 2, 1, 2, 0, 2])
with warnings.catch_warnings(record=True):
from sklearn.cross_validation import StratifiedKFold as OldSKF
cv = OldSKF(y_multiclass, n_folds=3)
wrapped_old_skf = _CVIterableWrapper(cv)
# Check if split works correctly
np.testing.assert_equal(list(cv), list(wrapped_old_skf.split()))
# Check if get_n_splits works correctly
assert_equal(len(cv), wrapped_old_skf.get_n_splits())
kf_iter = KFold(n_splits=5).split(X, y)
kf_iter_wrapped = check_cv(kf_iter)
# Since the wrapped iterable is enlisted and stored,
# split can be called any number of times to produce
# consistent results.
np.testing.assert_equal(list(kf_iter_wrapped.split(X, y)),
list(kf_iter_wrapped.split(X, y)))
# If the splits are randomized, successive calls to split yields different
# results
kf_randomized_iter = KFold(n_splits=5, shuffle=True).split(X, y)
kf_randomized_iter_wrapped = check_cv(kf_randomized_iter)
# numpy's assert_array_equal properly compares nested lists
np.testing.assert_equal(list(kf_randomized_iter_wrapped.split(X, y)),
list(kf_randomized_iter_wrapped.split(X, y)))
try:
np.testing.assert_equal(list(kf_iter_wrapped.split(X, y)),
list(kf_randomized_iter_wrapped.split(X, y)))
splits_are_equal = True
except AssertionError:
splits_are_equal = False
assert_false(splits_are_equal, "If the splits are randomized, "
"successive calls to split should yield different results")
def test_group_kfold():
rng = np.random.RandomState(0)
# Parameters of the test
n_groups = 15
n_samples = 1000
n_splits = 5
X = y = np.ones(n_samples)
# Construct the test data
tolerance = 0.05 * n_samples # 5 percent error allowed
groups = rng.randint(0, n_groups, n_samples)
ideal_n_groups_per_fold = n_samples // n_splits
len(np.unique(groups))
# Get the test fold indices from the test set indices of each fold
folds = np.zeros(n_samples)
lkf = GroupKFold(n_splits=n_splits)
for i, (_, test) in enumerate(lkf.split(X, y, groups)):
folds[test] = i
# Check that folds have approximately the same size
assert_equal(len(folds), len(groups))
for i in np.unique(folds):
assert_greater_equal(tolerance,
abs(sum(folds == i) - ideal_n_groups_per_fold))
# Check that each group appears only in 1 fold
for group in np.unique(groups):
assert_equal(len(np.unique(folds[groups == group])), 1)
# Check that no group is on both sides of the split
groups = np.asarray(groups, dtype=object)
for train, test in lkf.split(X, y, groups):
assert_equal(len(np.intersect1d(groups[train], groups[test])), 0)
# Construct the test data
groups = np.array(['Albert', 'Jean', 'Bertrand', 'Michel', 'Jean',
'Francis', 'Robert', 'Michel', 'Rachel', 'Lois',
'Michelle', 'Bernard', 'Marion', 'Laura', 'Jean',
'Rachel', 'Franck', 'John', 'Gael', 'Anna', 'Alix',
'Robert', 'Marion', 'David', 'Tony', 'Abel', 'Becky',
'Madmood', 'Cary', 'Mary', 'Alexandre', 'David',
'Francis', 'Barack', 'Abdoul', 'Rasha', 'Xi', 'Silvia'])
n_groups = len(np.unique(groups))
n_samples = len(groups)
n_splits = 5
tolerance = 0.05 * n_samples # 5 percent error allowed
ideal_n_groups_per_fold = n_samples // n_splits
X = y = np.ones(n_samples)
# Get the test fold indices from the test set indices of each fold
folds = np.zeros(n_samples)
for i, (_, test) in enumerate(lkf.split(X, y, groups)):
folds[test] = i
# Check that folds have approximately the same size
assert_equal(len(folds), len(groups))
for i in np.unique(folds):
assert_greater_equal(tolerance,
abs(sum(folds == i) - ideal_n_groups_per_fold))
# Check that each group appears only in 1 fold
with warnings.catch_warnings():
warnings.simplefilter("ignore", DeprecationWarning)
for group in np.unique(groups):
assert_equal(len(np.unique(folds[groups == group])), 1)
# Check that no group is on both sides of the split
groups = np.asarray(groups, dtype=object)
for train, test in lkf.split(X, y, groups):
assert_equal(len(np.intersect1d(groups[train], groups[test])), 0)
# groups can also be a list
cv_iter = list(lkf.split(X, y, groups.tolist()))
for (train1, test1), (train2, test2) in zip(lkf.split(X, y, groups),
cv_iter):
assert_array_equal(train1, train2)
assert_array_equal(test1, test2)
# Should fail if there are more folds than groups
groups = np.array([1, 1, 1, 2, 2])
X = y = np.ones(len(groups))
assert_raises_regexp(ValueError, "Cannot have number of splits.*greater",
next, GroupKFold(n_splits=3).split(X, y, groups))
def test_time_series_cv():
X = [[1, 2], [3, 4], [5, 6], [7, 8], [9, 10], [11, 12], [13, 14]]
# Should fail if there are more folds than samples
assert_raises_regexp(ValueError, "Cannot have number of folds.*greater",
next,
TimeSeriesSplit(n_splits=7).split(X))
tscv = TimeSeriesSplit(2)
# Manually check that Time Series CV preserves the data
# ordering on toy datasets
splits = tscv.split(X[:-1])
train, test = next(splits)
assert_array_equal(train, [0, 1])
assert_array_equal(test, [2, 3])
train, test = next(splits)
assert_array_equal(train, [0, 1, 2, 3])
assert_array_equal(test, [4, 5])
splits = TimeSeriesSplit(2).split(X)
train, test = next(splits)
assert_array_equal(train, [0, 1, 2])
assert_array_equal(test, [3, 4])
train, test = next(splits)
assert_array_equal(train, [0, 1, 2, 3, 4])
assert_array_equal(test, [5, 6])
# Check get_n_splits returns the correct number of splits
splits = TimeSeriesSplit(2).split(X)
n_splits_actual = len(list(splits))
assert_equal(n_splits_actual, tscv.get_n_splits())
assert_equal(n_splits_actual, 2)
def _check_time_series_max_train_size(splits, check_splits, max_train_size):
for (train, test), (check_train, check_test) in zip(splits, check_splits):
assert_array_equal(test, check_test)
assert_true(len(check_train) <= max_train_size)
suffix_start = max(len(train) - max_train_size, 0)
assert_array_equal(check_train, train[suffix_start:])
def test_time_series_max_train_size():
X = np.zeros((6, 1))
splits = TimeSeriesSplit(n_splits=3).split(X)
check_splits = TimeSeriesSplit(n_splits=3, max_train_size=3).split(X)
_check_time_series_max_train_size(splits, check_splits, max_train_size=3)
# Test for the case where the size of a fold is greater than max_train_size
check_splits = TimeSeriesSplit(n_splits=3, max_train_size=2).split(X)
_check_time_series_max_train_size(splits, check_splits, max_train_size=2)
# Test for the case where the size of each fold is less than max_train_size
check_splits = TimeSeriesSplit(n_splits=3, max_train_size=5).split(X)
_check_time_series_max_train_size(splits, check_splits, max_train_size=2)
def test_nested_cv():
# Test if nested cross validation works with different combinations of cv
rng = np.random.RandomState(0)
X, y = make_classification(n_samples=15, n_classes=2, random_state=0)
groups = rng.randint(0, 5, 15)
cvs = [LeaveOneGroupOut(), LeaveOneOut(), GroupKFold(), StratifiedKFold(),
StratifiedShuffleSplit(n_splits=3, random_state=0)]
for inner_cv, outer_cv in combinations_with_replacement(cvs, 2):
gs = GridSearchCV(Ridge(), param_grid={'alpha': [1, .1]},
cv=inner_cv)
cross_val_score(gs, X=X, y=y, groups=groups, cv=outer_cv,
fit_params={'groups': groups})
def test_train_test_default_warning():
assert_warns(FutureWarning, ShuffleSplit, train_size=0.75)
assert_warns(FutureWarning, GroupShuffleSplit, train_size=0.75)
assert_warns(FutureWarning, StratifiedShuffleSplit, train_size=0.75)
assert_warns(FutureWarning, train_test_split, range(3),
train_size=0.75)
def test_build_repr():
class MockSplitter:
def __init__(self, a, b=0, c=None):
self.a = a
self.b = b
self.c = c
def __repr__(self):
return _build_repr(self)
assert_equal(repr(MockSplitter(5, 6)), "MockSplitter(a=5, b=6, c=None)")
| 57,285 | 38.34478 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/model_selection/tests/test_search.py | """Test the search module"""
from collections import Iterable, Sized
from sklearn.externals.six.moves import cStringIO as StringIO
from sklearn.externals.six.moves import xrange
from sklearn.externals.joblib._compat import PY3_OR_LATER
from itertools import chain, product
import pickle
import sys
from types import GeneratorType
import re
import numpy as np
import scipy.sparse as sp
from sklearn.utils.fixes import sp_version
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_not_equal
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import assert_warns_message
from sklearn.utils.testing import assert_no_warnings
from sklearn.utils.testing import assert_raise_message
from sklearn.utils.testing import assert_false, assert_true
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.mocking import CheckingClassifier, MockDataFrame
from scipy.stats import bernoulli, expon, uniform
from sklearn.base import BaseEstimator
from sklearn.base import clone
from sklearn.exceptions import NotFittedError
from sklearn.datasets import make_classification
from sklearn.datasets import make_blobs
from sklearn.datasets import make_multilabel_classification
from sklearn.model_selection import fit_grid_point
from sklearn.model_selection import KFold
from sklearn.model_selection import StratifiedKFold
from sklearn.model_selection import StratifiedShuffleSplit
from sklearn.model_selection import LeaveOneGroupOut
from sklearn.model_selection import LeavePGroupsOut
from sklearn.model_selection import GroupKFold
from sklearn.model_selection import GroupShuffleSplit
from sklearn.model_selection import GridSearchCV
from sklearn.model_selection import RandomizedSearchCV
from sklearn.model_selection import ParameterGrid
from sklearn.model_selection import ParameterSampler
from sklearn.model_selection._validation import FitFailedWarning
from sklearn.svm import LinearSVC, SVC
from sklearn.tree import DecisionTreeRegressor
from sklearn.tree import DecisionTreeClassifier
from sklearn.cluster import KMeans
from sklearn.neighbors import KernelDensity
from sklearn.metrics import f1_score
from sklearn.metrics import recall_score
from sklearn.metrics import accuracy_score
from sklearn.metrics import make_scorer
from sklearn.metrics import roc_auc_score
from sklearn.preprocessing import Imputer
from sklearn.pipeline import Pipeline
from sklearn.linear_model import Ridge, SGDClassifier
from sklearn.model_selection.tests.common import OneTimeSplitter
# Neither of the following two estimators inherit from BaseEstimator,
# to test hyperparameter search on user-defined classifiers.
class MockClassifier(object):
"""Dummy classifier to test the parameter search algorithms"""
def __init__(self, foo_param=0):
self.foo_param = foo_param
def fit(self, X, Y):
assert_true(len(X) == len(Y))
self.classes_ = np.unique(Y)
return self
def predict(self, T):
return T.shape[0]
def transform(self, X):
return X + self.foo_param
def inverse_transform(self, X):
return X - self.foo_param
predict_proba = predict
predict_log_proba = predict
decision_function = predict
def score(self, X=None, Y=None):
if self.foo_param > 1:
score = 1.
else:
score = 0.
return score
def get_params(self, deep=False):
return {'foo_param': self.foo_param}
def set_params(self, **params):
self.foo_param = params['foo_param']
return self
class LinearSVCNoScore(LinearSVC):
"""An LinearSVC classifier that has no score method."""
@property
def score(self):
raise AttributeError
X = np.array([[-1, -1], [-2, -1], [1, 1], [2, 1]])
y = np.array([1, 1, 2, 2])
def assert_grid_iter_equals_getitem(grid):
assert_equal(list(grid), [grid[i] for i in range(len(grid))])
def test_parameter_grid():
# Test basic properties of ParameterGrid.
params1 = {"foo": [1, 2, 3]}
grid1 = ParameterGrid(params1)
assert_true(isinstance(grid1, Iterable))
assert_true(isinstance(grid1, Sized))
assert_equal(len(grid1), 3)
assert_grid_iter_equals_getitem(grid1)
params2 = {"foo": [4, 2],
"bar": ["ham", "spam", "eggs"]}
grid2 = ParameterGrid(params2)
assert_equal(len(grid2), 6)
# loop to assert we can iterate over the grid multiple times
for i in xrange(2):
# tuple + chain transforms {"a": 1, "b": 2} to ("a", 1, "b", 2)
points = set(tuple(chain(*(sorted(p.items())))) for p in grid2)
assert_equal(points,
set(("bar", x, "foo", y)
for x, y in product(params2["bar"], params2["foo"])))
assert_grid_iter_equals_getitem(grid2)
# Special case: empty grid (useful to get default estimator settings)
empty = ParameterGrid({})
assert_equal(len(empty), 1)
assert_equal(list(empty), [{}])
assert_grid_iter_equals_getitem(empty)
assert_raises(IndexError, lambda: empty[1])
has_empty = ParameterGrid([{'C': [1, 10]}, {}, {'C': [.5]}])
assert_equal(len(has_empty), 4)
assert_equal(list(has_empty), [{'C': 1}, {'C': 10}, {}, {'C': .5}])
assert_grid_iter_equals_getitem(has_empty)
def test_grid_search():
# Test that the best estimator contains the right value for foo_param
clf = MockClassifier()
grid_search = GridSearchCV(clf, {'foo_param': [1, 2, 3]}, verbose=3)
# make sure it selects the smallest parameter in case of ties
old_stdout = sys.stdout
sys.stdout = StringIO()
grid_search.fit(X, y)
sys.stdout = old_stdout
assert_equal(grid_search.best_estimator_.foo_param, 2)
assert_array_equal(grid_search.cv_results_["param_foo_param"].data,
[1, 2, 3])
# Smoke test the score etc:
grid_search.score(X, y)
grid_search.predict_proba(X)
grid_search.decision_function(X)
grid_search.transform(X)
# Test exception handling on scoring
grid_search.scoring = 'sklearn'
assert_raises(ValueError, grid_search.fit, X, y)
def check_hyperparameter_searcher_with_fit_params(klass, **klass_kwargs):
X = np.arange(100).reshape(10, 10)
y = np.array([0] * 5 + [1] * 5)
clf = CheckingClassifier(expected_fit_params=['spam', 'eggs'])
searcher = klass(clf, {'foo_param': [1, 2, 3]}, cv=2, **klass_kwargs)
# The CheckingClassifier generates an assertion error if
# a parameter is missing or has length != len(X).
assert_raise_message(AssertionError,
"Expected fit parameter(s) ['eggs'] not seen.",
searcher.fit, X, y, spam=np.ones(10))
assert_raise_message(AssertionError,
"Fit parameter spam has length 1; expected 4.",
searcher.fit, X, y, spam=np.ones(1),
eggs=np.zeros(10))
searcher.fit(X, y, spam=np.ones(10), eggs=np.zeros(10))
def test_grid_search_with_fit_params():
check_hyperparameter_searcher_with_fit_params(GridSearchCV)
def test_random_search_with_fit_params():
check_hyperparameter_searcher_with_fit_params(RandomizedSearchCV, n_iter=1)
def test_grid_search_fit_params_deprecation():
# NOTE: Remove this test in v0.21
# Use of `fit_params` in the class constructor is deprecated,
# but will still work until v0.21.
X = np.arange(100).reshape(10, 10)
y = np.array([0] * 5 + [1] * 5)
clf = CheckingClassifier(expected_fit_params=['spam'])
grid_search = GridSearchCV(clf, {'foo_param': [1, 2, 3]},
fit_params={'spam': np.ones(10)})
assert_warns(DeprecationWarning, grid_search.fit, X, y)
def test_grid_search_fit_params_two_places():
# NOTE: Remove this test in v0.21
# If users try to input fit parameters in both
# the constructor (deprecated use) and the `fit`
# method, we'll ignore the values passed to the constructor.
X = np.arange(100).reshape(10, 10)
y = np.array([0] * 5 + [1] * 5)
clf = CheckingClassifier(expected_fit_params=['spam'])
# The "spam" array is too short and will raise an
# error in the CheckingClassifier if used.
grid_search = GridSearchCV(clf, {'foo_param': [1, 2, 3]},
fit_params={'spam': np.ones(1)})
expected_warning = ('Ignoring fit_params passed as a constructor '
'argument in favor of keyword arguments to '
'the "fit" method.')
assert_warns_message(RuntimeWarning, expected_warning,
grid_search.fit, X, y, spam=np.ones(10))
# Verify that `fit` prefers its own kwargs by giving valid
# kwargs in the constructor and invalid in the method call
grid_search = GridSearchCV(clf, {'foo_param': [1, 2, 3]},
fit_params={'spam': np.ones(10)})
assert_raise_message(AssertionError, "Fit parameter spam has length 1",
grid_search.fit, X, y, spam=np.ones(1))
@ignore_warnings
def test_grid_search_no_score():
# Test grid-search on classifier that has no score function.
clf = LinearSVC(random_state=0)
X, y = make_blobs(random_state=0, centers=2)
Cs = [.1, 1, 10]
clf_no_score = LinearSVCNoScore(random_state=0)
grid_search = GridSearchCV(clf, {'C': Cs}, scoring='accuracy')
grid_search.fit(X, y)
grid_search_no_score = GridSearchCV(clf_no_score, {'C': Cs},
scoring='accuracy')
# smoketest grid search
grid_search_no_score.fit(X, y)
# check that best params are equal
assert_equal(grid_search_no_score.best_params_, grid_search.best_params_)
# check that we can call score and that it gives the correct result
assert_equal(grid_search.score(X, y), grid_search_no_score.score(X, y))
# giving no scoring function raises an error
grid_search_no_score = GridSearchCV(clf_no_score, {'C': Cs})
assert_raise_message(TypeError, "no scoring", grid_search_no_score.fit,
[[1]])
def test_grid_search_score_method():
X, y = make_classification(n_samples=100, n_classes=2, flip_y=.2,
random_state=0)
clf = LinearSVC(random_state=0)
grid = {'C': [.1]}
search_no_scoring = GridSearchCV(clf, grid, scoring=None).fit(X, y)
search_accuracy = GridSearchCV(clf, grid, scoring='accuracy').fit(X, y)
search_no_score_method_auc = GridSearchCV(LinearSVCNoScore(), grid,
scoring='roc_auc').fit(X, y)
search_auc = GridSearchCV(clf, grid, scoring='roc_auc').fit(X, y)
# Check warning only occurs in situation where behavior changed:
# estimator requires score method to compete with scoring parameter
score_no_scoring = search_no_scoring.score(X, y)
score_accuracy = search_accuracy.score(X, y)
score_no_score_auc = search_no_score_method_auc.score(X, y)
score_auc = search_auc.score(X, y)
# ensure the test is sane
assert_true(score_auc < 1.0)
assert_true(score_accuracy < 1.0)
assert_not_equal(score_auc, score_accuracy)
assert_almost_equal(score_accuracy, score_no_scoring)
assert_almost_equal(score_auc, score_no_score_auc)
def test_grid_search_groups():
# Check if ValueError (when groups is None) propagates to GridSearchCV
# And also check if groups is correctly passed to the cv object
rng = np.random.RandomState(0)
X, y = make_classification(n_samples=15, n_classes=2, random_state=0)
groups = rng.randint(0, 3, 15)
clf = LinearSVC(random_state=0)
grid = {'C': [1]}
group_cvs = [LeaveOneGroupOut(), LeavePGroupsOut(2), GroupKFold(),
GroupShuffleSplit()]
for cv in group_cvs:
gs = GridSearchCV(clf, grid, cv=cv)
assert_raise_message(ValueError,
"The 'groups' parameter should not be None.",
gs.fit, X, y)
gs.fit(X, y, groups=groups)
non_group_cvs = [StratifiedKFold(), StratifiedShuffleSplit()]
for cv in non_group_cvs:
gs = GridSearchCV(clf, grid, cv=cv)
# Should not raise an error
gs.fit(X, y)
def test_return_train_score_warn():
# Test that warnings are raised. Will be removed in 0.21
X = np.arange(100).reshape(10, 10)
y = np.array([0] * 5 + [1] * 5)
grid = {'C': [1, 2]}
estimators = [GridSearchCV(LinearSVC(random_state=0), grid),
RandomizedSearchCV(LinearSVC(random_state=0), grid,
n_iter=2)]
result = {}
for estimator in estimators:
for val in [True, False, 'warn']:
estimator.set_params(return_train_score=val)
result[val] = assert_no_warnings(estimator.fit, X, y).cv_results_
train_keys = ['split0_train_score', 'split1_train_score',
'split2_train_score', 'mean_train_score', 'std_train_score']
for key in train_keys:
msg = (
'You are accessing a training score ({!r}), '
'which will not be available by default '
'any more in 0.21. If you need training scores, '
'please set return_train_score=True').format(key)
train_score = assert_warns_message(FutureWarning, msg,
result['warn'].get, key)
assert np.allclose(train_score, result[True][key])
assert key not in result[False]
for key in result['warn']:
if key not in train_keys:
assert_no_warnings(result['warn'].get, key)
def test_classes__property():
# Test that classes_ property matches best_estimator_.classes_
X = np.arange(100).reshape(10, 10)
y = np.array([0] * 5 + [1] * 5)
Cs = [.1, 1, 10]
grid_search = GridSearchCV(LinearSVC(random_state=0), {'C': Cs})
grid_search.fit(X, y)
assert_array_equal(grid_search.best_estimator_.classes_,
grid_search.classes_)
# Test that regressors do not have a classes_ attribute
grid_search = GridSearchCV(Ridge(), {'alpha': [1.0, 2.0]})
grid_search.fit(X, y)
assert_false(hasattr(grid_search, 'classes_'))
# Test that the grid searcher has no classes_ attribute before it's fit
grid_search = GridSearchCV(LinearSVC(random_state=0), {'C': Cs})
assert_false(hasattr(grid_search, 'classes_'))
# Test that the grid searcher has no classes_ attribute without a refit
grid_search = GridSearchCV(LinearSVC(random_state=0),
{'C': Cs}, refit=False)
grid_search.fit(X, y)
assert_false(hasattr(grid_search, 'classes_'))
def test_trivial_cv_results_attr():
# Test search over a "grid" with only one point.
# Non-regression test: grid_scores_ wouldn't be set by GridSearchCV.
clf = MockClassifier()
grid_search = GridSearchCV(clf, {'foo_param': [1]})
grid_search.fit(X, y)
assert_true(hasattr(grid_search, "cv_results_"))
random_search = RandomizedSearchCV(clf, {'foo_param': [0]}, n_iter=1)
random_search.fit(X, y)
assert_true(hasattr(grid_search, "cv_results_"))
def test_no_refit():
# Test that GSCV can be used for model selection alone without refitting
clf = MockClassifier()
for scoring in [None, ['accuracy', 'precision']]:
grid_search = GridSearchCV(clf, {'foo_param': [1, 2, 3]}, refit=False)
grid_search.fit(X, y)
assert_true(not hasattr(grid_search, "best_estimator_") and
hasattr(grid_search, "best_index_") and
hasattr(grid_search, "best_params_"))
# Make sure the functions predict/transform etc raise meaningful
# error messages
for fn_name in ('predict', 'predict_proba', 'predict_log_proba',
'transform', 'inverse_transform'):
assert_raise_message(NotFittedError,
('refit=False. %s is available only after '
'refitting on the best parameters'
% fn_name), getattr(grid_search, fn_name), X)
# Test that an invalid refit param raises appropriate error messages
for refit in ["", 5, True, 'recall', 'accuracy']:
assert_raise_message(ValueError, "For multi-metric scoring, the "
"parameter refit must be set to a scorer key",
GridSearchCV(clf, {}, refit=refit,
scoring={'acc': 'accuracy',
'prec': 'precision'}).fit,
X, y)
def test_grid_search_error():
# Test that grid search will capture errors on data with different length
X_, y_ = make_classification(n_samples=200, n_features=100, random_state=0)
clf = LinearSVC()
cv = GridSearchCV(clf, {'C': [0.1, 1.0]})
assert_raises(ValueError, cv.fit, X_[:180], y_)
def test_grid_search_one_grid_point():
X_, y_ = make_classification(n_samples=200, n_features=100, random_state=0)
param_dict = {"C": [1.0], "kernel": ["rbf"], "gamma": [0.1]}
clf = SVC()
cv = GridSearchCV(clf, param_dict)
cv.fit(X_, y_)
clf = SVC(C=1.0, kernel="rbf", gamma=0.1)
clf.fit(X_, y_)
assert_array_equal(clf.dual_coef_, cv.best_estimator_.dual_coef_)
def test_grid_search_when_param_grid_includes_range():
# Test that the best estimator contains the right value for foo_param
clf = MockClassifier()
grid_search = None
if PY3_OR_LATER:
grid_search = GridSearchCV(clf, {'foo_param': range(1, 4)})
else:
grid_search = GridSearchCV(clf, {'foo_param': xrange(1, 4)})
grid_search.fit(X, y)
assert_equal(grid_search.best_estimator_.foo_param, 2)
def test_grid_search_bad_param_grid():
param_dict = {"C": 1.0}
clf = SVC()
assert_raise_message(
ValueError,
"Parameter values for parameter (C) need to be a sequence"
"(but not a string) or np.ndarray.",
GridSearchCV, clf, param_dict)
param_dict = {"C": []}
clf = SVC()
assert_raise_message(
ValueError,
"Parameter values for parameter (C) need to be a non-empty sequence.",
GridSearchCV, clf, param_dict)
param_dict = {"C": "1,2,3"}
clf = SVC()
assert_raise_message(
ValueError,
"Parameter values for parameter (C) need to be a sequence"
"(but not a string) or np.ndarray.",
GridSearchCV, clf, param_dict)
param_dict = {"C": np.ones(6).reshape(3, 2)}
clf = SVC()
assert_raises(ValueError, GridSearchCV, clf, param_dict)
def test_grid_search_sparse():
# Test that grid search works with both dense and sparse matrices
X_, y_ = make_classification(n_samples=200, n_features=100, random_state=0)
clf = LinearSVC()
cv = GridSearchCV(clf, {'C': [0.1, 1.0]})
cv.fit(X_[:180], y_[:180])
y_pred = cv.predict(X_[180:])
C = cv.best_estimator_.C
X_ = sp.csr_matrix(X_)
clf = LinearSVC()
cv = GridSearchCV(clf, {'C': [0.1, 1.0]})
cv.fit(X_[:180].tocoo(), y_[:180])
y_pred2 = cv.predict(X_[180:])
C2 = cv.best_estimator_.C
assert_true(np.mean(y_pred == y_pred2) >= .9)
assert_equal(C, C2)
def test_grid_search_sparse_scoring():
X_, y_ = make_classification(n_samples=200, n_features=100, random_state=0)
clf = LinearSVC()
cv = GridSearchCV(clf, {'C': [0.1, 1.0]}, scoring="f1")
cv.fit(X_[:180], y_[:180])
y_pred = cv.predict(X_[180:])
C = cv.best_estimator_.C
X_ = sp.csr_matrix(X_)
clf = LinearSVC()
cv = GridSearchCV(clf, {'C': [0.1, 1.0]}, scoring="f1")
cv.fit(X_[:180], y_[:180])
y_pred2 = cv.predict(X_[180:])
C2 = cv.best_estimator_.C
assert_array_equal(y_pred, y_pred2)
assert_equal(C, C2)
# Smoke test the score
# np.testing.assert_allclose(f1_score(cv.predict(X_[:180]), y[:180]),
# cv.score(X_[:180], y[:180]))
# test loss where greater is worse
def f1_loss(y_true_, y_pred_):
return -f1_score(y_true_, y_pred_)
F1Loss = make_scorer(f1_loss, greater_is_better=False)
cv = GridSearchCV(clf, {'C': [0.1, 1.0]}, scoring=F1Loss)
cv.fit(X_[:180], y_[:180])
y_pred3 = cv.predict(X_[180:])
C3 = cv.best_estimator_.C
assert_equal(C, C3)
assert_array_equal(y_pred, y_pred3)
def test_grid_search_precomputed_kernel():
# Test that grid search works when the input features are given in the
# form of a precomputed kernel matrix
X_, y_ = make_classification(n_samples=200, n_features=100, random_state=0)
# compute the training kernel matrix corresponding to the linear kernel
K_train = np.dot(X_[:180], X_[:180].T)
y_train = y_[:180]
clf = SVC(kernel='precomputed')
cv = GridSearchCV(clf, {'C': [0.1, 1.0]})
cv.fit(K_train, y_train)
assert_true(cv.best_score_ >= 0)
# compute the test kernel matrix
K_test = np.dot(X_[180:], X_[:180].T)
y_test = y_[180:]
y_pred = cv.predict(K_test)
assert_true(np.mean(y_pred == y_test) >= 0)
# test error is raised when the precomputed kernel is not array-like
# or sparse
assert_raises(ValueError, cv.fit, K_train.tolist(), y_train)
def test_grid_search_precomputed_kernel_error_nonsquare():
# Test that grid search returns an error with a non-square precomputed
# training kernel matrix
K_train = np.zeros((10, 20))
y_train = np.ones((10, ))
clf = SVC(kernel='precomputed')
cv = GridSearchCV(clf, {'C': [0.1, 1.0]})
assert_raises(ValueError, cv.fit, K_train, y_train)
class BrokenClassifier(BaseEstimator):
"""Broken classifier that cannot be fit twice"""
def __init__(self, parameter=None):
self.parameter = parameter
def fit(self, X, y):
assert_true(not hasattr(self, 'has_been_fit_'))
self.has_been_fit_ = True
def predict(self, X):
return np.zeros(X.shape[0])
@ignore_warnings
def test_refit():
# Regression test for bug in refitting
# Simulates re-fitting a broken estimator; this used to break with
# sparse SVMs.
X = np.arange(100).reshape(10, 10)
y = np.array([0] * 5 + [1] * 5)
clf = GridSearchCV(BrokenClassifier(), [{'parameter': [0, 1]}],
scoring="precision", refit=True)
clf.fit(X, y)
def test_gridsearch_nd():
# Pass X as list in GridSearchCV
X_4d = np.arange(10 * 5 * 3 * 2).reshape(10, 5, 3, 2)
y_3d = np.arange(10 * 7 * 11).reshape(10, 7, 11)
check_X = lambda x: x.shape[1:] == (5, 3, 2)
check_y = lambda x: x.shape[1:] == (7, 11)
clf = CheckingClassifier(check_X=check_X, check_y=check_y)
grid_search = GridSearchCV(clf, {'foo_param': [1, 2, 3]})
grid_search.fit(X_4d, y_3d).score(X, y)
assert_true(hasattr(grid_search, "cv_results_"))
def test_X_as_list():
# Pass X as list in GridSearchCV
X = np.arange(100).reshape(10, 10)
y = np.array([0] * 5 + [1] * 5)
clf = CheckingClassifier(check_X=lambda x: isinstance(x, list))
cv = KFold(n_splits=3)
grid_search = GridSearchCV(clf, {'foo_param': [1, 2, 3]}, cv=cv)
grid_search.fit(X.tolist(), y).score(X, y)
assert_true(hasattr(grid_search, "cv_results_"))
def test_y_as_list():
# Pass y as list in GridSearchCV
X = np.arange(100).reshape(10, 10)
y = np.array([0] * 5 + [1] * 5)
clf = CheckingClassifier(check_y=lambda x: isinstance(x, list))
cv = KFold(n_splits=3)
grid_search = GridSearchCV(clf, {'foo_param': [1, 2, 3]}, cv=cv)
grid_search.fit(X, y.tolist()).score(X, y)
assert_true(hasattr(grid_search, "cv_results_"))
@ignore_warnings
def test_pandas_input():
# check cross_val_score doesn't destroy pandas dataframe
types = [(MockDataFrame, MockDataFrame)]
try:
from pandas import Series, DataFrame
types.append((DataFrame, Series))
except ImportError:
pass
X = np.arange(100).reshape(10, 10)
y = np.array([0] * 5 + [1] * 5)
for InputFeatureType, TargetType in types:
# X dataframe, y series
X_df, y_ser = InputFeatureType(X), TargetType(y)
def check_df(x):
return isinstance(x, InputFeatureType)
def check_series(x):
return isinstance(x, TargetType)
clf = CheckingClassifier(check_X=check_df, check_y=check_series)
grid_search = GridSearchCV(clf, {'foo_param': [1, 2, 3]})
grid_search.fit(X_df, y_ser).score(X_df, y_ser)
grid_search.predict(X_df)
assert_true(hasattr(grid_search, "cv_results_"))
def test_unsupervised_grid_search():
# test grid-search with unsupervised estimator
X, y = make_blobs(random_state=0)
km = KMeans(random_state=0)
# Multi-metric evaluation unsupervised
scoring = ['adjusted_rand_score', 'fowlkes_mallows_score']
for refit in ['adjusted_rand_score', 'fowlkes_mallows_score']:
grid_search = GridSearchCV(km, param_grid=dict(n_clusters=[2, 3, 4]),
scoring=scoring, refit=refit)
grid_search.fit(X, y)
# Both ARI and FMS can find the right number :)
assert_equal(grid_search.best_params_["n_clusters"], 3)
# Single metric evaluation unsupervised
grid_search = GridSearchCV(km, param_grid=dict(n_clusters=[2, 3, 4]),
scoring='fowlkes_mallows_score')
grid_search.fit(X, y)
assert_equal(grid_search.best_params_["n_clusters"], 3)
# Now without a score, and without y
grid_search = GridSearchCV(km, param_grid=dict(n_clusters=[2, 3, 4]))
grid_search.fit(X)
assert_equal(grid_search.best_params_["n_clusters"], 4)
def test_gridsearch_no_predict():
# test grid-search with an estimator without predict.
# slight duplication of a test from KDE
def custom_scoring(estimator, X):
return 42 if estimator.bandwidth == .1 else 0
X, _ = make_blobs(cluster_std=.1, random_state=1,
centers=[[0, 1], [1, 0], [0, 0]])
search = GridSearchCV(KernelDensity(),
param_grid=dict(bandwidth=[.01, .1, 1]),
scoring=custom_scoring)
search.fit(X)
assert_equal(search.best_params_['bandwidth'], .1)
assert_equal(search.best_score_, 42)
def test_param_sampler():
# test basic properties of param sampler
param_distributions = {"kernel": ["rbf", "linear"],
"C": uniform(0, 1)}
sampler = ParameterSampler(param_distributions=param_distributions,
n_iter=10, random_state=0)
samples = [x for x in sampler]
assert_equal(len(samples), 10)
for sample in samples:
assert_true(sample["kernel"] in ["rbf", "linear"])
assert_true(0 <= sample["C"] <= 1)
# test that repeated calls yield identical parameters
param_distributions = {"C": [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]}
sampler = ParameterSampler(param_distributions=param_distributions,
n_iter=3, random_state=0)
assert_equal([x for x in sampler], [x for x in sampler])
if sp_version >= (0, 16):
param_distributions = {"C": uniform(0, 1)}
sampler = ParameterSampler(param_distributions=param_distributions,
n_iter=10, random_state=0)
assert_equal([x for x in sampler], [x for x in sampler])
def check_cv_results_array_types(search, param_keys, score_keys):
# Check if the search `cv_results`'s array are of correct types
cv_results = search.cv_results_
assert_true(all(isinstance(cv_results[param], np.ma.MaskedArray)
for param in param_keys))
assert_true(all(cv_results[key].dtype == object for key in param_keys))
assert_false(any(isinstance(cv_results[key], np.ma.MaskedArray)
for key in score_keys))
assert_true(all(cv_results[key].dtype == np.float64
for key in score_keys if not key.startswith('rank')))
scorer_keys = search.scorer_.keys() if search.multimetric_ else ['score']
for key in scorer_keys:
assert_true(cv_results['rank_test_%s' % key].dtype == np.int32)
def check_cv_results_keys(cv_results, param_keys, score_keys, n_cand):
# Test the search.cv_results_ contains all the required results
assert_array_equal(sorted(cv_results.keys()),
sorted(param_keys + score_keys + ('params',)))
assert_true(all(cv_results[key].shape == (n_cand,)
for key in param_keys + score_keys))
def check_cv_results_grid_scores_consistency(search):
# TODO Remove test in 0.20
if search.multimetric_:
assert_raise_message(AttributeError, "not available for multi-metric",
getattr, search, 'grid_scores_')
else:
cv_results = search.cv_results_
res_scores = np.vstack(list([cv_results["split%d_test_score" % i]
for i in range(search.n_splits_)])).T
res_means = cv_results["mean_test_score"]
res_params = cv_results["params"]
n_cand = len(res_params)
grid_scores = assert_warns(DeprecationWarning, getattr,
search, 'grid_scores_')
assert_equal(len(grid_scores), n_cand)
# Check consistency of the structure of grid_scores
for i in range(n_cand):
assert_equal(grid_scores[i].parameters, res_params[i])
assert_array_equal(grid_scores[i].cv_validation_scores,
res_scores[i, :])
assert_array_equal(grid_scores[i].mean_validation_score,
res_means[i])
def test_grid_search_cv_results():
X, y = make_classification(n_samples=50, n_features=4,
random_state=42)
n_splits = 3
n_grid_points = 6
params = [dict(kernel=['rbf', ], C=[1, 10], gamma=[0.1, 1]),
dict(kernel=['poly', ], degree=[1, 2])]
param_keys = ('param_C', 'param_degree', 'param_gamma', 'param_kernel')
score_keys = ('mean_test_score', 'mean_train_score',
'rank_test_score',
'split0_test_score', 'split1_test_score',
'split2_test_score',
'split0_train_score', 'split1_train_score',
'split2_train_score',
'std_test_score', 'std_train_score',
'mean_fit_time', 'std_fit_time',
'mean_score_time', 'std_score_time')
n_candidates = n_grid_points
for iid in (False, True):
search = GridSearchCV(SVC(), cv=n_splits, iid=iid, param_grid=params)
search.fit(X, y)
assert_equal(iid, search.iid)
cv_results = search.cv_results_
# Check if score and timing are reasonable
assert_true(all(cv_results['rank_test_score'] >= 1))
assert_true(all(cv_results[k] >= 0) for k in score_keys
if k is not 'rank_test_score')
assert_true(all(cv_results[k] <= 1) for k in score_keys
if 'time' not in k and
k is not 'rank_test_score')
# Check cv_results structure
check_cv_results_array_types(search, param_keys, score_keys)
check_cv_results_keys(cv_results, param_keys, score_keys, n_candidates)
# Check masking
cv_results = search.cv_results_
n_candidates = len(search.cv_results_['params'])
assert_true(all((cv_results['param_C'].mask[i] and
cv_results['param_gamma'].mask[i] and
not cv_results['param_degree'].mask[i])
for i in range(n_candidates)
if cv_results['param_kernel'][i] == 'linear'))
assert_true(all((not cv_results['param_C'].mask[i] and
not cv_results['param_gamma'].mask[i] and
cv_results['param_degree'].mask[i])
for i in range(n_candidates)
if cv_results['param_kernel'][i] == 'rbf'))
check_cv_results_grid_scores_consistency(search)
def test_random_search_cv_results():
X, y = make_classification(n_samples=50, n_features=4, random_state=42)
n_splits = 3
n_search_iter = 30
params = dict(C=expon(scale=10), gamma=expon(scale=0.1))
param_keys = ('param_C', 'param_gamma')
score_keys = ('mean_test_score', 'mean_train_score',
'rank_test_score',
'split0_test_score', 'split1_test_score',
'split2_test_score',
'split0_train_score', 'split1_train_score',
'split2_train_score',
'std_test_score', 'std_train_score',
'mean_fit_time', 'std_fit_time',
'mean_score_time', 'std_score_time')
n_cand = n_search_iter
for iid in (False, True):
search = RandomizedSearchCV(SVC(), n_iter=n_search_iter, cv=n_splits,
iid=iid, param_distributions=params)
search.fit(X, y)
assert_equal(iid, search.iid)
cv_results = search.cv_results_
# Check results structure
check_cv_results_array_types(search, param_keys, score_keys)
check_cv_results_keys(cv_results, param_keys, score_keys, n_cand)
# For random_search, all the param array vals should be unmasked
assert_false(any(cv_results['param_C'].mask) or
any(cv_results['param_gamma'].mask))
check_cv_results_grid_scores_consistency(search)
def test_search_iid_param():
# Test the IID parameter
# noise-free simple 2d-data
X, y = make_blobs(centers=[[0, 0], [1, 0], [0, 1], [1, 1]], random_state=0,
cluster_std=0.1, shuffle=False, n_samples=80)
# split dataset into two folds that are not iid
# first one contains data of all 4 blobs, second only from two.
mask = np.ones(X.shape[0], dtype=np.bool)
mask[np.where(y == 1)[0][::2]] = 0
mask[np.where(y == 2)[0][::2]] = 0
# this leads to perfect classification on one fold and a score of 1/3 on
# the other
# create "cv" for splits
cv = [[mask, ~mask], [~mask, mask]]
# once with iid=True (default)
grid_search = GridSearchCV(SVC(), param_grid={'C': [1, 10]}, cv=cv)
random_search = RandomizedSearchCV(SVC(), n_iter=2,
param_distributions={'C': [1, 10]},
cv=cv)
for search in (grid_search, random_search):
search.fit(X, y)
assert_true(search.iid)
test_cv_scores = np.array(list(search.cv_results_['split%d_test_score'
% s_i][0]
for s_i in range(search.n_splits_)))
train_cv_scores = np.array(list(search.cv_results_['split%d_train_'
'score' % s_i][0]
for s_i in range(search.n_splits_)))
test_mean = search.cv_results_['mean_test_score'][0]
test_std = search.cv_results_['std_test_score'][0]
train_cv_scores = np.array(list(search.cv_results_['split%d_train_'
'score' % s_i][0]
for s_i in range(search.n_splits_)))
train_mean = search.cv_results_['mean_train_score'][0]
train_std = search.cv_results_['std_train_score'][0]
# Test the first candidate
assert_equal(search.cv_results_['param_C'][0], 1)
assert_array_almost_equal(test_cv_scores, [1, 1. / 3.])
assert_array_almost_equal(train_cv_scores, [1, 1])
# for first split, 1/4 of dataset is in test, for second 3/4.
# take weighted average and weighted std
expected_test_mean = 1 * 1. / 4. + 1. / 3. * 3. / 4.
expected_test_std = np.sqrt(1. / 4 * (expected_test_mean - 1) ** 2 +
3. / 4 * (expected_test_mean - 1. / 3.) **
2)
assert_almost_equal(test_mean, expected_test_mean)
assert_almost_equal(test_std, expected_test_std)
# For the train scores, we do not take a weighted mean irrespective of
# i.i.d. or not
assert_almost_equal(train_mean, 1)
assert_almost_equal(train_std, 0)
# once with iid=False
grid_search = GridSearchCV(SVC(),
param_grid={'C': [1, 10]},
cv=cv, iid=False)
random_search = RandomizedSearchCV(SVC(), n_iter=2,
param_distributions={'C': [1, 10]},
cv=cv, iid=False)
for search in (grid_search, random_search):
search.fit(X, y)
assert_false(search.iid)
test_cv_scores = np.array(list(search.cv_results_['split%d_test_score'
% s][0]
for s in range(search.n_splits_)))
test_mean = search.cv_results_['mean_test_score'][0]
test_std = search.cv_results_['std_test_score'][0]
train_cv_scores = np.array(list(search.cv_results_['split%d_train_'
'score' % s][0]
for s in range(search.n_splits_)))
train_mean = search.cv_results_['mean_train_score'][0]
train_std = search.cv_results_['std_train_score'][0]
assert_equal(search.cv_results_['param_C'][0], 1)
# scores are the same as above
assert_array_almost_equal(test_cv_scores, [1, 1. / 3.])
# Unweighted mean/std is used
assert_almost_equal(test_mean, np.mean(test_cv_scores))
assert_almost_equal(test_std, np.std(test_cv_scores))
# For the train scores, we do not take a weighted mean irrespective of
# i.i.d. or not
assert_almost_equal(train_mean, 1)
assert_almost_equal(train_std, 0)
def test_grid_search_cv_results_multimetric():
X, y = make_classification(n_samples=50, n_features=4, random_state=42)
n_splits = 3
params = [dict(kernel=['rbf', ], C=[1, 10], gamma=[0.1, 1]),
dict(kernel=['poly', ], degree=[1, 2])]
for iid in (False, True):
grid_searches = []
for scoring in ({'accuracy': make_scorer(accuracy_score),
'recall': make_scorer(recall_score)},
'accuracy', 'recall'):
grid_search = GridSearchCV(SVC(), cv=n_splits, iid=iid,
param_grid=params, scoring=scoring,
refit=False)
grid_search.fit(X, y)
assert_equal(grid_search.iid, iid)
grid_searches.append(grid_search)
compare_cv_results_multimetric_with_single(*grid_searches, iid=iid)
def test_random_search_cv_results_multimetric():
X, y = make_classification(n_samples=50, n_features=4, random_state=42)
n_splits = 3
n_search_iter = 30
scoring = ('accuracy', 'recall')
# Scipy 0.12's stats dists do not accept seed, hence we use param grid
params = dict(C=np.logspace(-10, 1), gamma=np.logspace(-5, 0, base=0.1))
for iid in (True, False):
for refit in (True, False):
random_searches = []
for scoring in (('accuracy', 'recall'), 'accuracy', 'recall'):
# If True, for multi-metric pass refit='accuracy'
if refit:
refit = 'accuracy' if isinstance(scoring, tuple) else refit
clf = SVC(probability=True, random_state=42)
random_search = RandomizedSearchCV(clf, n_iter=n_search_iter,
cv=n_splits, iid=iid,
param_distributions=params,
scoring=scoring,
refit=refit, random_state=0)
random_search.fit(X, y)
random_searches.append(random_search)
compare_cv_results_multimetric_with_single(*random_searches,
iid=iid)
if refit:
compare_refit_methods_when_refit_with_acc(
random_searches[0], random_searches[1], refit)
def compare_cv_results_multimetric_with_single(
search_multi, search_acc, search_rec, iid):
"""Compare multi-metric cv_results with the ensemble of multiple
single metric cv_results from single metric grid/random search"""
assert_equal(search_multi.iid, iid)
assert_true(search_multi.multimetric_)
assert_array_equal(sorted(search_multi.scorer_),
('accuracy', 'recall'))
cv_results_multi = search_multi.cv_results_
cv_results_acc_rec = {re.sub('_score$', '_accuracy', k): v
for k, v in search_acc.cv_results_.items()}
cv_results_acc_rec.update({re.sub('_score$', '_recall', k): v
for k, v in search_rec.cv_results_.items()})
# Check if score and timing are reasonable, also checks if the keys
# are present
assert_true(all((np.all(cv_results_multi[k] <= 1) for k in (
'mean_score_time', 'std_score_time', 'mean_fit_time',
'std_fit_time'))))
# Compare the keys, other than time keys, among multi-metric and
# single metric grid search results. np.testing.assert_equal performs a
# deep nested comparison of the two cv_results dicts
np.testing.assert_equal({k: v for k, v in cv_results_multi.items()
if not k.endswith('_time')},
{k: v for k, v in cv_results_acc_rec.items()
if not k.endswith('_time')})
def compare_refit_methods_when_refit_with_acc(search_multi, search_acc, refit):
"""Compare refit multi-metric search methods with single metric methods"""
if refit:
assert_equal(search_multi.refit, 'accuracy')
else:
assert_false(search_multi.refit)
assert_equal(search_acc.refit, refit)
X, y = make_blobs(n_samples=100, n_features=4, random_state=42)
for method in ('predict', 'predict_proba', 'predict_log_proba'):
assert_almost_equal(getattr(search_multi, method)(X),
getattr(search_acc, method)(X))
assert_almost_equal(search_multi.score(X, y), search_acc.score(X, y))
for key in ('best_index_', 'best_score_', 'best_params_'):
assert_equal(getattr(search_multi, key), getattr(search_acc, key))
def test_search_cv_results_rank_tie_breaking():
X, y = make_blobs(n_samples=50, random_state=42)
# The two C values are close enough to give similar models
# which would result in a tie of their mean cv-scores
param_grid = {'C': [1, 1.001, 0.001]}
grid_search = GridSearchCV(SVC(), param_grid=param_grid)
random_search = RandomizedSearchCV(SVC(), n_iter=3,
param_distributions=param_grid)
for search in (grid_search, random_search):
search.fit(X, y)
cv_results = search.cv_results_
# Check tie breaking strategy -
# Check that there is a tie in the mean scores between
# candidates 1 and 2 alone
assert_almost_equal(cv_results['mean_test_score'][0],
cv_results['mean_test_score'][1])
assert_almost_equal(cv_results['mean_train_score'][0],
cv_results['mean_train_score'][1])
assert_false(np.allclose(cv_results['mean_test_score'][1],
cv_results['mean_test_score'][2]))
assert_false(np.allclose(cv_results['mean_train_score'][1],
cv_results['mean_train_score'][2]))
# 'min' rank should be assigned to the tied candidates
assert_almost_equal(search.cv_results_['rank_test_score'], [1, 1, 3])
def test_search_cv_results_none_param():
X, y = [[1], [2], [3], [4], [5]], [0, 0, 0, 0, 1]
estimators = (DecisionTreeRegressor(), DecisionTreeClassifier())
est_parameters = {"random_state": [0, None]}
cv = KFold(random_state=0)
for est in estimators:
grid_search = GridSearchCV(est, est_parameters, cv=cv).fit(X, y)
assert_array_equal(grid_search.cv_results_['param_random_state'],
[0, None])
@ignore_warnings()
def test_search_cv_timing():
svc = LinearSVC(random_state=0)
X = [[1, ], [2, ], [3, ], [4, ]]
y = [0, 1, 1, 0]
gs = GridSearchCV(svc, {'C': [0, 1]}, cv=2, error_score=0)
rs = RandomizedSearchCV(svc, {'C': [0, 1]}, cv=2, error_score=0, n_iter=2)
for search in (gs, rs):
search.fit(X, y)
for key in ['mean_fit_time', 'std_fit_time']:
# NOTE The precision of time.time in windows is not high
# enough for the fit/score times to be non-zero for trivial X and y
assert_true(np.all(search.cv_results_[key] >= 0))
assert_true(np.all(search.cv_results_[key] < 1))
for key in ['mean_score_time', 'std_score_time']:
assert_true(search.cv_results_[key][1] >= 0)
assert_true(search.cv_results_[key][0] == 0.0)
assert_true(np.all(search.cv_results_[key] < 1))
def test_grid_search_correct_score_results():
# test that correct scores are used
n_splits = 3
clf = LinearSVC(random_state=0)
X, y = make_blobs(random_state=0, centers=2)
Cs = [.1, 1, 10]
for score in ['f1', 'roc_auc']:
grid_search = GridSearchCV(clf, {'C': Cs}, scoring=score, cv=n_splits)
cv_results = grid_search.fit(X, y).cv_results_
# Test scorer names
result_keys = list(cv_results.keys())
expected_keys = (("mean_test_score", "rank_test_score") +
tuple("split%d_test_score" % cv_i
for cv_i in range(n_splits)))
assert_true(all(np.in1d(expected_keys, result_keys)))
cv = StratifiedKFold(n_splits=n_splits)
n_splits = grid_search.n_splits_
for candidate_i, C in enumerate(Cs):
clf.set_params(C=C)
cv_scores = np.array(
list(grid_search.cv_results_['split%d_test_score'
% s][candidate_i]
for s in range(n_splits)))
for i, (train, test) in enumerate(cv.split(X, y)):
clf.fit(X[train], y[train])
if score == "f1":
correct_score = f1_score(y[test], clf.predict(X[test]))
elif score == "roc_auc":
dec = clf.decision_function(X[test])
correct_score = roc_auc_score(y[test], dec)
assert_almost_equal(correct_score, cv_scores[i])
def test_fit_grid_point():
X, y = make_classification(random_state=0)
cv = StratifiedKFold(random_state=0)
svc = LinearSVC(random_state=0)
scorer = make_scorer(accuracy_score)
for params in ({'C': 0.1}, {'C': 0.01}, {'C': 0.001}):
for train, test in cv.split(X, y):
this_scores, this_params, n_test_samples = fit_grid_point(
X, y, clone(svc), params, train, test,
scorer, verbose=False)
est = clone(svc).set_params(**params)
est.fit(X[train], y[train])
expected_score = scorer(est, X[test], y[test])
# Test the return values of fit_grid_point
assert_almost_equal(this_scores, expected_score)
assert_equal(params, this_params)
assert_equal(n_test_samples, test.size)
# Should raise an error upon multimetric scorer
assert_raise_message(ValueError, "scoring value should either be a "
"callable, string or None.", fit_grid_point, X, y,
svc, params, train, test, {'score': scorer},
verbose=True)
def test_pickle():
# Test that a fit search can be pickled
clf = MockClassifier()
grid_search = GridSearchCV(clf, {'foo_param': [1, 2, 3]}, refit=True)
grid_search.fit(X, y)
grid_search_pickled = pickle.loads(pickle.dumps(grid_search))
assert_array_almost_equal(grid_search.predict(X),
grid_search_pickled.predict(X))
random_search = RandomizedSearchCV(clf, {'foo_param': [1, 2, 3]},
refit=True, n_iter=3)
random_search.fit(X, y)
random_search_pickled = pickle.loads(pickle.dumps(random_search))
assert_array_almost_equal(random_search.predict(X),
random_search_pickled.predict(X))
def test_grid_search_with_multioutput_data():
# Test search with multi-output estimator
X, y = make_multilabel_classification(return_indicator=True,
random_state=0)
est_parameters = {"max_depth": [1, 2, 3, 4]}
cv = KFold(random_state=0)
estimators = [DecisionTreeRegressor(random_state=0),
DecisionTreeClassifier(random_state=0)]
# Test with grid search cv
for est in estimators:
grid_search = GridSearchCV(est, est_parameters, cv=cv)
grid_search.fit(X, y)
res_params = grid_search.cv_results_['params']
for cand_i in range(len(res_params)):
est.set_params(**res_params[cand_i])
for i, (train, test) in enumerate(cv.split(X, y)):
est.fit(X[train], y[train])
correct_score = est.score(X[test], y[test])
assert_almost_equal(
correct_score,
grid_search.cv_results_['split%d_test_score' % i][cand_i])
# Test with a randomized search
for est in estimators:
random_search = RandomizedSearchCV(est, est_parameters,
cv=cv, n_iter=3)
random_search.fit(X, y)
res_params = random_search.cv_results_['params']
for cand_i in range(len(res_params)):
est.set_params(**res_params[cand_i])
for i, (train, test) in enumerate(cv.split(X, y)):
est.fit(X[train], y[train])
correct_score = est.score(X[test], y[test])
assert_almost_equal(
correct_score,
random_search.cv_results_['split%d_test_score'
% i][cand_i])
def test_predict_proba_disabled():
# Test predict_proba when disabled on estimator.
X = np.arange(20).reshape(5, -1)
y = [0, 0, 1, 1, 1]
clf = SVC(probability=False)
gs = GridSearchCV(clf, {}, cv=2).fit(X, y)
assert_false(hasattr(gs, "predict_proba"))
def test_grid_search_allows_nans():
# Test GridSearchCV with Imputer
X = np.arange(20, dtype=np.float64).reshape(5, -1)
X[2, :] = np.nan
y = [0, 0, 1, 1, 1]
p = Pipeline([
('imputer', Imputer(strategy='mean', missing_values='NaN')),
('classifier', MockClassifier()),
])
GridSearchCV(p, {'classifier__foo_param': [1, 2, 3]}, cv=2).fit(X, y)
class FailingClassifier(BaseEstimator):
"""Classifier that raises a ValueError on fit()"""
FAILING_PARAMETER = 2
def __init__(self, parameter=None):
self.parameter = parameter
def fit(self, X, y=None):
if self.parameter == FailingClassifier.FAILING_PARAMETER:
raise ValueError("Failing classifier failed as required")
def predict(self, X):
return np.zeros(X.shape[0])
def test_grid_search_failing_classifier():
# GridSearchCV with on_error != 'raise'
# Ensures that a warning is raised and score reset where appropriate.
X, y = make_classification(n_samples=20, n_features=10, random_state=0)
clf = FailingClassifier()
# refit=False because we only want to check that errors caused by fits
# to individual folds will be caught and warnings raised instead. If
# refit was done, then an exception would be raised on refit and not
# caught by grid_search (expected behavior), and this would cause an
# error in this test.
gs = GridSearchCV(clf, [{'parameter': [0, 1, 2]}], scoring='accuracy',
refit=False, error_score=0.0)
assert_warns(FitFailedWarning, gs.fit, X, y)
n_candidates = len(gs.cv_results_['params'])
# Ensure that grid scores were set to zero as required for those fits
# that are expected to fail.
def get_cand_scores(i):
return np.array(list(gs.cv_results_['split%d_test_score' % s][i]
for s in range(gs.n_splits_)))
assert all((np.all(get_cand_scores(cand_i) == 0.0)
for cand_i in range(n_candidates)
if gs.cv_results_['param_parameter'][cand_i] ==
FailingClassifier.FAILING_PARAMETER))
gs = GridSearchCV(clf, [{'parameter': [0, 1, 2]}], scoring='accuracy',
refit=False, error_score=float('nan'))
assert_warns(FitFailedWarning, gs.fit, X, y)
n_candidates = len(gs.cv_results_['params'])
assert all(np.all(np.isnan(get_cand_scores(cand_i)))
for cand_i in range(n_candidates)
if gs.cv_results_['param_parameter'][cand_i] ==
FailingClassifier.FAILING_PARAMETER)
def test_grid_search_failing_classifier_raise():
# GridSearchCV with on_error == 'raise' raises the error
X, y = make_classification(n_samples=20, n_features=10, random_state=0)
clf = FailingClassifier()
# refit=False because we want to test the behaviour of the grid search part
gs = GridSearchCV(clf, [{'parameter': [0, 1, 2]}], scoring='accuracy',
refit=False, error_score='raise')
# FailingClassifier issues a ValueError so this is what we look for.
assert_raises(ValueError, gs.fit, X, y)
def test_parameters_sampler_replacement():
# raise error if n_iter too large
params = {'first': [0, 1], 'second': ['a', 'b', 'c']}
sampler = ParameterSampler(params, n_iter=7)
assert_raises(ValueError, list, sampler)
# degenerates to GridSearchCV if n_iter the same as grid_size
sampler = ParameterSampler(params, n_iter=6)
samples = list(sampler)
assert_equal(len(samples), 6)
for values in ParameterGrid(params):
assert_true(values in samples)
# test sampling without replacement in a large grid
params = {'a': range(10), 'b': range(10), 'c': range(10)}
sampler = ParameterSampler(params, n_iter=99, random_state=42)
samples = list(sampler)
assert_equal(len(samples), 99)
hashable_samples = ["a%db%dc%d" % (p['a'], p['b'], p['c'])
for p in samples]
assert_equal(len(set(hashable_samples)), 99)
# doesn't go into infinite loops
params_distribution = {'first': bernoulli(.5), 'second': ['a', 'b', 'c']}
sampler = ParameterSampler(params_distribution, n_iter=7)
samples = list(sampler)
assert_equal(len(samples), 7)
def test_stochastic_gradient_loss_param():
# Make sure the predict_proba works when loss is specified
# as one of the parameters in the param_grid.
param_grid = {
'loss': ['log'],
}
X = np.arange(24).reshape(6, -1)
y = [0, 0, 0, 1, 1, 1]
clf = GridSearchCV(estimator=SGDClassifier(tol=1e-3, loss='hinge'),
param_grid=param_grid)
# When the estimator is not fitted, `predict_proba` is not available as the
# loss is 'hinge'.
assert_false(hasattr(clf, "predict_proba"))
clf.fit(X, y)
clf.predict_proba(X)
clf.predict_log_proba(X)
# Make sure `predict_proba` is not available when setting loss=['hinge']
# in param_grid
param_grid = {
'loss': ['hinge'],
}
clf = GridSearchCV(estimator=SGDClassifier(tol=1e-3, loss='hinge'),
param_grid=param_grid)
assert_false(hasattr(clf, "predict_proba"))
clf.fit(X, y)
assert_false(hasattr(clf, "predict_proba"))
def test_search_train_scores_set_to_false():
X = np.arange(6).reshape(6, -1)
y = [0, 0, 0, 1, 1, 1]
clf = LinearSVC(random_state=0)
gs = GridSearchCV(clf, param_grid={'C': [0.1, 0.2]},
return_train_score=False)
gs.fit(X, y)
def test_grid_search_cv_splits_consistency():
# Check if a one time iterable is accepted as a cv parameter.
n_samples = 100
n_splits = 5
X, y = make_classification(n_samples=n_samples, random_state=0)
gs = GridSearchCV(LinearSVC(random_state=0),
param_grid={'C': [0.1, 0.2, 0.3]},
cv=OneTimeSplitter(n_splits=n_splits,
n_samples=n_samples))
gs.fit(X, y)
gs2 = GridSearchCV(LinearSVC(random_state=0),
param_grid={'C': [0.1, 0.2, 0.3]},
cv=KFold(n_splits=n_splits))
gs2.fit(X, y)
# Give generator as a cv parameter
assert_true(isinstance(KFold(n_splits=n_splits,
shuffle=True, random_state=0).split(X, y),
GeneratorType))
gs3 = GridSearchCV(LinearSVC(random_state=0),
param_grid={'C': [0.1, 0.2, 0.3]},
cv=KFold(n_splits=n_splits, shuffle=True,
random_state=0).split(X, y))
gs3.fit(X, y)
gs4 = GridSearchCV(LinearSVC(random_state=0),
param_grid={'C': [0.1, 0.2, 0.3]},
cv=KFold(n_splits=n_splits, shuffle=True,
random_state=0))
gs4.fit(X, y)
def _pop_time_keys(cv_results):
for key in ('mean_fit_time', 'std_fit_time',
'mean_score_time', 'std_score_time'):
cv_results.pop(key)
return cv_results
# Check if generators are supported as cv and
# that the splits are consistent
np.testing.assert_equal(_pop_time_keys(gs3.cv_results_),
_pop_time_keys(gs4.cv_results_))
# OneTimeSplitter is a non-re-entrant cv where split can be called only
# once if ``cv.split`` is called once per param setting in GridSearchCV.fit
# the 2nd and 3rd parameter will not be evaluated as no train/test indices
# will be generated for the 2nd and subsequent cv.split calls.
# This is a check to make sure cv.split is not called once per param
# setting.
np.testing.assert_equal({k: v for k, v in gs.cv_results_.items()
if not k.endswith('_time')},
{k: v for k, v in gs2.cv_results_.items()
if not k.endswith('_time')})
# Check consistency of folds across the parameters
gs = GridSearchCV(LinearSVC(random_state=0),
param_grid={'C': [0.1, 0.1, 0.2, 0.2]},
cv=KFold(n_splits=n_splits, shuffle=True))
gs.fit(X, y)
# As the first two param settings (C=0.1) and the next two param
# settings (C=0.2) are same, the test and train scores must also be
# same as long as the same train/test indices are generated for all
# the cv splits, for both param setting
for score_type in ('train', 'test'):
per_param_scores = {}
for param_i in range(4):
per_param_scores[param_i] = list(
gs.cv_results_['split%d_%s_score' % (s, score_type)][param_i]
for s in range(5))
assert_array_almost_equal(per_param_scores[0],
per_param_scores[1])
assert_array_almost_equal(per_param_scores[2],
per_param_scores[3])
def test_transform_inverse_transform_round_trip():
clf = MockClassifier()
grid_search = GridSearchCV(clf, {'foo_param': [1, 2, 3]}, verbose=3)
grid_search.fit(X, y)
X_round_trip = grid_search.inverse_transform(grid_search.transform(X))
assert_array_equal(X, X_round_trip)
| 60,512 | 38.732764 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/model_selection/tests/common.py | """
Common utilities for testing model selection.
"""
import numpy as np
from sklearn.model_selection import KFold
class OneTimeSplitter:
"""A wrapper to make KFold single entry cv iterator"""
def __init__(self, n_splits=4, n_samples=99):
self.n_splits = n_splits
self.n_samples = n_samples
self.indices = iter(KFold(n_splits=n_splits).split(np.ones(n_samples)))
def split(self, X=None, y=None, groups=None):
"""Split can be called only once"""
for index in self.indices:
yield index
def get_n_splits(self, X=None, y=None, groups=None):
return self.n_splits
| 640 | 25.708333 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/model_selection/tests/__init__.py | 0 | 0 | 0 | py |
|
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/model_selection/tests/test_validation.py | """Test the validation module"""
from __future__ import division
import sys
import warnings
import tempfile
import os
from time import sleep
import numpy as np
from scipy.sparse import coo_matrix, csr_matrix
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import assert_false
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_raise_message
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import assert_warns_message
from sklearn.utils.testing import assert_no_warnings
from sklearn.utils.testing import assert_raises_regex
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_less
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.mocking import CheckingClassifier, MockDataFrame
from sklearn.model_selection import cross_val_score
from sklearn.model_selection import cross_val_predict
from sklearn.model_selection import cross_validate
from sklearn.model_selection import permutation_test_score
from sklearn.model_selection import KFold
from sklearn.model_selection import StratifiedKFold
from sklearn.model_selection import LeaveOneOut
from sklearn.model_selection import LeaveOneGroupOut
from sklearn.model_selection import LeavePGroupsOut
from sklearn.model_selection import GroupKFold
from sklearn.model_selection import GroupShuffleSplit
from sklearn.model_selection import learning_curve
from sklearn.model_selection import validation_curve
from sklearn.model_selection._validation import _check_is_permutation
from sklearn.datasets import make_regression
from sklearn.datasets import load_boston
from sklearn.datasets import load_iris
from sklearn.datasets import load_digits
from sklearn.metrics import explained_variance_score
from sklearn.metrics import make_scorer
from sklearn.metrics import accuracy_score
from sklearn.metrics import confusion_matrix
from sklearn.metrics import precision_recall_fscore_support
from sklearn.metrics import precision_score
from sklearn.metrics import r2_score
from sklearn.metrics.scorer import check_scoring
from sklearn.linear_model import Ridge, LogisticRegression, SGDClassifier
from sklearn.linear_model import PassiveAggressiveClassifier, RidgeClassifier
from sklearn.neighbors import KNeighborsClassifier
from sklearn.svm import SVC
from sklearn.cluster import KMeans
from sklearn.preprocessing import Imputer
from sklearn.preprocessing import LabelEncoder
from sklearn.pipeline import Pipeline
from sklearn.externals.six.moves import cStringIO as StringIO
from sklearn.base import BaseEstimator
from sklearn.base import clone
from sklearn.multiclass import OneVsRestClassifier
from sklearn.utils import shuffle
from sklearn.datasets import make_classification
from sklearn.datasets import make_multilabel_classification
from sklearn.model_selection.tests.common import OneTimeSplitter
from sklearn.model_selection import GridSearchCV
try:
WindowsError
except NameError:
WindowsError = None
class MockImprovingEstimator(BaseEstimator):
"""Dummy classifier to test the learning curve"""
def __init__(self, n_max_train_sizes):
self.n_max_train_sizes = n_max_train_sizes
self.train_sizes = 0
self.X_subset = None
def fit(self, X_subset, y_subset=None):
self.X_subset = X_subset
self.train_sizes = X_subset.shape[0]
return self
def predict(self, X):
raise NotImplementedError
def score(self, X=None, Y=None):
# training score becomes worse (2 -> 1), test error better (0 -> 1)
if self._is_training_data(X):
return 2. - float(self.train_sizes) / self.n_max_train_sizes
else:
return float(self.train_sizes) / self.n_max_train_sizes
def _is_training_data(self, X):
return X is self.X_subset
class MockIncrementalImprovingEstimator(MockImprovingEstimator):
"""Dummy classifier that provides partial_fit"""
def __init__(self, n_max_train_sizes):
super(MockIncrementalImprovingEstimator,
self).__init__(n_max_train_sizes)
self.x = None
def _is_training_data(self, X):
return self.x in X
def partial_fit(self, X, y=None, **params):
self.train_sizes += X.shape[0]
self.x = X[0]
class MockEstimatorWithParameter(BaseEstimator):
"""Dummy classifier to test the validation curve"""
def __init__(self, param=0.5):
self.X_subset = None
self.param = param
def fit(self, X_subset, y_subset):
self.X_subset = X_subset
self.train_sizes = X_subset.shape[0]
return self
def predict(self, X):
raise NotImplementedError
def score(self, X=None, y=None):
return self.param if self._is_training_data(X) else 1 - self.param
def _is_training_data(self, X):
return X is self.X_subset
class MockEstimatorWithSingleFitCallAllowed(MockEstimatorWithParameter):
"""Dummy classifier that disallows repeated calls of fit method"""
def fit(self, X_subset, y_subset):
assert_false(
hasattr(self, 'fit_called_'),
'fit is called the second time'
)
self.fit_called_ = True
return super(type(self), self).fit(X_subset, y_subset)
def predict(self, X):
raise NotImplementedError
class MockClassifier(object):
"""Dummy classifier to test the cross-validation"""
def __init__(self, a=0, allow_nd=False):
self.a = a
self.allow_nd = allow_nd
def fit(self, X, Y=None, sample_weight=None, class_prior=None,
sparse_sample_weight=None, sparse_param=None, dummy_int=None,
dummy_str=None, dummy_obj=None, callback=None):
"""The dummy arguments are to test that this fit function can
accept non-array arguments through cross-validation, such as:
- int
- str (this is actually array-like)
- object
- function
"""
self.dummy_int = dummy_int
self.dummy_str = dummy_str
self.dummy_obj = dummy_obj
if callback is not None:
callback(self)
if self.allow_nd:
X = X.reshape(len(X), -1)
if X.ndim >= 3 and not self.allow_nd:
raise ValueError('X cannot be d')
if sample_weight is not None:
assert_true(sample_weight.shape[0] == X.shape[0],
'MockClassifier extra fit_param sample_weight.shape[0]'
' is {0}, should be {1}'.format(sample_weight.shape[0],
X.shape[0]))
if class_prior is not None:
assert_true(class_prior.shape[0] == len(np.unique(y)),
'MockClassifier extra fit_param class_prior.shape[0]'
' is {0}, should be {1}'.format(class_prior.shape[0],
len(np.unique(y))))
if sparse_sample_weight is not None:
fmt = ('MockClassifier extra fit_param sparse_sample_weight'
'.shape[0] is {0}, should be {1}')
assert_true(sparse_sample_weight.shape[0] == X.shape[0],
fmt.format(sparse_sample_weight.shape[0], X.shape[0]))
if sparse_param is not None:
fmt = ('MockClassifier extra fit_param sparse_param.shape '
'is ({0}, {1}), should be ({2}, {3})')
assert_true(sparse_param.shape == P_sparse.shape,
fmt.format(sparse_param.shape[0],
sparse_param.shape[1],
P_sparse.shape[0], P_sparse.shape[1]))
return self
def predict(self, T):
if self.allow_nd:
T = T.reshape(len(T), -1)
return T[:, 0]
def score(self, X=None, Y=None):
return 1. / (1 + np.abs(self.a))
def get_params(self, deep=False):
return {'a': self.a, 'allow_nd': self.allow_nd}
# XXX: use 2D array, since 1D X is being detected as a single sample in
# check_consistent_length
X = np.ones((10, 2))
X_sparse = coo_matrix(X)
y = np.array([0, 0, 1, 1, 2, 2, 3, 3, 4, 4])
# The number of samples per class needs to be > n_splits,
# for StratifiedKFold(n_splits=3)
y2 = np.array([1, 1, 1, 2, 2, 2, 3, 3, 3, 3])
P_sparse = coo_matrix(np.eye(5))
def test_cross_val_score():
clf = MockClassifier()
for a in range(-10, 10):
clf.a = a
# Smoke test
scores = cross_val_score(clf, X, y2)
assert_array_equal(scores, clf.score(X, y2))
# test with multioutput y
multioutput_y = np.column_stack([y2, y2[::-1]])
scores = cross_val_score(clf, X_sparse, multioutput_y)
assert_array_equal(scores, clf.score(X_sparse, multioutput_y))
scores = cross_val_score(clf, X_sparse, y2)
assert_array_equal(scores, clf.score(X_sparse, y2))
# test with multioutput y
scores = cross_val_score(clf, X_sparse, multioutput_y)
assert_array_equal(scores, clf.score(X_sparse, multioutput_y))
# test with X and y as list
list_check = lambda x: isinstance(x, list)
clf = CheckingClassifier(check_X=list_check)
scores = cross_val_score(clf, X.tolist(), y2.tolist())
clf = CheckingClassifier(check_y=list_check)
scores = cross_val_score(clf, X, y2.tolist())
assert_raises(ValueError, cross_val_score, clf, X, y2, scoring="sklearn")
# test with 3d X and
X_3d = X[:, :, np.newaxis]
clf = MockClassifier(allow_nd=True)
scores = cross_val_score(clf, X_3d, y2)
clf = MockClassifier(allow_nd=False)
assert_raises(ValueError, cross_val_score, clf, X_3d, y2)
def test_cross_validate_invalid_scoring_param():
X, y = make_classification(random_state=0)
estimator = MockClassifier()
# Test the errors
error_message_regexp = ".*must be unique strings.*"
# List/tuple of callables should raise a message advising users to use
# dict of names to callables mapping
assert_raises_regex(ValueError, error_message_regexp,
cross_validate, estimator, X, y,
scoring=(make_scorer(precision_score),
make_scorer(accuracy_score)))
assert_raises_regex(ValueError, error_message_regexp,
cross_validate, estimator, X, y,
scoring=(make_scorer(precision_score),))
# So should empty lists/tuples
assert_raises_regex(ValueError, error_message_regexp + "Empty list.*",
cross_validate, estimator, X, y, scoring=())
# So should duplicated entries
assert_raises_regex(ValueError, error_message_regexp + "Duplicate.*",
cross_validate, estimator, X, y,
scoring=('f1_micro', 'f1_micro'))
# Nested Lists should raise a generic error message
assert_raises_regex(ValueError, error_message_regexp,
cross_validate, estimator, X, y,
scoring=[[make_scorer(precision_score)]])
error_message_regexp = (".*should either be.*string or callable.*for "
"single.*.*dict.*for multi.*")
# Empty dict should raise invalid scoring error
assert_raises_regex(ValueError, "An empty dict",
cross_validate, estimator, X, y, scoring=(dict()))
# And so should any other invalid entry
assert_raises_regex(ValueError, error_message_regexp,
cross_validate, estimator, X, y, scoring=5)
multiclass_scorer = make_scorer(precision_recall_fscore_support)
# Multiclass Scorers that return multiple values are not supported yet
assert_raises_regex(ValueError,
"Classification metrics can't handle a mix of "
"binary and continuous targets",
cross_validate, estimator, X, y,
scoring=multiclass_scorer)
assert_raises_regex(ValueError,
"Classification metrics can't handle a mix of "
"binary and continuous targets",
cross_validate, estimator, X, y,
scoring={"foo": multiclass_scorer})
multivalued_scorer = make_scorer(confusion_matrix)
# Multiclass Scorers that return multiple values are not supported yet
assert_raises_regex(ValueError, "scoring must return a number, got",
cross_validate, SVC(), X, y,
scoring=multivalued_scorer)
assert_raises_regex(ValueError, "scoring must return a number, got",
cross_validate, SVC(), X, y,
scoring={"foo": multivalued_scorer})
assert_raises_regex(ValueError, "'mse' is not a valid scoring value.",
cross_validate, SVC(), X, y, scoring="mse")
def test_cross_validate():
# Compute train and test mse/r2 scores
cv = KFold(n_splits=5)
# Regression
X_reg, y_reg = make_regression(n_samples=30, random_state=0)
reg = Ridge(random_state=0)
# Classification
X_clf, y_clf = make_classification(n_samples=30, random_state=0)
clf = SVC(kernel="linear", random_state=0)
for X, y, est in ((X_reg, y_reg, reg), (X_clf, y_clf, clf)):
# It's okay to evaluate regression metrics on classification too
mse_scorer = check_scoring(est, 'neg_mean_squared_error')
r2_scorer = check_scoring(est, 'r2')
train_mse_scores = []
test_mse_scores = []
train_r2_scores = []
test_r2_scores = []
for train, test in cv.split(X, y):
est = clone(reg).fit(X[train], y[train])
train_mse_scores.append(mse_scorer(est, X[train], y[train]))
train_r2_scores.append(r2_scorer(est, X[train], y[train]))
test_mse_scores.append(mse_scorer(est, X[test], y[test]))
test_r2_scores.append(r2_scorer(est, X[test], y[test]))
train_mse_scores = np.array(train_mse_scores)
test_mse_scores = np.array(test_mse_scores)
train_r2_scores = np.array(train_r2_scores)
test_r2_scores = np.array(test_r2_scores)
scores = (train_mse_scores, test_mse_scores, train_r2_scores,
test_r2_scores)
yield check_cross_validate_single_metric, est, X, y, scores
yield check_cross_validate_multi_metric, est, X, y, scores
def test_cross_validate_return_train_score_warn():
# Test that warnings are raised. Will be removed in 0.21
X, y = make_classification(random_state=0)
estimator = MockClassifier()
result = {}
for val in [False, True, 'warn']:
result[val] = assert_no_warnings(cross_validate, estimator, X, y,
return_train_score=val)
msg = (
'You are accessing a training score ({!r}), '
'which will not be available by default '
'any more in 0.21. If you need training scores, '
'please set return_train_score=True').format('train_score')
train_score = assert_warns_message(FutureWarning, msg,
result['warn'].get, 'train_score')
assert np.allclose(train_score, result[True]['train_score'])
assert 'train_score' not in result[False]
def check_cross_validate_single_metric(clf, X, y, scores):
(train_mse_scores, test_mse_scores, train_r2_scores,
test_r2_scores) = scores
# Test single metric evaluation when scoring is string or singleton list
for (return_train_score, dict_len) in ((True, 4), (False, 3)):
# Single metric passed as a string
if return_train_score:
# It must be True by default
mse_scores_dict = cross_validate(clf, X, y, cv=5,
scoring='neg_mean_squared_error')
assert_array_almost_equal(mse_scores_dict['train_score'],
train_mse_scores)
else:
mse_scores_dict = cross_validate(clf, X, y, cv=5,
scoring='neg_mean_squared_error',
return_train_score=False)
assert_true(isinstance(mse_scores_dict, dict))
assert_equal(len(mse_scores_dict), dict_len)
assert_array_almost_equal(mse_scores_dict['test_score'],
test_mse_scores)
# Single metric passed as a list
if return_train_score:
# It must be True by default
r2_scores_dict = cross_validate(clf, X, y, cv=5, scoring=['r2'])
assert_array_almost_equal(r2_scores_dict['train_r2'],
train_r2_scores)
else:
r2_scores_dict = cross_validate(clf, X, y, cv=5, scoring=['r2'],
return_train_score=False)
assert_true(isinstance(r2_scores_dict, dict))
assert_equal(len(r2_scores_dict), dict_len)
assert_array_almost_equal(r2_scores_dict['test_r2'], test_r2_scores)
def check_cross_validate_multi_metric(clf, X, y, scores):
# Test multimetric evaluation when scoring is a list / dict
(train_mse_scores, test_mse_scores, train_r2_scores,
test_r2_scores) = scores
all_scoring = (('r2', 'neg_mean_squared_error'),
{'r2': make_scorer(r2_score),
'neg_mean_squared_error': 'neg_mean_squared_error'})
keys_sans_train = set(('test_r2', 'test_neg_mean_squared_error',
'fit_time', 'score_time'))
keys_with_train = keys_sans_train.union(
set(('train_r2', 'train_neg_mean_squared_error')))
for return_train_score in (True, False):
for scoring in all_scoring:
if return_train_score:
# return_train_score must be True by default
cv_results = cross_validate(clf, X, y, cv=5, scoring=scoring)
assert_array_almost_equal(cv_results['train_r2'],
train_r2_scores)
assert_array_almost_equal(
cv_results['train_neg_mean_squared_error'],
train_mse_scores)
else:
cv_results = cross_validate(clf, X, y, cv=5, scoring=scoring,
return_train_score=False)
assert_true(isinstance(cv_results, dict))
assert_equal(set(cv_results.keys()),
keys_with_train if return_train_score
else keys_sans_train)
assert_array_almost_equal(cv_results['test_r2'], test_r2_scores)
assert_array_almost_equal(
cv_results['test_neg_mean_squared_error'], test_mse_scores)
# Make sure all the arrays are of np.ndarray type
assert type(cv_results['test_r2']) == np.ndarray
assert (type(cv_results['test_neg_mean_squared_error']) ==
np.ndarray)
assert type(cv_results['fit_time']) == np.ndarray
assert type(cv_results['score_time']) == np.ndarray
# Ensure all the times are within sane limits
assert np.all(cv_results['fit_time'] >= 0)
assert np.all(cv_results['fit_time'] < 10)
assert np.all(cv_results['score_time'] >= 0)
assert np.all(cv_results['score_time'] < 10)
def test_cross_val_score_predict_groups():
# Check if ValueError (when groups is None) propagates to cross_val_score
# and cross_val_predict
# And also check if groups is correctly passed to the cv object
X, y = make_classification(n_samples=20, n_classes=2, random_state=0)
clf = SVC(kernel="linear")
group_cvs = [LeaveOneGroupOut(), LeavePGroupsOut(2), GroupKFold(),
GroupShuffleSplit()]
for cv in group_cvs:
assert_raise_message(ValueError,
"The 'groups' parameter should not be None.",
cross_val_score, estimator=clf, X=X, y=y, cv=cv)
assert_raise_message(ValueError,
"The 'groups' parameter should not be None.",
cross_val_predict, estimator=clf, X=X, y=y, cv=cv)
def test_cross_val_score_pandas():
# check cross_val_score doesn't destroy pandas dataframe
types = [(MockDataFrame, MockDataFrame)]
try:
from pandas import Series, DataFrame
types.append((Series, DataFrame))
except ImportError:
pass
for TargetType, InputFeatureType in types:
# X dataframe, y series
# 3 fold cross val is used so we need atleast 3 samples per class
X_df, y_ser = InputFeatureType(X), TargetType(y2)
check_df = lambda x: isinstance(x, InputFeatureType)
check_series = lambda x: isinstance(x, TargetType)
clf = CheckingClassifier(check_X=check_df, check_y=check_series)
cross_val_score(clf, X_df, y_ser)
def test_cross_val_score_mask():
# test that cross_val_score works with boolean masks
svm = SVC(kernel="linear")
iris = load_iris()
X, y = iris.data, iris.target
kfold = KFold(5)
scores_indices = cross_val_score(svm, X, y, cv=kfold)
kfold = KFold(5)
cv_masks = []
for train, test in kfold.split(X, y):
mask_train = np.zeros(len(y), dtype=np.bool)
mask_test = np.zeros(len(y), dtype=np.bool)
mask_train[train] = 1
mask_test[test] = 1
cv_masks.append((train, test))
scores_masks = cross_val_score(svm, X, y, cv=cv_masks)
assert_array_equal(scores_indices, scores_masks)
def test_cross_val_score_precomputed():
# test for svm with precomputed kernel
svm = SVC(kernel="precomputed")
iris = load_iris()
X, y = iris.data, iris.target
linear_kernel = np.dot(X, X.T)
score_precomputed = cross_val_score(svm, linear_kernel, y)
svm = SVC(kernel="linear")
score_linear = cross_val_score(svm, X, y)
assert_array_almost_equal(score_precomputed, score_linear)
# test with callable
svm = SVC(kernel=lambda x, y: np.dot(x, y.T))
score_callable = cross_val_score(svm, X, y)
assert_array_almost_equal(score_precomputed, score_callable)
# Error raised for non-square X
svm = SVC(kernel="precomputed")
assert_raises(ValueError, cross_val_score, svm, X, y)
# test error is raised when the precomputed kernel is not array-like
# or sparse
assert_raises(ValueError, cross_val_score, svm,
linear_kernel.tolist(), y)
def test_cross_val_score_fit_params():
clf = MockClassifier()
n_samples = X.shape[0]
n_classes = len(np.unique(y))
W_sparse = coo_matrix((np.array([1]), (np.array([1]), np.array([0]))),
shape=(10, 1))
P_sparse = coo_matrix(np.eye(5))
DUMMY_INT = 42
DUMMY_STR = '42'
DUMMY_OBJ = object()
def assert_fit_params(clf):
# Function to test that the values are passed correctly to the
# classifier arguments for non-array type
assert_equal(clf.dummy_int, DUMMY_INT)
assert_equal(clf.dummy_str, DUMMY_STR)
assert_equal(clf.dummy_obj, DUMMY_OBJ)
fit_params = {'sample_weight': np.ones(n_samples),
'class_prior': np.ones(n_classes) / n_classes,
'sparse_sample_weight': W_sparse,
'sparse_param': P_sparse,
'dummy_int': DUMMY_INT,
'dummy_str': DUMMY_STR,
'dummy_obj': DUMMY_OBJ,
'callback': assert_fit_params}
cross_val_score(clf, X, y, fit_params=fit_params)
def test_cross_val_score_score_func():
clf = MockClassifier()
_score_func_args = []
def score_func(y_test, y_predict):
_score_func_args.append((y_test, y_predict))
return 1.0
with warnings.catch_warnings(record=True):
scoring = make_scorer(score_func)
score = cross_val_score(clf, X, y, scoring=scoring, cv=3)
assert_array_equal(score, [1.0, 1.0, 1.0])
# Test that score function is called only 3 times (for cv=3)
assert len(_score_func_args) == 3
def test_cross_val_score_errors():
class BrokenEstimator:
pass
assert_raises(TypeError, cross_val_score, BrokenEstimator(), X)
def test_cross_val_score_with_score_func_classification():
iris = load_iris()
clf = SVC(kernel='linear')
# Default score (should be the accuracy score)
scores = cross_val_score(clf, iris.data, iris.target, cv=5)
assert_array_almost_equal(scores, [0.97, 1., 0.97, 0.97, 1.], 2)
# Correct classification score (aka. zero / one score) - should be the
# same as the default estimator score
zo_scores = cross_val_score(clf, iris.data, iris.target,
scoring="accuracy", cv=5)
assert_array_almost_equal(zo_scores, [0.97, 1., 0.97, 0.97, 1.], 2)
# F1 score (class are balanced so f1_score should be equal to zero/one
# score
f1_scores = cross_val_score(clf, iris.data, iris.target,
scoring="f1_weighted", cv=5)
assert_array_almost_equal(f1_scores, [0.97, 1., 0.97, 0.97, 1.], 2)
def test_cross_val_score_with_score_func_regression():
X, y = make_regression(n_samples=30, n_features=20, n_informative=5,
random_state=0)
reg = Ridge()
# Default score of the Ridge regression estimator
scores = cross_val_score(reg, X, y, cv=5)
assert_array_almost_equal(scores, [0.94, 0.97, 0.97, 0.99, 0.92], 2)
# R2 score (aka. determination coefficient) - should be the
# same as the default estimator score
r2_scores = cross_val_score(reg, X, y, scoring="r2", cv=5)
assert_array_almost_equal(r2_scores, [0.94, 0.97, 0.97, 0.99, 0.92], 2)
# Mean squared error; this is a loss function, so "scores" are negative
neg_mse_scores = cross_val_score(reg, X, y, cv=5,
scoring="neg_mean_squared_error")
expected_neg_mse = np.array([-763.07, -553.16, -274.38, -273.26, -1681.99])
assert_array_almost_equal(neg_mse_scores, expected_neg_mse, 2)
# Explained variance
scoring = make_scorer(explained_variance_score)
ev_scores = cross_val_score(reg, X, y, cv=5, scoring=scoring)
assert_array_almost_equal(ev_scores, [0.94, 0.97, 0.97, 0.99, 0.92], 2)
def test_permutation_score():
iris = load_iris()
X = iris.data
X_sparse = coo_matrix(X)
y = iris.target
svm = SVC(kernel='linear')
cv = StratifiedKFold(2)
score, scores, pvalue = permutation_test_score(
svm, X, y, n_permutations=30, cv=cv, scoring="accuracy")
assert_greater(score, 0.9)
assert_almost_equal(pvalue, 0.0, 1)
score_group, _, pvalue_group = permutation_test_score(
svm, X, y, n_permutations=30, cv=cv, scoring="accuracy",
groups=np.ones(y.size), random_state=0)
assert_true(score_group == score)
assert_true(pvalue_group == pvalue)
# check that we obtain the same results with a sparse representation
svm_sparse = SVC(kernel='linear')
cv_sparse = StratifiedKFold(2)
score_group, _, pvalue_group = permutation_test_score(
svm_sparse, X_sparse, y, n_permutations=30, cv=cv_sparse,
scoring="accuracy", groups=np.ones(y.size), random_state=0)
assert_true(score_group == score)
assert_true(pvalue_group == pvalue)
# test with custom scoring object
def custom_score(y_true, y_pred):
return (((y_true == y_pred).sum() - (y_true != y_pred).sum()) /
y_true.shape[0])
scorer = make_scorer(custom_score)
score, _, pvalue = permutation_test_score(
svm, X, y, n_permutations=100, scoring=scorer, cv=cv, random_state=0)
assert_almost_equal(score, .93, 2)
assert_almost_equal(pvalue, 0.01, 3)
# set random y
y = np.mod(np.arange(len(y)), 3)
score, scores, pvalue = permutation_test_score(
svm, X, y, n_permutations=30, cv=cv, scoring="accuracy")
assert_less(score, 0.5)
assert_greater(pvalue, 0.2)
def test_permutation_test_score_allow_nans():
# Check that permutation_test_score allows input data with NaNs
X = np.arange(200, dtype=np.float64).reshape(10, -1)
X[2, :] = np.nan
y = np.repeat([0, 1], X.shape[0] / 2)
p = Pipeline([
('imputer', Imputer(strategy='mean', missing_values='NaN')),
('classifier', MockClassifier()),
])
permutation_test_score(p, X, y, cv=5)
def test_cross_val_score_allow_nans():
# Check that cross_val_score allows input data with NaNs
X = np.arange(200, dtype=np.float64).reshape(10, -1)
X[2, :] = np.nan
y = np.repeat([0, 1], X.shape[0] / 2)
p = Pipeline([
('imputer', Imputer(strategy='mean', missing_values='NaN')),
('classifier', MockClassifier()),
])
cross_val_score(p, X, y, cv=5)
def test_cross_val_score_multilabel():
X = np.array([[-3, 4], [2, 4], [3, 3], [0, 2], [-3, 1],
[-2, 1], [0, 0], [-2, -1], [-1, -2], [1, -2]])
y = np.array([[1, 1], [0, 1], [0, 1], [0, 1], [1, 1],
[0, 1], [1, 0], [1, 1], [1, 0], [0, 0]])
clf = KNeighborsClassifier(n_neighbors=1)
scoring_micro = make_scorer(precision_score, average='micro')
scoring_macro = make_scorer(precision_score, average='macro')
scoring_samples = make_scorer(precision_score, average='samples')
score_micro = cross_val_score(clf, X, y, scoring=scoring_micro, cv=5)
score_macro = cross_val_score(clf, X, y, scoring=scoring_macro, cv=5)
score_samples = cross_val_score(clf, X, y, scoring=scoring_samples, cv=5)
assert_almost_equal(score_micro, [1, 1 / 2, 3 / 4, 1 / 2, 1 / 3])
assert_almost_equal(score_macro, [1, 1 / 2, 3 / 4, 1 / 2, 1 / 4])
assert_almost_equal(score_samples, [1, 1 / 2, 3 / 4, 1 / 2, 1 / 4])
def test_cross_val_predict():
boston = load_boston()
X, y = boston.data, boston.target
cv = KFold()
est = Ridge()
# Naive loop (should be same as cross_val_predict):
preds2 = np.zeros_like(y)
for train, test in cv.split(X, y):
est.fit(X[train], y[train])
preds2[test] = est.predict(X[test])
preds = cross_val_predict(est, X, y, cv=cv)
assert_array_almost_equal(preds, preds2)
preds = cross_val_predict(est, X, y)
assert_equal(len(preds), len(y))
cv = LeaveOneOut()
preds = cross_val_predict(est, X, y, cv=cv)
assert_equal(len(preds), len(y))
Xsp = X.copy()
Xsp *= (Xsp > np.median(Xsp))
Xsp = coo_matrix(Xsp)
preds = cross_val_predict(est, Xsp, y)
assert_array_almost_equal(len(preds), len(y))
preds = cross_val_predict(KMeans(), X)
assert_equal(len(preds), len(y))
class BadCV():
def split(self, X, y=None, groups=None):
for i in range(4):
yield np.array([0, 1, 2, 3]), np.array([4, 5, 6, 7, 8])
assert_raises(ValueError, cross_val_predict, est, X, y, cv=BadCV())
X, y = load_iris(return_X_y=True)
warning_message = ('Number of classes in training fold (2) does '
'not match total number of classes (3). '
'Results may not be appropriate for your use case.')
assert_warns_message(RuntimeWarning, warning_message,
cross_val_predict, LogisticRegression(),
X, y, method='predict_proba', cv=KFold(2))
def test_cross_val_predict_decision_function_shape():
X, y = make_classification(n_classes=2, n_samples=50, random_state=0)
preds = cross_val_predict(LogisticRegression(), X, y,
method='decision_function')
assert_equal(preds.shape, (50,))
X, y = load_iris(return_X_y=True)
preds = cross_val_predict(LogisticRegression(), X, y,
method='decision_function')
assert_equal(preds.shape, (150, 3))
# This specifically tests imbalanced splits for binary
# classification with decision_function. This is only
# applicable to classifiers that can be fit on a single
# class.
X = X[:100]
y = y[:100]
assert_raise_message(ValueError,
'Only 1 class/es in training fold, this'
' is not supported for decision_function'
' with imbalanced folds. To fix '
'this, use a cross-validation technique '
'resulting in properly stratified folds',
cross_val_predict, RidgeClassifier(), X, y,
method='decision_function', cv=KFold(2))
X, y = load_digits(return_X_y=True)
est = SVC(kernel='linear', decision_function_shape='ovo')
preds = cross_val_predict(est,
X, y,
method='decision_function')
assert_equal(preds.shape, (1797, 45))
ind = np.argsort(y)
X, y = X[ind], y[ind]
assert_raises_regex(ValueError,
'Output shape \(599L?, 21L?\) of decision_function '
'does not match number of classes \(7\) in fold. '
'Irregular decision_function .*',
cross_val_predict, est, X, y,
cv=KFold(n_splits=3), method='decision_function')
def test_cross_val_predict_predict_proba_shape():
X, y = make_classification(n_classes=2, n_samples=50, random_state=0)
preds = cross_val_predict(LogisticRegression(), X, y,
method='predict_proba')
assert_equal(preds.shape, (50, 2))
X, y = load_iris(return_X_y=True)
preds = cross_val_predict(LogisticRegression(), X, y,
method='predict_proba')
assert_equal(preds.shape, (150, 3))
def test_cross_val_predict_predict_log_proba_shape():
X, y = make_classification(n_classes=2, n_samples=50, random_state=0)
preds = cross_val_predict(LogisticRegression(), X, y,
method='predict_log_proba')
assert_equal(preds.shape, (50, 2))
X, y = load_iris(return_X_y=True)
preds = cross_val_predict(LogisticRegression(), X, y,
method='predict_log_proba')
assert_equal(preds.shape, (150, 3))
def test_cross_val_predict_input_types():
iris = load_iris()
X, y = iris.data, iris.target
X_sparse = coo_matrix(X)
multioutput_y = np.column_stack([y, y[::-1]])
clf = Ridge(fit_intercept=False, random_state=0)
# 3 fold cv is used --> atleast 3 samples per class
# Smoke test
predictions = cross_val_predict(clf, X, y)
assert_equal(predictions.shape, (150,))
# test with multioutput y
predictions = cross_val_predict(clf, X_sparse, multioutput_y)
assert_equal(predictions.shape, (150, 2))
predictions = cross_val_predict(clf, X_sparse, y)
assert_array_equal(predictions.shape, (150,))
# test with multioutput y
predictions = cross_val_predict(clf, X_sparse, multioutput_y)
assert_array_equal(predictions.shape, (150, 2))
# test with X and y as list
list_check = lambda x: isinstance(x, list)
clf = CheckingClassifier(check_X=list_check)
predictions = cross_val_predict(clf, X.tolist(), y.tolist())
clf = CheckingClassifier(check_y=list_check)
predictions = cross_val_predict(clf, X, y.tolist())
# test with X and y as list and non empty method
predictions = cross_val_predict(LogisticRegression(), X.tolist(),
y.tolist(), method='decision_function')
predictions = cross_val_predict(LogisticRegression(), X,
y.tolist(), method='decision_function')
# test with 3d X and
X_3d = X[:, :, np.newaxis]
check_3d = lambda x: x.ndim == 3
clf = CheckingClassifier(check_X=check_3d)
predictions = cross_val_predict(clf, X_3d, y)
assert_array_equal(predictions.shape, (150,))
def test_cross_val_predict_pandas():
# check cross_val_score doesn't destroy pandas dataframe
types = [(MockDataFrame, MockDataFrame)]
try:
from pandas import Series, DataFrame
types.append((Series, DataFrame))
except ImportError:
pass
for TargetType, InputFeatureType in types:
# X dataframe, y series
X_df, y_ser = InputFeatureType(X), TargetType(y2)
check_df = lambda x: isinstance(x, InputFeatureType)
check_series = lambda x: isinstance(x, TargetType)
clf = CheckingClassifier(check_X=check_df, check_y=check_series)
cross_val_predict(clf, X_df, y_ser)
def test_cross_val_score_sparse_fit_params():
iris = load_iris()
X, y = iris.data, iris.target
clf = MockClassifier()
fit_params = {'sparse_sample_weight': coo_matrix(np.eye(X.shape[0]))}
a = cross_val_score(clf, X, y, fit_params=fit_params)
assert_array_equal(a, np.ones(3))
def test_learning_curve():
n_samples = 30
n_splits = 3
X, y = make_classification(n_samples=n_samples, n_features=1,
n_informative=1, n_redundant=0, n_classes=2,
n_clusters_per_class=1, random_state=0)
estimator = MockImprovingEstimator(n_samples * ((n_splits - 1) / n_splits))
for shuffle_train in [False, True]:
with warnings.catch_warnings(record=True) as w:
train_sizes, train_scores, test_scores = learning_curve(
estimator, X, y, cv=KFold(n_splits=n_splits),
train_sizes=np.linspace(0.1, 1.0, 10),
shuffle=shuffle_train)
if len(w) > 0:
raise RuntimeError("Unexpected warning: %r" % w[0].message)
assert_equal(train_scores.shape, (10, 3))
assert_equal(test_scores.shape, (10, 3))
assert_array_equal(train_sizes, np.linspace(2, 20, 10))
assert_array_almost_equal(train_scores.mean(axis=1),
np.linspace(1.9, 1.0, 10))
assert_array_almost_equal(test_scores.mean(axis=1),
np.linspace(0.1, 1.0, 10))
# Test a custom cv splitter that can iterate only once
with warnings.catch_warnings(record=True) as w:
train_sizes2, train_scores2, test_scores2 = learning_curve(
estimator, X, y,
cv=OneTimeSplitter(n_splits=n_splits, n_samples=n_samples),
train_sizes=np.linspace(0.1, 1.0, 10),
shuffle=shuffle_train)
if len(w) > 0:
raise RuntimeError("Unexpected warning: %r" % w[0].message)
assert_array_almost_equal(train_scores2, train_scores)
assert_array_almost_equal(test_scores2, test_scores)
def test_learning_curve_unsupervised():
X, _ = make_classification(n_samples=30, n_features=1, n_informative=1,
n_redundant=0, n_classes=2,
n_clusters_per_class=1, random_state=0)
estimator = MockImprovingEstimator(20)
train_sizes, train_scores, test_scores = learning_curve(
estimator, X, y=None, cv=3, train_sizes=np.linspace(0.1, 1.0, 10))
assert_array_equal(train_sizes, np.linspace(2, 20, 10))
assert_array_almost_equal(train_scores.mean(axis=1),
np.linspace(1.9, 1.0, 10))
assert_array_almost_equal(test_scores.mean(axis=1),
np.linspace(0.1, 1.0, 10))
def test_learning_curve_verbose():
X, y = make_classification(n_samples=30, n_features=1, n_informative=1,
n_redundant=0, n_classes=2,
n_clusters_per_class=1, random_state=0)
estimator = MockImprovingEstimator(20)
old_stdout = sys.stdout
sys.stdout = StringIO()
try:
train_sizes, train_scores, test_scores = \
learning_curve(estimator, X, y, cv=3, verbose=1)
finally:
out = sys.stdout.getvalue()
sys.stdout.close()
sys.stdout = old_stdout
assert("[learning_curve]" in out)
def test_learning_curve_incremental_learning_not_possible():
X, y = make_classification(n_samples=2, n_features=1, n_informative=1,
n_redundant=0, n_classes=2,
n_clusters_per_class=1, random_state=0)
# The mockup does not have partial_fit()
estimator = MockImprovingEstimator(1)
assert_raises(ValueError, learning_curve, estimator, X, y,
exploit_incremental_learning=True)
def test_learning_curve_incremental_learning():
X, y = make_classification(n_samples=30, n_features=1, n_informative=1,
n_redundant=0, n_classes=2,
n_clusters_per_class=1, random_state=0)
estimator = MockIncrementalImprovingEstimator(20)
for shuffle_train in [False, True]:
train_sizes, train_scores, test_scores = learning_curve(
estimator, X, y, cv=3, exploit_incremental_learning=True,
train_sizes=np.linspace(0.1, 1.0, 10), shuffle=shuffle_train)
assert_array_equal(train_sizes, np.linspace(2, 20, 10))
assert_array_almost_equal(train_scores.mean(axis=1),
np.linspace(1.9, 1.0, 10))
assert_array_almost_equal(test_scores.mean(axis=1),
np.linspace(0.1, 1.0, 10))
def test_learning_curve_incremental_learning_unsupervised():
X, _ = make_classification(n_samples=30, n_features=1, n_informative=1,
n_redundant=0, n_classes=2,
n_clusters_per_class=1, random_state=0)
estimator = MockIncrementalImprovingEstimator(20)
train_sizes, train_scores, test_scores = learning_curve(
estimator, X, y=None, cv=3, exploit_incremental_learning=True,
train_sizes=np.linspace(0.1, 1.0, 10))
assert_array_equal(train_sizes, np.linspace(2, 20, 10))
assert_array_almost_equal(train_scores.mean(axis=1),
np.linspace(1.9, 1.0, 10))
assert_array_almost_equal(test_scores.mean(axis=1),
np.linspace(0.1, 1.0, 10))
def test_learning_curve_batch_and_incremental_learning_are_equal():
X, y = make_classification(n_samples=30, n_features=1, n_informative=1,
n_redundant=0, n_classes=2,
n_clusters_per_class=1, random_state=0)
train_sizes = np.linspace(0.2, 1.0, 5)
estimator = PassiveAggressiveClassifier(max_iter=1, tol=None,
shuffle=False)
train_sizes_inc, train_scores_inc, test_scores_inc = \
learning_curve(
estimator, X, y, train_sizes=train_sizes,
cv=3, exploit_incremental_learning=True)
train_sizes_batch, train_scores_batch, test_scores_batch = \
learning_curve(
estimator, X, y, cv=3, train_sizes=train_sizes,
exploit_incremental_learning=False)
assert_array_equal(train_sizes_inc, train_sizes_batch)
assert_array_almost_equal(train_scores_inc.mean(axis=1),
train_scores_batch.mean(axis=1))
assert_array_almost_equal(test_scores_inc.mean(axis=1),
test_scores_batch.mean(axis=1))
def test_learning_curve_n_sample_range_out_of_bounds():
X, y = make_classification(n_samples=30, n_features=1, n_informative=1,
n_redundant=0, n_classes=2,
n_clusters_per_class=1, random_state=0)
estimator = MockImprovingEstimator(20)
assert_raises(ValueError, learning_curve, estimator, X, y, cv=3,
train_sizes=[0, 1])
assert_raises(ValueError, learning_curve, estimator, X, y, cv=3,
train_sizes=[0.0, 1.0])
assert_raises(ValueError, learning_curve, estimator, X, y, cv=3,
train_sizes=[0.1, 1.1])
assert_raises(ValueError, learning_curve, estimator, X, y, cv=3,
train_sizes=[0, 20])
assert_raises(ValueError, learning_curve, estimator, X, y, cv=3,
train_sizes=[1, 21])
def test_learning_curve_remove_duplicate_sample_sizes():
X, y = make_classification(n_samples=3, n_features=1, n_informative=1,
n_redundant=0, n_classes=2,
n_clusters_per_class=1, random_state=0)
estimator = MockImprovingEstimator(2)
train_sizes, _, _ = assert_warns(
RuntimeWarning, learning_curve, estimator, X, y, cv=3,
train_sizes=np.linspace(0.33, 1.0, 3))
assert_array_equal(train_sizes, [1, 2])
def test_learning_curve_with_boolean_indices():
X, y = make_classification(n_samples=30, n_features=1, n_informative=1,
n_redundant=0, n_classes=2,
n_clusters_per_class=1, random_state=0)
estimator = MockImprovingEstimator(20)
cv = KFold(n_splits=3)
train_sizes, train_scores, test_scores = learning_curve(
estimator, X, y, cv=cv, train_sizes=np.linspace(0.1, 1.0, 10))
assert_array_equal(train_sizes, np.linspace(2, 20, 10))
assert_array_almost_equal(train_scores.mean(axis=1),
np.linspace(1.9, 1.0, 10))
assert_array_almost_equal(test_scores.mean(axis=1),
np.linspace(0.1, 1.0, 10))
def test_learning_curve_with_shuffle():
# Following test case was designed this way to verify the code
# changes made in pull request: #7506.
X = np.array([[1, 2], [3, 4], [5, 6], [7, 8], [11, 12], [13, 14], [15, 16],
[17, 18], [19, 20], [7, 8], [9, 10], [11, 12], [13, 14],
[15, 16], [17, 18]])
y = np.array([1, 1, 1, 2, 3, 4, 1, 1, 2, 3, 4, 1, 2, 3, 4])
groups = np.array([1, 1, 1, 1, 1, 1, 3, 3, 3, 3, 3, 4, 4, 4, 4])
# Splits on these groups fail without shuffle as the first iteration
# of the learning curve doesn't contain label 4 in the training set.
estimator = PassiveAggressiveClassifier(max_iter=5, tol=None,
shuffle=False)
cv = GroupKFold(n_splits=2)
train_sizes_batch, train_scores_batch, test_scores_batch = learning_curve(
estimator, X, y, cv=cv, n_jobs=1, train_sizes=np.linspace(0.3, 1.0, 3),
groups=groups, shuffle=True, random_state=2)
assert_array_almost_equal(train_scores_batch.mean(axis=1),
np.array([0.75, 0.3, 0.36111111]))
assert_array_almost_equal(test_scores_batch.mean(axis=1),
np.array([0.36111111, 0.25, 0.25]))
assert_raises(ValueError, learning_curve, estimator, X, y, cv=cv, n_jobs=1,
train_sizes=np.linspace(0.3, 1.0, 3), groups=groups)
train_sizes_inc, train_scores_inc, test_scores_inc = learning_curve(
estimator, X, y, cv=cv, n_jobs=1, train_sizes=np.linspace(0.3, 1.0, 3),
groups=groups, shuffle=True, random_state=2,
exploit_incremental_learning=True)
assert_array_almost_equal(train_scores_inc.mean(axis=1),
train_scores_batch.mean(axis=1))
assert_array_almost_equal(test_scores_inc.mean(axis=1),
test_scores_batch.mean(axis=1))
def test_validation_curve():
X, y = make_classification(n_samples=2, n_features=1, n_informative=1,
n_redundant=0, n_classes=2,
n_clusters_per_class=1, random_state=0)
param_range = np.linspace(0, 1, 10)
with warnings.catch_warnings(record=True) as w:
train_scores, test_scores = validation_curve(
MockEstimatorWithParameter(), X, y, param_name="param",
param_range=param_range, cv=2
)
if len(w) > 0:
raise RuntimeError("Unexpected warning: %r" % w[0].message)
assert_array_almost_equal(train_scores.mean(axis=1), param_range)
assert_array_almost_equal(test_scores.mean(axis=1), 1 - param_range)
def test_validation_curve_clone_estimator():
X, y = make_classification(n_samples=2, n_features=1, n_informative=1,
n_redundant=0, n_classes=2,
n_clusters_per_class=1, random_state=0)
param_range = np.linspace(1, 0, 10)
_, _ = validation_curve(
MockEstimatorWithSingleFitCallAllowed(), X, y,
param_name="param", param_range=param_range, cv=2
)
def test_validation_curve_cv_splits_consistency():
n_samples = 100
n_splits = 5
X, y = make_classification(n_samples=100, random_state=0)
scores1 = validation_curve(SVC(kernel='linear', random_state=0), X, y,
'C', [0.1, 0.1, 0.2, 0.2],
cv=OneTimeSplitter(n_splits=n_splits,
n_samples=n_samples))
# The OneTimeSplitter is a non-re-entrant cv splitter. Unless, the
# `split` is called for each parameter, the following should produce
# identical results for param setting 1 and param setting 2 as both have
# the same C value.
assert_array_almost_equal(*np.vsplit(np.hstack(scores1)[(0, 2, 1, 3), :],
2))
scores2 = validation_curve(SVC(kernel='linear', random_state=0), X, y,
'C', [0.1, 0.1, 0.2, 0.2],
cv=KFold(n_splits=n_splits, shuffle=True))
# For scores2, compare the 1st and 2nd parameter's scores
# (Since the C value for 1st two param setting is 0.1, they must be
# consistent unless the train test folds differ between the param settings)
assert_array_almost_equal(*np.vsplit(np.hstack(scores2)[(0, 2, 1, 3), :],
2))
scores3 = validation_curve(SVC(kernel='linear', random_state=0), X, y,
'C', [0.1, 0.1, 0.2, 0.2],
cv=KFold(n_splits=n_splits))
# OneTimeSplitter is basically unshuffled KFold(n_splits=5). Sanity check.
assert_array_almost_equal(np.array(scores3), np.array(scores1))
def test_check_is_permutation():
rng = np.random.RandomState(0)
p = np.arange(100)
rng.shuffle(p)
assert_true(_check_is_permutation(p, 100))
assert_false(_check_is_permutation(np.delete(p, 23), 100))
p[0] = 23
assert_false(_check_is_permutation(p, 100))
# Check if the additional duplicate indices are caught
assert_false(_check_is_permutation(np.hstack((p, 0)), 100))
def test_cross_val_predict_sparse_prediction():
# check that cross_val_predict gives same result for sparse and dense input
X, y = make_multilabel_classification(n_classes=2, n_labels=1,
allow_unlabeled=False,
return_indicator=True,
random_state=1)
X_sparse = csr_matrix(X)
y_sparse = csr_matrix(y)
classif = OneVsRestClassifier(SVC(kernel='linear'))
preds = cross_val_predict(classif, X, y, cv=10)
preds_sparse = cross_val_predict(classif, X_sparse, y_sparse, cv=10)
preds_sparse = preds_sparse.toarray()
assert_array_almost_equal(preds_sparse, preds)
def check_cross_val_predict_with_method(est):
iris = load_iris()
X, y = iris.data, iris.target
X, y = shuffle(X, y, random_state=0)
classes = len(set(y))
kfold = KFold()
methods = ['decision_function', 'predict_proba', 'predict_log_proba']
for method in methods:
predictions = cross_val_predict(est, X, y, method=method)
assert_equal(len(predictions), len(y))
expected_predictions = np.zeros([len(y), classes])
func = getattr(est, method)
# Naive loop (should be same as cross_val_predict):
for train, test in kfold.split(X, y):
est.fit(X[train], y[train])
expected_predictions[test] = func(X[test])
predictions = cross_val_predict(est, X, y, method=method,
cv=kfold)
assert_array_almost_equal(expected_predictions, predictions)
# Test alternative representations of y
predictions_y1 = cross_val_predict(est, X, y + 1, method=method,
cv=kfold)
assert_array_equal(predictions, predictions_y1)
predictions_y2 = cross_val_predict(est, X, y - 2, method=method,
cv=kfold)
assert_array_equal(predictions, predictions_y2)
predictions_ystr = cross_val_predict(est, X, y.astype('str'),
method=method, cv=kfold)
assert_array_equal(predictions, predictions_ystr)
def test_cross_val_predict_with_method():
check_cross_val_predict_with_method(LogisticRegression())
def test_cross_val_predict_method_checking():
# Regression test for issue #9639. Tests that cross_val_predict does not
# check estimator methods (e.g. predict_proba) before fitting
est = SGDClassifier(loss='log', random_state=2)
check_cross_val_predict_with_method(est)
def test_gridsearchcv_cross_val_predict_with_method():
est = GridSearchCV(LogisticRegression(random_state=42),
{'C': [0.1, 1]},
cv=2)
check_cross_val_predict_with_method(est)
def get_expected_predictions(X, y, cv, classes, est, method):
expected_predictions = np.zeros([len(y), classes])
func = getattr(est, method)
for train, test in cv.split(X, y):
est.fit(X[train], y[train])
expected_predictions_ = func(X[test])
# To avoid 2 dimensional indexing
if method is 'predict_proba':
exp_pred_test = np.zeros((len(test), classes))
else:
exp_pred_test = np.full((len(test), classes),
np.finfo(expected_predictions.dtype).min)
exp_pred_test[:, est.classes_] = expected_predictions_
expected_predictions[test] = exp_pred_test
return expected_predictions
def test_cross_val_predict_class_subset():
X = np.arange(200).reshape(100, 2)
y = np.array([x//10 for x in range(100)])
classes = 10
kfold3 = KFold(n_splits=3)
kfold4 = KFold(n_splits=4)
le = LabelEncoder()
methods = ['decision_function', 'predict_proba', 'predict_log_proba']
for method in methods:
est = LogisticRegression()
# Test with n_splits=3
predictions = cross_val_predict(est, X, y, method=method,
cv=kfold3)
# Runs a naive loop (should be same as cross_val_predict):
expected_predictions = get_expected_predictions(X, y, kfold3, classes,
est, method)
assert_array_almost_equal(expected_predictions, predictions)
# Test with n_splits=4
predictions = cross_val_predict(est, X, y, method=method,
cv=kfold4)
expected_predictions = get_expected_predictions(X, y, kfold4, classes,
est, method)
assert_array_almost_equal(expected_predictions, predictions)
# Testing unordered labels
y = shuffle(np.repeat(range(10), 10), random_state=0)
predictions = cross_val_predict(est, X, y, method=method,
cv=kfold3)
y = le.fit_transform(y)
expected_predictions = get_expected_predictions(X, y, kfold3, classes,
est, method)
assert_array_almost_equal(expected_predictions, predictions)
def test_score_memmap():
# Ensure a scalar score of memmap type is accepted
iris = load_iris()
X, y = iris.data, iris.target
clf = MockClassifier()
tf = tempfile.NamedTemporaryFile(mode='wb', delete=False)
tf.write(b'Hello world!!!!!')
tf.close()
scores = np.memmap(tf.name, dtype=np.float64)
score = np.memmap(tf.name, shape=(), mode='r', dtype=np.float64)
try:
cross_val_score(clf, X, y, scoring=lambda est, X, y: score)
# non-scalar should still fail
assert_raises(ValueError, cross_val_score, clf, X, y,
scoring=lambda est, X, y: scores)
finally:
# Best effort to release the mmap file handles before deleting the
# backing file under Windows
scores, score = None, None
for _ in range(3):
try:
os.unlink(tf.name)
break
except WindowsError:
sleep(1.)
def test_permutation_test_score_pandas():
# check permutation_test_score doesn't destroy pandas dataframe
types = [(MockDataFrame, MockDataFrame)]
try:
from pandas import Series, DataFrame
types.append((Series, DataFrame))
except ImportError:
pass
for TargetType, InputFeatureType in types:
# X dataframe, y series
iris = load_iris()
X, y = iris.data, iris.target
X_df, y_ser = InputFeatureType(X), TargetType(y)
check_df = lambda x: isinstance(x, InputFeatureType)
check_series = lambda x: isinstance(x, TargetType)
clf = CheckingClassifier(check_X=check_df, check_y=check_series)
permutation_test_score(clf, X_df, y_ser)
| 57,672 | 39.500702 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/tree/export.py | """
This module defines export functions for decision trees.
"""
# Authors: Gilles Louppe <[email protected]>
# Peter Prettenhofer <[email protected]>
# Brian Holt <[email protected]>
# Noel Dawe <[email protected]>
# Satrajit Gosh <[email protected]>
# Trevor Stephens <[email protected]>
# Li Li <[email protected]>
# License: BSD 3 clause
from numbers import Integral
import numpy as np
import warnings
from ..externals import six
from ..utils.validation import check_is_fitted
from . import _criterion
from . import _tree
def _color_brew(n):
"""Generate n colors with equally spaced hues.
Parameters
----------
n : int
The number of colors required.
Returns
-------
color_list : list, length n
List of n tuples of form (R, G, B) being the components of each color.
"""
color_list = []
# Initialize saturation & value; calculate chroma & value shift
s, v = 0.75, 0.9
c = s * v
m = v - c
for h in np.arange(25, 385, 360. / n).astype(int):
# Calculate some intermediate values
h_bar = h / 60.
x = c * (1 - abs((h_bar % 2) - 1))
# Initialize RGB with same hue & chroma as our color
rgb = [(c, x, 0),
(x, c, 0),
(0, c, x),
(0, x, c),
(x, 0, c),
(c, 0, x),
(c, x, 0)]
r, g, b = rgb[int(h_bar)]
# Shift the initial RGB values to match value and store
rgb = [(int(255 * (r + m))),
(int(255 * (g + m))),
(int(255 * (b + m)))]
color_list.append(rgb)
return color_list
class Sentinel(object):
def __repr__(self):
return '"tree.dot"'
SENTINEL = Sentinel()
def export_graphviz(decision_tree, out_file=SENTINEL, max_depth=None,
feature_names=None, class_names=None, label='all',
filled=False, leaves_parallel=False, impurity=True,
node_ids=False, proportion=False, rotate=False,
rounded=False, special_characters=False, precision=3):
"""Export a decision tree in DOT format.
This function generates a GraphViz representation of the decision tree,
which is then written into `out_file`. Once exported, graphical renderings
can be generated using, for example::
$ dot -Tps tree.dot -o tree.ps (PostScript format)
$ dot -Tpng tree.dot -o tree.png (PNG format)
The sample counts that are shown are weighted with any sample_weights that
might be present.
Read more in the :ref:`User Guide <tree>`.
Parameters
----------
decision_tree : decision tree classifier
The decision tree to be exported to GraphViz.
out_file : file object or string, optional (default='tree.dot')
Handle or name of the output file. If ``None``, the result is
returned as a string. This will the default from version 0.20.
max_depth : int, optional (default=None)
The maximum depth of the representation. If None, the tree is fully
generated.
feature_names : list of strings, optional (default=None)
Names of each of the features.
class_names : list of strings, bool or None, optional (default=None)
Names of each of the target classes in ascending numerical order.
Only relevant for classification and not supported for multi-output.
If ``True``, shows a symbolic representation of the class name.
label : {'all', 'root', 'none'}, optional (default='all')
Whether to show informative labels for impurity, etc.
Options include 'all' to show at every node, 'root' to show only at
the top root node, or 'none' to not show at any node.
filled : bool, optional (default=False)
When set to ``True``, paint nodes to indicate majority class for
classification, extremity of values for regression, or purity of node
for multi-output.
leaves_parallel : bool, optional (default=False)
When set to ``True``, draw all leaf nodes at the bottom of the tree.
impurity : bool, optional (default=True)
When set to ``True``, show the impurity at each node.
node_ids : bool, optional (default=False)
When set to ``True``, show the ID number on each node.
proportion : bool, optional (default=False)
When set to ``True``, change the display of 'values' and/or 'samples'
to be proportions and percentages respectively.
rotate : bool, optional (default=False)
When set to ``True``, orient tree left to right rather than top-down.
rounded : bool, optional (default=False)
When set to ``True``, draw node boxes with rounded corners and use
Helvetica fonts instead of Times-Roman.
special_characters : bool, optional (default=False)
When set to ``False``, ignore special characters for PostScript
compatibility.
precision : int, optional (default=3)
Number of digits of precision for floating point in the values of
impurity, threshold and value attributes of each node.
Returns
-------
dot_data : string
String representation of the input tree in GraphViz dot format.
Only returned if ``out_file`` is None.
.. versionadded:: 0.18
Examples
--------
>>> from sklearn.datasets import load_iris
>>> from sklearn import tree
>>> clf = tree.DecisionTreeClassifier()
>>> iris = load_iris()
>>> clf = clf.fit(iris.data, iris.target)
>>> tree.export_graphviz(clf,
... out_file='tree.dot') # doctest: +SKIP
"""
def get_color(value):
# Find the appropriate color & intensity for a node
if colors['bounds'] is None:
# Classification tree
color = list(colors['rgb'][np.argmax(value)])
sorted_values = sorted(value, reverse=True)
if len(sorted_values) == 1:
alpha = 0
else:
alpha = int(np.round(255 * (sorted_values[0] -
sorted_values[1]) /
(1 - sorted_values[1]), 0))
else:
# Regression tree or multi-output
color = list(colors['rgb'][0])
alpha = int(np.round(255 * ((value - colors['bounds'][0]) /
(colors['bounds'][1] -
colors['bounds'][0])), 0))
# Return html color code in #RRGGBBAA format
color.append(alpha)
hex_codes = [str(i) for i in range(10)]
hex_codes.extend(['a', 'b', 'c', 'd', 'e', 'f'])
color = [hex_codes[c // 16] + hex_codes[c % 16] for c in color]
return '#' + ''.join(color)
def node_to_str(tree, node_id, criterion):
# Generate the node content string
if tree.n_outputs == 1:
value = tree.value[node_id][0, :]
else:
value = tree.value[node_id]
# Should labels be shown?
labels = (label == 'root' and node_id == 0) or label == 'all'
# PostScript compatibility for special characters
if special_characters:
characters = ['#', '<SUB>', '</SUB>', '≤', '<br/>', '>']
node_string = '<'
else:
characters = ['#', '[', ']', '<=', '\\n', '"']
node_string = '"'
# Write node ID
if node_ids:
if labels:
node_string += 'node '
node_string += characters[0] + str(node_id) + characters[4]
# Write decision criteria
if tree.children_left[node_id] != _tree.TREE_LEAF:
# Always write node decision criteria, except for leaves
if feature_names is not None:
feature = feature_names[tree.feature[node_id]]
else:
feature = "X%s%s%s" % (characters[1],
tree.feature[node_id],
characters[2])
node_string += '%s %s %s%s' % (feature,
characters[3],
round(tree.threshold[node_id],
precision),
characters[4])
# Write impurity
if impurity:
if isinstance(criterion, _criterion.FriedmanMSE):
criterion = "friedman_mse"
elif not isinstance(criterion, six.string_types):
criterion = "impurity"
if labels:
node_string += '%s = ' % criterion
node_string += (str(round(tree.impurity[node_id], precision)) +
characters[4])
# Write node sample count
if labels:
node_string += 'samples = '
if proportion:
percent = (100. * tree.n_node_samples[node_id] /
float(tree.n_node_samples[0]))
node_string += (str(round(percent, 1)) + '%' +
characters[4])
else:
node_string += (str(tree.n_node_samples[node_id]) +
characters[4])
# Write node class distribution / regression value
if proportion and tree.n_classes[0] != 1:
# For classification this will show the proportion of samples
value = value / tree.weighted_n_node_samples[node_id]
if labels:
node_string += 'value = '
if tree.n_classes[0] == 1:
# Regression
value_text = np.around(value, precision)
elif proportion:
# Classification
value_text = np.around(value, precision)
elif np.all(np.equal(np.mod(value, 1), 0)):
# Classification without floating-point weights
value_text = value.astype(int)
else:
# Classification with floating-point weights
value_text = np.around(value, precision)
# Strip whitespace
value_text = str(value_text.astype('S32')).replace("b'", "'")
value_text = value_text.replace("' '", ", ").replace("'", "")
if tree.n_classes[0] == 1 and tree.n_outputs == 1:
value_text = value_text.replace("[", "").replace("]", "")
value_text = value_text.replace("\n ", characters[4])
node_string += value_text + characters[4]
# Write node majority class
if (class_names is not None and
tree.n_classes[0] != 1 and
tree.n_outputs == 1):
# Only done for single-output classification trees
if labels:
node_string += 'class = '
if class_names is not True:
class_name = class_names[np.argmax(value)]
else:
class_name = "y%s%s%s" % (characters[1],
np.argmax(value),
characters[2])
node_string += class_name
# Clean up any trailing newlines
if node_string[-2:] == '\\n':
node_string = node_string[:-2]
if node_string[-5:] == '<br/>':
node_string = node_string[:-5]
return node_string + characters[5]
def recurse(tree, node_id, criterion, parent=None, depth=0):
if node_id == _tree.TREE_LEAF:
raise ValueError("Invalid node_id %s" % _tree.TREE_LEAF)
left_child = tree.children_left[node_id]
right_child = tree.children_right[node_id]
# Add node with description
if max_depth is None or depth <= max_depth:
# Collect ranks for 'leaf' option in plot_options
if left_child == _tree.TREE_LEAF:
ranks['leaves'].append(str(node_id))
elif str(depth) not in ranks:
ranks[str(depth)] = [str(node_id)]
else:
ranks[str(depth)].append(str(node_id))
out_file.write('%d [label=%s'
% (node_id,
node_to_str(tree, node_id, criterion)))
if filled:
# Fetch appropriate color for node
if 'rgb' not in colors:
# Initialize colors and bounds if required
colors['rgb'] = _color_brew(tree.n_classes[0])
if tree.n_outputs != 1:
# Find max and min impurities for multi-output
colors['bounds'] = (np.min(-tree.impurity),
np.max(-tree.impurity))
elif (tree.n_classes[0] == 1 and
len(np.unique(tree.value)) != 1):
# Find max and min values in leaf nodes for regression
colors['bounds'] = (np.min(tree.value),
np.max(tree.value))
if tree.n_outputs == 1:
node_val = (tree.value[node_id][0, :] /
tree.weighted_n_node_samples[node_id])
if tree.n_classes[0] == 1:
# Regression
node_val = tree.value[node_id][0, :]
else:
# If multi-output color node by impurity
node_val = -tree.impurity[node_id]
out_file.write(', fillcolor="%s"' % get_color(node_val))
out_file.write('] ;\n')
if parent is not None:
# Add edge to parent
out_file.write('%d -> %d' % (parent, node_id))
if parent == 0:
# Draw True/False labels if parent is root node
angles = np.array([45, -45]) * ((rotate - .5) * -2)
out_file.write(' [labeldistance=2.5, labelangle=')
if node_id == 1:
out_file.write('%d, headlabel="True"]' % angles[0])
else:
out_file.write('%d, headlabel="False"]' % angles[1])
out_file.write(' ;\n')
if left_child != _tree.TREE_LEAF:
recurse(tree, left_child, criterion=criterion, parent=node_id,
depth=depth + 1)
recurse(tree, right_child, criterion=criterion, parent=node_id,
depth=depth + 1)
else:
ranks['leaves'].append(str(node_id))
out_file.write('%d [label="(...)"' % node_id)
if filled:
# color cropped nodes grey
out_file.write(', fillcolor="#C0C0C0"')
out_file.write('] ;\n' % node_id)
if parent is not None:
# Add edge to parent
out_file.write('%d -> %d ;\n' % (parent, node_id))
check_is_fitted(decision_tree, 'tree_')
own_file = False
return_string = False
try:
if out_file == SENTINEL:
warnings.warn("out_file can be set to None starting from 0.18. "
"This will be the default in 0.20.",
DeprecationWarning)
out_file = "tree.dot"
if isinstance(out_file, six.string_types):
if six.PY3:
out_file = open(out_file, "w", encoding="utf-8")
else:
out_file = open(out_file, "wb")
own_file = True
if out_file is None:
return_string = True
out_file = six.StringIO()
if isinstance(precision, Integral):
if precision < 0:
raise ValueError("'precision' should be greater or equal to 0."
" Got {} instead.".format(precision))
else:
raise ValueError("'precision' should be an integer. Got {}"
" instead.".format(type(precision)))
# Check length of feature_names before getting into the tree node
# Raise error if length of feature_names does not match
# n_features_ in the decision_tree
if feature_names is not None:
if len(feature_names) != decision_tree.n_features_:
raise ValueError("Length of feature_names, %d "
"does not match number of features, %d"
% (len(feature_names),
decision_tree.n_features_))
# The depth of each node for plotting with 'leaf' option
ranks = {'leaves': []}
# The colors to render each node with
colors = {'bounds': None}
out_file.write('digraph Tree {\n')
# Specify node aesthetics
out_file.write('node [shape=box')
rounded_filled = []
if filled:
rounded_filled.append('filled')
if rounded:
rounded_filled.append('rounded')
if len(rounded_filled) > 0:
out_file.write(', style="%s", color="black"'
% ", ".join(rounded_filled))
if rounded:
out_file.write(', fontname=helvetica')
out_file.write('] ;\n')
# Specify graph & edge aesthetics
if leaves_parallel:
out_file.write('graph [ranksep=equally, splines=polyline] ;\n')
if rounded:
out_file.write('edge [fontname=helvetica] ;\n')
if rotate:
out_file.write('rankdir=LR ;\n')
# Now recurse the tree and add node & edge attributes
if isinstance(decision_tree, _tree.Tree):
recurse(decision_tree, 0, criterion="impurity")
else:
recurse(decision_tree.tree_, 0, criterion=decision_tree.criterion)
# If required, draw leaf nodes at same depth as each other
if leaves_parallel:
for rank in sorted(ranks):
out_file.write("{rank=same ; " +
"; ".join(r for r in ranks[rank]) + "} ;\n")
out_file.write("}")
if return_string:
return out_file.getvalue()
finally:
if own_file:
out_file.close()
| 18,313 | 37.23382 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/tree/tree.py | """
This module gathers tree-based methods, including decision, regression and
randomized trees. Single and multi-output problems are both handled.
"""
# Authors: Gilles Louppe <[email protected]>
# Peter Prettenhofer <[email protected]>
# Brian Holt <[email protected]>
# Noel Dawe <[email protected]>
# Satrajit Gosh <[email protected]>
# Joly Arnaud <[email protected]>
# Fares Hedayati <[email protected]>
# Nelson Liu <[email protected]>
#
# License: BSD 3 clause
from __future__ import division
import numbers
import warnings
from abc import ABCMeta
from abc import abstractmethod
from math import ceil
import numpy as np
from scipy.sparse import issparse
from ..base import BaseEstimator
from ..base import ClassifierMixin
from ..base import RegressorMixin
from ..base import is_classifier
from ..externals import six
from ..utils import check_array
from ..utils import check_random_state
from ..utils import compute_sample_weight
from ..utils.multiclass import check_classification_targets
from ..utils.validation import check_is_fitted
from ._criterion import Criterion
from ._splitter import Splitter
from ._tree import DepthFirstTreeBuilder
from ._tree import BestFirstTreeBuilder
from ._tree import Tree
from . import _tree, _splitter, _criterion
__all__ = ["DecisionTreeClassifier",
"DecisionTreeRegressor",
"ExtraTreeClassifier",
"ExtraTreeRegressor"]
# =============================================================================
# Types and constants
# =============================================================================
DTYPE = _tree.DTYPE
DOUBLE = _tree.DOUBLE
CRITERIA_CLF = {"gini": _criterion.Gini, "entropy": _criterion.Entropy}
CRITERIA_REG = {"mse": _criterion.MSE, "friedman_mse": _criterion.FriedmanMSE,
"mae": _criterion.MAE}
DENSE_SPLITTERS = {"best": _splitter.BestSplitter,
"random": _splitter.RandomSplitter}
SPARSE_SPLITTERS = {"best": _splitter.BestSparseSplitter,
"random": _splitter.RandomSparseSplitter}
# =============================================================================
# Base decision tree
# =============================================================================
class BaseDecisionTree(six.with_metaclass(ABCMeta, BaseEstimator)):
"""Base class for decision trees.
Warning: This class should not be used directly.
Use derived classes instead.
"""
@abstractmethod
def __init__(self,
criterion,
splitter,
max_depth,
min_samples_split,
min_samples_leaf,
min_weight_fraction_leaf,
max_features,
max_leaf_nodes,
random_state,
min_impurity_decrease,
min_impurity_split,
class_weight=None,
presort=False):
self.criterion = criterion
self.splitter = splitter
self.max_depth = max_depth
self.min_samples_split = min_samples_split
self.min_samples_leaf = min_samples_leaf
self.min_weight_fraction_leaf = min_weight_fraction_leaf
self.max_features = max_features
self.random_state = random_state
self.max_leaf_nodes = max_leaf_nodes
self.min_impurity_decrease = min_impurity_decrease
self.min_impurity_split = min_impurity_split
self.class_weight = class_weight
self.presort = presort
def fit(self, X, y, sample_weight=None, check_input=True,
X_idx_sorted=None):
random_state = check_random_state(self.random_state)
if check_input:
X = check_array(X, dtype=DTYPE, accept_sparse="csc")
y = check_array(y, ensure_2d=False, dtype=None)
if issparse(X):
X.sort_indices()
if X.indices.dtype != np.intc or X.indptr.dtype != np.intc:
raise ValueError("No support for np.int64 index based "
"sparse matrices")
# Determine output settings
n_samples, self.n_features_ = X.shape
is_classification = is_classifier(self)
y = np.atleast_1d(y)
expanded_class_weight = None
if y.ndim == 1:
# reshape is necessary to preserve the data contiguity against vs
# [:, np.newaxis] that does not.
y = np.reshape(y, (-1, 1))
self.n_outputs_ = y.shape[1]
if is_classification:
check_classification_targets(y)
y = np.copy(y)
self.classes_ = []
self.n_classes_ = []
if self.class_weight is not None:
y_original = np.copy(y)
y_encoded = np.zeros(y.shape, dtype=np.int)
for k in range(self.n_outputs_):
classes_k, y_encoded[:, k] = np.unique(y[:, k],
return_inverse=True)
self.classes_.append(classes_k)
self.n_classes_.append(classes_k.shape[0])
y = y_encoded
if self.class_weight is not None:
expanded_class_weight = compute_sample_weight(
self.class_weight, y_original)
else:
self.classes_ = [None] * self.n_outputs_
self.n_classes_ = [1] * self.n_outputs_
self.n_classes_ = np.array(self.n_classes_, dtype=np.intp)
if getattr(y, "dtype", None) != DOUBLE or not y.flags.contiguous:
y = np.ascontiguousarray(y, dtype=DOUBLE)
# Check parameters
max_depth = ((2 ** 31) - 1 if self.max_depth is None
else self.max_depth)
max_leaf_nodes = (-1 if self.max_leaf_nodes is None
else self.max_leaf_nodes)
if isinstance(self.min_samples_leaf, (numbers.Integral, np.integer)):
if not 1 <= self.min_samples_leaf:
raise ValueError("min_samples_leaf must be at least 1 "
"or in (0, 0.5], got %s"
% self.min_samples_leaf)
min_samples_leaf = self.min_samples_leaf
else: # float
if not 0. < self.min_samples_leaf <= 0.5:
raise ValueError("min_samples_leaf must be at least 1 "
"or in (0, 0.5], got %s"
% self.min_samples_leaf)
min_samples_leaf = int(ceil(self.min_samples_leaf * n_samples))
if isinstance(self.min_samples_split, (numbers.Integral, np.integer)):
if not 2 <= self.min_samples_split:
raise ValueError("min_samples_split must be an integer "
"greater than 1 or a float in (0.0, 1.0]; "
"got the integer %s"
% self.min_samples_split)
min_samples_split = self.min_samples_split
else: # float
if not 0. < self.min_samples_split <= 1.:
raise ValueError("min_samples_split must be an integer "
"greater than 1 or a float in (0.0, 1.0]; "
"got the float %s"
% self.min_samples_split)
min_samples_split = int(ceil(self.min_samples_split * n_samples))
min_samples_split = max(2, min_samples_split)
min_samples_split = max(min_samples_split, 2 * min_samples_leaf)
if isinstance(self.max_features, six.string_types):
if self.max_features == "auto":
if is_classification:
max_features = max(1, int(np.sqrt(self.n_features_)))
else:
max_features = self.n_features_
elif self.max_features == "sqrt":
max_features = max(1, int(np.sqrt(self.n_features_)))
elif self.max_features == "log2":
max_features = max(1, int(np.log2(self.n_features_)))
else:
raise ValueError(
'Invalid value for max_features. Allowed string '
'values are "auto", "sqrt" or "log2".')
elif self.max_features is None:
max_features = self.n_features_
elif isinstance(self.max_features, (numbers.Integral, np.integer)):
max_features = self.max_features
else: # float
if self.max_features > 0.0:
max_features = max(1,
int(self.max_features * self.n_features_))
else:
max_features = 0
self.max_features_ = max_features
if len(y) != n_samples:
raise ValueError("Number of labels=%d does not match "
"number of samples=%d" % (len(y), n_samples))
if not 0 <= self.min_weight_fraction_leaf <= 0.5:
raise ValueError("min_weight_fraction_leaf must in [0, 0.5]")
if max_depth <= 0:
raise ValueError("max_depth must be greater than zero. ")
if not (0 < max_features <= self.n_features_):
raise ValueError("max_features must be in (0, n_features]")
if not isinstance(max_leaf_nodes, (numbers.Integral, np.integer)):
raise ValueError("max_leaf_nodes must be integral number but was "
"%r" % max_leaf_nodes)
if -1 < max_leaf_nodes < 2:
raise ValueError(("max_leaf_nodes {0} must be either None "
"or larger than 1").format(max_leaf_nodes))
if sample_weight is not None:
if (getattr(sample_weight, "dtype", None) != DOUBLE or
not sample_weight.flags.contiguous):
sample_weight = np.ascontiguousarray(
sample_weight, dtype=DOUBLE)
if len(sample_weight.shape) > 1:
raise ValueError("Sample weights array has more "
"than one dimension: %d" %
len(sample_weight.shape))
if len(sample_weight) != n_samples:
raise ValueError("Number of weights=%d does not match "
"number of samples=%d" %
(len(sample_weight), n_samples))
if expanded_class_weight is not None:
if sample_weight is not None:
sample_weight = sample_weight * expanded_class_weight
else:
sample_weight = expanded_class_weight
# Set min_weight_leaf from min_weight_fraction_leaf
if sample_weight is None:
min_weight_leaf = (self.min_weight_fraction_leaf *
n_samples)
else:
min_weight_leaf = (self.min_weight_fraction_leaf *
np.sum(sample_weight))
if self.min_impurity_split is not None:
warnings.warn("The min_impurity_split parameter is deprecated and"
" will be removed in version 0.21. "
"Use the min_impurity_decrease parameter instead.",
DeprecationWarning)
min_impurity_split = self.min_impurity_split
else:
min_impurity_split = 1e-7
if min_impurity_split < 0.:
raise ValueError("min_impurity_split must be greater than "
"or equal to 0")
if self.min_impurity_decrease < 0.:
raise ValueError("min_impurity_decrease must be greater than "
"or equal to 0")
presort = self.presort
# Allow presort to be 'auto', which means True if the dataset is dense,
# otherwise it will be False.
if self.presort == 'auto' and issparse(X):
presort = False
elif self.presort == 'auto':
presort = True
if presort is True and issparse(X):
raise ValueError("Presorting is not supported for sparse "
"matrices.")
# If multiple trees are built on the same dataset, we only want to
# presort once. Splitters now can accept presorted indices if desired,
# but do not handle any presorting themselves. Ensemble algorithms
# which desire presorting must do presorting themselves and pass that
# matrix into each tree.
if X_idx_sorted is None and presort:
X_idx_sorted = np.asfortranarray(np.argsort(X, axis=0),
dtype=np.int32)
if presort and X_idx_sorted.shape != X.shape:
raise ValueError("The shape of X (X.shape = {}) doesn't match "
"the shape of X_idx_sorted (X_idx_sorted"
".shape = {})".format(X.shape,
X_idx_sorted.shape))
# Build tree
criterion = self.criterion
if not isinstance(criterion, Criterion):
if is_classification:
criterion = CRITERIA_CLF[self.criterion](self.n_outputs_,
self.n_classes_)
else:
criterion = CRITERIA_REG[self.criterion](self.n_outputs_,
n_samples)
SPLITTERS = SPARSE_SPLITTERS if issparse(X) else DENSE_SPLITTERS
splitter = self.splitter
if not isinstance(self.splitter, Splitter):
splitter = SPLITTERS[self.splitter](criterion,
self.max_features_,
min_samples_leaf,
min_weight_leaf,
random_state,
self.presort)
self.tree_ = Tree(self.n_features_, self.n_classes_, self.n_outputs_)
# Use BestFirst if max_leaf_nodes given; use DepthFirst otherwise
if max_leaf_nodes < 0:
builder = DepthFirstTreeBuilder(splitter, min_samples_split,
min_samples_leaf,
min_weight_leaf,
max_depth,
self.min_impurity_decrease,
min_impurity_split)
else:
builder = BestFirstTreeBuilder(splitter, min_samples_split,
min_samples_leaf,
min_weight_leaf,
max_depth,
max_leaf_nodes,
self.min_impurity_decrease,
min_impurity_split)
builder.build(self.tree_, X, y, sample_weight, X_idx_sorted)
if self.n_outputs_ == 1:
self.n_classes_ = self.n_classes_[0]
self.classes_ = self.classes_[0]
return self
def _validate_X_predict(self, X, check_input):
"""Validate X whenever one tries to predict, apply, predict_proba"""
if check_input:
X = check_array(X, dtype=DTYPE, accept_sparse="csr")
if issparse(X) and (X.indices.dtype != np.intc or
X.indptr.dtype != np.intc):
raise ValueError("No support for np.int64 index based "
"sparse matrices")
n_features = X.shape[1]
if self.n_features_ != n_features:
raise ValueError("Number of features of the model must "
"match the input. Model n_features is %s and "
"input n_features is %s "
% (self.n_features_, n_features))
return X
def predict(self, X, check_input=True):
"""Predict class or regression value for X.
For a classification model, the predicted class for each sample in X is
returned. For a regression model, the predicted value based on X is
returned.
Parameters
----------
X : array-like or sparse matrix of shape = [n_samples, n_features]
The input samples. Internally, it will be converted to
``dtype=np.float32`` and if a sparse matrix is provided
to a sparse ``csr_matrix``.
check_input : boolean, (default=True)
Allow to bypass several input checking.
Don't use this parameter unless you know what you do.
Returns
-------
y : array of shape = [n_samples] or [n_samples, n_outputs]
The predicted classes, or the predict values.
"""
check_is_fitted(self, 'tree_')
X = self._validate_X_predict(X, check_input)
proba = self.tree_.predict(X)
n_samples = X.shape[0]
# Classification
if is_classifier(self):
if self.n_outputs_ == 1:
return self.classes_.take(np.argmax(proba, axis=1), axis=0)
else:
predictions = np.zeros((n_samples, self.n_outputs_))
for k in range(self.n_outputs_):
predictions[:, k] = self.classes_[k].take(
np.argmax(proba[:, k], axis=1),
axis=0)
return predictions
# Regression
else:
if self.n_outputs_ == 1:
return proba[:, 0]
else:
return proba[:, :, 0]
def apply(self, X, check_input=True):
"""
Returns the index of the leaf that each sample is predicted as.
.. versionadded:: 0.17
Parameters
----------
X : array_like or sparse matrix, shape = [n_samples, n_features]
The input samples. Internally, it will be converted to
``dtype=np.float32`` and if a sparse matrix is provided
to a sparse ``csr_matrix``.
check_input : boolean, (default=True)
Allow to bypass several input checking.
Don't use this parameter unless you know what you do.
Returns
-------
X_leaves : array_like, shape = [n_samples,]
For each datapoint x in X, return the index of the leaf x
ends up in. Leaves are numbered within
``[0; self.tree_.node_count)``, possibly with gaps in the
numbering.
"""
check_is_fitted(self, 'tree_')
X = self._validate_X_predict(X, check_input)
return self.tree_.apply(X)
def decision_path(self, X, check_input=True):
"""Return the decision path in the tree
.. versionadded:: 0.18
Parameters
----------
X : array_like or sparse matrix, shape = [n_samples, n_features]
The input samples. Internally, it will be converted to
``dtype=np.float32`` and if a sparse matrix is provided
to a sparse ``csr_matrix``.
check_input : boolean, (default=True)
Allow to bypass several input checking.
Don't use this parameter unless you know what you do.
Returns
-------
indicator : sparse csr array, shape = [n_samples, n_nodes]
Return a node indicator matrix where non zero elements
indicates that the samples goes through the nodes.
"""
X = self._validate_X_predict(X, check_input)
return self.tree_.decision_path(X)
@property
def feature_importances_(self):
"""Return the feature importances.
The importance of a feature is computed as the (normalized) total
reduction of the criterion brought by that feature.
It is also known as the Gini importance.
Returns
-------
feature_importances_ : array, shape = [n_features]
"""
check_is_fitted(self, 'tree_')
return self.tree_.compute_feature_importances()
# =============================================================================
# Public estimators
# =============================================================================
class DecisionTreeClassifier(BaseDecisionTree, ClassifierMixin):
"""A decision tree classifier.
Read more in the :ref:`User Guide <tree>`.
Parameters
----------
criterion : string, optional (default="gini")
The function to measure the quality of a split. Supported criteria are
"gini" for the Gini impurity and "entropy" for the information gain.
splitter : string, optional (default="best")
The strategy used to choose the split at each node. Supported
strategies are "best" to choose the best split and "random" to choose
the best random split.
max_depth : int or None, optional (default=None)
The maximum depth of the tree. If None, then nodes are expanded until
all leaves are pure or until all leaves contain less than
min_samples_split samples.
min_samples_split : int, float, optional (default=2)
The minimum number of samples required to split an internal node:
- If int, then consider `min_samples_split` as the minimum number.
- If float, then `min_samples_split` is a percentage and
`ceil(min_samples_split * n_samples)` are the minimum
number of samples for each split.
.. versionchanged:: 0.18
Added float values for percentages.
min_samples_leaf : int, float, optional (default=1)
The minimum number of samples required to be at a leaf node:
- If int, then consider `min_samples_leaf` as the minimum number.
- If float, then `min_samples_leaf` is a percentage and
`ceil(min_samples_leaf * n_samples)` are the minimum
number of samples for each node.
.. versionchanged:: 0.18
Added float values for percentages.
min_weight_fraction_leaf : float, optional (default=0.)
The minimum weighted fraction of the sum total of weights (of all
the input samples) required to be at a leaf node. Samples have
equal weight when sample_weight is not provided.
max_features : int, float, string or None, optional (default=None)
The number of features to consider when looking for the best split:
- If int, then consider `max_features` features at each split.
- If float, then `max_features` is a percentage and
`int(max_features * n_features)` features are considered at each
split.
- If "auto", then `max_features=sqrt(n_features)`.
- If "sqrt", then `max_features=sqrt(n_features)`.
- If "log2", then `max_features=log2(n_features)`.
- If None, then `max_features=n_features`.
Note: the search for a split does not stop until at least one
valid partition of the node samples is found, even if it requires to
effectively inspect more than ``max_features`` features.
random_state : int, RandomState instance or None, optional (default=None)
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
max_leaf_nodes : int or None, optional (default=None)
Grow a tree with ``max_leaf_nodes`` in best-first fashion.
Best nodes are defined as relative reduction in impurity.
If None then unlimited number of leaf nodes.
min_impurity_decrease : float, optional (default=0.)
A node will be split if this split induces a decrease of the impurity
greater than or equal to this value.
The weighted impurity decrease equation is the following::
N_t / N * (impurity - N_t_R / N_t * right_impurity
- N_t_L / N_t * left_impurity)
where ``N`` is the total number of samples, ``N_t`` is the number of
samples at the current node, ``N_t_L`` is the number of samples in the
left child, and ``N_t_R`` is the number of samples in the right child.
``N``, ``N_t``, ``N_t_R`` and ``N_t_L`` all refer to the weighted sum,
if ``sample_weight`` is passed.
.. versionadded:: 0.19
min_impurity_split : float,
Threshold for early stopping in tree growth. A node will split
if its impurity is above the threshold, otherwise it is a leaf.
.. deprecated:: 0.19
``min_impurity_split`` has been deprecated in favor of
``min_impurity_decrease`` in 0.19 and will be removed in 0.21.
Use ``min_impurity_decrease`` instead.
class_weight : dict, list of dicts, "balanced" or None, default=None
Weights associated with classes in the form ``{class_label: weight}``.
If not given, all classes are supposed to have weight one. For
multi-output problems, a list of dicts can be provided in the same
order as the columns of y.
Note that for multioutput (including multilabel) weights should be
defined for each class of every column in its own dict. For example,
for four-class multilabel classification weights should be
[{0: 1, 1: 1}, {0: 1, 1: 5}, {0: 1, 1: 1}, {0: 1, 1: 1}] instead of
[{1:1}, {2:5}, {3:1}, {4:1}].
The "balanced" mode uses the values of y to automatically adjust
weights inversely proportional to class frequencies in the input data
as ``n_samples / (n_classes * np.bincount(y))``
For multi-output, the weights of each column of y will be multiplied.
Note that these weights will be multiplied with sample_weight (passed
through the fit method) if sample_weight is specified.
presort : bool, optional (default=False)
Whether to presort the data to speed up the finding of best splits in
fitting. For the default settings of a decision tree on large
datasets, setting this to true may slow down the training process.
When using either a smaller dataset or a restricted depth, this may
speed up the training.
Attributes
----------
classes_ : array of shape = [n_classes] or a list of such arrays
The classes labels (single output problem),
or a list of arrays of class labels (multi-output problem).
feature_importances_ : array of shape = [n_features]
The feature importances. The higher, the more important the
feature. The importance of a feature is computed as the (normalized)
total reduction of the criterion brought by that feature. It is also
known as the Gini importance [4]_.
max_features_ : int,
The inferred value of max_features.
n_classes_ : int or list
The number of classes (for single output problems),
or a list containing the number of classes for each
output (for multi-output problems).
n_features_ : int
The number of features when ``fit`` is performed.
n_outputs_ : int
The number of outputs when ``fit`` is performed.
tree_ : Tree object
The underlying Tree object.
Notes
-----
The default values for the parameters controlling the size of the trees
(e.g. ``max_depth``, ``min_samples_leaf``, etc.) lead to fully grown and
unpruned trees which can potentially be very large on some data sets. To
reduce memory consumption, the complexity and size of the trees should be
controlled by setting those parameter values.
The features are always randomly permuted at each split. Therefore,
the best found split may vary, even with the same training data and
``max_features=n_features``, if the improvement of the criterion is
identical for several splits enumerated during the search of the best
split. To obtain a deterministic behaviour during fitting,
``random_state`` has to be fixed.
See also
--------
DecisionTreeRegressor
References
----------
.. [1] https://en.wikipedia.org/wiki/Decision_tree_learning
.. [2] L. Breiman, J. Friedman, R. Olshen, and C. Stone, "Classification
and Regression Trees", Wadsworth, Belmont, CA, 1984.
.. [3] T. Hastie, R. Tibshirani and J. Friedman. "Elements of Statistical
Learning", Springer, 2009.
.. [4] L. Breiman, and A. Cutler, "Random Forests",
http://www.stat.berkeley.edu/~breiman/RandomForests/cc_home.htm
Examples
--------
>>> from sklearn.datasets import load_iris
>>> from sklearn.model_selection import cross_val_score
>>> from sklearn.tree import DecisionTreeClassifier
>>> clf = DecisionTreeClassifier(random_state=0)
>>> iris = load_iris()
>>> cross_val_score(clf, iris.data, iris.target, cv=10)
... # doctest: +SKIP
...
array([ 1. , 0.93..., 0.86..., 0.93..., 0.93...,
0.93..., 0.93..., 1. , 0.93..., 1. ])
"""
def __init__(self,
criterion="gini",
splitter="best",
max_depth=None,
min_samples_split=2,
min_samples_leaf=1,
min_weight_fraction_leaf=0.,
max_features=None,
random_state=None,
max_leaf_nodes=None,
min_impurity_decrease=0.,
min_impurity_split=None,
class_weight=None,
presort=False):
super(DecisionTreeClassifier, self).__init__(
criterion=criterion,
splitter=splitter,
max_depth=max_depth,
min_samples_split=min_samples_split,
min_samples_leaf=min_samples_leaf,
min_weight_fraction_leaf=min_weight_fraction_leaf,
max_features=max_features,
max_leaf_nodes=max_leaf_nodes,
class_weight=class_weight,
random_state=random_state,
min_impurity_decrease=min_impurity_decrease,
min_impurity_split=min_impurity_split,
presort=presort)
def fit(self, X, y, sample_weight=None, check_input=True,
X_idx_sorted=None):
"""Build a decision tree classifier from the training set (X, y).
Parameters
----------
X : array-like or sparse matrix, shape = [n_samples, n_features]
The training input samples. Internally, it will be converted to
``dtype=np.float32`` and if a sparse matrix is provided
to a sparse ``csc_matrix``.
y : array-like, shape = [n_samples] or [n_samples, n_outputs]
The target values (class labels) as integers or strings.
sample_weight : array-like, shape = [n_samples] or None
Sample weights. If None, then samples are equally weighted. Splits
that would create child nodes with net zero or negative weight are
ignored while searching for a split in each node. Splits are also
ignored if they would result in any single class carrying a
negative weight in either child node.
check_input : boolean, (default=True)
Allow to bypass several input checking.
Don't use this parameter unless you know what you do.
X_idx_sorted : array-like, shape = [n_samples, n_features], optional
The indexes of the sorted training input samples. If many tree
are grown on the same dataset, this allows the ordering to be
cached between trees. If None, the data will be sorted here.
Don't use this parameter unless you know what to do.
Returns
-------
self : object
Returns self.
"""
super(DecisionTreeClassifier, self).fit(
X, y,
sample_weight=sample_weight,
check_input=check_input,
X_idx_sorted=X_idx_sorted)
return self
def predict_proba(self, X, check_input=True):
"""Predict class probabilities of the input samples X.
The predicted class probability is the fraction of samples of the same
class in a leaf.
check_input : boolean, (default=True)
Allow to bypass several input checking.
Don't use this parameter unless you know what you do.
Parameters
----------
X : array-like or sparse matrix of shape = [n_samples, n_features]
The input samples. Internally, it will be converted to
``dtype=np.float32`` and if a sparse matrix is provided
to a sparse ``csr_matrix``.
check_input : bool
Run check_array on X.
Returns
-------
p : array of shape = [n_samples, n_classes], or a list of n_outputs
such arrays if n_outputs > 1.
The class probabilities of the input samples. The order of the
classes corresponds to that in the attribute `classes_`.
"""
check_is_fitted(self, 'tree_')
X = self._validate_X_predict(X, check_input)
proba = self.tree_.predict(X)
if self.n_outputs_ == 1:
proba = proba[:, :self.n_classes_]
normalizer = proba.sum(axis=1)[:, np.newaxis]
normalizer[normalizer == 0.0] = 1.0
proba /= normalizer
return proba
else:
all_proba = []
for k in range(self.n_outputs_):
proba_k = proba[:, k, :self.n_classes_[k]]
normalizer = proba_k.sum(axis=1)[:, np.newaxis]
normalizer[normalizer == 0.0] = 1.0
proba_k /= normalizer
all_proba.append(proba_k)
return all_proba
def predict_log_proba(self, X):
"""Predict class log-probabilities of the input samples X.
Parameters
----------
X : array-like or sparse matrix of shape = [n_samples, n_features]
The input samples. Internally, it will be converted to
``dtype=np.float32`` and if a sparse matrix is provided
to a sparse ``csr_matrix``.
Returns
-------
p : array of shape = [n_samples, n_classes], or a list of n_outputs
such arrays if n_outputs > 1.
The class log-probabilities of the input samples. The order of the
classes corresponds to that in the attribute `classes_`.
"""
proba = self.predict_proba(X)
if self.n_outputs_ == 1:
return np.log(proba)
else:
for k in range(self.n_outputs_):
proba[k] = np.log(proba[k])
return proba
class DecisionTreeRegressor(BaseDecisionTree, RegressorMixin):
"""A decision tree regressor.
Read more in the :ref:`User Guide <tree>`.
Parameters
----------
criterion : string, optional (default="mse")
The function to measure the quality of a split. Supported criteria
are "mse" for the mean squared error, which is equal to variance
reduction as feature selection criterion and minimizes the L2 loss
using the mean of each terminal node, "friedman_mse", which uses mean
squared error with Friedman's improvement score for potential splits,
and "mae" for the mean absolute error, which minimizes the L1 loss
using the median of each terminal node.
.. versionadded:: 0.18
Mean Absolute Error (MAE) criterion.
splitter : string, optional (default="best")
The strategy used to choose the split at each node. Supported
strategies are "best" to choose the best split and "random" to choose
the best random split.
max_depth : int or None, optional (default=None)
The maximum depth of the tree. If None, then nodes are expanded until
all leaves are pure or until all leaves contain less than
min_samples_split samples.
min_samples_split : int, float, optional (default=2)
The minimum number of samples required to split an internal node:
- If int, then consider `min_samples_split` as the minimum number.
- If float, then `min_samples_split` is a percentage and
`ceil(min_samples_split * n_samples)` are the minimum
number of samples for each split.
.. versionchanged:: 0.18
Added float values for percentages.
min_samples_leaf : int, float, optional (default=1)
The minimum number of samples required to be at a leaf node:
- If int, then consider `min_samples_leaf` as the minimum number.
- If float, then `min_samples_leaf` is a percentage and
`ceil(min_samples_leaf * n_samples)` are the minimum
number of samples for each node.
.. versionchanged:: 0.18
Added float values for percentages.
min_weight_fraction_leaf : float, optional (default=0.)
The minimum weighted fraction of the sum total of weights (of all
the input samples) required to be at a leaf node. Samples have
equal weight when sample_weight is not provided.
max_features : int, float, string or None, optional (default=None)
The number of features to consider when looking for the best split:
- If int, then consider `max_features` features at each split.
- If float, then `max_features` is a percentage and
`int(max_features * n_features)` features are considered at each
split.
- If "auto", then `max_features=n_features`.
- If "sqrt", then `max_features=sqrt(n_features)`.
- If "log2", then `max_features=log2(n_features)`.
- If None, then `max_features=n_features`.
Note: the search for a split does not stop until at least one
valid partition of the node samples is found, even if it requires to
effectively inspect more than ``max_features`` features.
random_state : int, RandomState instance or None, optional (default=None)
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
max_leaf_nodes : int or None, optional (default=None)
Grow a tree with ``max_leaf_nodes`` in best-first fashion.
Best nodes are defined as relative reduction in impurity.
If None then unlimited number of leaf nodes.
min_impurity_decrease : float, optional (default=0.)
A node will be split if this split induces a decrease of the impurity
greater than or equal to this value.
The weighted impurity decrease equation is the following::
N_t / N * (impurity - N_t_R / N_t * right_impurity
- N_t_L / N_t * left_impurity)
where ``N`` is the total number of samples, ``N_t`` is the number of
samples at the current node, ``N_t_L`` is the number of samples in the
left child, and ``N_t_R`` is the number of samples in the right child.
``N``, ``N_t``, ``N_t_R`` and ``N_t_L`` all refer to the weighted sum,
if ``sample_weight`` is passed.
.. versionadded:: 0.19
min_impurity_split : float,
Threshold for early stopping in tree growth. A node will split
if its impurity is above the threshold, otherwise it is a leaf.
.. deprecated:: 0.19
``min_impurity_split`` has been deprecated in favor of
``min_impurity_decrease`` in 0.19 and will be removed in 0.21.
Use ``min_impurity_decrease`` instead.
presort : bool, optional (default=False)
Whether to presort the data to speed up the finding of best splits in
fitting. For the default settings of a decision tree on large
datasets, setting this to true may slow down the training process.
When using either a smaller dataset or a restricted depth, this may
speed up the training.
Attributes
----------
feature_importances_ : array of shape = [n_features]
The feature importances.
The higher, the more important the feature.
The importance of a feature is computed as the
(normalized) total reduction of the criterion brought
by that feature. It is also known as the Gini importance [4]_.
max_features_ : int,
The inferred value of max_features.
n_features_ : int
The number of features when ``fit`` is performed.
n_outputs_ : int
The number of outputs when ``fit`` is performed.
tree_ : Tree object
The underlying Tree object.
Notes
-----
The default values for the parameters controlling the size of the trees
(e.g. ``max_depth``, ``min_samples_leaf``, etc.) lead to fully grown and
unpruned trees which can potentially be very large on some data sets. To
reduce memory consumption, the complexity and size of the trees should be
controlled by setting those parameter values.
The features are always randomly permuted at each split. Therefore,
the best found split may vary, even with the same training data and
``max_features=n_features``, if the improvement of the criterion is
identical for several splits enumerated during the search of the best
split. To obtain a deterministic behaviour during fitting,
``random_state`` has to be fixed.
See also
--------
DecisionTreeClassifier
References
----------
.. [1] https://en.wikipedia.org/wiki/Decision_tree_learning
.. [2] L. Breiman, J. Friedman, R. Olshen, and C. Stone, "Classification
and Regression Trees", Wadsworth, Belmont, CA, 1984.
.. [3] T. Hastie, R. Tibshirani and J. Friedman. "Elements of Statistical
Learning", Springer, 2009.
.. [4] L. Breiman, and A. Cutler, "Random Forests",
http://www.stat.berkeley.edu/~breiman/RandomForests/cc_home.htm
Examples
--------
>>> from sklearn.datasets import load_boston
>>> from sklearn.model_selection import cross_val_score
>>> from sklearn.tree import DecisionTreeRegressor
>>> boston = load_boston()
>>> regressor = DecisionTreeRegressor(random_state=0)
>>> cross_val_score(regressor, boston.data, boston.target, cv=10)
... # doctest: +SKIP
...
array([ 0.61..., 0.57..., -0.34..., 0.41..., 0.75...,
0.07..., 0.29..., 0.33..., -1.42..., -1.77...])
"""
def __init__(self,
criterion="mse",
splitter="best",
max_depth=None,
min_samples_split=2,
min_samples_leaf=1,
min_weight_fraction_leaf=0.,
max_features=None,
random_state=None,
max_leaf_nodes=None,
min_impurity_decrease=0.,
min_impurity_split=None,
presort=False):
super(DecisionTreeRegressor, self).__init__(
criterion=criterion,
splitter=splitter,
max_depth=max_depth,
min_samples_split=min_samples_split,
min_samples_leaf=min_samples_leaf,
min_weight_fraction_leaf=min_weight_fraction_leaf,
max_features=max_features,
max_leaf_nodes=max_leaf_nodes,
random_state=random_state,
min_impurity_decrease=min_impurity_decrease,
min_impurity_split=min_impurity_split,
presort=presort)
def fit(self, X, y, sample_weight=None, check_input=True,
X_idx_sorted=None):
"""Build a decision tree regressor from the training set (X, y).
Parameters
----------
X : array-like or sparse matrix, shape = [n_samples, n_features]
The training input samples. Internally, it will be converted to
``dtype=np.float32`` and if a sparse matrix is provided
to a sparse ``csc_matrix``.
y : array-like, shape = [n_samples] or [n_samples, n_outputs]
The target values (real numbers). Use ``dtype=np.float64`` and
``order='C'`` for maximum efficiency.
sample_weight : array-like, shape = [n_samples] or None
Sample weights. If None, then samples are equally weighted. Splits
that would create child nodes with net zero or negative weight are
ignored while searching for a split in each node.
check_input : boolean, (default=True)
Allow to bypass several input checking.
Don't use this parameter unless you know what you do.
X_idx_sorted : array-like, shape = [n_samples, n_features], optional
The indexes of the sorted training input samples. If many tree
are grown on the same dataset, this allows the ordering to be
cached between trees. If None, the data will be sorted here.
Don't use this parameter unless you know what to do.
Returns
-------
self : object
Returns self.
"""
super(DecisionTreeRegressor, self).fit(
X, y,
sample_weight=sample_weight,
check_input=check_input,
X_idx_sorted=X_idx_sorted)
return self
class ExtraTreeClassifier(DecisionTreeClassifier):
"""An extremely randomized tree classifier.
Extra-trees differ from classic decision trees in the way they are built.
When looking for the best split to separate the samples of a node into two
groups, random splits are drawn for each of the `max_features` randomly
selected features and the best split among those is chosen. When
`max_features` is set 1, this amounts to building a totally random
decision tree.
Warning: Extra-trees should only be used within ensemble methods.
Read more in the :ref:`User Guide <tree>`.
Parameters
----------
criterion : string, optional (default="gini")
The function to measure the quality of a split. Supported criteria are
"gini" for the Gini impurity and "entropy" for the information gain.
splitter : string, optional (default="best")
The strategy used to choose the split at each node. Supported
strategies are "best" to choose the best split and "random" to choose
the best random split.
max_depth : int or None, optional (default=None)
The maximum depth of the tree. If None, then nodes are expanded until
all leaves are pure or until all leaves contain less than
min_samples_split samples.
min_samples_split : int, float, optional (default=2)
The minimum number of samples required to split an internal node:
- If int, then consider `min_samples_split` as the minimum number.
- If float, then `min_samples_split` is a percentage and
`ceil(min_samples_split * n_samples)` are the minimum
number of samples for each split.
.. versionchanged:: 0.18
Added float values for percentages.
min_samples_leaf : int, float, optional (default=1)
The minimum number of samples required to be at a leaf node:
- If int, then consider `min_samples_leaf` as the minimum number.
- If float, then `min_samples_leaf` is a percentage and
`ceil(min_samples_leaf * n_samples)` are the minimum
number of samples for each node.
.. versionchanged:: 0.18
Added float values for percentages.
min_weight_fraction_leaf : float, optional (default=0.)
The minimum weighted fraction of the sum total of weights (of all
the input samples) required to be at a leaf node. Samples have
equal weight when sample_weight is not provided.
max_features : int, float, string or None, optional (default=None)
The number of features to consider when looking for the best split:
- If int, then consider `max_features` features at each split.
- If float, then `max_features` is a percentage and
`int(max_features * n_features)` features are considered at each
split.
- If "auto", then `max_features=sqrt(n_features)`.
- If "sqrt", then `max_features=sqrt(n_features)`.
- If "log2", then `max_features=log2(n_features)`.
- If None, then `max_features=n_features`.
Note: the search for a split does not stop until at least one
valid partition of the node samples is found, even if it requires to
effectively inspect more than ``max_features`` features.
random_state : int, RandomState instance or None, optional (default=None)
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
max_leaf_nodes : int or None, optional (default=None)
Grow a tree with ``max_leaf_nodes`` in best-first fashion.
Best nodes are defined as relative reduction in impurity.
If None then unlimited number of leaf nodes.
min_impurity_decrease : float, optional (default=0.)
A node will be split if this split induces a decrease of the impurity
greater than or equal to this value.
The weighted impurity decrease equation is the following::
N_t / N * (impurity - N_t_R / N_t * right_impurity
- N_t_L / N_t * left_impurity)
where ``N`` is the total number of samples, ``N_t`` is the number of
samples at the current node, ``N_t_L`` is the number of samples in the
left child, and ``N_t_R`` is the number of samples in the right child.
``N``, ``N_t``, ``N_t_R`` and ``N_t_L`` all refer to the weighted sum,
if ``sample_weight`` is passed.
.. versionadded:: 0.19
min_impurity_split : float,
Threshold for early stopping in tree growth. A node will split
if its impurity is above the threshold, otherwise it is a leaf.
.. deprecated:: 0.19
``min_impurity_split`` has been deprecated in favor of
``min_impurity_decrease`` in 0.19 and will be removed in 0.21.
Use ``min_impurity_decrease`` instead.
class_weight : dict, list of dicts, "balanced" or None, default=None
Weights associated with classes in the form ``{class_label: weight}``.
If not given, all classes are supposed to have weight one. For
multi-output problems, a list of dicts can be provided in the same
order as the columns of y.
Note that for multioutput (including multilabel) weights should be
defined for each class of every column in its own dict. For example,
for four-class multilabel classification weights should be
[{0: 1, 1: 1}, {0: 1, 1: 5}, {0: 1, 1: 1}, {0: 1, 1: 1}] instead of
[{1:1}, {2:5}, {3:1}, {4:1}].
The "balanced" mode uses the values of y to automatically adjust
weights inversely proportional to class frequencies in the input data
as ``n_samples / (n_classes * np.bincount(y))``
For multi-output, the weights of each column of y will be multiplied.
Note that these weights will be multiplied with sample_weight (passed
through the fit method) if sample_weight is specified.
See also
--------
ExtraTreeRegressor, ExtraTreesClassifier, ExtraTreesRegressor
Notes
-----
The default values for the parameters controlling the size of the trees
(e.g. ``max_depth``, ``min_samples_leaf``, etc.) lead to fully grown and
unpruned trees which can potentially be very large on some data sets. To
reduce memory consumption, the complexity and size of the trees should be
controlled by setting those parameter values.
References
----------
.. [1] P. Geurts, D. Ernst., and L. Wehenkel, "Extremely randomized trees",
Machine Learning, 63(1), 3-42, 2006.
"""
def __init__(self,
criterion="gini",
splitter="random",
max_depth=None,
min_samples_split=2,
min_samples_leaf=1,
min_weight_fraction_leaf=0.,
max_features="auto",
random_state=None,
max_leaf_nodes=None,
min_impurity_decrease=0.,
min_impurity_split=None,
class_weight=None):
super(ExtraTreeClassifier, self).__init__(
criterion=criterion,
splitter=splitter,
max_depth=max_depth,
min_samples_split=min_samples_split,
min_samples_leaf=min_samples_leaf,
min_weight_fraction_leaf=min_weight_fraction_leaf,
max_features=max_features,
max_leaf_nodes=max_leaf_nodes,
class_weight=class_weight,
min_impurity_decrease=min_impurity_decrease,
min_impurity_split=min_impurity_split,
random_state=random_state)
class ExtraTreeRegressor(DecisionTreeRegressor):
"""An extremely randomized tree regressor.
Extra-trees differ from classic decision trees in the way they are built.
When looking for the best split to separate the samples of a node into two
groups, random splits are drawn for each of the `max_features` randomly
selected features and the best split among those is chosen. When
`max_features` is set 1, this amounts to building a totally random
decision tree.
Warning: Extra-trees should only be used within ensemble methods.
Read more in the :ref:`User Guide <tree>`.
Parameters
----------
criterion : string, optional (default="mse")
The function to measure the quality of a split. Supported criteria
are "mse" for the mean squared error, which is equal to variance
reduction as feature selection criterion, and "mae" for the mean
absolute error.
.. versionadded:: 0.18
Mean Absolute Error (MAE) criterion.
splitter : string, optional (default="best")
The strategy used to choose the split at each node. Supported
strategies are "best" to choose the best split and "random" to choose
the best random split.
max_depth : int or None, optional (default=None)
The maximum depth of the tree. If None, then nodes are expanded until
all leaves are pure or until all leaves contain less than
min_samples_split samples.
min_samples_split : int, float, optional (default=2)
The minimum number of samples required to split an internal node:
- If int, then consider `min_samples_split` as the minimum number.
- If float, then `min_samples_split` is a percentage and
`ceil(min_samples_split * n_samples)` are the minimum
number of samples for each split.
.. versionchanged:: 0.18
Added float values for percentages.
min_samples_leaf : int, float, optional (default=1)
The minimum number of samples required to be at a leaf node:
- If int, then consider `min_samples_leaf` as the minimum number.
- If float, then `min_samples_leaf` is a percentage and
`ceil(min_samples_leaf * n_samples)` are the minimum
number of samples for each node.
.. versionchanged:: 0.18
Added float values for percentages.
min_weight_fraction_leaf : float, optional (default=0.)
The minimum weighted fraction of the sum total of weights (of all
the input samples) required to be at a leaf node. Samples have
equal weight when sample_weight is not provided.
max_features : int, float, string or None, optional (default=None)
The number of features to consider when looking for the best split:
- If int, then consider `max_features` features at each split.
- If float, then `max_features` is a percentage and
`int(max_features * n_features)` features are considered at each
split.
- If "auto", then `max_features=n_features`.
- If "sqrt", then `max_features=sqrt(n_features)`.
- If "log2", then `max_features=log2(n_features)`.
- If None, then `max_features=n_features`.
Note: the search for a split does not stop until at least one
valid partition of the node samples is found, even if it requires to
effectively inspect more than ``max_features`` features.
random_state : int, RandomState instance or None, optional (default=None)
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
min_impurity_decrease : float, optional (default=0.)
A node will be split if this split induces a decrease of the impurity
greater than or equal to this value.
The weighted impurity decrease equation is the following::
N_t / N * (impurity - N_t_R / N_t * right_impurity
- N_t_L / N_t * left_impurity)
where ``N`` is the total number of samples, ``N_t`` is the number of
samples at the current node, ``N_t_L`` is the number of samples in the
left child, and ``N_t_R`` is the number of samples in the right child.
``N``, ``N_t``, ``N_t_R`` and ``N_t_L`` all refer to the weighted sum,
if ``sample_weight`` is passed.
.. versionadded:: 0.19
min_impurity_split : float,
Threshold for early stopping in tree growth. A node will split
if its impurity is above the threshold, otherwise it is a leaf.
.. deprecated:: 0.19
``min_impurity_split`` has been deprecated in favor of
``min_impurity_decrease`` in 0.19 and will be removed in 0.21.
Use ``min_impurity_decrease`` instead.
max_leaf_nodes : int or None, optional (default=None)
Grow a tree with ``max_leaf_nodes`` in best-first fashion.
Best nodes are defined as relative reduction in impurity.
If None then unlimited number of leaf nodes.
See also
--------
ExtraTreeClassifier, ExtraTreesClassifier, ExtraTreesRegressor
Notes
-----
The default values for the parameters controlling the size of the trees
(e.g. ``max_depth``, ``min_samples_leaf``, etc.) lead to fully grown and
unpruned trees which can potentially be very large on some data sets. To
reduce memory consumption, the complexity and size of the trees should be
controlled by setting those parameter values.
References
----------
.. [1] P. Geurts, D. Ernst., and L. Wehenkel, "Extremely randomized trees",
Machine Learning, 63(1), 3-42, 2006.
"""
def __init__(self,
criterion="mse",
splitter="random",
max_depth=None,
min_samples_split=2,
min_samples_leaf=1,
min_weight_fraction_leaf=0.,
max_features="auto",
random_state=None,
min_impurity_decrease=0.,
min_impurity_split=None,
max_leaf_nodes=None):
super(ExtraTreeRegressor, self).__init__(
criterion=criterion,
splitter=splitter,
max_depth=max_depth,
min_samples_split=min_samples_split,
min_samples_leaf=min_samples_leaf,
min_weight_fraction_leaf=min_weight_fraction_leaf,
max_features=max_features,
max_leaf_nodes=max_leaf_nodes,
min_impurity_decrease=min_impurity_decrease,
min_impurity_split=min_impurity_split,
random_state=random_state)
| 60,518 | 40.309898 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/tree/setup.py | import os
import numpy
from numpy.distutils.misc_util import Configuration
def configuration(parent_package="", top_path=None):
config = Configuration("tree", parent_package, top_path)
libraries = []
if os.name == 'posix':
libraries.append('m')
config.add_extension("_tree",
sources=["_tree.pyx"],
include_dirs=[numpy.get_include()],
libraries=libraries,
extra_compile_args=["-O3"])
config.add_extension("_splitter",
sources=["_splitter.pyx"],
include_dirs=[numpy.get_include()],
libraries=libraries,
extra_compile_args=["-O3"])
config.add_extension("_criterion",
sources=["_criterion.pyx"],
include_dirs=[numpy.get_include()],
libraries=libraries,
extra_compile_args=["-O3"])
config.add_extension("_utils",
sources=["_utils.pyx"],
include_dirs=[numpy.get_include()],
libraries=libraries,
extra_compile_args=["-O3"])
config.add_subpackage("tests")
return config
if __name__ == "__main__":
from numpy.distutils.core import setup
setup(**configuration().todict())
| 1,420 | 34.525 | 60 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/tree/__init__.py | """
The :mod:`sklearn.tree` module includes decision tree-based models for
classification and regression.
"""
from .tree import DecisionTreeClassifier
from .tree import DecisionTreeRegressor
from .tree import ExtraTreeClassifier
from .tree import ExtraTreeRegressor
from .export import export_graphviz
__all__ = ["DecisionTreeClassifier", "DecisionTreeRegressor",
"ExtraTreeClassifier", "ExtraTreeRegressor", "export_graphviz"]
| 441 | 30.571429 | 74 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/tree/tests/test_tree.py | """
Testing for the tree module (sklearn.tree).
"""
import copy
import pickle
from functools import partial
from itertools import product
import struct
import numpy as np
from scipy.sparse import csc_matrix
from scipy.sparse import csr_matrix
from scipy.sparse import coo_matrix
from sklearn.random_projection import sparse_random_matrix
from sklearn.metrics import accuracy_score
from sklearn.metrics import mean_squared_error
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_in
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_greater_equal
from sklearn.utils.testing import assert_less
from sklearn.utils.testing import assert_less_equal
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import assert_warns_message
from sklearn.utils.testing import raises
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.validation import check_random_state
from sklearn.exceptions import NotFittedError
from sklearn.tree import DecisionTreeClassifier
from sklearn.tree import DecisionTreeRegressor
from sklearn.tree import ExtraTreeClassifier
from sklearn.tree import ExtraTreeRegressor
from sklearn import tree
from sklearn.tree._tree import TREE_LEAF
from sklearn.tree.tree import CRITERIA_CLF
from sklearn.tree.tree import CRITERIA_REG
from sklearn import datasets
from sklearn.utils import compute_sample_weight
CLF_CRITERIONS = ("gini", "entropy")
REG_CRITERIONS = ("mse", "mae", "friedman_mse")
CLF_TREES = {
"DecisionTreeClassifier": DecisionTreeClassifier,
"Presort-DecisionTreeClassifier": partial(DecisionTreeClassifier,
presort=True),
"ExtraTreeClassifier": ExtraTreeClassifier,
}
REG_TREES = {
"DecisionTreeRegressor": DecisionTreeRegressor,
"Presort-DecisionTreeRegressor": partial(DecisionTreeRegressor,
presort=True),
"ExtraTreeRegressor": ExtraTreeRegressor,
}
ALL_TREES = dict()
ALL_TREES.update(CLF_TREES)
ALL_TREES.update(REG_TREES)
SPARSE_TREES = ["DecisionTreeClassifier", "DecisionTreeRegressor",
"ExtraTreeClassifier", "ExtraTreeRegressor"]
X_small = np.array([
[0, 0, 4, 0, 0, 0, 1, -14, 0, -4, 0, 0, 0, 0, ],
[0, 0, 5, 3, 0, -4, 0, 0, 1, -5, 0.2, 0, 4, 1, ],
[-1, -1, 0, 0, -4.5, 0, 0, 2.1, 1, 0, 0, -4.5, 0, 1, ],
[-1, -1, 0, -1.2, 0, 0, 0, 0, 0, 0, 0.2, 0, 0, 1, ],
[-1, -1, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 1, ],
[-1, -2, 0, 4, -3, 10, 4, 0, -3.2, 0, 4, 3, -4, 1, ],
[2.11, 0, -6, -0.5, 0, 11, 0, 0, -3.2, 6, 0.5, 0, -3, 1, ],
[2.11, 0, -6, -0.5, 0, 11, 0, 0, -3.2, 6, 0, 0, -2, 1, ],
[2.11, 8, -6, -0.5, 0, 11, 0, 0, -3.2, 6, 0, 0, -2, 1, ],
[2.11, 8, -6, -0.5, 0, 11, 0, 0, -3.2, 6, 0.5, 0, -1, 0, ],
[2, 8, 5, 1, 0.5, -4, 10, 0, 1, -5, 3, 0, 2, 0, ],
[2, 0, 1, 1, 1, -1, 1, 0, 0, -2, 3, 0, 1, 0, ],
[2, 0, 1, 2, 3, -1, 10, 2, 0, -1, 1, 2, 2, 0, ],
[1, 1, 0, 2, 2, -1, 1, 2, 0, -5, 1, 2, 3, 0, ],
[3, 1, 0, 3, 0, -4, 10, 0, 1, -5, 3, 0, 3, 1, ],
[2.11, 8, -6, -0.5, 0, 1, 0, 0, -3.2, 6, 0.5, 0, -3, 1, ],
[2.11, 8, -6, -0.5, 0, 1, 0, 0, -3.2, 6, 1.5, 1, -1, -1, ],
[2.11, 8, -6, -0.5, 0, 10, 0, 0, -3.2, 6, 0.5, 0, -1, -1, ],
[2, 0, 5, 1, 0.5, -2, 10, 0, 1, -5, 3, 1, 0, -1, ],
[2, 0, 1, 1, 1, -2, 1, 0, 0, -2, 0, 0, 0, 1, ],
[2, 1, 1, 1, 2, -1, 10, 2, 0, -1, 0, 2, 1, 1, ],
[1, 1, 0, 0, 1, -3, 1, 2, 0, -5, 1, 2, 1, 1, ],
[3, 1, 0, 1, 0, -4, 1, 0, 1, -2, 0, 0, 1, 0, ]])
y_small = [1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0,
0, 0]
y_small_reg = [1.0, 2.1, 1.2, 0.05, 10, 2.4, 3.1, 1.01, 0.01, 2.98, 3.1, 1.1,
0.0, 1.2, 2, 11, 0, 0, 4.5, 0.201, 1.06, 0.9, 0]
# toy sample
X = [[-2, -1], [-1, -1], [-1, -2], [1, 1], [1, 2], [2, 1]]
y = [-1, -1, -1, 1, 1, 1]
T = [[-1, -1], [2, 2], [3, 2]]
true_result = [-1, 1, 1]
# also load the iris dataset
# and randomly permute it
iris = datasets.load_iris()
rng = np.random.RandomState(1)
perm = rng.permutation(iris.target.size)
iris.data = iris.data[perm]
iris.target = iris.target[perm]
# also load the boston dataset
# and randomly permute it
boston = datasets.load_boston()
perm = rng.permutation(boston.target.size)
boston.data = boston.data[perm]
boston.target = boston.target[perm]
digits = datasets.load_digits()
perm = rng.permutation(digits.target.size)
digits.data = digits.data[perm]
digits.target = digits.target[perm]
random_state = check_random_state(0)
X_multilabel, y_multilabel = datasets.make_multilabel_classification(
random_state=0, n_samples=30, n_features=10)
X_sparse_pos = random_state.uniform(size=(20, 5))
X_sparse_pos[X_sparse_pos <= 0.8] = 0.
y_random = random_state.randint(0, 4, size=(20, ))
X_sparse_mix = sparse_random_matrix(20, 10, density=0.25, random_state=0)
DATASETS = {
"iris": {"X": iris.data, "y": iris.target},
"boston": {"X": boston.data, "y": boston.target},
"digits": {"X": digits.data, "y": digits.target},
"toy": {"X": X, "y": y},
"clf_small": {"X": X_small, "y": y_small},
"reg_small": {"X": X_small, "y": y_small_reg},
"multilabel": {"X": X_multilabel, "y": y_multilabel},
"sparse-pos": {"X": X_sparse_pos, "y": y_random},
"sparse-neg": {"X": - X_sparse_pos, "y": y_random},
"sparse-mix": {"X": X_sparse_mix, "y": y_random},
"zeros": {"X": np.zeros((20, 3)), "y": y_random}
}
for name in DATASETS:
DATASETS[name]["X_sparse"] = csc_matrix(DATASETS[name]["X"])
def assert_tree_equal(d, s, message):
assert_equal(s.node_count, d.node_count,
"{0}: inequal number of node ({1} != {2})"
"".format(message, s.node_count, d.node_count))
assert_array_equal(d.children_right, s.children_right,
message + ": inequal children_right")
assert_array_equal(d.children_left, s.children_left,
message + ": inequal children_left")
external = d.children_right == TREE_LEAF
internal = np.logical_not(external)
assert_array_equal(d.feature[internal], s.feature[internal],
message + ": inequal features")
assert_array_equal(d.threshold[internal], s.threshold[internal],
message + ": inequal threshold")
assert_array_equal(d.n_node_samples.sum(), s.n_node_samples.sum(),
message + ": inequal sum(n_node_samples)")
assert_array_equal(d.n_node_samples, s.n_node_samples,
message + ": inequal n_node_samples")
assert_almost_equal(d.impurity, s.impurity,
err_msg=message + ": inequal impurity")
assert_array_almost_equal(d.value[external], s.value[external],
err_msg=message + ": inequal value")
def test_classification_toy():
# Check classification on a toy dataset.
for name, Tree in CLF_TREES.items():
clf = Tree(random_state=0)
clf.fit(X, y)
assert_array_equal(clf.predict(T), true_result,
"Failed with {0}".format(name))
clf = Tree(max_features=1, random_state=1)
clf.fit(X, y)
assert_array_equal(clf.predict(T), true_result,
"Failed with {0}".format(name))
def test_weighted_classification_toy():
# Check classification on a weighted toy dataset.
for name, Tree in CLF_TREES.items():
clf = Tree(random_state=0)
clf.fit(X, y, sample_weight=np.ones(len(X)))
assert_array_equal(clf.predict(T), true_result,
"Failed with {0}".format(name))
clf.fit(X, y, sample_weight=np.ones(len(X)) * 0.5)
assert_array_equal(clf.predict(T), true_result,
"Failed with {0}".format(name))
def test_regression_toy():
# Check regression on a toy dataset.
for name, Tree in REG_TREES.items():
reg = Tree(random_state=1)
reg.fit(X, y)
assert_almost_equal(reg.predict(T), true_result,
err_msg="Failed with {0}".format(name))
clf = Tree(max_features=1, random_state=1)
clf.fit(X, y)
assert_almost_equal(reg.predict(T), true_result,
err_msg="Failed with {0}".format(name))
def test_xor():
# Check on a XOR problem
y = np.zeros((10, 10))
y[:5, :5] = 1
y[5:, 5:] = 1
gridx, gridy = np.indices(y.shape)
X = np.vstack([gridx.ravel(), gridy.ravel()]).T
y = y.ravel()
for name, Tree in CLF_TREES.items():
clf = Tree(random_state=0)
clf.fit(X, y)
assert_equal(clf.score(X, y), 1.0,
"Failed with {0}".format(name))
clf = Tree(random_state=0, max_features=1)
clf.fit(X, y)
assert_equal(clf.score(X, y), 1.0,
"Failed with {0}".format(name))
def test_iris():
# Check consistency on dataset iris.
for (name, Tree), criterion in product(CLF_TREES.items(), CLF_CRITERIONS):
clf = Tree(criterion=criterion, random_state=0)
clf.fit(iris.data, iris.target)
score = accuracy_score(clf.predict(iris.data), iris.target)
assert_greater(score, 0.9,
"Failed with {0}, criterion = {1} and score = {2}"
"".format(name, criterion, score))
clf = Tree(criterion=criterion, max_features=2, random_state=0)
clf.fit(iris.data, iris.target)
score = accuracy_score(clf.predict(iris.data), iris.target)
assert_greater(score, 0.5,
"Failed with {0}, criterion = {1} and score = {2}"
"".format(name, criterion, score))
def test_boston():
# Check consistency on dataset boston house prices.
for (name, Tree), criterion in product(REG_TREES.items(), REG_CRITERIONS):
reg = Tree(criterion=criterion, random_state=0)
reg.fit(boston.data, boston.target)
score = mean_squared_error(boston.target, reg.predict(boston.data))
assert_less(score, 1,
"Failed with {0}, criterion = {1} and score = {2}"
"".format(name, criterion, score))
# using fewer features reduces the learning ability of this tree,
# but reduces training time.
reg = Tree(criterion=criterion, max_features=6, random_state=0)
reg.fit(boston.data, boston.target)
score = mean_squared_error(boston.target, reg.predict(boston.data))
assert_less(score, 2,
"Failed with {0}, criterion = {1} and score = {2}"
"".format(name, criterion, score))
def test_probability():
# Predict probabilities using DecisionTreeClassifier.
for name, Tree in CLF_TREES.items():
clf = Tree(max_depth=1, max_features=1, random_state=42)
clf.fit(iris.data, iris.target)
prob_predict = clf.predict_proba(iris.data)
assert_array_almost_equal(np.sum(prob_predict, 1),
np.ones(iris.data.shape[0]),
err_msg="Failed with {0}".format(name))
assert_array_equal(np.argmax(prob_predict, 1),
clf.predict(iris.data),
err_msg="Failed with {0}".format(name))
assert_almost_equal(clf.predict_proba(iris.data),
np.exp(clf.predict_log_proba(iris.data)), 8,
err_msg="Failed with {0}".format(name))
def test_arrayrepr():
# Check the array representation.
# Check resize
X = np.arange(10000)[:, np.newaxis]
y = np.arange(10000)
for name, Tree in REG_TREES.items():
reg = Tree(max_depth=None, random_state=0)
reg.fit(X, y)
def test_pure_set():
# Check when y is pure.
X = [[-2, -1], [-1, -1], [-1, -2], [1, 1], [1, 2], [2, 1]]
y = [1, 1, 1, 1, 1, 1]
for name, TreeClassifier in CLF_TREES.items():
clf = TreeClassifier(random_state=0)
clf.fit(X, y)
assert_array_equal(clf.predict(X), y,
err_msg="Failed with {0}".format(name))
for name, TreeRegressor in REG_TREES.items():
reg = TreeRegressor(random_state=0)
reg.fit(X, y)
assert_almost_equal(reg.predict(X), y,
err_msg="Failed with {0}".format(name))
def test_numerical_stability():
# Check numerical stability.
X = np.array([
[152.08097839, 140.40744019, 129.75102234, 159.90493774],
[142.50700378, 135.81935120, 117.82884979, 162.75781250],
[127.28772736, 140.40744019, 129.75102234, 159.90493774],
[132.37025452, 143.71923828, 138.35694885, 157.84558105],
[103.10237122, 143.71928406, 138.35696411, 157.84559631],
[127.71276855, 143.71923828, 138.35694885, 157.84558105],
[120.91514587, 140.40744019, 129.75102234, 159.90493774]])
y = np.array(
[1., 0.70209277, 0.53896582, 0., 0.90914464, 0.48026916, 0.49622521])
with np.errstate(all="raise"):
for name, Tree in REG_TREES.items():
reg = Tree(random_state=0)
reg.fit(X, y)
reg.fit(X, -y)
reg.fit(-X, y)
reg.fit(-X, -y)
def test_importances():
# Check variable importances.
X, y = datasets.make_classification(n_samples=5000,
n_features=10,
n_informative=3,
n_redundant=0,
n_repeated=0,
shuffle=False,
random_state=0)
for name, Tree in CLF_TREES.items():
clf = Tree(random_state=0)
clf.fit(X, y)
importances = clf.feature_importances_
n_important = np.sum(importances > 0.1)
assert_equal(importances.shape[0], 10, "Failed with {0}".format(name))
assert_equal(n_important, 3, "Failed with {0}".format(name))
# Check on iris that importances are the same for all builders
clf = DecisionTreeClassifier(random_state=0)
clf.fit(iris.data, iris.target)
clf2 = DecisionTreeClassifier(random_state=0,
max_leaf_nodes=len(iris.data))
clf2.fit(iris.data, iris.target)
assert_array_equal(clf.feature_importances_,
clf2.feature_importances_)
@raises(ValueError)
def test_importances_raises():
# Check if variable importance before fit raises ValueError.
clf = DecisionTreeClassifier()
clf.feature_importances_
def test_importances_gini_equal_mse():
# Check that gini is equivalent to mse for binary output variable
X, y = datasets.make_classification(n_samples=2000,
n_features=10,
n_informative=3,
n_redundant=0,
n_repeated=0,
shuffle=False,
random_state=0)
# The gini index and the mean square error (variance) might differ due
# to numerical instability. Since those instabilities mainly occurs at
# high tree depth, we restrict this maximal depth.
clf = DecisionTreeClassifier(criterion="gini", max_depth=5,
random_state=0).fit(X, y)
reg = DecisionTreeRegressor(criterion="mse", max_depth=5,
random_state=0).fit(X, y)
assert_almost_equal(clf.feature_importances_, reg.feature_importances_)
assert_array_equal(clf.tree_.feature, reg.tree_.feature)
assert_array_equal(clf.tree_.children_left, reg.tree_.children_left)
assert_array_equal(clf.tree_.children_right, reg.tree_.children_right)
assert_array_equal(clf.tree_.n_node_samples, reg.tree_.n_node_samples)
def test_max_features():
# Check max_features.
for name, TreeRegressor in REG_TREES.items():
reg = TreeRegressor(max_features="auto")
reg.fit(boston.data, boston.target)
assert_equal(reg.max_features_, boston.data.shape[1])
for name, TreeClassifier in CLF_TREES.items():
clf = TreeClassifier(max_features="auto")
clf.fit(iris.data, iris.target)
assert_equal(clf.max_features_, 2)
for name, TreeEstimator in ALL_TREES.items():
est = TreeEstimator(max_features="sqrt")
est.fit(iris.data, iris.target)
assert_equal(est.max_features_,
int(np.sqrt(iris.data.shape[1])))
est = TreeEstimator(max_features="log2")
est.fit(iris.data, iris.target)
assert_equal(est.max_features_,
int(np.log2(iris.data.shape[1])))
est = TreeEstimator(max_features=1)
est.fit(iris.data, iris.target)
assert_equal(est.max_features_, 1)
est = TreeEstimator(max_features=3)
est.fit(iris.data, iris.target)
assert_equal(est.max_features_, 3)
est = TreeEstimator(max_features=0.01)
est.fit(iris.data, iris.target)
assert_equal(est.max_features_, 1)
est = TreeEstimator(max_features=0.5)
est.fit(iris.data, iris.target)
assert_equal(est.max_features_,
int(0.5 * iris.data.shape[1]))
est = TreeEstimator(max_features=1.0)
est.fit(iris.data, iris.target)
assert_equal(est.max_features_, iris.data.shape[1])
est = TreeEstimator(max_features=None)
est.fit(iris.data, iris.target)
assert_equal(est.max_features_, iris.data.shape[1])
# use values of max_features that are invalid
est = TreeEstimator(max_features=10)
assert_raises(ValueError, est.fit, X, y)
est = TreeEstimator(max_features=-1)
assert_raises(ValueError, est.fit, X, y)
est = TreeEstimator(max_features=0.0)
assert_raises(ValueError, est.fit, X, y)
est = TreeEstimator(max_features=1.5)
assert_raises(ValueError, est.fit, X, y)
est = TreeEstimator(max_features="foobar")
assert_raises(ValueError, est.fit, X, y)
def test_error():
# Test that it gives proper exception on deficient input.
for name, TreeEstimator in CLF_TREES.items():
# predict before fit
est = TreeEstimator()
assert_raises(NotFittedError, est.predict_proba, X)
est.fit(X, y)
X2 = [[-2, -1, 1]] # wrong feature shape for sample
assert_raises(ValueError, est.predict_proba, X2)
for name, TreeEstimator in ALL_TREES.items():
# Invalid values for parameters
assert_raises(ValueError, TreeEstimator(min_samples_leaf=-1).fit, X, y)
assert_raises(ValueError, TreeEstimator(min_samples_leaf=.6).fit, X, y)
assert_raises(ValueError, TreeEstimator(min_samples_leaf=0.).fit, X, y)
assert_raises(ValueError, TreeEstimator(min_samples_leaf=3.).fit, X, y)
assert_raises(ValueError,
TreeEstimator(min_weight_fraction_leaf=-1).fit,
X, y)
assert_raises(ValueError,
TreeEstimator(min_weight_fraction_leaf=0.51).fit,
X, y)
assert_raises(ValueError, TreeEstimator(min_samples_split=-1).fit,
X, y)
assert_raises(ValueError, TreeEstimator(min_samples_split=0.0).fit,
X, y)
assert_raises(ValueError, TreeEstimator(min_samples_split=1.1).fit,
X, y)
assert_raises(ValueError, TreeEstimator(min_samples_split=2.5).fit,
X, y)
assert_raises(ValueError, TreeEstimator(max_depth=-1).fit, X, y)
assert_raises(ValueError, TreeEstimator(max_features=42).fit, X, y)
assert_raises(ValueError, TreeEstimator(min_impurity_split=-1.0).fit,
X, y)
assert_raises(ValueError,
TreeEstimator(min_impurity_decrease=-1.0).fit, X, y)
# Wrong dimensions
est = TreeEstimator()
y2 = y[:-1]
assert_raises(ValueError, est.fit, X, y2)
# Test with arrays that are non-contiguous.
Xf = np.asfortranarray(X)
est = TreeEstimator()
est.fit(Xf, y)
assert_almost_equal(est.predict(T), true_result)
# predict before fitting
est = TreeEstimator()
assert_raises(NotFittedError, est.predict, T)
# predict on vector with different dims
est.fit(X, y)
t = np.asarray(T)
assert_raises(ValueError, est.predict, t[:, 1:])
# wrong sample shape
Xt = np.array(X).T
est = TreeEstimator()
est.fit(np.dot(X, Xt), y)
assert_raises(ValueError, est.predict, X)
assert_raises(ValueError, est.apply, X)
clf = TreeEstimator()
clf.fit(X, y)
assert_raises(ValueError, clf.predict, Xt)
assert_raises(ValueError, clf.apply, Xt)
# apply before fitting
est = TreeEstimator()
assert_raises(NotFittedError, est.apply, T)
def test_min_samples_split():
"""Test min_samples_split parameter"""
X = np.asfortranarray(iris.data.astype(tree._tree.DTYPE))
y = iris.target
# test both DepthFirstTreeBuilder and BestFirstTreeBuilder
# by setting max_leaf_nodes
for max_leaf_nodes, name in product((None, 1000), ALL_TREES.keys()):
TreeEstimator = ALL_TREES[name]
# test for integer parameter
est = TreeEstimator(min_samples_split=10,
max_leaf_nodes=max_leaf_nodes,
random_state=0)
est.fit(X, y)
# count samples on nodes, -1 means it is a leaf
node_samples = est.tree_.n_node_samples[est.tree_.children_left != -1]
assert_greater(np.min(node_samples), 9,
"Failed with {0}".format(name))
# test for float parameter
est = TreeEstimator(min_samples_split=0.2,
max_leaf_nodes=max_leaf_nodes,
random_state=0)
est.fit(X, y)
# count samples on nodes, -1 means it is a leaf
node_samples = est.tree_.n_node_samples[est.tree_.children_left != -1]
assert_greater(np.min(node_samples), 9,
"Failed with {0}".format(name))
def test_min_samples_leaf():
# Test if leaves contain more than leaf_count training examples
X = np.asfortranarray(iris.data.astype(tree._tree.DTYPE))
y = iris.target
# test both DepthFirstTreeBuilder and BestFirstTreeBuilder
# by setting max_leaf_nodes
for max_leaf_nodes, name in product((None, 1000), ALL_TREES.keys()):
TreeEstimator = ALL_TREES[name]
# test integer parameter
est = TreeEstimator(min_samples_leaf=5,
max_leaf_nodes=max_leaf_nodes,
random_state=0)
est.fit(X, y)
out = est.tree_.apply(X)
node_counts = np.bincount(out)
# drop inner nodes
leaf_count = node_counts[node_counts != 0]
assert_greater(np.min(leaf_count), 4,
"Failed with {0}".format(name))
# test float parameter
est = TreeEstimator(min_samples_leaf=0.1,
max_leaf_nodes=max_leaf_nodes,
random_state=0)
est.fit(X, y)
out = est.tree_.apply(X)
node_counts = np.bincount(out)
# drop inner nodes
leaf_count = node_counts[node_counts != 0]
assert_greater(np.min(leaf_count), 4,
"Failed with {0}".format(name))
def check_min_weight_fraction_leaf(name, datasets, sparse=False):
"""Test if leaves contain at least min_weight_fraction_leaf of the
training set"""
if sparse:
X = DATASETS[datasets]["X_sparse"].astype(np.float32)
else:
X = DATASETS[datasets]["X"].astype(np.float32)
y = DATASETS[datasets]["y"]
weights = rng.rand(X.shape[0])
total_weight = np.sum(weights)
TreeEstimator = ALL_TREES[name]
# test both DepthFirstTreeBuilder and BestFirstTreeBuilder
# by setting max_leaf_nodes
for max_leaf_nodes, frac in product((None, 1000), np.linspace(0, 0.5, 6)):
est = TreeEstimator(min_weight_fraction_leaf=frac,
max_leaf_nodes=max_leaf_nodes,
random_state=0)
est.fit(X, y, sample_weight=weights)
if sparse:
out = est.tree_.apply(X.tocsr())
else:
out = est.tree_.apply(X)
node_weights = np.bincount(out, weights=weights)
# drop inner nodes
leaf_weights = node_weights[node_weights != 0]
assert_greater_equal(
np.min(leaf_weights),
total_weight * est.min_weight_fraction_leaf,
"Failed with {0} "
"min_weight_fraction_leaf={1}".format(
name, est.min_weight_fraction_leaf))
# test case with no weights passed in
total_weight = X.shape[0]
for max_leaf_nodes, frac in product((None, 1000), np.linspace(0, 0.5, 6)):
est = TreeEstimator(min_weight_fraction_leaf=frac,
max_leaf_nodes=max_leaf_nodes,
random_state=0)
est.fit(X, y)
if sparse:
out = est.tree_.apply(X.tocsr())
else:
out = est.tree_.apply(X)
node_weights = np.bincount(out)
# drop inner nodes
leaf_weights = node_weights[node_weights != 0]
assert_greater_equal(
np.min(leaf_weights),
total_weight * est.min_weight_fraction_leaf,
"Failed with {0} "
"min_weight_fraction_leaf={1}".format(
name, est.min_weight_fraction_leaf))
def test_min_weight_fraction_leaf():
# Check on dense input
for name in ALL_TREES:
yield check_min_weight_fraction_leaf, name, "iris"
# Check on sparse input
for name in SPARSE_TREES:
yield check_min_weight_fraction_leaf, name, "multilabel", True
def check_min_weight_fraction_leaf_with_min_samples_leaf(name, datasets,
sparse=False):
"""Test the interaction between min_weight_fraction_leaf and min_samples_leaf
when sample_weights is not provided in fit."""
if sparse:
X = DATASETS[datasets]["X_sparse"].astype(np.float32)
else:
X = DATASETS[datasets]["X"].astype(np.float32)
y = DATASETS[datasets]["y"]
total_weight = X.shape[0]
TreeEstimator = ALL_TREES[name]
for max_leaf_nodes, frac in product((None, 1000), np.linspace(0, 0.5, 3)):
# test integer min_samples_leaf
est = TreeEstimator(min_weight_fraction_leaf=frac,
max_leaf_nodes=max_leaf_nodes,
min_samples_leaf=5,
random_state=0)
est.fit(X, y)
if sparse:
out = est.tree_.apply(X.tocsr())
else:
out = est.tree_.apply(X)
node_weights = np.bincount(out)
# drop inner nodes
leaf_weights = node_weights[node_weights != 0]
assert_greater_equal(
np.min(leaf_weights),
max((total_weight *
est.min_weight_fraction_leaf), 5),
"Failed with {0} "
"min_weight_fraction_leaf={1}, "
"min_samples_leaf={2}".format(name,
est.min_weight_fraction_leaf,
est.min_samples_leaf))
for max_leaf_nodes, frac in product((None, 1000), np.linspace(0, 0.5, 3)):
# test float min_samples_leaf
est = TreeEstimator(min_weight_fraction_leaf=frac,
max_leaf_nodes=max_leaf_nodes,
min_samples_leaf=.1,
random_state=0)
est.fit(X, y)
if sparse:
out = est.tree_.apply(X.tocsr())
else:
out = est.tree_.apply(X)
node_weights = np.bincount(out)
# drop inner nodes
leaf_weights = node_weights[node_weights != 0]
assert_greater_equal(
np.min(leaf_weights),
max((total_weight * est.min_weight_fraction_leaf),
(total_weight * est.min_samples_leaf)),
"Failed with {0} "
"min_weight_fraction_leaf={1}, "
"min_samples_leaf={2}".format(name,
est.min_weight_fraction_leaf,
est.min_samples_leaf))
def test_min_weight_fraction_leaf_with_min_samples_leaf():
# Check on dense input
for name in ALL_TREES:
yield (check_min_weight_fraction_leaf_with_min_samples_leaf,
name, "iris")
# Check on sparse input
for name in SPARSE_TREES:
yield (check_min_weight_fraction_leaf_with_min_samples_leaf,
name, "multilabel", True)
def test_min_impurity_split():
# test if min_impurity_split creates leaves with impurity
# [0, min_impurity_split) when min_samples_leaf = 1 and
# min_samples_split = 2.
X = np.asfortranarray(iris.data.astype(tree._tree.DTYPE))
y = iris.target
# test both DepthFirstTreeBuilder and BestFirstTreeBuilder
# by setting max_leaf_nodes
for max_leaf_nodes, name in product((None, 1000), ALL_TREES.keys()):
TreeEstimator = ALL_TREES[name]
min_impurity_split = .5
# verify leaf nodes without min_impurity_split less than
# impurity 1e-7
est = TreeEstimator(max_leaf_nodes=max_leaf_nodes,
random_state=0)
assert_true(est.min_impurity_split is None,
"Failed, min_impurity_split = {0} > 1e-7".format(
est.min_impurity_split))
try:
assert_warns(DeprecationWarning, est.fit, X, y)
except AssertionError:
pass
for node in range(est.tree_.node_count):
if (est.tree_.children_left[node] == TREE_LEAF or
est.tree_.children_right[node] == TREE_LEAF):
assert_equal(est.tree_.impurity[node], 0.,
"Failed with {0} "
"min_impurity_split={1}".format(
est.tree_.impurity[node],
est.min_impurity_split))
# verify leaf nodes have impurity [0,min_impurity_split] when using
# min_impurity_split
est = TreeEstimator(max_leaf_nodes=max_leaf_nodes,
min_impurity_split=min_impurity_split,
random_state=0)
assert_warns_message(DeprecationWarning,
"Use the min_impurity_decrease",
est.fit, X, y)
for node in range(est.tree_.node_count):
if (est.tree_.children_left[node] == TREE_LEAF or
est.tree_.children_right[node] == TREE_LEAF):
assert_greater_equal(est.tree_.impurity[node], 0,
"Failed with {0}, "
"min_impurity_split={1}".format(
est.tree_.impurity[node],
est.min_impurity_split))
assert_less_equal(est.tree_.impurity[node], min_impurity_split,
"Failed with {0}, "
"min_impurity_split={1}".format(
est.tree_.impurity[node],
est.min_impurity_split))
def test_min_impurity_decrease():
# test if min_impurity_decrease ensure that a split is made only if
# if the impurity decrease is atleast that value
X, y = datasets.make_classification(n_samples=10000, random_state=42)
# test both DepthFirstTreeBuilder and BestFirstTreeBuilder
# by setting max_leaf_nodes
for max_leaf_nodes, name in product((None, 1000), ALL_TREES.keys()):
TreeEstimator = ALL_TREES[name]
# Check default value of min_impurity_decrease, 1e-7
est1 = TreeEstimator(max_leaf_nodes=max_leaf_nodes, random_state=0)
# Check with explicit value of 0.05
est2 = TreeEstimator(max_leaf_nodes=max_leaf_nodes,
min_impurity_decrease=0.05, random_state=0)
# Check with a much lower value of 0.0001
est3 = TreeEstimator(max_leaf_nodes=max_leaf_nodes,
min_impurity_decrease=0.0001, random_state=0)
# Check with a much lower value of 0.1
est4 = TreeEstimator(max_leaf_nodes=max_leaf_nodes,
min_impurity_decrease=0.1, random_state=0)
for est, expected_decrease in ((est1, 1e-7), (est2, 0.05),
(est3, 0.0001), (est4, 0.1)):
assert_less_equal(est.min_impurity_decrease, expected_decrease,
"Failed, min_impurity_decrease = {0} > {1}"
.format(est.min_impurity_decrease,
expected_decrease))
est.fit(X, y)
for node in range(est.tree_.node_count):
# If current node is a not leaf node, check if the split was
# justified w.r.t the min_impurity_decrease
if est.tree_.children_left[node] != TREE_LEAF:
imp_parent = est.tree_.impurity[node]
wtd_n_node = est.tree_.weighted_n_node_samples[node]
left = est.tree_.children_left[node]
wtd_n_left = est.tree_.weighted_n_node_samples[left]
imp_left = est.tree_.impurity[left]
wtd_imp_left = wtd_n_left * imp_left
right = est.tree_.children_right[node]
wtd_n_right = est.tree_.weighted_n_node_samples[right]
imp_right = est.tree_.impurity[right]
wtd_imp_right = wtd_n_right * imp_right
wtd_avg_left_right_imp = wtd_imp_right + wtd_imp_left
wtd_avg_left_right_imp /= wtd_n_node
fractional_node_weight = (
est.tree_.weighted_n_node_samples[node] / X.shape[0])
actual_decrease = fractional_node_weight * (
imp_parent - wtd_avg_left_right_imp)
assert_greater_equal(actual_decrease, expected_decrease,
"Failed with {0} "
"expected min_impurity_decrease={1}"
.format(actual_decrease,
expected_decrease))
for name, TreeEstimator in ALL_TREES.items():
if "Classifier" in name:
X, y = iris.data, iris.target
else:
X, y = boston.data, boston.target
est = TreeEstimator(random_state=0)
est.fit(X, y)
score = est.score(X, y)
fitted_attribute = dict()
for attribute in ["max_depth", "node_count", "capacity"]:
fitted_attribute[attribute] = getattr(est.tree_, attribute)
serialized_object = pickle.dumps(est)
est2 = pickle.loads(serialized_object)
assert_equal(type(est2), est.__class__)
score2 = est2.score(X, y)
assert_equal(score, score2,
"Failed to generate same score after pickling "
"with {0}".format(name))
for attribute in fitted_attribute:
assert_equal(getattr(est2.tree_, attribute),
fitted_attribute[attribute],
"Failed to generate same attribute {0} after "
"pickling with {1}".format(attribute, name))
def test_multioutput():
# Check estimators on multi-output problems.
X = [[-2, -1],
[-1, -1],
[-1, -2],
[1, 1],
[1, 2],
[2, 1],
[-2, 1],
[-1, 1],
[-1, 2],
[2, -1],
[1, -1],
[1, -2]]
y = [[-1, 0],
[-1, 0],
[-1, 0],
[1, 1],
[1, 1],
[1, 1],
[-1, 2],
[-1, 2],
[-1, 2],
[1, 3],
[1, 3],
[1, 3]]
T = [[-1, -1], [1, 1], [-1, 1], [1, -1]]
y_true = [[-1, 0], [1, 1], [-1, 2], [1, 3]]
# toy classification problem
for name, TreeClassifier in CLF_TREES.items():
clf = TreeClassifier(random_state=0)
y_hat = clf.fit(X, y).predict(T)
assert_array_equal(y_hat, y_true)
assert_equal(y_hat.shape, (4, 2))
proba = clf.predict_proba(T)
assert_equal(len(proba), 2)
assert_equal(proba[0].shape, (4, 2))
assert_equal(proba[1].shape, (4, 4))
log_proba = clf.predict_log_proba(T)
assert_equal(len(log_proba), 2)
assert_equal(log_proba[0].shape, (4, 2))
assert_equal(log_proba[1].shape, (4, 4))
# toy regression problem
for name, TreeRegressor in REG_TREES.items():
reg = TreeRegressor(random_state=0)
y_hat = reg.fit(X, y).predict(T)
assert_almost_equal(y_hat, y_true)
assert_equal(y_hat.shape, (4, 2))
def test_classes_shape():
# Test that n_classes_ and classes_ have proper shape.
for name, TreeClassifier in CLF_TREES.items():
# Classification, single output
clf = TreeClassifier(random_state=0)
clf.fit(X, y)
assert_equal(clf.n_classes_, 2)
assert_array_equal(clf.classes_, [-1, 1])
# Classification, multi-output
_y = np.vstack((y, np.array(y) * 2)).T
clf = TreeClassifier(random_state=0)
clf.fit(X, _y)
assert_equal(len(clf.n_classes_), 2)
assert_equal(len(clf.classes_), 2)
assert_array_equal(clf.n_classes_, [2, 2])
assert_array_equal(clf.classes_, [[-1, 1], [-2, 2]])
def test_unbalanced_iris():
# Check class rebalancing.
unbalanced_X = iris.data[:125]
unbalanced_y = iris.target[:125]
sample_weight = compute_sample_weight("balanced", unbalanced_y)
for name, TreeClassifier in CLF_TREES.items():
clf = TreeClassifier(random_state=0)
clf.fit(unbalanced_X, unbalanced_y, sample_weight=sample_weight)
assert_almost_equal(clf.predict(unbalanced_X), unbalanced_y)
def test_memory_layout():
# Check that it works no matter the memory layout
for (name, TreeEstimator), dtype in product(ALL_TREES.items(),
[np.float64, np.float32]):
est = TreeEstimator(random_state=0)
# Nothing
X = np.asarray(iris.data, dtype=dtype)
y = iris.target
assert_array_equal(est.fit(X, y).predict(X), y)
# C-order
X = np.asarray(iris.data, order="C", dtype=dtype)
y = iris.target
assert_array_equal(est.fit(X, y).predict(X), y)
# F-order
X = np.asarray(iris.data, order="F", dtype=dtype)
y = iris.target
assert_array_equal(est.fit(X, y).predict(X), y)
# Contiguous
X = np.ascontiguousarray(iris.data, dtype=dtype)
y = iris.target
assert_array_equal(est.fit(X, y).predict(X), y)
if not est.presort:
# csr matrix
X = csr_matrix(iris.data, dtype=dtype)
y = iris.target
assert_array_equal(est.fit(X, y).predict(X), y)
# csc_matrix
X = csc_matrix(iris.data, dtype=dtype)
y = iris.target
assert_array_equal(est.fit(X, y).predict(X), y)
# Strided
X = np.asarray(iris.data[::3], dtype=dtype)
y = iris.target[::3]
assert_array_equal(est.fit(X, y).predict(X), y)
def test_sample_weight():
# Check sample weighting.
# Test that zero-weighted samples are not taken into account
X = np.arange(100)[:, np.newaxis]
y = np.ones(100)
y[:50] = 0.0
sample_weight = np.ones(100)
sample_weight[y == 0] = 0.0
clf = DecisionTreeClassifier(random_state=0)
clf.fit(X, y, sample_weight=sample_weight)
assert_array_equal(clf.predict(X), np.ones(100))
# Test that low weighted samples are not taken into account at low depth
X = np.arange(200)[:, np.newaxis]
y = np.zeros(200)
y[50:100] = 1
y[100:200] = 2
X[100:200, 0] = 200
sample_weight = np.ones(200)
sample_weight[y == 2] = .51 # Samples of class '2' are still weightier
clf = DecisionTreeClassifier(max_depth=1, random_state=0)
clf.fit(X, y, sample_weight=sample_weight)
assert_equal(clf.tree_.threshold[0], 149.5)
sample_weight[y == 2] = .5 # Samples of class '2' are no longer weightier
clf = DecisionTreeClassifier(max_depth=1, random_state=0)
clf.fit(X, y, sample_weight=sample_weight)
assert_equal(clf.tree_.threshold[0], 49.5) # Threshold should have moved
# Test that sample weighting is the same as having duplicates
X = iris.data
y = iris.target
duplicates = rng.randint(0, X.shape[0], 100)
clf = DecisionTreeClassifier(random_state=1)
clf.fit(X[duplicates], y[duplicates])
sample_weight = np.bincount(duplicates, minlength=X.shape[0])
clf2 = DecisionTreeClassifier(random_state=1)
clf2.fit(X, y, sample_weight=sample_weight)
internal = clf.tree_.children_left != tree._tree.TREE_LEAF
assert_array_almost_equal(clf.tree_.threshold[internal],
clf2.tree_.threshold[internal])
def test_sample_weight_invalid():
# Check sample weighting raises errors.
X = np.arange(100)[:, np.newaxis]
y = np.ones(100)
y[:50] = 0.0
clf = DecisionTreeClassifier(random_state=0)
sample_weight = np.random.rand(100, 1)
assert_raises(ValueError, clf.fit, X, y, sample_weight=sample_weight)
sample_weight = np.array(0)
assert_raises(ValueError, clf.fit, X, y, sample_weight=sample_weight)
sample_weight = np.ones(101)
assert_raises(ValueError, clf.fit, X, y, sample_weight=sample_weight)
sample_weight = np.ones(99)
assert_raises(ValueError, clf.fit, X, y, sample_weight=sample_weight)
def check_class_weights(name):
"""Check class_weights resemble sample_weights behavior."""
TreeClassifier = CLF_TREES[name]
# Iris is balanced, so no effect expected for using 'balanced' weights
clf1 = TreeClassifier(random_state=0)
clf1.fit(iris.data, iris.target)
clf2 = TreeClassifier(class_weight='balanced', random_state=0)
clf2.fit(iris.data, iris.target)
assert_almost_equal(clf1.feature_importances_, clf2.feature_importances_)
# Make a multi-output problem with three copies of Iris
iris_multi = np.vstack((iris.target, iris.target, iris.target)).T
# Create user-defined weights that should balance over the outputs
clf3 = TreeClassifier(class_weight=[{0: 2., 1: 2., 2: 1.},
{0: 2., 1: 1., 2: 2.},
{0: 1., 1: 2., 2: 2.}],
random_state=0)
clf3.fit(iris.data, iris_multi)
assert_almost_equal(clf2.feature_importances_, clf3.feature_importances_)
# Check against multi-output "auto" which should also have no effect
clf4 = TreeClassifier(class_weight='balanced', random_state=0)
clf4.fit(iris.data, iris_multi)
assert_almost_equal(clf3.feature_importances_, clf4.feature_importances_)
# Inflate importance of class 1, check against user-defined weights
sample_weight = np.ones(iris.target.shape)
sample_weight[iris.target == 1] *= 100
class_weight = {0: 1., 1: 100., 2: 1.}
clf1 = TreeClassifier(random_state=0)
clf1.fit(iris.data, iris.target, sample_weight)
clf2 = TreeClassifier(class_weight=class_weight, random_state=0)
clf2.fit(iris.data, iris.target)
assert_almost_equal(clf1.feature_importances_, clf2.feature_importances_)
# Check that sample_weight and class_weight are multiplicative
clf1 = TreeClassifier(random_state=0)
clf1.fit(iris.data, iris.target, sample_weight ** 2)
clf2 = TreeClassifier(class_weight=class_weight, random_state=0)
clf2.fit(iris.data, iris.target, sample_weight)
assert_almost_equal(clf1.feature_importances_, clf2.feature_importances_)
def test_class_weights():
for name in CLF_TREES:
yield check_class_weights, name
def check_class_weight_errors(name):
# Test if class_weight raises errors and warnings when expected.
TreeClassifier = CLF_TREES[name]
_y = np.vstack((y, np.array(y) * 2)).T
# Invalid preset string
clf = TreeClassifier(class_weight='the larch', random_state=0)
assert_raises(ValueError, clf.fit, X, y)
assert_raises(ValueError, clf.fit, X, _y)
# Not a list or preset for multi-output
clf = TreeClassifier(class_weight=1, random_state=0)
assert_raises(ValueError, clf.fit, X, _y)
# Incorrect length list for multi-output
clf = TreeClassifier(class_weight=[{-1: 0.5, 1: 1.}], random_state=0)
assert_raises(ValueError, clf.fit, X, _y)
def test_class_weight_errors():
for name in CLF_TREES:
yield check_class_weight_errors, name
def test_max_leaf_nodes():
# Test greedy trees with max_depth + 1 leafs.
from sklearn.tree._tree import TREE_LEAF
X, y = datasets.make_hastie_10_2(n_samples=100, random_state=1)
k = 4
for name, TreeEstimator in ALL_TREES.items():
est = TreeEstimator(max_depth=None, max_leaf_nodes=k + 1).fit(X, y)
tree = est.tree_
assert_equal((tree.children_left == TREE_LEAF).sum(), k + 1)
# max_leaf_nodes in (0, 1) should raise ValueError
est = TreeEstimator(max_depth=None, max_leaf_nodes=0)
assert_raises(ValueError, est.fit, X, y)
est = TreeEstimator(max_depth=None, max_leaf_nodes=1)
assert_raises(ValueError, est.fit, X, y)
est = TreeEstimator(max_depth=None, max_leaf_nodes=0.1)
assert_raises(ValueError, est.fit, X, y)
def test_max_leaf_nodes_max_depth():
# Test precedence of max_leaf_nodes over max_depth.
X, y = datasets.make_hastie_10_2(n_samples=100, random_state=1)
k = 4
for name, TreeEstimator in ALL_TREES.items():
est = TreeEstimator(max_depth=1, max_leaf_nodes=k).fit(X, y)
tree = est.tree_
assert_greater(tree.max_depth, 1)
def test_arrays_persist():
# Ensure property arrays' memory stays alive when tree disappears
# non-regression for #2726
for attr in ['n_classes', 'value', 'children_left', 'children_right',
'threshold', 'impurity', 'feature', 'n_node_samples']:
value = getattr(DecisionTreeClassifier().fit([[0], [1]], [0, 1]).tree_, attr)
# if pointing to freed memory, contents may be arbitrary
assert_true(-3 <= value.flat[0] < 3,
'Array points to arbitrary memory')
def test_only_constant_features():
random_state = check_random_state(0)
X = np.zeros((10, 20))
y = random_state.randint(0, 2, (10, ))
for name, TreeEstimator in ALL_TREES.items():
est = TreeEstimator(random_state=0)
est.fit(X, y)
assert_equal(est.tree_.max_depth, 0)
def test_behaviour_constant_feature_after_splits():
X = np.transpose(np.vstack(([[0, 0, 0, 0, 0, 1, 2, 4, 5, 6, 7]],
np.zeros((4, 11)))))
y = [0, 0, 0, 1, 1, 2, 2, 2, 3, 3, 3]
for name, TreeEstimator in ALL_TREES.items():
# do not check extra random trees
if "ExtraTree" not in name:
est = TreeEstimator(random_state=0, max_features=1)
est.fit(X, y)
assert_equal(est.tree_.max_depth, 2)
assert_equal(est.tree_.node_count, 5)
def test_with_only_one_non_constant_features():
X = np.hstack([np.array([[1.], [1.], [0.], [0.]]),
np.zeros((4, 1000))])
y = np.array([0., 1., 0., 1.0])
for name, TreeEstimator in CLF_TREES.items():
est = TreeEstimator(random_state=0, max_features=1)
est.fit(X, y)
assert_equal(est.tree_.max_depth, 1)
assert_array_equal(est.predict_proba(X), 0.5 * np.ones((4, 2)))
for name, TreeEstimator in REG_TREES.items():
est = TreeEstimator(random_state=0, max_features=1)
est.fit(X, y)
assert_equal(est.tree_.max_depth, 1)
assert_array_equal(est.predict(X), 0.5 * np.ones((4, )))
def test_big_input():
# Test if the warning for too large inputs is appropriate.
X = np.repeat(10 ** 40., 4).astype(np.float64).reshape(-1, 1)
clf = DecisionTreeClassifier()
try:
clf.fit(X, [0, 1, 0, 1])
except ValueError as e:
assert_in("float32", str(e))
def test_realloc():
from sklearn.tree._utils import _realloc_test
assert_raises(MemoryError, _realloc_test)
def test_huge_allocations():
n_bits = 8 * struct.calcsize("P")
X = np.random.randn(10, 2)
y = np.random.randint(0, 2, 10)
# Sanity check: we cannot request more memory than the size of the address
# space. Currently raises OverflowError.
huge = 2 ** (n_bits + 1)
clf = DecisionTreeClassifier(splitter='best', max_leaf_nodes=huge)
assert_raises(Exception, clf.fit, X, y)
# Non-regression test: MemoryError used to be dropped by Cython
# because of missing "except *".
huge = 2 ** (n_bits - 1) - 1
clf = DecisionTreeClassifier(splitter='best', max_leaf_nodes=huge)
assert_raises(MemoryError, clf.fit, X, y)
def check_sparse_input(tree, dataset, max_depth=None):
TreeEstimator = ALL_TREES[tree]
X = DATASETS[dataset]["X"]
X_sparse = DATASETS[dataset]["X_sparse"]
y = DATASETS[dataset]["y"]
# Gain testing time
if dataset in ["digits", "boston"]:
n_samples = X.shape[0] // 5
X = X[:n_samples]
X_sparse = X_sparse[:n_samples]
y = y[:n_samples]
for sparse_format in (csr_matrix, csc_matrix, coo_matrix):
X_sparse = sparse_format(X_sparse)
# Check the default (depth first search)
d = TreeEstimator(random_state=0, max_depth=max_depth).fit(X, y)
s = TreeEstimator(random_state=0, max_depth=max_depth).fit(X_sparse, y)
assert_tree_equal(d.tree_, s.tree_,
"{0} with dense and sparse format gave different "
"trees".format(tree))
y_pred = d.predict(X)
if tree in CLF_TREES:
y_proba = d.predict_proba(X)
y_log_proba = d.predict_log_proba(X)
for sparse_matrix in (csr_matrix, csc_matrix, coo_matrix):
X_sparse_test = sparse_matrix(X_sparse, dtype=np.float32)
assert_array_almost_equal(s.predict(X_sparse_test), y_pred)
if tree in CLF_TREES:
assert_array_almost_equal(s.predict_proba(X_sparse_test),
y_proba)
assert_array_almost_equal(s.predict_log_proba(X_sparse_test),
y_log_proba)
def test_sparse_input():
for tree_type, dataset in product(SPARSE_TREES, ("clf_small", "toy",
"digits", "multilabel",
"sparse-pos",
"sparse-neg",
"sparse-mix", "zeros")):
max_depth = 3 if dataset == "digits" else None
yield (check_sparse_input, tree_type, dataset, max_depth)
# Due to numerical instability of MSE and too strict test, we limit the
# maximal depth
for tree_type, dataset in product(SPARSE_TREES, ["boston", "reg_small"]):
if tree_type in REG_TREES:
yield (check_sparse_input, tree_type, dataset, 2)
def check_sparse_parameters(tree, dataset):
TreeEstimator = ALL_TREES[tree]
X = DATASETS[dataset]["X"]
X_sparse = DATASETS[dataset]["X_sparse"]
y = DATASETS[dataset]["y"]
# Check max_features
d = TreeEstimator(random_state=0, max_features=1, max_depth=2).fit(X, y)
s = TreeEstimator(random_state=0, max_features=1,
max_depth=2).fit(X_sparse, y)
assert_tree_equal(d.tree_, s.tree_,
"{0} with dense and sparse format gave different "
"trees".format(tree))
assert_array_almost_equal(s.predict(X), d.predict(X))
# Check min_samples_split
d = TreeEstimator(random_state=0, max_features=1,
min_samples_split=10).fit(X, y)
s = TreeEstimator(random_state=0, max_features=1,
min_samples_split=10).fit(X_sparse, y)
assert_tree_equal(d.tree_, s.tree_,
"{0} with dense and sparse format gave different "
"trees".format(tree))
assert_array_almost_equal(s.predict(X), d.predict(X))
# Check min_samples_leaf
d = TreeEstimator(random_state=0,
min_samples_leaf=X_sparse.shape[0] // 2).fit(X, y)
s = TreeEstimator(random_state=0,
min_samples_leaf=X_sparse.shape[0] // 2).fit(X_sparse, y)
assert_tree_equal(d.tree_, s.tree_,
"{0} with dense and sparse format gave different "
"trees".format(tree))
assert_array_almost_equal(s.predict(X), d.predict(X))
# Check best-first search
d = TreeEstimator(random_state=0, max_leaf_nodes=3).fit(X, y)
s = TreeEstimator(random_state=0, max_leaf_nodes=3).fit(X_sparse, y)
assert_tree_equal(d.tree_, s.tree_,
"{0} with dense and sparse format gave different "
"trees".format(tree))
assert_array_almost_equal(s.predict(X), d.predict(X))
def test_sparse_parameters():
for tree_type, dataset in product(SPARSE_TREES, ["sparse-pos",
"sparse-neg",
"sparse-mix", "zeros"]):
yield (check_sparse_parameters, tree_type, dataset)
def check_sparse_criterion(tree, dataset):
TreeEstimator = ALL_TREES[tree]
X = DATASETS[dataset]["X"]
X_sparse = DATASETS[dataset]["X_sparse"]
y = DATASETS[dataset]["y"]
# Check various criterion
CRITERIONS = REG_CRITERIONS if tree in REG_TREES else CLF_CRITERIONS
for criterion in CRITERIONS:
d = TreeEstimator(random_state=0, max_depth=3,
criterion=criterion).fit(X, y)
s = TreeEstimator(random_state=0, max_depth=3,
criterion=criterion).fit(X_sparse, y)
assert_tree_equal(d.tree_, s.tree_,
"{0} with dense and sparse format gave different "
"trees".format(tree))
assert_array_almost_equal(s.predict(X), d.predict(X))
def test_sparse_criterion():
for tree_type, dataset in product(SPARSE_TREES, ["sparse-pos",
"sparse-neg",
"sparse-mix", "zeros"]):
yield (check_sparse_criterion, tree_type, dataset)
def check_explicit_sparse_zeros(tree, max_depth=3,
n_features=10):
TreeEstimator = ALL_TREES[tree]
# n_samples set n_feature to ease construction of a simultaneous
# construction of a csr and csc matrix
n_samples = n_features
samples = np.arange(n_samples)
# Generate X, y
random_state = check_random_state(0)
indices = []
data = []
offset = 0
indptr = [offset]
for i in range(n_features):
n_nonzero_i = random_state.binomial(n_samples, 0.5)
indices_i = random_state.permutation(samples)[:n_nonzero_i]
indices.append(indices_i)
data_i = random_state.binomial(3, 0.5, size=(n_nonzero_i, )) - 1
data.append(data_i)
offset += n_nonzero_i
indptr.append(offset)
indices = np.concatenate(indices)
data = np.array(np.concatenate(data), dtype=np.float32)
X_sparse = csc_matrix((data, indices, indptr),
shape=(n_samples, n_features))
X = X_sparse.toarray()
X_sparse_test = csr_matrix((data, indices, indptr),
shape=(n_samples, n_features))
X_test = X_sparse_test.toarray()
y = random_state.randint(0, 3, size=(n_samples, ))
# Ensure that X_sparse_test owns its data, indices and indptr array
X_sparse_test = X_sparse_test.copy()
# Ensure that we have explicit zeros
assert_greater((X_sparse.data == 0.).sum(), 0)
assert_greater((X_sparse_test.data == 0.).sum(), 0)
# Perform the comparison
d = TreeEstimator(random_state=0, max_depth=max_depth).fit(X, y)
s = TreeEstimator(random_state=0, max_depth=max_depth).fit(X_sparse, y)
assert_tree_equal(d.tree_, s.tree_,
"{0} with dense and sparse format gave different "
"trees".format(tree))
Xs = (X_test, X_sparse_test)
for X1, X2 in product(Xs, Xs):
assert_array_almost_equal(s.tree_.apply(X1), d.tree_.apply(X2))
assert_array_almost_equal(s.apply(X1), d.apply(X2))
assert_array_almost_equal(s.apply(X1), s.tree_.apply(X1))
assert_array_almost_equal(s.tree_.decision_path(X1).toarray(),
d.tree_.decision_path(X2).toarray())
assert_array_almost_equal(s.decision_path(X1).toarray(),
d.decision_path(X2).toarray())
assert_array_almost_equal(s.decision_path(X1).toarray(),
s.tree_.decision_path(X1).toarray())
assert_array_almost_equal(s.predict(X1), d.predict(X2))
if tree in CLF_TREES:
assert_array_almost_equal(s.predict_proba(X1),
d.predict_proba(X2))
def test_explicit_sparse_zeros():
for tree_type in SPARSE_TREES:
yield (check_explicit_sparse_zeros, tree_type)
@ignore_warnings
def check_raise_error_on_1d_input(name):
TreeEstimator = ALL_TREES[name]
X = iris.data[:, 0].ravel()
X_2d = iris.data[:, 0].reshape((-1, 1))
y = iris.target
assert_raises(ValueError, TreeEstimator(random_state=0).fit, X, y)
est = TreeEstimator(random_state=0)
est.fit(X_2d, y)
assert_raises(ValueError, est.predict, [X])
@ignore_warnings
def test_1d_input():
for name in ALL_TREES:
yield check_raise_error_on_1d_input, name
def _check_min_weight_leaf_split_level(TreeEstimator, X, y, sample_weight):
# Private function to keep pretty printing in nose yielded tests
est = TreeEstimator(random_state=0)
est.fit(X, y, sample_weight=sample_weight)
assert_equal(est.tree_.max_depth, 1)
est = TreeEstimator(random_state=0, min_weight_fraction_leaf=0.4)
est.fit(X, y, sample_weight=sample_weight)
assert_equal(est.tree_.max_depth, 0)
def check_min_weight_leaf_split_level(name):
TreeEstimator = ALL_TREES[name]
X = np.array([[0], [0], [0], [0], [1]])
y = [0, 0, 0, 0, 1]
sample_weight = [0.2, 0.2, 0.2, 0.2, 0.2]
_check_min_weight_leaf_split_level(TreeEstimator, X, y, sample_weight)
if not TreeEstimator().presort:
_check_min_weight_leaf_split_level(TreeEstimator, csc_matrix(X), y,
sample_weight)
def test_min_weight_leaf_split_level():
for name in ALL_TREES:
yield check_min_weight_leaf_split_level, name
def check_public_apply(name):
X_small32 = X_small.astype(tree._tree.DTYPE)
est = ALL_TREES[name]()
est.fit(X_small, y_small)
assert_array_equal(est.apply(X_small),
est.tree_.apply(X_small32))
def check_public_apply_sparse(name):
X_small32 = csr_matrix(X_small.astype(tree._tree.DTYPE))
est = ALL_TREES[name]()
est.fit(X_small, y_small)
assert_array_equal(est.apply(X_small),
est.tree_.apply(X_small32))
def test_public_apply():
for name in ALL_TREES:
yield (check_public_apply, name)
for name in SPARSE_TREES:
yield (check_public_apply_sparse, name)
def check_presort_sparse(est, X, y):
assert_raises(ValueError, est.fit, X, y)
def test_presort_sparse():
ests = (DecisionTreeClassifier(presort=True),
DecisionTreeRegressor(presort=True))
sparse_matrices = (csr_matrix, csc_matrix, coo_matrix)
y, X = datasets.make_multilabel_classification(random_state=0,
n_samples=50,
n_features=1,
n_classes=20)
y = y[:, 0]
for est, sparse_matrix in product(ests, sparse_matrices):
yield check_presort_sparse, est, sparse_matrix(X), y
def test_decision_path_hardcoded():
X = iris.data
y = iris.target
est = DecisionTreeClassifier(random_state=0, max_depth=1).fit(X, y)
node_indicator = est.decision_path(X[:2]).toarray()
assert_array_equal(node_indicator, [[1, 1, 0], [1, 0, 1]])
def check_decision_path(name):
X = iris.data
y = iris.target
n_samples = X.shape[0]
TreeEstimator = ALL_TREES[name]
est = TreeEstimator(random_state=0, max_depth=2)
est.fit(X, y)
node_indicator_csr = est.decision_path(X)
node_indicator = node_indicator_csr.toarray()
assert_equal(node_indicator.shape, (n_samples, est.tree_.node_count))
# Assert that leaves index are correct
leaves = est.apply(X)
leave_indicator = [node_indicator[i, j] for i, j in enumerate(leaves)]
assert_array_almost_equal(leave_indicator, np.ones(shape=n_samples))
# Ensure only one leave node per sample
all_leaves = est.tree_.children_left == TREE_LEAF
assert_array_almost_equal(np.dot(node_indicator, all_leaves),
np.ones(shape=n_samples))
# Ensure max depth is consistent with sum of indicator
max_depth = node_indicator.sum(axis=1).max()
assert_less_equal(est.tree_.max_depth, max_depth)
def test_decision_path():
for name in ALL_TREES:
yield (check_decision_path, name)
def check_no_sparse_y_support(name):
X, y = X_multilabel, csr_matrix(y_multilabel)
TreeEstimator = ALL_TREES[name]
assert_raises(TypeError, TreeEstimator(random_state=0).fit, X, y)
def test_no_sparse_y_support():
# Currently we don't support sparse y
for name in ALL_TREES:
yield (check_no_sparse_y_support, name)
def test_mae():
# check MAE criterion produces correct results
# on small toy dataset
dt_mae = DecisionTreeRegressor(random_state=0, criterion="mae",
max_leaf_nodes=2)
dt_mae.fit([[3], [5], [3], [8], [5]], [6, 7, 3, 4, 3])
assert_array_equal(dt_mae.tree_.impurity, [1.4, 1.5, 4.0/3.0])
assert_array_equal(dt_mae.tree_.value.flat, [4, 4.5, 4.0])
dt_mae.fit([[3], [5], [3], [8], [5]], [6, 7, 3, 4, 3],
[0.6, 0.3, 0.1, 1.0, 0.3])
assert_array_equal(dt_mae.tree_.impurity, [7.0/2.3, 3.0/0.7, 4.0/1.6])
assert_array_equal(dt_mae.tree_.value.flat, [4.0, 6.0, 4.0])
def test_criterion_copy():
# Let's check whether copy of our criterion has the same type
# and properties as original
n_outputs = 3
n_classes = np.arange(3, dtype=np.intp)
n_samples = 100
def _pickle_copy(obj):
return pickle.loads(pickle.dumps(obj))
for copy_func in [copy.copy, copy.deepcopy, _pickle_copy]:
for _, typename in CRITERIA_CLF.items():
criteria = typename(n_outputs, n_classes)
result = copy_func(criteria).__reduce__()
typename_, (n_outputs_, n_classes_), _ = result
assert_equal(typename, typename_)
assert_equal(n_outputs, n_outputs_)
assert_array_equal(n_classes, n_classes_)
for _, typename in CRITERIA_REG.items():
criteria = typename(n_outputs, n_samples)
result = copy_func(criteria).__reduce__()
typename_, (n_outputs_, n_samples_), _ = result
assert_equal(typename, typename_)
assert_equal(n_outputs, n_outputs_)
assert_equal(n_samples, n_samples_)
| 64,758 | 36.650581 | 85 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/tree/tests/test_export.py | """
Testing for export functions of decision trees (sklearn.tree.export).
"""
from re import finditer, search
from numpy.random import RandomState
from sklearn.base import is_classifier
from sklearn.tree import DecisionTreeClassifier, DecisionTreeRegressor
from sklearn.ensemble import GradientBoostingClassifier
from sklearn.tree import export_graphviz
from sklearn.externals.six import StringIO
from sklearn.utils.testing import (assert_in, assert_equal, assert_raises,
assert_less_equal, assert_raises_regex,
assert_raise_message)
from sklearn.exceptions import NotFittedError
# toy sample
X = [[-2, -1], [-1, -1], [-1, -2], [1, 1], [1, 2], [2, 1]]
y = [-1, -1, -1, 1, 1, 1]
y2 = [[-1, 1], [-1, 1], [-1, 1], [1, 2], [1, 2], [1, 3]]
w = [1, 1, 1, .5, .5, .5]
y_degraded = [1, 1, 1, 1, 1, 1]
def test_graphviz_toy():
# Check correctness of export_graphviz
clf = DecisionTreeClassifier(max_depth=3,
min_samples_split=2,
criterion="gini",
random_state=2)
clf.fit(X, y)
# Test export code
contents1 = export_graphviz(clf, out_file=None)
contents2 = 'digraph Tree {\n' \
'node [shape=box] ;\n' \
'0 [label="X[0] <= 0.0\\ngini = 0.5\\nsamples = 6\\n' \
'value = [3, 3]"] ;\n' \
'1 [label="gini = 0.0\\nsamples = 3\\nvalue = [3, 0]"] ;\n' \
'0 -> 1 [labeldistance=2.5, labelangle=45, ' \
'headlabel="True"] ;\n' \
'2 [label="gini = 0.0\\nsamples = 3\\nvalue = [0, 3]"] ;\n' \
'0 -> 2 [labeldistance=2.5, labelangle=-45, ' \
'headlabel="False"] ;\n' \
'}'
assert_equal(contents1, contents2)
# Test with feature_names
contents1 = export_graphviz(clf, feature_names=["feature0", "feature1"],
out_file=None)
contents2 = 'digraph Tree {\n' \
'node [shape=box] ;\n' \
'0 [label="feature0 <= 0.0\\ngini = 0.5\\nsamples = 6\\n' \
'value = [3, 3]"] ;\n' \
'1 [label="gini = 0.0\\nsamples = 3\\nvalue = [3, 0]"] ;\n' \
'0 -> 1 [labeldistance=2.5, labelangle=45, ' \
'headlabel="True"] ;\n' \
'2 [label="gini = 0.0\\nsamples = 3\\nvalue = [0, 3]"] ;\n' \
'0 -> 2 [labeldistance=2.5, labelangle=-45, ' \
'headlabel="False"] ;\n' \
'}'
assert_equal(contents1, contents2)
# Test with class_names
contents1 = export_graphviz(clf, class_names=["yes", "no"], out_file=None)
contents2 = 'digraph Tree {\n' \
'node [shape=box] ;\n' \
'0 [label="X[0] <= 0.0\\ngini = 0.5\\nsamples = 6\\n' \
'value = [3, 3]\\nclass = yes"] ;\n' \
'1 [label="gini = 0.0\\nsamples = 3\\nvalue = [3, 0]\\n' \
'class = yes"] ;\n' \
'0 -> 1 [labeldistance=2.5, labelangle=45, ' \
'headlabel="True"] ;\n' \
'2 [label="gini = 0.0\\nsamples = 3\\nvalue = [0, 3]\\n' \
'class = no"] ;\n' \
'0 -> 2 [labeldistance=2.5, labelangle=-45, ' \
'headlabel="False"] ;\n' \
'}'
assert_equal(contents1, contents2)
# Test plot_options
contents1 = export_graphviz(clf, filled=True, impurity=False,
proportion=True, special_characters=True,
rounded=True, out_file=None)
contents2 = 'digraph Tree {\n' \
'node [shape=box, style="filled, rounded", color="black", ' \
'fontname=helvetica] ;\n' \
'edge [fontname=helvetica] ;\n' \
'0 [label=<X<SUB>0</SUB> ≤ 0.0<br/>samples = 100.0%<br/>' \
'value = [0.5, 0.5]>, fillcolor="#e5813900"] ;\n' \
'1 [label=<samples = 50.0%<br/>value = [1.0, 0.0]>, ' \
'fillcolor="#e58139ff"] ;\n' \
'0 -> 1 [labeldistance=2.5, labelangle=45, ' \
'headlabel="True"] ;\n' \
'2 [label=<samples = 50.0%<br/>value = [0.0, 1.0]>, ' \
'fillcolor="#399de5ff"] ;\n' \
'0 -> 2 [labeldistance=2.5, labelangle=-45, ' \
'headlabel="False"] ;\n' \
'}'
assert_equal(contents1, contents2)
# Test max_depth
contents1 = export_graphviz(clf, max_depth=0,
class_names=True, out_file=None)
contents2 = 'digraph Tree {\n' \
'node [shape=box] ;\n' \
'0 [label="X[0] <= 0.0\\ngini = 0.5\\nsamples = 6\\n' \
'value = [3, 3]\\nclass = y[0]"] ;\n' \
'1 [label="(...)"] ;\n' \
'0 -> 1 ;\n' \
'2 [label="(...)"] ;\n' \
'0 -> 2 ;\n' \
'}'
assert_equal(contents1, contents2)
# Test max_depth with plot_options
contents1 = export_graphviz(clf, max_depth=0, filled=True,
out_file=None, node_ids=True)
contents2 = 'digraph Tree {\n' \
'node [shape=box, style="filled", color="black"] ;\n' \
'0 [label="node #0\\nX[0] <= 0.0\\ngini = 0.5\\n' \
'samples = 6\\nvalue = [3, 3]", fillcolor="#e5813900"] ;\n' \
'1 [label="(...)", fillcolor="#C0C0C0"] ;\n' \
'0 -> 1 ;\n' \
'2 [label="(...)", fillcolor="#C0C0C0"] ;\n' \
'0 -> 2 ;\n' \
'}'
assert_equal(contents1, contents2)
# Test multi-output with weighted samples
clf = DecisionTreeClassifier(max_depth=2,
min_samples_split=2,
criterion="gini",
random_state=2)
clf = clf.fit(X, y2, sample_weight=w)
contents1 = export_graphviz(clf, filled=True,
impurity=False, out_file=None)
contents2 = 'digraph Tree {\n' \
'node [shape=box, style="filled", color="black"] ;\n' \
'0 [label="X[0] <= 0.0\\nsamples = 6\\n' \
'value = [[3.0, 1.5, 0.0]\\n' \
'[3.0, 1.0, 0.5]]", fillcolor="#e5813900"] ;\n' \
'1 [label="samples = 3\\nvalue = [[3, 0, 0]\\n' \
'[3, 0, 0]]", fillcolor="#e58139ff"] ;\n' \
'0 -> 1 [labeldistance=2.5, labelangle=45, ' \
'headlabel="True"] ;\n' \
'2 [label="X[0] <= 1.5\\nsamples = 3\\n' \
'value = [[0.0, 1.5, 0.0]\\n' \
'[0.0, 1.0, 0.5]]", fillcolor="#e5813986"] ;\n' \
'0 -> 2 [labeldistance=2.5, labelangle=-45, ' \
'headlabel="False"] ;\n' \
'3 [label="samples = 2\\nvalue = [[0, 1, 0]\\n' \
'[0, 1, 0]]", fillcolor="#e58139ff"] ;\n' \
'2 -> 3 ;\n' \
'4 [label="samples = 1\\nvalue = [[0.0, 0.5, 0.0]\\n' \
'[0.0, 0.0, 0.5]]", fillcolor="#e58139ff"] ;\n' \
'2 -> 4 ;\n' \
'}'
assert_equal(contents1, contents2)
# Test regression output with plot_options
clf = DecisionTreeRegressor(max_depth=3,
min_samples_split=2,
criterion="mse",
random_state=2)
clf.fit(X, y)
contents1 = export_graphviz(clf, filled=True, leaves_parallel=True,
out_file=None, rotate=True, rounded=True)
contents2 = 'digraph Tree {\n' \
'node [shape=box, style="filled, rounded", color="black", ' \
'fontname=helvetica] ;\n' \
'graph [ranksep=equally, splines=polyline] ;\n' \
'edge [fontname=helvetica] ;\n' \
'rankdir=LR ;\n' \
'0 [label="X[0] <= 0.0\\nmse = 1.0\\nsamples = 6\\n' \
'value = 0.0", fillcolor="#e5813980"] ;\n' \
'1 [label="mse = 0.0\\nsamples = 3\\nvalue = -1.0", ' \
'fillcolor="#e5813900"] ;\n' \
'0 -> 1 [labeldistance=2.5, labelangle=-45, ' \
'headlabel="True"] ;\n' \
'2 [label="mse = 0.0\\nsamples = 3\\nvalue = 1.0", ' \
'fillcolor="#e58139ff"] ;\n' \
'0 -> 2 [labeldistance=2.5, labelangle=45, ' \
'headlabel="False"] ;\n' \
'{rank=same ; 0} ;\n' \
'{rank=same ; 1; 2} ;\n' \
'}'
assert_equal(contents1, contents2)
# Test classifier with degraded learning set
clf = DecisionTreeClassifier(max_depth=3)
clf.fit(X, y_degraded)
contents1 = export_graphviz(clf, filled=True, out_file=None)
contents2 = 'digraph Tree {\n' \
'node [shape=box, style="filled", color="black"] ;\n' \
'0 [label="gini = 0.0\\nsamples = 6\\nvalue = 6.0", ' \
'fillcolor="#e5813900"] ;\n' \
'}'
assert_equal(contents1, contents2)
def test_graphviz_errors():
# Check for errors of export_graphviz
clf = DecisionTreeClassifier(max_depth=3, min_samples_split=2)
# Check not-fitted decision tree error
out = StringIO()
assert_raises(NotFittedError, export_graphviz, clf, out)
clf.fit(X, y)
# Check if it errors when length of feature_names
# mismatches with number of features
message = ("Length of feature_names, "
"1 does not match number of features, 2")
assert_raise_message(ValueError, message, export_graphviz, clf, None,
feature_names=["a"])
message = ("Length of feature_names, "
"3 does not match number of features, 2")
assert_raise_message(ValueError, message, export_graphviz, clf, None,
feature_names=["a", "b", "c"])
# Check class_names error
out = StringIO()
assert_raises(IndexError, export_graphviz, clf, out, class_names=[])
# Check precision error
out = StringIO()
assert_raises_regex(ValueError, "should be greater or equal",
export_graphviz, clf, out, precision=-1)
assert_raises_regex(ValueError, "should be an integer",
export_graphviz, clf, out, precision="1")
def test_friedman_mse_in_graphviz():
clf = DecisionTreeRegressor(criterion="friedman_mse", random_state=0)
clf.fit(X, y)
dot_data = StringIO()
export_graphviz(clf, out_file=dot_data)
clf = GradientBoostingClassifier(n_estimators=2, random_state=0)
clf.fit(X, y)
for estimator in clf.estimators_:
export_graphviz(estimator[0], out_file=dot_data)
for finding in finditer("\[.*?samples.*?\]", dot_data.getvalue()):
assert_in("friedman_mse", finding.group())
def test_precision():
rng_reg = RandomState(2)
rng_clf = RandomState(8)
for X, y, clf in zip(
(rng_reg.random_sample((5, 2)),
rng_clf.random_sample((1000, 4))),
(rng_reg.random_sample((5, )),
rng_clf.randint(2, size=(1000, ))),
(DecisionTreeRegressor(criterion="friedman_mse", random_state=0,
max_depth=1),
DecisionTreeClassifier(max_depth=1, random_state=0))):
clf.fit(X, y)
for precision in (4, 3):
dot_data = export_graphviz(clf, out_file=None, precision=precision,
proportion=True)
# With the current random state, the impurity and the threshold
# will have the number of precision set in the export_graphviz
# function. We will check the number of precision with a strict
# equality. The value reported will have only 2 precision and
# therefore, only a less equal comparison will be done.
# check value
for finding in finditer("value = \d+\.\d+", dot_data):
assert_less_equal(
len(search("\.\d+", finding.group()).group()),
precision + 1)
# check impurity
if is_classifier(clf):
pattern = "gini = \d+\.\d+"
else:
pattern = "friedman_mse = \d+\.\d+"
# check impurity
for finding in finditer(pattern, dot_data):
assert_equal(len(search("\.\d+", finding.group()).group()),
precision + 1)
# check threshold
for finding in finditer("<= \d+\.\d+", dot_data):
assert_equal(len(search("\.\d+", finding.group()).group()),
precision + 1)
| 12,894 | 40.866883 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/tree/tests/__init__.py | 0 | 0 | 0 | py |
|
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/ransac.py | # coding: utf-8
# Author: Johannes Schönberger
#
# License: BSD 3 clause
import numpy as np
import warnings
from ..base import BaseEstimator, MetaEstimatorMixin, RegressorMixin, clone
from ..utils import check_random_state, check_array, check_consistent_length
from ..utils.random import sample_without_replacement
from ..utils.validation import check_is_fitted
from .base import LinearRegression
from ..utils.validation import has_fit_parameter
_EPSILON = np.spacing(1)
def _dynamic_max_trials(n_inliers, n_samples, min_samples, probability):
"""Determine number trials such that at least one outlier-free subset is
sampled for the given inlier/outlier ratio.
Parameters
----------
n_inliers : int
Number of inliers in the data.
n_samples : int
Total number of samples in the data.
min_samples : int
Minimum number of samples chosen randomly from original data.
probability : float
Probability (confidence) that one outlier-free sample is generated.
Returns
-------
trials : int
Number of trials.
"""
inlier_ratio = n_inliers / float(n_samples)
nom = max(_EPSILON, 1 - probability)
denom = max(_EPSILON, 1 - inlier_ratio ** min_samples)
if nom == 1:
return 0
if denom == 1:
return float('inf')
return abs(float(np.ceil(np.log(nom) / np.log(denom))))
class RANSACRegressor(BaseEstimator, MetaEstimatorMixin, RegressorMixin):
"""RANSAC (RANdom SAmple Consensus) algorithm.
RANSAC is an iterative algorithm for the robust estimation of parameters
from a subset of inliers from the complete data set. More information can
be found in the general documentation of linear models.
A detailed description of the algorithm can be found in the documentation
of the ``linear_model`` sub-package.
Read more in the :ref:`User Guide <ransac_regression>`.
Parameters
----------
base_estimator : object, optional
Base estimator object which implements the following methods:
* `fit(X, y)`: Fit model to given training data and target values.
* `score(X, y)`: Returns the mean accuracy on the given test data,
which is used for the stop criterion defined by `stop_score`.
Additionally, the score is used to decide which of two equally
large consensus sets is chosen as the better one.
If `base_estimator` is None, then
``base_estimator=sklearn.linear_model.LinearRegression()`` is used for
target values of dtype float.
Note that the current implementation only supports regression
estimators.
min_samples : int (>= 1) or float ([0, 1]), optional
Minimum number of samples chosen randomly from original data. Treated
as an absolute number of samples for `min_samples >= 1`, treated as a
relative number `ceil(min_samples * X.shape[0]`) for
`min_samples < 1`. This is typically chosen as the minimal number of
samples necessary to estimate the given `base_estimator`. By default a
``sklearn.linear_model.LinearRegression()`` estimator is assumed and
`min_samples` is chosen as ``X.shape[1] + 1``.
residual_threshold : float, optional
Maximum residual for a data sample to be classified as an inlier.
By default the threshold is chosen as the MAD (median absolute
deviation) of the target values `y`.
is_data_valid : callable, optional
This function is called with the randomly selected data before the
model is fitted to it: `is_data_valid(X, y)`. If its return value is
False the current randomly chosen sub-sample is skipped.
is_model_valid : callable, optional
This function is called with the estimated model and the randomly
selected data: `is_model_valid(model, X, y)`. If its return value is
False the current randomly chosen sub-sample is skipped.
Rejecting samples with this function is computationally costlier than
with `is_data_valid`. `is_model_valid` should therefore only be used if
the estimated model is needed for making the rejection decision.
max_trials : int, optional
Maximum number of iterations for random sample selection.
max_skips : int, optional
Maximum number of iterations that can be skipped due to finding zero
inliers or invalid data defined by ``is_data_valid`` or invalid models
defined by ``is_model_valid``.
.. versionadded:: 0.19
stop_n_inliers : int, optional
Stop iteration if at least this number of inliers are found.
stop_score : float, optional
Stop iteration if score is greater equal than this threshold.
stop_probability : float in range [0, 1], optional
RANSAC iteration stops if at least one outlier-free set of the training
data is sampled in RANSAC. This requires to generate at least N
samples (iterations)::
N >= log(1 - probability) / log(1 - e**m)
where the probability (confidence) is typically set to high value such
as 0.99 (the default) and e is the current fraction of inliers w.r.t.
the total number of samples.
residual_metric : callable, optional
Metric to reduce the dimensionality of the residuals to 1 for
multi-dimensional target values ``y.shape[1] > 1``. By default the sum
of absolute differences is used::
lambda dy: np.sum(np.abs(dy), axis=1)
.. deprecated:: 0.18
``residual_metric`` is deprecated from 0.18 and will be removed in
0.20. Use ``loss`` instead.
loss : string, callable, optional, default "absolute_loss"
String inputs, "absolute_loss" and "squared_loss" are supported which
find the absolute loss and squared loss per sample
respectively.
If ``loss`` is a callable, then it should be a function that takes
two arrays as inputs, the true and predicted value and returns a 1-D
array with the i-th value of the array corresponding to the loss
on ``X[i]``.
If the loss on a sample is greater than the ``residual_threshold``,
then this sample is classified as an outlier.
random_state : int, RandomState instance or None, optional, default None
The generator used to initialize the centers. If int, random_state is
the seed used by the random number generator; If RandomState instance,
random_state is the random number generator; If None, the random number
generator is the RandomState instance used by `np.random`.
Attributes
----------
estimator_ : object
Best fitted model (copy of the `base_estimator` object).
n_trials_ : int
Number of random selection trials until one of the stop criteria is
met. It is always ``<= max_trials``.
inlier_mask_ : bool array of shape [n_samples]
Boolean mask of inliers classified as ``True``.
n_skips_no_inliers_ : int
Number of iterations skipped due to finding zero inliers.
.. versionadded:: 0.19
n_skips_invalid_data_ : int
Number of iterations skipped due to invalid data defined by
``is_data_valid``.
.. versionadded:: 0.19
n_skips_invalid_model_ : int
Number of iterations skipped due to an invalid model defined by
``is_model_valid``.
.. versionadded:: 0.19
References
----------
.. [1] https://en.wikipedia.org/wiki/RANSAC
.. [2] http://www.cs.columbia.edu/~belhumeur/courses/compPhoto/ransac.pdf
.. [3] http://www.bmva.org/bmvc/2009/Papers/Paper355/Paper355.pdf
"""
def __init__(self, base_estimator=None, min_samples=None,
residual_threshold=None, is_data_valid=None,
is_model_valid=None, max_trials=100, max_skips=np.inf,
stop_n_inliers=np.inf, stop_score=np.inf,
stop_probability=0.99, residual_metric=None,
loss='absolute_loss', random_state=None):
self.base_estimator = base_estimator
self.min_samples = min_samples
self.residual_threshold = residual_threshold
self.is_data_valid = is_data_valid
self.is_model_valid = is_model_valid
self.max_trials = max_trials
self.max_skips = max_skips
self.stop_n_inliers = stop_n_inliers
self.stop_score = stop_score
self.stop_probability = stop_probability
self.residual_metric = residual_metric
self.random_state = random_state
self.loss = loss
def fit(self, X, y, sample_weight=None):
"""Fit estimator using RANSAC algorithm.
Parameters
----------
X : array-like or sparse matrix, shape [n_samples, n_features]
Training data.
y : array-like, shape = [n_samples] or [n_samples, n_targets]
Target values.
sample_weight : array-like, shape = [n_samples]
Individual weights for each sample
raises error if sample_weight is passed and base_estimator
fit method does not support it.
Raises
------
ValueError
If no valid consensus set could be found. This occurs if
`is_data_valid` and `is_model_valid` return False for all
`max_trials` randomly chosen sub-samples.
"""
X = check_array(X, accept_sparse='csr')
y = check_array(y, ensure_2d=False)
check_consistent_length(X, y)
if self.base_estimator is not None:
base_estimator = clone(self.base_estimator)
else:
base_estimator = LinearRegression()
if self.min_samples is None:
# assume linear model by default
min_samples = X.shape[1] + 1
elif 0 < self.min_samples < 1:
min_samples = np.ceil(self.min_samples * X.shape[0])
elif self.min_samples >= 1:
if self.min_samples % 1 != 0:
raise ValueError("Absolute number of samples must be an "
"integer value.")
min_samples = self.min_samples
else:
raise ValueError("Value for `min_samples` must be scalar and "
"positive.")
if min_samples > X.shape[0]:
raise ValueError("`min_samples` may not be larger than number "
"of samples ``X.shape[0]``.")
if self.stop_probability < 0 or self.stop_probability > 1:
raise ValueError("`stop_probability` must be in range [0, 1].")
if self.residual_threshold is None:
# MAD (median absolute deviation)
residual_threshold = np.median(np.abs(y - np.median(y)))
else:
residual_threshold = self.residual_threshold
if self.residual_metric is not None:
warnings.warn(
"'residual_metric' was deprecated in version 0.18 and "
"will be removed in version 0.20. Use 'loss' instead.",
DeprecationWarning)
if self.loss == "absolute_loss":
if y.ndim == 1:
loss_function = lambda y_true, y_pred: np.abs(y_true - y_pred)
else:
loss_function = lambda \
y_true, y_pred: np.sum(np.abs(y_true - y_pred), axis=1)
elif self.loss == "squared_loss":
if y.ndim == 1:
loss_function = lambda y_true, y_pred: (y_true - y_pred) ** 2
else:
loss_function = lambda \
y_true, y_pred: np.sum((y_true - y_pred) ** 2, axis=1)
elif callable(self.loss):
loss_function = self.loss
else:
raise ValueError(
"loss should be 'absolute_loss', 'squared_loss' or a callable."
"Got %s. " % self.loss)
random_state = check_random_state(self.random_state)
try: # Not all estimator accept a random_state
base_estimator.set_params(random_state=random_state)
except ValueError:
pass
estimator_fit_has_sample_weight = has_fit_parameter(base_estimator,
"sample_weight")
estimator_name = type(base_estimator).__name__
if (sample_weight is not None and not
estimator_fit_has_sample_weight):
raise ValueError("%s does not support sample_weight. Samples"
" weights are only used for the calibration"
" itself." % estimator_name)
if sample_weight is not None:
sample_weight = np.asarray(sample_weight)
n_inliers_best = 1
score_best = -np.inf
inlier_mask_best = None
X_inlier_best = None
y_inlier_best = None
self.n_skips_no_inliers_ = 0
self.n_skips_invalid_data_ = 0
self.n_skips_invalid_model_ = 0
# number of data samples
n_samples = X.shape[0]
sample_idxs = np.arange(n_samples)
n_samples, _ = X.shape
self.n_trials_ = 0
max_trials = self.max_trials
while self.n_trials_ < max_trials:
self.n_trials_ += 1
if (self.n_skips_no_inliers_ + self.n_skips_invalid_data_ +
self.n_skips_invalid_model_) > self.max_skips:
break
# choose random sample set
subset_idxs = sample_without_replacement(n_samples, min_samples,
random_state=random_state)
X_subset = X[subset_idxs]
y_subset = y[subset_idxs]
# check if random sample set is valid
if (self.is_data_valid is not None
and not self.is_data_valid(X_subset, y_subset)):
self.n_skips_invalid_data_ += 1
continue
# fit model for current random sample set
if sample_weight is None:
base_estimator.fit(X_subset, y_subset)
else:
base_estimator.fit(X_subset, y_subset,
sample_weight=sample_weight[subset_idxs])
# check if estimated model is valid
if (self.is_model_valid is not None and not
self.is_model_valid(base_estimator, X_subset, y_subset)):
self.n_skips_invalid_model_ += 1
continue
# residuals of all data for current random sample model
y_pred = base_estimator.predict(X)
# XXX: Deprecation: Remove this if block in 0.20
if self.residual_metric is not None:
diff = y_pred - y
if diff.ndim == 1:
diff = diff.reshape(-1, 1)
residuals_subset = self.residual_metric(diff)
else:
residuals_subset = loss_function(y, y_pred)
# classify data into inliers and outliers
inlier_mask_subset = residuals_subset < residual_threshold
n_inliers_subset = np.sum(inlier_mask_subset)
# less inliers -> skip current random sample
if n_inliers_subset < n_inliers_best:
self.n_skips_no_inliers_ += 1
continue
# extract inlier data set
inlier_idxs_subset = sample_idxs[inlier_mask_subset]
X_inlier_subset = X[inlier_idxs_subset]
y_inlier_subset = y[inlier_idxs_subset]
# score of inlier data set
score_subset = base_estimator.score(X_inlier_subset,
y_inlier_subset)
# same number of inliers but worse score -> skip current random
# sample
if (n_inliers_subset == n_inliers_best
and score_subset < score_best):
continue
# save current random sample as best sample
n_inliers_best = n_inliers_subset
score_best = score_subset
inlier_mask_best = inlier_mask_subset
X_inlier_best = X_inlier_subset
y_inlier_best = y_inlier_subset
max_trials = min(
max_trials,
_dynamic_max_trials(n_inliers_best, n_samples,
min_samples, self.stop_probability))
# break if sufficient number of inliers or score is reached
if n_inliers_best >= self.stop_n_inliers or \
score_best >= self.stop_score:
break
# if none of the iterations met the required criteria
if inlier_mask_best is None:
if ((self.n_skips_no_inliers_ + self.n_skips_invalid_data_ +
self.n_skips_invalid_model_) > self.max_skips):
raise ValueError(
"RANSAC skipped more iterations than `max_skips` without"
" finding a valid consensus set. Iterations were skipped"
" because each randomly chosen sub-sample failed the"
" passing criteria. See estimator attributes for"
" diagnostics (n_skips*).")
else:
raise ValueError(
"RANSAC could not find a valid consensus set. All"
" `max_trials` iterations were skipped because each"
" randomly chosen sub-sample failed the passing criteria."
" See estimator attributes for diagnostics (n_skips*).")
else:
if (self.n_skips_no_inliers_ + self.n_skips_invalid_data_ +
self.n_skips_invalid_model_) > self.max_skips:
warnings.warn("RANSAC found a valid consensus set but exited"
" early due to skipping more iterations than"
" `max_skips`. See estimator attributes for"
" diagnostics (n_skips*).",
UserWarning)
# estimate final model using all inliers
base_estimator.fit(X_inlier_best, y_inlier_best)
self.estimator_ = base_estimator
self.inlier_mask_ = inlier_mask_best
return self
def predict(self, X):
"""Predict using the estimated model.
This is a wrapper for `estimator_.predict(X)`.
Parameters
----------
X : numpy array of shape [n_samples, n_features]
Returns
-------
y : array, shape = [n_samples] or [n_samples, n_targets]
Returns predicted values.
"""
check_is_fitted(self, 'estimator_')
return self.estimator_.predict(X)
def score(self, X, y):
"""Returns the score of the prediction.
This is a wrapper for `estimator_.score(X, y)`.
Parameters
----------
X : numpy array or sparse matrix of shape [n_samples, n_features]
Training data.
y : array, shape = [n_samples] or [n_samples, n_targets]
Target values.
Returns
-------
z : float
Score of the prediction.
"""
check_is_fitted(self, 'estimator_')
return self.estimator_.score(X, y)
| 19,389 | 37.472222 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/base.py | """
Generalized Linear models.
"""
# Author: Alexandre Gramfort <[email protected]>
# Fabian Pedregosa <[email protected]>
# Olivier Grisel <[email protected]>
# Vincent Michel <[email protected]>
# Peter Prettenhofer <[email protected]>
# Mathieu Blondel <[email protected]>
# Lars Buitinck
# Maryan Morel <[email protected]>
# Giorgio Patrini <[email protected]>
# License: BSD 3 clause
from __future__ import division
from abc import ABCMeta, abstractmethod
import numbers
import warnings
import numpy as np
import scipy.sparse as sp
from scipy import linalg
from scipy import sparse
from ..externals import six
from ..externals.joblib import Parallel, delayed
from ..base import BaseEstimator, ClassifierMixin, RegressorMixin
from ..utils import check_array, check_X_y, deprecated, as_float_array
from ..utils.validation import FLOAT_DTYPES
from ..utils import check_random_state
from ..utils.extmath import safe_sparse_dot
from ..utils.sparsefuncs import mean_variance_axis, inplace_column_scale
from ..utils.fixes import sparse_lsqr
from ..utils.seq_dataset import ArrayDataset, CSRDataset
from ..utils.validation import check_is_fitted
from ..exceptions import NotFittedError
from ..preprocessing.data import normalize as f_normalize
# TODO: bayesian_ridge_regression and bayesian_regression_ard
# should be squashed into its respective objects.
SPARSE_INTERCEPT_DECAY = 0.01
# For sparse data intercept updates are scaled by this decay factor to avoid
# intercept oscillation.
def make_dataset(X, y, sample_weight, random_state=None):
"""Create ``Dataset`` abstraction for sparse and dense inputs.
This also returns the ``intercept_decay`` which is different
for sparse datasets.
"""
rng = check_random_state(random_state)
# seed should never be 0 in SequentialDataset
seed = rng.randint(1, np.iinfo(np.int32).max)
if sp.issparse(X):
dataset = CSRDataset(X.data, X.indptr, X.indices, y, sample_weight,
seed=seed)
intercept_decay = SPARSE_INTERCEPT_DECAY
else:
dataset = ArrayDataset(X, y, sample_weight, seed=seed)
intercept_decay = 1.0
return dataset, intercept_decay
@deprecated("sparse_center_data was deprecated in version 0.18 and will be "
"removed in 0.20. Use utilities in preprocessing.data instead")
def sparse_center_data(X, y, fit_intercept, normalize=False):
"""
Compute information needed to center data to have mean zero along
axis 0. Be aware that X will not be centered since it would break
the sparsity, but will be normalized if asked so.
"""
if fit_intercept:
# we might require not to change the csr matrix sometimes
# store a copy if normalize is True.
# Change dtype to float64 since mean_variance_axis accepts
# it that way.
if sp.isspmatrix(X) and X.getformat() == 'csr':
X = sp.csr_matrix(X, copy=normalize, dtype=np.float64)
else:
X = sp.csc_matrix(X, copy=normalize, dtype=np.float64)
X_offset, X_var = mean_variance_axis(X, axis=0)
if normalize:
# transform variance to std in-place
X_var *= X.shape[0]
X_std = np.sqrt(X_var, X_var)
del X_var
X_std[X_std == 0] = 1
inplace_column_scale(X, 1. / X_std)
else:
X_std = np.ones(X.shape[1])
y_offset = y.mean(axis=0)
y = y - y_offset
else:
X_offset = np.zeros(X.shape[1])
X_std = np.ones(X.shape[1])
y_offset = 0. if y.ndim == 1 else np.zeros(y.shape[1], dtype=X.dtype)
return X, y, X_offset, y_offset, X_std
@deprecated("center_data was deprecated in version 0.18 and will be removed "
"in 0.20. Use utilities in preprocessing.data instead")
def center_data(X, y, fit_intercept, normalize=False, copy=True,
sample_weight=None):
"""
Centers data to have mean zero along axis 0. This is here because
nearly all linear models will want their data to be centered.
If sample_weight is not None, then the weighted mean of X and y
is zero, and not the mean itself
"""
X = as_float_array(X, copy)
if fit_intercept:
if isinstance(sample_weight, numbers.Number):
sample_weight = None
if sp.issparse(X):
X_offset = np.zeros(X.shape[1])
X_std = np.ones(X.shape[1])
else:
X_offset = np.average(X, axis=0, weights=sample_weight)
X -= X_offset
# XXX: currently scaled to variance=n_samples
if normalize:
X_std = np.sqrt(np.sum(X ** 2, axis=0))
X_std[X_std == 0] = 1
X /= X_std
else:
X_std = np.ones(X.shape[1])
y_offset = np.average(y, axis=0, weights=sample_weight)
y = y - y_offset
else:
X_offset = np.zeros(X.shape[1])
X_std = np.ones(X.shape[1])
y_offset = 0. if y.ndim == 1 else np.zeros(y.shape[1], dtype=X.dtype)
return X, y, X_offset, y_offset, X_std
def _preprocess_data(X, y, fit_intercept, normalize=False, copy=True,
sample_weight=None, return_mean=False):
"""
Centers data to have mean zero along axis 0. If fit_intercept=False or if
the X is a sparse matrix, no centering is done, but normalization can still
be applied. The function returns the statistics necessary to reconstruct
the input data, which are X_offset, y_offset, X_scale, such that the output
X = (X - X_offset) / X_scale
X_scale is the L2 norm of X - X_offset. If sample_weight is not None,
then the weighted mean of X and y is zero, and not the mean itself. If
return_mean=True, the mean, eventually weighted, is returned, independently
of whether X was centered (option used for optimization with sparse data in
coordinate_descend).
This is here because nearly all linear models will want their data to be
centered. This function also systematically makes y consistent with X.dtype
"""
if isinstance(sample_weight, numbers.Number):
sample_weight = None
X = check_array(X, copy=copy, accept_sparse=['csr', 'csc'],
dtype=FLOAT_DTYPES)
y = np.asarray(y, dtype=X.dtype)
if fit_intercept:
if sp.issparse(X):
X_offset, X_var = mean_variance_axis(X, axis=0)
if not return_mean:
X_offset[:] = X.dtype.type(0)
if normalize:
# TODO: f_normalize could be used here as well but the function
# inplace_csr_row_normalize_l2 must be changed such that it
# can return also the norms computed internally
# transform variance to norm in-place
X_var *= X.shape[0]
X_scale = np.sqrt(X_var, X_var)
del X_var
X_scale[X_scale == 0] = 1
inplace_column_scale(X, 1. / X_scale)
else:
X_scale = np.ones(X.shape[1], dtype=X.dtype)
else:
X_offset = np.average(X, axis=0, weights=sample_weight)
X -= X_offset
if normalize:
X, X_scale = f_normalize(X, axis=0, copy=False,
return_norm=True)
else:
X_scale = np.ones(X.shape[1], dtype=X.dtype)
y_offset = np.average(y, axis=0, weights=sample_weight)
y = y - y_offset
else:
X_offset = np.zeros(X.shape[1], dtype=X.dtype)
X_scale = np.ones(X.shape[1], dtype=X.dtype)
if y.ndim == 1:
y_offset = X.dtype.type(0)
else:
y_offset = np.zeros(y.shape[1], dtype=X.dtype)
return X, y, X_offset, y_offset, X_scale
# TODO: _rescale_data should be factored into _preprocess_data.
# Currently, the fact that sag implements its own way to deal with
# sample_weight makes the refactoring tricky.
def _rescale_data(X, y, sample_weight):
"""Rescale data so as to support sample_weight"""
n_samples = X.shape[0]
sample_weight = sample_weight * np.ones(n_samples)
sample_weight = np.sqrt(sample_weight)
sw_matrix = sparse.dia_matrix((sample_weight, 0),
shape=(n_samples, n_samples))
X = safe_sparse_dot(sw_matrix, X)
y = safe_sparse_dot(sw_matrix, y)
return X, y
class LinearModel(six.with_metaclass(ABCMeta, BaseEstimator)):
"""Base class for Linear Models"""
@abstractmethod
def fit(self, X, y):
"""Fit model."""
def _decision_function(self, X):
check_is_fitted(self, "coef_")
X = check_array(X, accept_sparse=['csr', 'csc', 'coo'])
return safe_sparse_dot(X, self.coef_.T,
dense_output=True) + self.intercept_
def predict(self, X):
"""Predict using the linear model
Parameters
----------
X : {array-like, sparse matrix}, shape = (n_samples, n_features)
Samples.
Returns
-------
C : array, shape = (n_samples,)
Returns predicted values.
"""
return self._decision_function(X)
_preprocess_data = staticmethod(_preprocess_data)
def _set_intercept(self, X_offset, y_offset, X_scale):
"""Set the intercept_
"""
if self.fit_intercept:
self.coef_ = self.coef_ / X_scale
self.intercept_ = y_offset - np.dot(X_offset, self.coef_.T)
else:
self.intercept_ = 0.
# XXX Should this derive from LinearModel? It should be a mixin, not an ABC.
# Maybe the n_features checking can be moved to LinearModel.
class LinearClassifierMixin(ClassifierMixin):
"""Mixin for linear classifiers.
Handles prediction for sparse and dense X.
"""
def decision_function(self, X):
"""Predict confidence scores for samples.
The confidence score for a sample is the signed distance of that
sample to the hyperplane.
Parameters
----------
X : {array-like, sparse matrix}, shape = (n_samples, n_features)
Samples.
Returns
-------
array, shape=(n_samples,) if n_classes == 2 else (n_samples, n_classes)
Confidence scores per (sample, class) combination. In the binary
case, confidence score for self.classes_[1] where >0 means this
class would be predicted.
"""
if not hasattr(self, 'coef_') or self.coef_ is None:
raise NotFittedError("This %(name)s instance is not fitted "
"yet" % {'name': type(self).__name__})
X = check_array(X, accept_sparse='csr')
n_features = self.coef_.shape[1]
if X.shape[1] != n_features:
raise ValueError("X has %d features per sample; expecting %d"
% (X.shape[1], n_features))
scores = safe_sparse_dot(X, self.coef_.T,
dense_output=True) + self.intercept_
return scores.ravel() if scores.shape[1] == 1 else scores
def predict(self, X):
"""Predict class labels for samples in X.
Parameters
----------
X : {array-like, sparse matrix}, shape = [n_samples, n_features]
Samples.
Returns
-------
C : array, shape = [n_samples]
Predicted class label per sample.
"""
scores = self.decision_function(X)
if len(scores.shape) == 1:
indices = (scores > 0).astype(np.int)
else:
indices = scores.argmax(axis=1)
return self.classes_[indices]
def _predict_proba_lr(self, X):
"""Probability estimation for OvR logistic regression.
Positive class probabilities are computed as
1. / (1. + np.exp(-self.decision_function(X)));
multiclass is handled by normalizing that over all classes.
"""
prob = self.decision_function(X)
prob *= -1
np.exp(prob, prob)
prob += 1
np.reciprocal(prob, prob)
if prob.ndim == 1:
return np.vstack([1 - prob, prob]).T
else:
# OvR normalization, like LibLinear's predict_probability
prob /= prob.sum(axis=1).reshape((prob.shape[0], -1))
return prob
class SparseCoefMixin(object):
"""Mixin for converting coef_ to and from CSR format.
L1-regularizing estimators should inherit this.
"""
def densify(self):
"""Convert coefficient matrix to dense array format.
Converts the ``coef_`` member (back) to a numpy.ndarray. This is the
default format of ``coef_`` and is required for fitting, so calling
this method is only required on models that have previously been
sparsified; otherwise, it is a no-op.
Returns
-------
self : estimator
"""
msg = "Estimator, %(name)s, must be fitted before densifying."
check_is_fitted(self, "coef_", msg=msg)
if sp.issparse(self.coef_):
self.coef_ = self.coef_.toarray()
return self
def sparsify(self):
"""Convert coefficient matrix to sparse format.
Converts the ``coef_`` member to a scipy.sparse matrix, which for
L1-regularized models can be much more memory- and storage-efficient
than the usual numpy.ndarray representation.
The ``intercept_`` member is not converted.
Notes
-----
For non-sparse models, i.e. when there are not many zeros in ``coef_``,
this may actually *increase* memory usage, so use this method with
care. A rule of thumb is that the number of zero elements, which can
be computed with ``(coef_ == 0).sum()``, must be more than 50% for this
to provide significant benefits.
After calling this method, further fitting with the partial_fit
method (if any) will not work until you call densify.
Returns
-------
self : estimator
"""
msg = "Estimator, %(name)s, must be fitted before sparsifying."
check_is_fitted(self, "coef_", msg=msg)
self.coef_ = sp.csr_matrix(self.coef_)
return self
class LinearRegression(LinearModel, RegressorMixin):
"""
Ordinary least squares Linear Regression.
Parameters
----------
fit_intercept : boolean, optional, default True
whether to calculate the intercept for this model. If set
to False, no intercept will be used in calculations
(e.g. data is expected to be already centered).
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit`` on
an estimator with ``normalize=False``.
copy_X : boolean, optional, default True
If True, X will be copied; else, it may be overwritten.
n_jobs : int, optional, default 1
The number of jobs to use for the computation.
If -1 all CPUs are used. This will only provide speedup for
n_targets > 1 and sufficient large problems.
Attributes
----------
coef_ : array, shape (n_features, ) or (n_targets, n_features)
Estimated coefficients for the linear regression problem.
If multiple targets are passed during the fit (y 2D), this
is a 2D array of shape (n_targets, n_features), while if only
one target is passed, this is a 1D array of length n_features.
intercept_ : array
Independent term in the linear model.
Notes
-----
From the implementation point of view, this is just plain Ordinary
Least Squares (scipy.linalg.lstsq) wrapped as a predictor object.
"""
def __init__(self, fit_intercept=True, normalize=False, copy_X=True,
n_jobs=1):
self.fit_intercept = fit_intercept
self.normalize = normalize
self.copy_X = copy_X
self.n_jobs = n_jobs
def fit(self, X, y, sample_weight=None):
"""
Fit linear model.
Parameters
----------
X : numpy array or sparse matrix of shape [n_samples,n_features]
Training data
y : numpy array of shape [n_samples, n_targets]
Target values. Will be cast to X's dtype if necessary
sample_weight : numpy array of shape [n_samples]
Individual weights for each sample
.. versionadded:: 0.17
parameter *sample_weight* support to LinearRegression.
Returns
-------
self : returns an instance of self.
"""
n_jobs_ = self.n_jobs
X, y = check_X_y(X, y, accept_sparse=['csr', 'csc', 'coo'],
y_numeric=True, multi_output=True)
if sample_weight is not None and np.atleast_1d(sample_weight).ndim > 1:
raise ValueError("Sample weights must be 1D array or scalar")
X, y, X_offset, y_offset, X_scale = self._preprocess_data(
X, y, fit_intercept=self.fit_intercept, normalize=self.normalize,
copy=self.copy_X, sample_weight=sample_weight)
if sample_weight is not None:
# Sample weight can be implemented via a simple rescaling.
X, y = _rescale_data(X, y, sample_weight)
if sp.issparse(X):
if y.ndim < 2:
out = sparse_lsqr(X, y)
self.coef_ = out[0]
self._residues = out[3]
else:
# sparse_lstsq cannot handle y with shape (M, K)
outs = Parallel(n_jobs=n_jobs_)(
delayed(sparse_lsqr)(X, y[:, j].ravel())
for j in range(y.shape[1]))
self.coef_ = np.vstack(out[0] for out in outs)
self._residues = np.vstack(out[3] for out in outs)
else:
self.coef_, self._residues, self.rank_, self.singular_ = \
linalg.lstsq(X, y)
self.coef_ = self.coef_.T
if y.ndim == 1:
self.coef_ = np.ravel(self.coef_)
self._set_intercept(X_offset, y_offset, X_scale)
return self
def _pre_fit(X, y, Xy, precompute, normalize, fit_intercept, copy):
"""Aux function used at beginning of fit in linear models"""
n_samples, n_features = X.shape
if sparse.isspmatrix(X):
# copy is not needed here as X is not modified inplace when X is sparse
precompute = False
X, y, X_offset, y_offset, X_scale = _preprocess_data(
X, y, fit_intercept=fit_intercept, normalize=normalize,
copy=False, return_mean=True)
else:
# copy was done in fit if necessary
X, y, X_offset, y_offset, X_scale = _preprocess_data(
X, y, fit_intercept=fit_intercept, normalize=normalize, copy=copy)
if hasattr(precompute, '__array__') and (
fit_intercept and not np.allclose(X_offset, np.zeros(n_features)) or
normalize and not np.allclose(X_scale, np.ones(n_features))):
warnings.warn("Gram matrix was provided but X was centered"
" to fit intercept, "
"or X was normalized : recomputing Gram matrix.",
UserWarning)
# recompute Gram
precompute = 'auto'
Xy = None
# precompute if n_samples > n_features
if isinstance(precompute, six.string_types) and precompute == 'auto':
precompute = (n_samples > n_features)
if precompute is True:
# make sure that the 'precompute' array is contiguous.
precompute = np.empty(shape=(n_features, n_features), dtype=X.dtype,
order='C')
np.dot(X.T, X, out=precompute)
if not hasattr(precompute, '__array__'):
Xy = None # cannot use Xy if precompute is not Gram
if hasattr(precompute, '__array__') and Xy is None:
common_dtype = np.find_common_type([X.dtype, y.dtype], [])
if y.ndim == 1:
# Xy is 1d, make sure it is contiguous.
Xy = np.empty(shape=n_features, dtype=common_dtype, order='C')
np.dot(X.T, y, out=Xy)
else:
# Make sure that Xy is always F contiguous even if X or y are not
# contiguous: the goal is to make it fast to extract the data for a
# specific target.
n_targets = y.shape[1]
Xy = np.empty(shape=(n_features, n_targets), dtype=common_dtype,
order='F')
np.dot(y.T, X, out=Xy.T)
return X, y, X_offset, y_offset, X_scale, precompute, Xy
| 21,031 | 35.769231 | 80 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/logistic.py | """
Logistic Regression
"""
# Author: Gael Varoquaux <[email protected]>
# Fabian Pedregosa <[email protected]>
# Alexandre Gramfort <[email protected]>
# Manoj Kumar <[email protected]>
# Lars Buitinck
# Simon Wu <[email protected]>
# Arthur Mensch <[email protected]
import numbers
import warnings
import numpy as np
from scipy import optimize, sparse
from scipy.special import expit
from .base import LinearClassifierMixin, SparseCoefMixin, BaseEstimator
from .sag import sag_solver
from ..preprocessing import LabelEncoder, LabelBinarizer
from ..svm.base import _fit_liblinear
from ..utils import check_array, check_consistent_length, compute_class_weight
from ..utils import check_random_state
from ..utils.extmath import (log_logistic, safe_sparse_dot, softmax,
squared_norm)
from ..utils.extmath import row_norms
from ..utils.fixes import logsumexp
from ..utils.optimize import newton_cg
from ..utils.validation import check_X_y
from ..exceptions import NotFittedError
from ..utils.multiclass import check_classification_targets
from ..externals.joblib import Parallel, delayed
from ..model_selection import check_cv
from ..externals import six
from ..metrics import SCORERS
# .. some helper functions for logistic_regression_path ..
def _intercept_dot(w, X, y):
"""Computes y * np.dot(X, w).
It takes into consideration if the intercept should be fit or not.
Parameters
----------
w : ndarray, shape (n_features,) or (n_features + 1,)
Coefficient vector.
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data.
y : ndarray, shape (n_samples,)
Array of labels.
Returns
-------
w : ndarray, shape (n_features,)
Coefficient vector without the intercept weight (w[-1]) if the
intercept should be fit. Unchanged otherwise.
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data. Unchanged.
yz : float
y * np.dot(X, w).
"""
c = 0.
if w.size == X.shape[1] + 1:
c = w[-1]
w = w[:-1]
z = safe_sparse_dot(X, w) + c
yz = y * z
return w, c, yz
def _logistic_loss_and_grad(w, X, y, alpha, sample_weight=None):
"""Computes the logistic loss and gradient.
Parameters
----------
w : ndarray, shape (n_features,) or (n_features + 1,)
Coefficient vector.
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data.
y : ndarray, shape (n_samples,)
Array of labels.
alpha : float
Regularization parameter. alpha is equal to 1 / C.
sample_weight : array-like, shape (n_samples,) optional
Array of weights that are assigned to individual samples.
If not provided, then each sample is given unit weight.
Returns
-------
out : float
Logistic loss.
grad : ndarray, shape (n_features,) or (n_features + 1,)
Logistic gradient.
"""
n_samples, n_features = X.shape
grad = np.empty_like(w)
w, c, yz = _intercept_dot(w, X, y)
if sample_weight is None:
sample_weight = np.ones(n_samples)
# Logistic loss is the negative of the log of the logistic function.
out = -np.sum(sample_weight * log_logistic(yz)) + .5 * alpha * np.dot(w, w)
z = expit(yz)
z0 = sample_weight * (z - 1) * y
grad[:n_features] = safe_sparse_dot(X.T, z0) + alpha * w
# Case where we fit the intercept.
if grad.shape[0] > n_features:
grad[-1] = z0.sum()
return out, grad
def _logistic_loss(w, X, y, alpha, sample_weight=None):
"""Computes the logistic loss.
Parameters
----------
w : ndarray, shape (n_features,) or (n_features + 1,)
Coefficient vector.
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data.
y : ndarray, shape (n_samples,)
Array of labels.
alpha : float
Regularization parameter. alpha is equal to 1 / C.
sample_weight : array-like, shape (n_samples,) optional
Array of weights that are assigned to individual samples.
If not provided, then each sample is given unit weight.
Returns
-------
out : float
Logistic loss.
"""
w, c, yz = _intercept_dot(w, X, y)
if sample_weight is None:
sample_weight = np.ones(y.shape[0])
# Logistic loss is the negative of the log of the logistic function.
out = -np.sum(sample_weight * log_logistic(yz)) + .5 * alpha * np.dot(w, w)
return out
def _logistic_grad_hess(w, X, y, alpha, sample_weight=None):
"""Computes the gradient and the Hessian, in the case of a logistic loss.
Parameters
----------
w : ndarray, shape (n_features,) or (n_features + 1,)
Coefficient vector.
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data.
y : ndarray, shape (n_samples,)
Array of labels.
alpha : float
Regularization parameter. alpha is equal to 1 / C.
sample_weight : array-like, shape (n_samples,) optional
Array of weights that are assigned to individual samples.
If not provided, then each sample is given unit weight.
Returns
-------
grad : ndarray, shape (n_features,) or (n_features + 1,)
Logistic gradient.
Hs : callable
Function that takes the gradient as a parameter and returns the
matrix product of the Hessian and gradient.
"""
n_samples, n_features = X.shape
grad = np.empty_like(w)
fit_intercept = grad.shape[0] > n_features
w, c, yz = _intercept_dot(w, X, y)
if sample_weight is None:
sample_weight = np.ones(y.shape[0])
z = expit(yz)
z0 = sample_weight * (z - 1) * y
grad[:n_features] = safe_sparse_dot(X.T, z0) + alpha * w
# Case where we fit the intercept.
if fit_intercept:
grad[-1] = z0.sum()
# The mat-vec product of the Hessian
d = sample_weight * z * (1 - z)
if sparse.issparse(X):
dX = safe_sparse_dot(sparse.dia_matrix((d, 0),
shape=(n_samples, n_samples)), X)
else:
# Precompute as much as possible
dX = d[:, np.newaxis] * X
if fit_intercept:
# Calculate the double derivative with respect to intercept
# In the case of sparse matrices this returns a matrix object.
dd_intercept = np.squeeze(np.array(dX.sum(axis=0)))
def Hs(s):
ret = np.empty_like(s)
ret[:n_features] = X.T.dot(dX.dot(s[:n_features]))
ret[:n_features] += alpha * s[:n_features]
# For the fit intercept case.
if fit_intercept:
ret[:n_features] += s[-1] * dd_intercept
ret[-1] = dd_intercept.dot(s[:n_features])
ret[-1] += d.sum() * s[-1]
return ret
return grad, Hs
def _multinomial_loss(w, X, Y, alpha, sample_weight):
"""Computes multinomial loss and class probabilities.
Parameters
----------
w : ndarray, shape (n_classes * n_features,) or
(n_classes * (n_features + 1),)
Coefficient vector.
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data.
Y : ndarray, shape (n_samples, n_classes)
Transformed labels according to the output of LabelBinarizer.
alpha : float
Regularization parameter. alpha is equal to 1 / C.
sample_weight : array-like, shape (n_samples,) optional
Array of weights that are assigned to individual samples.
If not provided, then each sample is given unit weight.
Returns
-------
loss : float
Multinomial loss.
p : ndarray, shape (n_samples, n_classes)
Estimated class probabilities.
w : ndarray, shape (n_classes, n_features)
Reshaped param vector excluding intercept terms.
Reference
---------
Bishop, C. M. (2006). Pattern recognition and machine learning.
Springer. (Chapter 4.3.4)
"""
n_classes = Y.shape[1]
n_features = X.shape[1]
fit_intercept = w.size == (n_classes * (n_features + 1))
w = w.reshape(n_classes, -1)
sample_weight = sample_weight[:, np.newaxis]
if fit_intercept:
intercept = w[:, -1]
w = w[:, :-1]
else:
intercept = 0
p = safe_sparse_dot(X, w.T)
p += intercept
p -= logsumexp(p, axis=1)[:, np.newaxis]
loss = -(sample_weight * Y * p).sum()
loss += 0.5 * alpha * squared_norm(w)
p = np.exp(p, p)
return loss, p, w
def _multinomial_loss_grad(w, X, Y, alpha, sample_weight):
"""Computes the multinomial loss, gradient and class probabilities.
Parameters
----------
w : ndarray, shape (n_classes * n_features,) or
(n_classes * (n_features + 1),)
Coefficient vector.
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data.
Y : ndarray, shape (n_samples, n_classes)
Transformed labels according to the output of LabelBinarizer.
alpha : float
Regularization parameter. alpha is equal to 1 / C.
sample_weight : array-like, shape (n_samples,) optional
Array of weights that are assigned to individual samples.
Returns
-------
loss : float
Multinomial loss.
grad : ndarray, shape (n_classes * n_features,) or
(n_classes * (n_features + 1),)
Ravelled gradient of the multinomial loss.
p : ndarray, shape (n_samples, n_classes)
Estimated class probabilities
Reference
---------
Bishop, C. M. (2006). Pattern recognition and machine learning.
Springer. (Chapter 4.3.4)
"""
n_classes = Y.shape[1]
n_features = X.shape[1]
fit_intercept = (w.size == n_classes * (n_features + 1))
grad = np.zeros((n_classes, n_features + bool(fit_intercept)),
dtype=X.dtype)
loss, p, w = _multinomial_loss(w, X, Y, alpha, sample_weight)
sample_weight = sample_weight[:, np.newaxis]
diff = sample_weight * (p - Y)
grad[:, :n_features] = safe_sparse_dot(diff.T, X)
grad[:, :n_features] += alpha * w
if fit_intercept:
grad[:, -1] = diff.sum(axis=0)
return loss, grad.ravel(), p
def _multinomial_grad_hess(w, X, Y, alpha, sample_weight):
"""
Computes the gradient and the Hessian, in the case of a multinomial loss.
Parameters
----------
w : ndarray, shape (n_classes * n_features,) or
(n_classes * (n_features + 1),)
Coefficient vector.
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data.
Y : ndarray, shape (n_samples, n_classes)
Transformed labels according to the output of LabelBinarizer.
alpha : float
Regularization parameter. alpha is equal to 1 / C.
sample_weight : array-like, shape (n_samples,) optional
Array of weights that are assigned to individual samples.
Returns
-------
grad : array, shape (n_classes * n_features,) or
(n_classes * (n_features + 1),)
Ravelled gradient of the multinomial loss.
hessp : callable
Function that takes in a vector input of shape (n_classes * n_features)
or (n_classes * (n_features + 1)) and returns matrix-vector product
with hessian.
References
----------
Barak A. Pearlmutter (1993). Fast Exact Multiplication by the Hessian.
http://www.bcl.hamilton.ie/~barak/papers/nc-hessian.pdf
"""
n_features = X.shape[1]
n_classes = Y.shape[1]
fit_intercept = w.size == (n_classes * (n_features + 1))
# `loss` is unused. Refactoring to avoid computing it does not
# significantly speed up the computation and decreases readability
loss, grad, p = _multinomial_loss_grad(w, X, Y, alpha, sample_weight)
sample_weight = sample_weight[:, np.newaxis]
# Hessian-vector product derived by applying the R-operator on the gradient
# of the multinomial loss function.
def hessp(v):
v = v.reshape(n_classes, -1)
if fit_intercept:
inter_terms = v[:, -1]
v = v[:, :-1]
else:
inter_terms = 0
# r_yhat holds the result of applying the R-operator on the multinomial
# estimator.
r_yhat = safe_sparse_dot(X, v.T)
r_yhat += inter_terms
r_yhat += (-p * r_yhat).sum(axis=1)[:, np.newaxis]
r_yhat *= p
r_yhat *= sample_weight
hessProd = np.zeros((n_classes, n_features + bool(fit_intercept)))
hessProd[:, :n_features] = safe_sparse_dot(r_yhat.T, X)
hessProd[:, :n_features] += v * alpha
if fit_intercept:
hessProd[:, -1] = r_yhat.sum(axis=0)
return hessProd.ravel()
return grad, hessp
def _check_solver_option(solver, multi_class, penalty, dual):
if solver not in ['liblinear', 'newton-cg', 'lbfgs', 'sag', 'saga']:
raise ValueError("Logistic Regression supports only liblinear, "
"newton-cg, lbfgs, sag and saga solvers, got %s"
% solver)
if multi_class not in ['multinomial', 'ovr']:
raise ValueError("multi_class should be either multinomial or "
"ovr, got %s" % multi_class)
if multi_class == 'multinomial' and solver == 'liblinear':
raise ValueError("Solver %s does not support "
"a multinomial backend." % solver)
if solver not in ['liblinear', 'saga']:
if penalty != 'l2':
raise ValueError("Solver %s supports only l2 penalties, "
"got %s penalty." % (solver, penalty))
if solver != 'liblinear':
if dual:
raise ValueError("Solver %s supports only "
"dual=False, got dual=%s" % (solver, dual))
def logistic_regression_path(X, y, pos_class=None, Cs=10, fit_intercept=True,
max_iter=100, tol=1e-4, verbose=0,
solver='lbfgs', coef=None,
class_weight=None, dual=False, penalty='l2',
intercept_scaling=1., multi_class='ovr',
random_state=None, check_input=True,
max_squared_sum=None, sample_weight=None):
"""Compute a Logistic Regression model for a list of regularization
parameters.
This is an implementation that uses the result of the previous model
to speed up computations along the set of solutions, making it faster
than sequentially calling LogisticRegression for the different parameters.
Note that there will be no speedup with liblinear solver, since it does
not handle warm-starting.
Read more in the :ref:`User Guide <logistic_regression>`.
Parameters
----------
X : array-like or sparse matrix, shape (n_samples, n_features)
Input data.
y : array-like, shape (n_samples,)
Input data, target values.
pos_class : int, None
The class with respect to which we perform a one-vs-all fit.
If None, then it is assumed that the given problem is binary.
Cs : int | array-like, shape (n_cs,)
List of values for the regularization parameter or integer specifying
the number of regularization parameters that should be used. In this
case, the parameters will be chosen in a logarithmic scale between
1e-4 and 1e4.
fit_intercept : bool
Whether to fit an intercept for the model. In this case the shape of
the returned array is (n_cs, n_features + 1).
max_iter : int
Maximum number of iterations for the solver.
tol : float
Stopping criterion. For the newton-cg and lbfgs solvers, the iteration
will stop when ``max{|g_i | i = 1, ..., n} <= tol``
where ``g_i`` is the i-th component of the gradient.
verbose : int
For the liblinear and lbfgs solvers set verbose to any positive
number for verbosity.
solver : {'lbfgs', 'newton-cg', 'liblinear', 'sag', 'saga'}
Numerical solver to use.
coef : array-like, shape (n_features,), default None
Initialization value for coefficients of logistic regression.
Useless for liblinear solver.
class_weight : dict or 'balanced', optional
Weights associated with classes in the form ``{class_label: weight}``.
If not given, all classes are supposed to have weight one.
The "balanced" mode uses the values of y to automatically adjust
weights inversely proportional to class frequencies in the input data
as ``n_samples / (n_classes * np.bincount(y))``.
Note that these weights will be multiplied with sample_weight (passed
through the fit method) if sample_weight is specified.
dual : bool
Dual or primal formulation. Dual formulation is only implemented for
l2 penalty with liblinear solver. Prefer dual=False when
n_samples > n_features.
penalty : str, 'l1' or 'l2'
Used to specify the norm used in the penalization. The 'newton-cg',
'sag' and 'lbfgs' solvers support only l2 penalties.
intercept_scaling : float, default 1.
Useful only when the solver 'liblinear' is used
and self.fit_intercept is set to True. In this case, x becomes
[x, self.intercept_scaling],
i.e. a "synthetic" feature with constant value equal to
intercept_scaling is appended to the instance vector.
The intercept becomes ``intercept_scaling * synthetic_feature_weight``.
Note! the synthetic feature weight is subject to l1/l2 regularization
as all other features.
To lessen the effect of regularization on synthetic feature weight
(and therefore on the intercept) intercept_scaling has to be increased.
multi_class : str, {'ovr', 'multinomial'}
Multiclass option can be either 'ovr' or 'multinomial'. If the option
chosen is 'ovr', then a binary problem is fit for each label. Else
the loss minimised is the multinomial loss fit across
the entire probability distribution. Works only for the 'lbfgs' and
'newton-cg' solvers.
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator to use when shuffling
the data. If int, random_state is the seed used by the random number
generator; If RandomState instance, random_state is the random number
generator; If None, the random number generator is the RandomState
instance used by `np.random`. Used when ``solver`` == 'sag' or
'liblinear'.
check_input : bool, default True
If False, the input arrays X and y will not be checked.
max_squared_sum : float, default None
Maximum squared sum of X over samples. Used only in SAG solver.
If None, it will be computed, going through all the samples.
The value should be precomputed to speed up cross validation.
sample_weight : array-like, shape(n_samples,) optional
Array of weights that are assigned to individual samples.
If not provided, then each sample is given unit weight.
Returns
-------
coefs : ndarray, shape (n_cs, n_features) or (n_cs, n_features + 1)
List of coefficients for the Logistic Regression model. If
fit_intercept is set to True then the second dimension will be
n_features + 1, where the last item represents the intercept.
Cs : ndarray
Grid of Cs used for cross-validation.
n_iter : array, shape (n_cs,)
Actual number of iteration for each Cs.
Notes
-----
You might get slightly different results with the solver liblinear than
with the others since this uses LIBLINEAR which penalizes the intercept.
.. versionchanged:: 0.19
The "copy" parameter was removed.
"""
if isinstance(Cs, numbers.Integral):
Cs = np.logspace(-4, 4, Cs)
_check_solver_option(solver, multi_class, penalty, dual)
# Preprocessing.
if check_input:
X = check_array(X, accept_sparse='csr', dtype=np.float64)
y = check_array(y, ensure_2d=False, dtype=None)
check_consistent_length(X, y)
_, n_features = X.shape
classes = np.unique(y)
random_state = check_random_state(random_state)
if pos_class is None and multi_class != 'multinomial':
if (classes.size > 2):
raise ValueError('To fit OvR, use the pos_class argument')
# np.unique(y) gives labels in sorted order.
pos_class = classes[1]
# If sample weights exist, convert them to array (support for lists)
# and check length
# Otherwise set them to 1 for all examples
if sample_weight is not None:
sample_weight = np.array(sample_weight, dtype=X.dtype, order='C')
check_consistent_length(y, sample_weight)
else:
sample_weight = np.ones(X.shape[0], dtype=X.dtype)
# If class_weights is a dict (provided by the user), the weights
# are assigned to the original labels. If it is "balanced", then
# the class_weights are assigned after masking the labels with a OvR.
le = LabelEncoder()
if isinstance(class_weight, dict) or multi_class == 'multinomial':
class_weight_ = compute_class_weight(class_weight, classes, y)
sample_weight *= class_weight_[le.fit_transform(y)]
# For doing a ovr, we need to mask the labels first. for the
# multinomial case this is not necessary.
if multi_class == 'ovr':
w0 = np.zeros(n_features + int(fit_intercept), dtype=X.dtype)
mask_classes = np.array([-1, 1])
mask = (y == pos_class)
y_bin = np.ones(y.shape, dtype=X.dtype)
y_bin[~mask] = -1.
# for compute_class_weight
if class_weight == "balanced":
class_weight_ = compute_class_weight(class_weight, mask_classes,
y_bin)
sample_weight *= class_weight_[le.fit_transform(y_bin)]
else:
if solver not in ['sag', 'saga']:
lbin = LabelBinarizer()
Y_multi = lbin.fit_transform(y)
if Y_multi.shape[1] == 1:
Y_multi = np.hstack([1 - Y_multi, Y_multi])
else:
# SAG multinomial solver needs LabelEncoder, not LabelBinarizer
le = LabelEncoder()
Y_multi = le.fit_transform(y).astype(X.dtype, copy=False)
w0 = np.zeros((classes.size, n_features + int(fit_intercept)),
order='F', dtype=X.dtype)
if coef is not None:
# it must work both giving the bias term and not
if multi_class == 'ovr':
if coef.size not in (n_features, w0.size):
raise ValueError(
'Initialization coef is of shape %d, expected shape '
'%d or %d' % (coef.size, n_features, w0.size))
w0[:coef.size] = coef
else:
# For binary problems coef.shape[0] should be 1, otherwise it
# should be classes.size.
n_classes = classes.size
if n_classes == 2:
n_classes = 1
if (coef.shape[0] != n_classes or
coef.shape[1] not in (n_features, n_features + 1)):
raise ValueError(
'Initialization coef is of shape (%d, %d), expected '
'shape (%d, %d) or (%d, %d)' % (
coef.shape[0], coef.shape[1], classes.size,
n_features, classes.size, n_features + 1))
w0[:, :coef.shape[1]] = coef
if multi_class == 'multinomial':
# fmin_l_bfgs_b and newton-cg accepts only ravelled parameters.
if solver in ['lbfgs', 'newton-cg']:
w0 = w0.ravel()
target = Y_multi
if solver == 'lbfgs':
func = lambda x, *args: _multinomial_loss_grad(x, *args)[0:2]
elif solver == 'newton-cg':
func = lambda x, *args: _multinomial_loss(x, *args)[0]
grad = lambda x, *args: _multinomial_loss_grad(x, *args)[1]
hess = _multinomial_grad_hess
warm_start_sag = {'coef': w0.T}
else:
target = y_bin
if solver == 'lbfgs':
func = _logistic_loss_and_grad
elif solver == 'newton-cg':
func = _logistic_loss
grad = lambda x, *args: _logistic_loss_and_grad(x, *args)[1]
hess = _logistic_grad_hess
warm_start_sag = {'coef': np.expand_dims(w0, axis=1)}
coefs = list()
n_iter = np.zeros(len(Cs), dtype=np.int32)
for i, C in enumerate(Cs):
if solver == 'lbfgs':
try:
w0, loss, info = optimize.fmin_l_bfgs_b(
func, w0, fprime=None,
args=(X, target, 1. / C, sample_weight),
iprint=(verbose > 0) - 1, pgtol=tol, maxiter=max_iter)
except TypeError:
# old scipy doesn't have maxiter
w0, loss, info = optimize.fmin_l_bfgs_b(
func, w0, fprime=None,
args=(X, target, 1. / C, sample_weight),
iprint=(verbose > 0) - 1, pgtol=tol)
if info["warnflag"] == 1 and verbose > 0:
warnings.warn("lbfgs failed to converge. Increase the number "
"of iterations.")
try:
n_iter_i = info['nit'] - 1
except:
n_iter_i = info['funcalls'] - 1
elif solver == 'newton-cg':
args = (X, target, 1. / C, sample_weight)
w0, n_iter_i = newton_cg(hess, func, grad, w0, args=args,
maxiter=max_iter, tol=tol)
elif solver == 'liblinear':
coef_, intercept_, n_iter_i, = _fit_liblinear(
X, target, C, fit_intercept, intercept_scaling, None,
penalty, dual, verbose, max_iter, tol, random_state,
sample_weight=sample_weight)
if fit_intercept:
w0 = np.concatenate([coef_.ravel(), intercept_])
else:
w0 = coef_.ravel()
elif solver in ['sag', 'saga']:
if multi_class == 'multinomial':
target = target.astype(np.float64)
loss = 'multinomial'
else:
loss = 'log'
if penalty == 'l1':
alpha = 0.
beta = 1. / C
else:
alpha = 1. / C
beta = 0.
w0, n_iter_i, warm_start_sag = sag_solver(
X, target, sample_weight, loss, alpha,
beta, max_iter, tol,
verbose, random_state, False, max_squared_sum, warm_start_sag,
is_saga=(solver == 'saga'))
else:
raise ValueError("solver must be one of {'liblinear', 'lbfgs', "
"'newton-cg', 'sag'}, got '%s' instead" % solver)
if multi_class == 'multinomial':
multi_w0 = np.reshape(w0, (classes.size, -1))
if classes.size == 2:
multi_w0 = multi_w0[1][np.newaxis, :]
coefs.append(multi_w0)
else:
coefs.append(w0.copy())
n_iter[i] = n_iter_i
return coefs, np.array(Cs), n_iter
# helper function for LogisticCV
def _log_reg_scoring_path(X, y, train, test, pos_class=None, Cs=10,
scoring=None, fit_intercept=False,
max_iter=100, tol=1e-4, class_weight=None,
verbose=0, solver='lbfgs', penalty='l2',
dual=False, intercept_scaling=1.,
multi_class='ovr', random_state=None,
max_squared_sum=None, sample_weight=None):
"""Computes scores across logistic_regression_path
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data.
y : array-like, shape (n_samples,) or (n_samples, n_targets)
Target labels.
train : list of indices
The indices of the train set.
test : list of indices
The indices of the test set.
pos_class : int, None
The class with respect to which we perform a one-vs-all fit.
If None, then it is assumed that the given problem is binary.
Cs : list of floats | int
Each of the values in Cs describes the inverse of
regularization strength. If Cs is as an int, then a grid of Cs
values are chosen in a logarithmic scale between 1e-4 and 1e4.
If not provided, then a fixed set of values for Cs are used.
scoring : callable or None, optional, default: None
A string (see model evaluation documentation) or
a scorer callable object / function with signature
``scorer(estimator, X, y)``. For a list of scoring functions
that can be used, look at :mod:`sklearn.metrics`. The
default scoring option used is accuracy_score.
fit_intercept : bool
If False, then the bias term is set to zero. Else the last
term of each coef_ gives us the intercept.
max_iter : int
Maximum number of iterations for the solver.
tol : float
Tolerance for stopping criteria.
class_weight : dict or 'balanced', optional
Weights associated with classes in the form ``{class_label: weight}``.
If not given, all classes are supposed to have weight one.
The "balanced" mode uses the values of y to automatically adjust
weights inversely proportional to class frequencies in the input data
as ``n_samples / (n_classes * np.bincount(y))``
Note that these weights will be multiplied with sample_weight (passed
through the fit method) if sample_weight is specified.
verbose : int
For the liblinear and lbfgs solvers set verbose to any positive
number for verbosity.
solver : {'lbfgs', 'newton-cg', 'liblinear', 'sag', 'saga'}
Decides which solver to use.
penalty : str, 'l1' or 'l2'
Used to specify the norm used in the penalization. The 'newton-cg',
'sag' and 'lbfgs' solvers support only l2 penalties.
dual : bool
Dual or primal formulation. Dual formulation is only implemented for
l2 penalty with liblinear solver. Prefer dual=False when
n_samples > n_features.
intercept_scaling : float, default 1.
Useful only when the solver 'liblinear' is used
and self.fit_intercept is set to True. In this case, x becomes
[x, self.intercept_scaling],
i.e. a "synthetic" feature with constant value equals to
intercept_scaling is appended to the instance vector.
The intercept becomes intercept_scaling * synthetic feature weight
Note! the synthetic feature weight is subject to l1/l2 regularization
as all other features.
To lessen the effect of regularization on synthetic feature weight
(and therefore on the intercept) intercept_scaling has to be increased.
multi_class : str, {'ovr', 'multinomial'}
Multiclass option can be either 'ovr' or 'multinomial'. If the option
chosen is 'ovr', then a binary problem is fit for each label. Else
the loss minimised is the multinomial loss fit across
the entire probability distribution. Does not work for
liblinear solver.
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator to use when shuffling
the data. If int, random_state is the seed used by the random number
generator; If RandomState instance, random_state is the random number
generator; If None, the random number generator is the RandomState
instance used by `np.random`. Used when ``solver`` == 'sag' and
'liblinear'.
max_squared_sum : float, default None
Maximum squared sum of X over samples. Used only in SAG solver.
If None, it will be computed, going through all the samples.
The value should be precomputed to speed up cross validation.
sample_weight : array-like, shape(n_samples,) optional
Array of weights that are assigned to individual samples.
If not provided, then each sample is given unit weight.
Returns
-------
coefs : ndarray, shape (n_cs, n_features) or (n_cs, n_features + 1)
List of coefficients for the Logistic Regression model. If
fit_intercept is set to True then the second dimension will be
n_features + 1, where the last item represents the intercept.
Cs : ndarray
Grid of Cs used for cross-validation.
scores : ndarray, shape (n_cs,)
Scores obtained for each Cs.
n_iter : array, shape(n_cs,)
Actual number of iteration for each Cs.
"""
_check_solver_option(solver, multi_class, penalty, dual)
X_train = X[train]
X_test = X[test]
y_train = y[train]
y_test = y[test]
if sample_weight is not None:
sample_weight = check_array(sample_weight, ensure_2d=False)
check_consistent_length(y, sample_weight)
sample_weight = sample_weight[train]
coefs, Cs, n_iter = logistic_regression_path(
X_train, y_train, Cs=Cs, fit_intercept=fit_intercept,
solver=solver, max_iter=max_iter, class_weight=class_weight,
pos_class=pos_class, multi_class=multi_class,
tol=tol, verbose=verbose, dual=dual, penalty=penalty,
intercept_scaling=intercept_scaling, random_state=random_state,
check_input=False, max_squared_sum=max_squared_sum,
sample_weight=sample_weight)
log_reg = LogisticRegression(fit_intercept=fit_intercept)
# The score method of Logistic Regression has a classes_ attribute.
if multi_class == 'ovr':
log_reg.classes_ = np.array([-1, 1])
elif multi_class == 'multinomial':
log_reg.classes_ = np.unique(y_train)
else:
raise ValueError("multi_class should be either multinomial or ovr, "
"got %d" % multi_class)
if pos_class is not None:
mask = (y_test == pos_class)
y_test = np.ones(y_test.shape, dtype=np.float64)
y_test[~mask] = -1.
scores = list()
if isinstance(scoring, six.string_types):
scoring = SCORERS[scoring]
for w in coefs:
if multi_class == 'ovr':
w = w[np.newaxis, :]
if fit_intercept:
log_reg.coef_ = w[:, :-1]
log_reg.intercept_ = w[:, -1]
else:
log_reg.coef_ = w
log_reg.intercept_ = 0.
if scoring is None:
scores.append(log_reg.score(X_test, y_test))
else:
scores.append(scoring(log_reg, X_test, y_test))
return coefs, Cs, np.array(scores), n_iter
class LogisticRegression(BaseEstimator, LinearClassifierMixin,
SparseCoefMixin):
"""Logistic Regression (aka logit, MaxEnt) classifier.
In the multiclass case, the training algorithm uses the one-vs-rest (OvR)
scheme if the 'multi_class' option is set to 'ovr', and uses the cross-
entropy loss if the 'multi_class' option is set to 'multinomial'.
(Currently the 'multinomial' option is supported only by the 'lbfgs',
'sag' and 'newton-cg' solvers.)
This class implements regularized logistic regression using the
'liblinear' library, 'newton-cg', 'sag' and 'lbfgs' solvers. It can handle
both dense and sparse input. Use C-ordered arrays or CSR matrices
containing 64-bit floats for optimal performance; any other input format
will be converted (and copied).
The 'newton-cg', 'sag', and 'lbfgs' solvers support only L2 regularization
with primal formulation. The 'liblinear' solver supports both L1 and L2
regularization, with a dual formulation only for the L2 penalty.
Read more in the :ref:`User Guide <logistic_regression>`.
Parameters
----------
penalty : str, 'l1' or 'l2', default: 'l2'
Used to specify the norm used in the penalization. The 'newton-cg',
'sag' and 'lbfgs' solvers support only l2 penalties.
.. versionadded:: 0.19
l1 penalty with SAGA solver (allowing 'multinomial' + L1)
dual : bool, default: False
Dual or primal formulation. Dual formulation is only implemented for
l2 penalty with liblinear solver. Prefer dual=False when
n_samples > n_features.
tol : float, default: 1e-4
Tolerance for stopping criteria.
C : float, default: 1.0
Inverse of regularization strength; must be a positive float.
Like in support vector machines, smaller values specify stronger
regularization.
fit_intercept : bool, default: True
Specifies if a constant (a.k.a. bias or intercept) should be
added to the decision function.
intercept_scaling : float, default 1.
Useful only when the solver 'liblinear' is used
and self.fit_intercept is set to True. In this case, x becomes
[x, self.intercept_scaling],
i.e. a "synthetic" feature with constant value equal to
intercept_scaling is appended to the instance vector.
The intercept becomes ``intercept_scaling * synthetic_feature_weight``.
Note! the synthetic feature weight is subject to l1/l2 regularization
as all other features.
To lessen the effect of regularization on synthetic feature weight
(and therefore on the intercept) intercept_scaling has to be increased.
class_weight : dict or 'balanced', default: None
Weights associated with classes in the form ``{class_label: weight}``.
If not given, all classes are supposed to have weight one.
The "balanced" mode uses the values of y to automatically adjust
weights inversely proportional to class frequencies in the input data
as ``n_samples / (n_classes * np.bincount(y))``.
Note that these weights will be multiplied with sample_weight (passed
through the fit method) if sample_weight is specified.
.. versionadded:: 0.17
*class_weight='balanced'*
random_state : int, RandomState instance or None, optional, default: None
The seed of the pseudo random number generator to use when shuffling
the data. If int, random_state is the seed used by the random number
generator; If RandomState instance, random_state is the random number
generator; If None, the random number generator is the RandomState
instance used by `np.random`. Used when ``solver`` == 'sag' or
'liblinear'.
solver : {'newton-cg', 'lbfgs', 'liblinear', 'sag', 'saga'},
default: 'liblinear'
Algorithm to use in the optimization problem.
- For small datasets, 'liblinear' is a good choice, whereas 'sag' and
'saga' are faster for large ones.
- For multiclass problems, only 'newton-cg', 'sag', 'saga' and 'lbfgs'
handle multinomial loss; 'liblinear' is limited to one-versus-rest
schemes.
- 'newton-cg', 'lbfgs' and 'sag' only handle L2 penalty, whereas
'liblinear' and 'saga' handle L1 penalty.
Note that 'sag' and 'saga' fast convergence is only guaranteed on
features with approximately the same scale. You can
preprocess the data with a scaler from sklearn.preprocessing.
.. versionadded:: 0.17
Stochastic Average Gradient descent solver.
.. versionadded:: 0.19
SAGA solver.
max_iter : int, default: 100
Useful only for the newton-cg, sag and lbfgs solvers.
Maximum number of iterations taken for the solvers to converge.
multi_class : str, {'ovr', 'multinomial'}, default: 'ovr'
Multiclass option can be either 'ovr' or 'multinomial'. If the option
chosen is 'ovr', then a binary problem is fit for each label. Else
the loss minimised is the multinomial loss fit across
the entire probability distribution. Does not work for liblinear
solver.
.. versionadded:: 0.18
Stochastic Average Gradient descent solver for 'multinomial' case.
verbose : int, default: 0
For the liblinear and lbfgs solvers set verbose to any positive
number for verbosity.
warm_start : bool, default: False
When set to True, reuse the solution of the previous call to fit as
initialization, otherwise, just erase the previous solution.
Useless for liblinear solver.
.. versionadded:: 0.17
*warm_start* to support *lbfgs*, *newton-cg*, *sag*, *saga* solvers.
n_jobs : int, default: 1
Number of CPU cores used when parallelizing over classes if
multi_class='ovr'". This parameter is ignored when the ``solver``is set
to 'liblinear' regardless of whether 'multi_class' is specified or
not. If given a value of -1, all cores are used.
Attributes
----------
coef_ : array, shape (1, n_features) or (n_classes, n_features)
Coefficient of the features in the decision function.
`coef_` is of shape (1, n_features) when the given problem
is binary.
intercept_ : array, shape (1,) or (n_classes,)
Intercept (a.k.a. bias) added to the decision function.
If `fit_intercept` is set to False, the intercept is set to zero.
`intercept_` is of shape(1,) when the problem is binary.
n_iter_ : array, shape (n_classes,) or (1, )
Actual number of iterations for all classes. If binary or multinomial,
it returns only 1 element. For liblinear solver, only the maximum
number of iteration across all classes is given.
See also
--------
SGDClassifier : incrementally trained logistic regression (when given
the parameter ``loss="log"``).
sklearn.svm.LinearSVC : learns SVM models using the same algorithm.
Notes
-----
The underlying C implementation uses a random number generator to
select features when fitting the model. It is thus not uncommon,
to have slightly different results for the same input data. If
that happens, try with a smaller tol parameter.
Predict output may not match that of standalone liblinear in certain
cases. See :ref:`differences from liblinear <liblinear_differences>`
in the narrative documentation.
References
----------
LIBLINEAR -- A Library for Large Linear Classification
http://www.csie.ntu.edu.tw/~cjlin/liblinear/
SAG -- Mark Schmidt, Nicolas Le Roux, and Francis Bach
Minimizing Finite Sums with the Stochastic Average Gradient
https://hal.inria.fr/hal-00860051/document
SAGA -- Defazio, A., Bach F. & Lacoste-Julien S. (2014).
SAGA: A Fast Incremental Gradient Method With Support
for Non-Strongly Convex Composite Objectives
https://arxiv.org/abs/1407.0202
Hsiang-Fu Yu, Fang-Lan Huang, Chih-Jen Lin (2011). Dual coordinate descent
methods for logistic regression and maximum entropy models.
Machine Learning 85(1-2):41-75.
http://www.csie.ntu.edu.tw/~cjlin/papers/maxent_dual.pdf
"""
def __init__(self, penalty='l2', dual=False, tol=1e-4, C=1.0,
fit_intercept=True, intercept_scaling=1, class_weight=None,
random_state=None, solver='liblinear', max_iter=100,
multi_class='ovr', verbose=0, warm_start=False, n_jobs=1):
self.penalty = penalty
self.dual = dual
self.tol = tol
self.C = C
self.fit_intercept = fit_intercept
self.intercept_scaling = intercept_scaling
self.class_weight = class_weight
self.random_state = random_state
self.solver = solver
self.max_iter = max_iter
self.multi_class = multi_class
self.verbose = verbose
self.warm_start = warm_start
self.n_jobs = n_jobs
def fit(self, X, y, sample_weight=None):
"""Fit the model according to the given training data.
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training vector, where n_samples is the number of samples and
n_features is the number of features.
y : array-like, shape (n_samples,)
Target vector relative to X.
sample_weight : array-like, shape (n_samples,) optional
Array of weights that are assigned to individual samples.
If not provided, then each sample is given unit weight.
.. versionadded:: 0.17
*sample_weight* support to LogisticRegression.
Returns
-------
self : object
Returns self.
"""
if not isinstance(self.C, numbers.Number) or self.C < 0:
raise ValueError("Penalty term must be positive; got (C=%r)"
% self.C)
if not isinstance(self.max_iter, numbers.Number) or self.max_iter < 0:
raise ValueError("Maximum number of iteration must be positive;"
" got (max_iter=%r)" % self.max_iter)
if not isinstance(self.tol, numbers.Number) or self.tol < 0:
raise ValueError("Tolerance for stopping criteria must be "
"positive; got (tol=%r)" % self.tol)
if self.solver in ['newton-cg']:
_dtype = [np.float64, np.float32]
else:
_dtype = np.float64
X, y = check_X_y(X, y, accept_sparse='csr', dtype=_dtype,
order="C")
check_classification_targets(y)
self.classes_ = np.unique(y)
n_samples, n_features = X.shape
_check_solver_option(self.solver, self.multi_class, self.penalty,
self.dual)
if self.solver == 'liblinear':
if self.n_jobs != 1:
warnings.warn("'n_jobs' > 1 does not have any effect when"
" 'solver' is set to 'liblinear'. Got 'n_jobs'"
" = {}.".format(self.n_jobs))
self.coef_, self.intercept_, n_iter_ = _fit_liblinear(
X, y, self.C, self.fit_intercept, self.intercept_scaling,
self.class_weight, self.penalty, self.dual, self.verbose,
self.max_iter, self.tol, self.random_state,
sample_weight=sample_weight)
self.n_iter_ = np.array([n_iter_])
return self
if self.solver in ['sag', 'saga']:
max_squared_sum = row_norms(X, squared=True).max()
else:
max_squared_sum = None
n_classes = len(self.classes_)
classes_ = self.classes_
if n_classes < 2:
raise ValueError("This solver needs samples of at least 2 classes"
" in the data, but the data contains only one"
" class: %r" % classes_[0])
if len(self.classes_) == 2:
n_classes = 1
classes_ = classes_[1:]
if self.warm_start:
warm_start_coef = getattr(self, 'coef_', None)
else:
warm_start_coef = None
if warm_start_coef is not None and self.fit_intercept:
warm_start_coef = np.append(warm_start_coef,
self.intercept_[:, np.newaxis],
axis=1)
self.coef_ = list()
self.intercept_ = np.zeros(n_classes)
# Hack so that we iterate only once for the multinomial case.
if self.multi_class == 'multinomial':
classes_ = [None]
warm_start_coef = [warm_start_coef]
if warm_start_coef is None:
warm_start_coef = [None] * n_classes
path_func = delayed(logistic_regression_path)
# The SAG solver releases the GIL so it's more efficient to use
# threads for this solver.
if self.solver in ['sag', 'saga']:
backend = 'threading'
else:
backend = 'multiprocessing'
fold_coefs_ = Parallel(n_jobs=self.n_jobs, verbose=self.verbose,
backend=backend)(
path_func(X, y, pos_class=class_, Cs=[self.C],
fit_intercept=self.fit_intercept, tol=self.tol,
verbose=self.verbose, solver=self.solver,
multi_class=self.multi_class, max_iter=self.max_iter,
class_weight=self.class_weight, check_input=False,
random_state=self.random_state, coef=warm_start_coef_,
penalty=self.penalty,
max_squared_sum=max_squared_sum,
sample_weight=sample_weight)
for class_, warm_start_coef_ in zip(classes_, warm_start_coef))
fold_coefs_, _, n_iter_ = zip(*fold_coefs_)
self.n_iter_ = np.asarray(n_iter_, dtype=np.int32)[:, 0]
if self.multi_class == 'multinomial':
self.coef_ = fold_coefs_[0][0]
else:
self.coef_ = np.asarray(fold_coefs_)
self.coef_ = self.coef_.reshape(n_classes, n_features +
int(self.fit_intercept))
if self.fit_intercept:
self.intercept_ = self.coef_[:, -1]
self.coef_ = self.coef_[:, :-1]
return self
def predict_proba(self, X):
"""Probability estimates.
The returned estimates for all classes are ordered by the
label of classes.
For a multi_class problem, if multi_class is set to be "multinomial"
the softmax function is used to find the predicted probability of
each class.
Else use a one-vs-rest approach, i.e calculate the probability
of each class assuming it to be positive using the logistic function.
and normalize these values across all the classes.
Parameters
----------
X : array-like, shape = [n_samples, n_features]
Returns
-------
T : array-like, shape = [n_samples, n_classes]
Returns the probability of the sample for each class in the model,
where classes are ordered as they are in ``self.classes_``.
"""
if not hasattr(self, "coef_"):
raise NotFittedError("Call fit before prediction")
calculate_ovr = self.coef_.shape[0] == 1 or self.multi_class == "ovr"
if calculate_ovr:
return super(LogisticRegression, self)._predict_proba_lr(X)
else:
return softmax(self.decision_function(X), copy=False)
def predict_log_proba(self, X):
"""Log of probability estimates.
The returned estimates for all classes are ordered by the
label of classes.
Parameters
----------
X : array-like, shape = [n_samples, n_features]
Returns
-------
T : array-like, shape = [n_samples, n_classes]
Returns the log-probability of the sample for each class in the
model, where classes are ordered as they are in ``self.classes_``.
"""
return np.log(self.predict_proba(X))
class LogisticRegressionCV(LogisticRegression, BaseEstimator,
LinearClassifierMixin):
"""Logistic Regression CV (aka logit, MaxEnt) classifier.
This class implements logistic regression using liblinear, newton-cg, sag
of lbfgs optimizer. The newton-cg, sag and lbfgs solvers support only L2
regularization with primal formulation. The liblinear solver supports both
L1 and L2 regularization, with a dual formulation only for the L2 penalty.
For the grid of Cs values (that are set by default to be ten values in
a logarithmic scale between 1e-4 and 1e4), the best hyperparameter is
selected by the cross-validator StratifiedKFold, but it can be changed
using the cv parameter. In the case of newton-cg and lbfgs solvers,
we warm start along the path i.e guess the initial coefficients of the
present fit to be the coefficients got after convergence in the previous
fit, so it is supposed to be faster for high-dimensional dense data.
For a multiclass problem, the hyperparameters for each class are computed
using the best scores got by doing a one-vs-rest in parallel across all
folds and classes. Hence this is not the true multinomial loss.
Read more in the :ref:`User Guide <logistic_regression>`.
Parameters
----------
Cs : list of floats | int
Each of the values in Cs describes the inverse of regularization
strength. If Cs is as an int, then a grid of Cs values are chosen
in a logarithmic scale between 1e-4 and 1e4.
Like in support vector machines, smaller values specify stronger
regularization.
fit_intercept : bool, default: True
Specifies if a constant (a.k.a. bias or intercept) should be
added to the decision function.
cv : integer or cross-validation generator
The default cross-validation generator used is Stratified K-Folds.
If an integer is provided, then it is the number of folds used.
See the module :mod:`sklearn.model_selection` module for the
list of possible cross-validation objects.
dual : bool
Dual or primal formulation. Dual formulation is only implemented for
l2 penalty with liblinear solver. Prefer dual=False when
n_samples > n_features.
penalty : str, 'l1' or 'l2'
Used to specify the norm used in the penalization. The 'newton-cg',
'sag' and 'lbfgs' solvers support only l2 penalties.
scoring : string, callable, or None
A string (see model evaluation documentation) or
a scorer callable object / function with signature
``scorer(estimator, X, y)``. For a list of scoring functions
that can be used, look at :mod:`sklearn.metrics`. The
default scoring option used is 'accuracy'.
solver : {'newton-cg', 'lbfgs', 'liblinear', 'sag', 'saga'},
default: 'lbfgs'
Algorithm to use in the optimization problem.
- For small datasets, 'liblinear' is a good choice, whereas 'sag' and
'saga' are faster for large ones.
- For multiclass problems, only 'newton-cg', 'sag', 'saga' and 'lbfgs'
handle multinomial loss; 'liblinear' is limited to one-versus-rest
schemes.
- 'newton-cg', 'lbfgs' and 'sag' only handle L2 penalty, whereas
'liblinear' and 'saga' handle L1 penalty.
- 'liblinear' might be slower in LogisticRegressionCV because it does
not handle warm-starting.
Note that 'sag' and 'saga' fast convergence is only guaranteed on
features with approximately the same scale. You can preprocess the data
with a scaler from sklearn.preprocessing.
.. versionadded:: 0.17
Stochastic Average Gradient descent solver.
.. versionadded:: 0.19
SAGA solver.
tol : float, optional
Tolerance for stopping criteria.
max_iter : int, optional
Maximum number of iterations of the optimization algorithm.
class_weight : dict or 'balanced', optional
Weights associated with classes in the form ``{class_label: weight}``.
If not given, all classes are supposed to have weight one.
The "balanced" mode uses the values of y to automatically adjust
weights inversely proportional to class frequencies in the input data
as ``n_samples / (n_classes * np.bincount(y))``.
Note that these weights will be multiplied with sample_weight (passed
through the fit method) if sample_weight is specified.
.. versionadded:: 0.17
class_weight == 'balanced'
n_jobs : int, optional
Number of CPU cores used during the cross-validation loop. If given
a value of -1, all cores are used.
verbose : int
For the 'liblinear', 'sag' and 'lbfgs' solvers set verbose to any
positive number for verbosity.
refit : bool
If set to True, the scores are averaged across all folds, and the
coefs and the C that corresponds to the best score is taken, and a
final refit is done using these parameters.
Otherwise the coefs, intercepts and C that correspond to the
best scores across folds are averaged.
intercept_scaling : float, default 1.
Useful only when the solver 'liblinear' is used
and self.fit_intercept is set to True. In this case, x becomes
[x, self.intercept_scaling],
i.e. a "synthetic" feature with constant value equal to
intercept_scaling is appended to the instance vector.
The intercept becomes ``intercept_scaling * synthetic_feature_weight``.
Note! the synthetic feature weight is subject to l1/l2 regularization
as all other features.
To lessen the effect of regularization on synthetic feature weight
(and therefore on the intercept) intercept_scaling has to be increased.
multi_class : str, {'ovr', 'multinomial'}
Multiclass option can be either 'ovr' or 'multinomial'. If the option
chosen is 'ovr', then a binary problem is fit for each label. Else
the loss minimised is the multinomial loss fit across
the entire probability distribution. Works only for the 'newton-cg',
'sag', 'saga' and 'lbfgs' solver.
.. versionadded:: 0.18
Stochastic Average Gradient descent solver for 'multinomial' case.
random_state : int, RandomState instance or None, optional, default None
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
Attributes
----------
coef_ : array, shape (1, n_features) or (n_classes, n_features)
Coefficient of the features in the decision function.
`coef_` is of shape (1, n_features) when the given problem
is binary.
intercept_ : array, shape (1,) or (n_classes,)
Intercept (a.k.a. bias) added to the decision function.
If `fit_intercept` is set to False, the intercept is set to zero.
`intercept_` is of shape(1,) when the problem is binary.
Cs_ : array
Array of C i.e. inverse of regularization parameter values used
for cross-validation.
coefs_paths_ : array, shape ``(n_folds, len(Cs_), n_features)`` or \
``(n_folds, len(Cs_), n_features + 1)``
dict with classes as the keys, and the path of coefficients obtained
during cross-validating across each fold and then across each Cs
after doing an OvR for the corresponding class as values.
If the 'multi_class' option is set to 'multinomial', then
the coefs_paths are the coefficients corresponding to each class.
Each dict value has shape ``(n_folds, len(Cs_), n_features)`` or
``(n_folds, len(Cs_), n_features + 1)`` depending on whether the
intercept is fit or not.
scores_ : dict
dict with classes as the keys, and the values as the
grid of scores obtained during cross-validating each fold, after doing
an OvR for the corresponding class. If the 'multi_class' option
given is 'multinomial' then the same scores are repeated across
all classes, since this is the multinomial class.
Each dict value has shape (n_folds, len(Cs))
C_ : array, shape (n_classes,) or (n_classes - 1,)
Array of C that maps to the best scores across every class. If refit is
set to False, then for each class, the best C is the average of the
C's that correspond to the best scores for each fold.
`C_` is of shape(n_classes,) when the problem is binary.
n_iter_ : array, shape (n_classes, n_folds, n_cs) or (1, n_folds, n_cs)
Actual number of iterations for all classes, folds and Cs.
In the binary or multinomial cases, the first dimension is equal to 1.
See also
--------
LogisticRegression
"""
def __init__(self, Cs=10, fit_intercept=True, cv=None, dual=False,
penalty='l2', scoring=None, solver='lbfgs', tol=1e-4,
max_iter=100, class_weight=None, n_jobs=1, verbose=0,
refit=True, intercept_scaling=1., multi_class='ovr',
random_state=None):
self.Cs = Cs
self.fit_intercept = fit_intercept
self.cv = cv
self.dual = dual
self.penalty = penalty
self.scoring = scoring
self.tol = tol
self.max_iter = max_iter
self.class_weight = class_weight
self.n_jobs = n_jobs
self.verbose = verbose
self.solver = solver
self.refit = refit
self.intercept_scaling = intercept_scaling
self.multi_class = multi_class
self.random_state = random_state
def fit(self, X, y, sample_weight=None):
"""Fit the model according to the given training data.
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training vector, where n_samples is the number of samples and
n_features is the number of features.
y : array-like, shape (n_samples,)
Target vector relative to X.
sample_weight : array-like, shape (n_samples,) optional
Array of weights that are assigned to individual samples.
If not provided, then each sample is given unit weight.
Returns
-------
self : object
Returns self.
"""
_check_solver_option(self.solver, self.multi_class, self.penalty,
self.dual)
if not isinstance(self.max_iter, numbers.Number) or self.max_iter < 0:
raise ValueError("Maximum number of iteration must be positive;"
" got (max_iter=%r)" % self.max_iter)
if not isinstance(self.tol, numbers.Number) or self.tol < 0:
raise ValueError("Tolerance for stopping criteria must be "
"positive; got (tol=%r)" % self.tol)
X, y = check_X_y(X, y, accept_sparse='csr', dtype=np.float64,
order="C")
check_classification_targets(y)
class_weight = self.class_weight
# Encode for string labels
label_encoder = LabelEncoder().fit(y)
y = label_encoder.transform(y)
if isinstance(class_weight, dict):
class_weight = dict((label_encoder.transform([cls])[0], v)
for cls, v in class_weight.items())
# The original class labels
classes = self.classes_ = label_encoder.classes_
encoded_labels = label_encoder.transform(label_encoder.classes_)
if self.solver in ['sag', 'saga']:
max_squared_sum = row_norms(X, squared=True).max()
else:
max_squared_sum = None
# init cross-validation generator
cv = check_cv(self.cv, y, classifier=True)
folds = list(cv.split(X, y))
# Use the label encoded classes
n_classes = len(encoded_labels)
if n_classes < 2:
raise ValueError("This solver needs samples of at least 2 classes"
" in the data, but the data contains only one"
" class: %r" % classes[0])
if n_classes == 2:
# OvR in case of binary problems is as good as fitting
# the higher label
n_classes = 1
encoded_labels = encoded_labels[1:]
classes = classes[1:]
# We need this hack to iterate only once over labels, in the case of
# multi_class = multinomial, without changing the value of the labels.
if self.multi_class == 'multinomial':
iter_encoded_labels = iter_classes = [None]
else:
iter_encoded_labels = encoded_labels
iter_classes = classes
# compute the class weights for the entire dataset y
if class_weight == "balanced":
class_weight = compute_class_weight(class_weight,
np.arange(len(self.classes_)),
y)
class_weight = dict(enumerate(class_weight))
path_func = delayed(_log_reg_scoring_path)
# The SAG solver releases the GIL so it's more efficient to use
# threads for this solver.
if self.solver in ['sag', 'saga']:
backend = 'threading'
else:
backend = 'multiprocessing'
fold_coefs_ = Parallel(n_jobs=self.n_jobs, verbose=self.verbose,
backend=backend)(
path_func(X, y, train, test, pos_class=label, Cs=self.Cs,
fit_intercept=self.fit_intercept, penalty=self.penalty,
dual=self.dual, solver=self.solver, tol=self.tol,
max_iter=self.max_iter, verbose=self.verbose,
class_weight=class_weight, scoring=self.scoring,
multi_class=self.multi_class,
intercept_scaling=self.intercept_scaling,
random_state=self.random_state,
max_squared_sum=max_squared_sum,
sample_weight=sample_weight
)
for label in iter_encoded_labels
for train, test in folds)
if self.multi_class == 'multinomial':
multi_coefs_paths, Cs, multi_scores, n_iter_ = zip(*fold_coefs_)
multi_coefs_paths = np.asarray(multi_coefs_paths)
multi_scores = np.asarray(multi_scores)
# This is just to maintain API similarity between the ovr and
# multinomial option.
# Coefs_paths in now n_folds X len(Cs) X n_classes X n_features
# we need it to be n_classes X len(Cs) X n_folds X n_features
# to be similar to "ovr".
coefs_paths = np.rollaxis(multi_coefs_paths, 2, 0)
# Multinomial has a true score across all labels. Hence the
# shape is n_folds X len(Cs). We need to repeat this score
# across all labels for API similarity.
scores = np.tile(multi_scores, (n_classes, 1, 1))
self.Cs_ = Cs[0]
self.n_iter_ = np.reshape(n_iter_, (1, len(folds),
len(self.Cs_)))
else:
coefs_paths, Cs, scores, n_iter_ = zip(*fold_coefs_)
self.Cs_ = Cs[0]
coefs_paths = np.reshape(coefs_paths, (n_classes, len(folds),
len(self.Cs_), -1))
self.n_iter_ = np.reshape(n_iter_, (n_classes, len(folds),
len(self.Cs_)))
self.coefs_paths_ = dict(zip(classes, coefs_paths))
scores = np.reshape(scores, (n_classes, len(folds), -1))
self.scores_ = dict(zip(classes, scores))
self.C_ = list()
self.coef_ = np.empty((n_classes, X.shape[1]))
self.intercept_ = np.zeros(n_classes)
# hack to iterate only once for multinomial case.
if self.multi_class == 'multinomial':
scores = multi_scores
coefs_paths = multi_coefs_paths
for index, (cls, encoded_label) in enumerate(
zip(iter_classes, iter_encoded_labels)):
if self.multi_class == 'ovr':
# The scores_ / coefs_paths_ dict have unencoded class
# labels as their keys
scores = self.scores_[cls]
coefs_paths = self.coefs_paths_[cls]
if self.refit:
best_index = scores.sum(axis=0).argmax()
C_ = self.Cs_[best_index]
self.C_.append(C_)
if self.multi_class == 'multinomial':
coef_init = np.mean(coefs_paths[:, best_index, :, :],
axis=0)
else:
coef_init = np.mean(coefs_paths[:, best_index, :], axis=0)
# Note that y is label encoded and hence pos_class must be
# the encoded label / None (for 'multinomial')
w, _, _ = logistic_regression_path(
X, y, pos_class=encoded_label, Cs=[C_], solver=self.solver,
fit_intercept=self.fit_intercept, coef=coef_init,
max_iter=self.max_iter, tol=self.tol,
penalty=self.penalty,
class_weight=class_weight,
multi_class=self.multi_class,
verbose=max(0, self.verbose - 1),
random_state=self.random_state,
check_input=False, max_squared_sum=max_squared_sum,
sample_weight=sample_weight)
w = w[0]
else:
# Take the best scores across every fold and the average of all
# coefficients corresponding to the best scores.
best_indices = np.argmax(scores, axis=1)
w = np.mean([coefs_paths[i][best_indices[i]]
for i in range(len(folds))], axis=0)
self.C_.append(np.mean(self.Cs_[best_indices]))
if self.multi_class == 'multinomial':
self.C_ = np.tile(self.C_, n_classes)
self.coef_ = w[:, :X.shape[1]]
if self.fit_intercept:
self.intercept_ = w[:, -1]
else:
self.coef_[index] = w[: X.shape[1]]
if self.fit_intercept:
self.intercept_[index] = w[-1]
self.C_ = np.asarray(self.C_)
return self
| 70,480 | 38.463046 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/passive_aggressive.py | # Authors: Rob Zinkov, Mathieu Blondel
# License: BSD 3 clause
from .stochastic_gradient import BaseSGDClassifier
from .stochastic_gradient import BaseSGDRegressor
from .stochastic_gradient import DEFAULT_EPSILON
class PassiveAggressiveClassifier(BaseSGDClassifier):
"""Passive Aggressive Classifier
Read more in the :ref:`User Guide <passive_aggressive>`.
Parameters
----------
C : float
Maximum step size (regularization). Defaults to 1.0.
fit_intercept : bool, default=False
Whether the intercept should be estimated or not. If False, the
data is assumed to be already centered.
max_iter : int, optional
The maximum number of passes over the training data (aka epochs).
It only impacts the behavior in the ``fit`` method, and not the
`partial_fit`.
Defaults to 5. Defaults to 1000 from 0.21, or if tol is not None.
.. versionadded:: 0.19
tol : float or None, optional
The stopping criterion. If it is not None, the iterations will stop
when (loss > previous_loss - tol). Defaults to None.
Defaults to 1e-3 from 0.21.
.. versionadded:: 0.19
shuffle : bool, default=True
Whether or not the training data should be shuffled after each epoch.
verbose : integer, optional
The verbosity level
loss : string, optional
The loss function to be used:
hinge: equivalent to PA-I in the reference paper.
squared_hinge: equivalent to PA-II in the reference paper.
n_jobs : integer, optional
The number of CPUs to use to do the OVA (One Versus All, for
multi-class problems) computation. -1 means 'all CPUs'. Defaults
to 1.
random_state : int, RandomState instance or None, optional, default=None
The seed of the pseudo random number generator to use when shuffling
the data. If int, random_state is the seed used by the random number
generator; If RandomState instance, random_state is the random number
generator; If None, the random number generator is the RandomState
instance used by `np.random`.
warm_start : bool, optional
When set to True, reuse the solution of the previous call to fit as
initialization, otherwise, just erase the previous solution.
class_weight : dict, {class_label: weight} or "balanced" or None, optional
Preset for the class_weight fit parameter.
Weights associated with classes. If not given, all classes
are supposed to have weight one.
The "balanced" mode uses the values of y to automatically adjust
weights inversely proportional to class frequencies in the input data
as ``n_samples / (n_classes * np.bincount(y))``
.. versionadded:: 0.17
parameter *class_weight* to automatically weight samples.
average : bool or int, optional
When set to True, computes the averaged SGD weights and stores the
result in the ``coef_`` attribute. If set to an int greater than 1,
averaging will begin once the total number of samples seen reaches
average. So average=10 will begin averaging after seeing 10 samples.
.. versionadded:: 0.19
parameter *average* to use weights averaging in SGD
n_iter : int, optional
The number of passes over the training data (aka epochs).
Defaults to None. Deprecated, will be removed in 0.21.
.. versionchanged:: 0.19
Deprecated
Attributes
----------
coef_ : array, shape = [1, n_features] if n_classes == 2 else [n_classes,\
n_features]
Weights assigned to the features.
intercept_ : array, shape = [1] if n_classes == 2 else [n_classes]
Constants in decision function.
n_iter_ : int
The actual number of iterations to reach the stopping criterion.
For multiclass fits, it is the maximum over every binary fit.
Examples
--------
>>> from sklearn.linear_model import PassiveAggressiveClassifier
>>> from sklearn.datasets import make_classification
>>>
>>> X, y = make_classification(n_features=4, random_state=0)
>>> clf = PassiveAggressiveClassifier(random_state=0)
>>> clf.fit(X, y)
PassiveAggressiveClassifier(C=1.0, average=False, class_weight=None,
fit_intercept=True, loss='hinge', max_iter=None, n_iter=None,
n_jobs=1, random_state=0, shuffle=True, tol=None, verbose=0,
warm_start=False)
>>> print(clf.coef_)
[[ 0.49324685 1.0552176 1.49519589 1.33798314]]
>>> print(clf.intercept_)
[ 2.18438388]
>>> print(clf.predict([[0, 0, 0, 0]]))
[1]
See also
--------
SGDClassifier
Perceptron
References
----------
Online Passive-Aggressive Algorithms
<http://jmlr.csail.mit.edu/papers/volume7/crammer06a/crammer06a.pdf>
K. Crammer, O. Dekel, J. Keshat, S. Shalev-Shwartz, Y. Singer - JMLR (2006)
"""
def __init__(self, C=1.0, fit_intercept=True, max_iter=None, tol=None,
shuffle=True, verbose=0, loss="hinge", n_jobs=1,
random_state=None, warm_start=False, class_weight=None,
average=False, n_iter=None):
super(PassiveAggressiveClassifier, self).__init__(
penalty=None,
fit_intercept=fit_intercept,
max_iter=max_iter,
tol=tol,
shuffle=shuffle,
verbose=verbose,
random_state=random_state,
eta0=1.0,
warm_start=warm_start,
class_weight=class_weight,
average=average,
n_jobs=n_jobs,
n_iter=n_iter)
self.C = C
self.loss = loss
def partial_fit(self, X, y, classes=None):
"""Fit linear model with Passive Aggressive algorithm.
Parameters
----------
X : {array-like, sparse matrix}, shape = [n_samples, n_features]
Subset of the training data
y : numpy array of shape [n_samples]
Subset of the target values
classes : array, shape = [n_classes]
Classes across all calls to partial_fit.
Can be obtained by via `np.unique(y_all)`, where y_all is the
target vector of the entire dataset.
This argument is required for the first call to partial_fit
and can be omitted in the subsequent calls.
Note that y doesn't need to contain all labels in `classes`.
Returns
-------
self : returns an instance of self.
"""
if self.class_weight == 'balanced':
raise ValueError("class_weight 'balanced' is not supported for "
"partial_fit. For 'balanced' weights, use "
"`sklearn.utils.compute_class_weight` with "
"`class_weight='balanced'`. In place of y you "
"can use a large enough subset of the full "
"training set target to properly estimate the "
"class frequency distributions. Pass the "
"resulting weights as the class_weight "
"parameter.")
lr = "pa1" if self.loss == "hinge" else "pa2"
return self._partial_fit(X, y, alpha=1.0, C=self.C,
loss="hinge", learning_rate=lr, max_iter=1,
classes=classes, sample_weight=None,
coef_init=None, intercept_init=None)
def fit(self, X, y, coef_init=None, intercept_init=None):
"""Fit linear model with Passive Aggressive algorithm.
Parameters
----------
X : {array-like, sparse matrix}, shape = [n_samples, n_features]
Training data
y : numpy array of shape [n_samples]
Target values
coef_init : array, shape = [n_classes,n_features]
The initial coefficients to warm-start the optimization.
intercept_init : array, shape = [n_classes]
The initial intercept to warm-start the optimization.
Returns
-------
self : returns an instance of self.
"""
lr = "pa1" if self.loss == "hinge" else "pa2"
return self._fit(X, y, alpha=1.0, C=self.C,
loss="hinge", learning_rate=lr,
coef_init=coef_init, intercept_init=intercept_init)
class PassiveAggressiveRegressor(BaseSGDRegressor):
"""Passive Aggressive Regressor
Read more in the :ref:`User Guide <passive_aggressive>`.
Parameters
----------
C : float
Maximum step size (regularization). Defaults to 1.0.
fit_intercept : bool
Whether the intercept should be estimated or not. If False, the
data is assumed to be already centered. Defaults to True.
max_iter : int, optional
The maximum number of passes over the training data (aka epochs).
It only impacts the behavior in the ``fit`` method, and not the
`partial_fit`.
Defaults to 5. Defaults to 1000 from 0.21, or if tol is not None.
.. versionadded:: 0.19
tol : float or None, optional
The stopping criterion. If it is not None, the iterations will stop
when (loss > previous_loss - tol). Defaults to None.
Defaults to 1e-3 from 0.21.
.. versionadded:: 0.19
shuffle : bool, default=True
Whether or not the training data should be shuffled after each epoch.
verbose : integer, optional
The verbosity level
loss : string, optional
The loss function to be used:
epsilon_insensitive: equivalent to PA-I in the reference paper.
squared_epsilon_insensitive: equivalent to PA-II in the reference
paper.
epsilon : float
If the difference between the current prediction and the correct label
is below this threshold, the model is not updated.
random_state : int, RandomState instance or None, optional, default=None
The seed of the pseudo random number generator to use when shuffling
the data. If int, random_state is the seed used by the random number
generator; If RandomState instance, random_state is the random number
generator; If None, the random number generator is the RandomState
instance used by `np.random`.
warm_start : bool, optional
When set to True, reuse the solution of the previous call to fit as
initialization, otherwise, just erase the previous solution.
average : bool or int, optional
When set to True, computes the averaged SGD weights and stores the
result in the ``coef_`` attribute. If set to an int greater than 1,
averaging will begin once the total number of samples seen reaches
average. So average=10 will begin averaging after seeing 10 samples.
.. versionadded:: 0.19
parameter *average* to use weights averaging in SGD
n_iter : int, optional
The number of passes over the training data (aka epochs).
Defaults to None. Deprecated, will be removed in 0.21.
.. versionchanged:: 0.19
Deprecated
Attributes
----------
coef_ : array, shape = [1, n_features] if n_classes == 2 else [n_classes,\
n_features]
Weights assigned to the features.
intercept_ : array, shape = [1] if n_classes == 2 else [n_classes]
Constants in decision function.
n_iter_ : int
The actual number of iterations to reach the stopping criterion.
Examples
--------
>>> from sklearn.linear_model import PassiveAggressiveRegressor
>>> from sklearn.datasets import make_regression
>>>
>>> X, y = make_regression(n_features=4, random_state=0)
>>> regr = PassiveAggressiveRegressor(random_state=0)
>>> regr.fit(X, y)
PassiveAggressiveRegressor(C=1.0, average=False, epsilon=0.1,
fit_intercept=True, loss='epsilon_insensitive',
max_iter=None, n_iter=None, random_state=0, shuffle=True,
tol=None, verbose=0, warm_start=False)
>>> print(regr.coef_)
[ 20.48736655 34.18818427 67.59122734 87.94731329]
>>> print(regr.intercept_)
[-0.02306214]
>>> print(regr.predict([[0, 0, 0, 0]]))
[-0.02306214]
See also
--------
SGDRegressor
References
----------
Online Passive-Aggressive Algorithms
<http://jmlr.csail.mit.edu/papers/volume7/crammer06a/crammer06a.pdf>
K. Crammer, O. Dekel, J. Keshat, S. Shalev-Shwartz, Y. Singer - JMLR (2006)
"""
def __init__(self, C=1.0, fit_intercept=True, max_iter=None, tol=None,
shuffle=True, verbose=0, loss="epsilon_insensitive",
epsilon=DEFAULT_EPSILON, random_state=None, warm_start=False,
average=False, n_iter=None):
super(PassiveAggressiveRegressor, self).__init__(
penalty=None,
l1_ratio=0,
epsilon=epsilon,
eta0=1.0,
fit_intercept=fit_intercept,
max_iter=max_iter,
tol=tol,
shuffle=shuffle,
verbose=verbose,
random_state=random_state,
warm_start=warm_start,
average=average,
n_iter=n_iter)
self.C = C
self.loss = loss
def partial_fit(self, X, y):
"""Fit linear model with Passive Aggressive algorithm.
Parameters
----------
X : {array-like, sparse matrix}, shape = [n_samples, n_features]
Subset of training data
y : numpy array of shape [n_samples]
Subset of target values
Returns
-------
self : returns an instance of self.
"""
self._validate_params()
lr = "pa1" if self.loss == "epsilon_insensitive" else "pa2"
return self._partial_fit(X, y, alpha=1.0, C=self.C,
loss="epsilon_insensitive",
learning_rate=lr, max_iter=1,
sample_weight=None,
coef_init=None, intercept_init=None)
def fit(self, X, y, coef_init=None, intercept_init=None):
"""Fit linear model with Passive Aggressive algorithm.
Parameters
----------
X : {array-like, sparse matrix}, shape = [n_samples, n_features]
Training data
y : numpy array of shape [n_samples]
Target values
coef_init : array, shape = [n_features]
The initial coefficients to warm-start the optimization.
intercept_init : array, shape = [1]
The initial intercept to warm-start the optimization.
Returns
-------
self : returns an instance of self.
"""
lr = "pa1" if self.loss == "epsilon_insensitive" else "pa2"
return self._fit(X, y, alpha=1.0, C=self.C,
loss="epsilon_insensitive",
learning_rate=lr,
coef_init=coef_init,
intercept_init=intercept_init)
| 15,323 | 35.925301 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/ridge.py | """
Ridge regression
"""
# Author: Mathieu Blondel <[email protected]>
# Reuben Fletcher-Costin <[email protected]>
# Fabian Pedregosa <[email protected]>
# Michael Eickenberg <[email protected]>
# License: BSD 3 clause
from abc import ABCMeta, abstractmethod
import warnings
import numpy as np
from scipy import linalg
from scipy import sparse
from scipy.sparse import linalg as sp_linalg
from .base import LinearClassifierMixin, LinearModel, _rescale_data
from .sag import sag_solver
from ..base import RegressorMixin
from ..utils.extmath import safe_sparse_dot
from ..utils.extmath import row_norms
from ..utils import check_X_y
from ..utils import check_array
from ..utils import check_consistent_length
from ..utils import compute_sample_weight
from ..utils import column_or_1d
from ..preprocessing import LabelBinarizer
from ..model_selection import GridSearchCV
from ..externals import six
from ..metrics.scorer import check_scoring
def _solve_sparse_cg(X, y, alpha, max_iter=None, tol=1e-3, verbose=0):
n_samples, n_features = X.shape
X1 = sp_linalg.aslinearoperator(X)
coefs = np.empty((y.shape[1], n_features), dtype=X.dtype)
if n_features > n_samples:
def create_mv(curr_alpha):
def _mv(x):
return X1.matvec(X1.rmatvec(x)) + curr_alpha * x
return _mv
else:
def create_mv(curr_alpha):
def _mv(x):
return X1.rmatvec(X1.matvec(x)) + curr_alpha * x
return _mv
for i in range(y.shape[1]):
y_column = y[:, i]
mv = create_mv(alpha[i])
if n_features > n_samples:
# kernel ridge
# w = X.T * inv(X X^t + alpha*Id) y
C = sp_linalg.LinearOperator(
(n_samples, n_samples), matvec=mv, dtype=X.dtype)
coef, info = sp_linalg.cg(C, y_column, tol=tol)
coefs[i] = X1.rmatvec(coef)
else:
# linear ridge
# w = inv(X^t X + alpha*Id) * X.T y
y_column = X1.rmatvec(y_column)
C = sp_linalg.LinearOperator(
(n_features, n_features), matvec=mv, dtype=X.dtype)
coefs[i], info = sp_linalg.cg(C, y_column, maxiter=max_iter,
tol=tol)
if info < 0:
raise ValueError("Failed with error code %d" % info)
if max_iter is None and info > 0 and verbose:
warnings.warn("sparse_cg did not converge after %d iterations." %
info)
return coefs
def _solve_lsqr(X, y, alpha, max_iter=None, tol=1e-3):
n_samples, n_features = X.shape
coefs = np.empty((y.shape[1], n_features), dtype=X.dtype)
n_iter = np.empty(y.shape[1], dtype=np.int32)
# According to the lsqr documentation, alpha = damp^2.
sqrt_alpha = np.sqrt(alpha)
for i in range(y.shape[1]):
y_column = y[:, i]
info = sp_linalg.lsqr(X, y_column, damp=sqrt_alpha[i],
atol=tol, btol=tol, iter_lim=max_iter)
coefs[i] = info[0]
n_iter[i] = info[2]
return coefs, n_iter
def _solve_cholesky(X, y, alpha):
# w = inv(X^t X + alpha*Id) * X.T y
n_samples, n_features = X.shape
n_targets = y.shape[1]
A = safe_sparse_dot(X.T, X, dense_output=True)
Xy = safe_sparse_dot(X.T, y, dense_output=True)
one_alpha = np.array_equal(alpha, len(alpha) * [alpha[0]])
if one_alpha:
A.flat[::n_features + 1] += alpha[0]
return linalg.solve(A, Xy, sym_pos=True,
overwrite_a=True).T
else:
coefs = np.empty([n_targets, n_features], dtype=X.dtype)
for coef, target, current_alpha in zip(coefs, Xy.T, alpha):
A.flat[::n_features + 1] += current_alpha
coef[:] = linalg.solve(A, target, sym_pos=True,
overwrite_a=False).ravel()
A.flat[::n_features + 1] -= current_alpha
return coefs
def _solve_cholesky_kernel(K, y, alpha, sample_weight=None, copy=False):
# dual_coef = inv(X X^t + alpha*Id) y
n_samples = K.shape[0]
n_targets = y.shape[1]
if copy:
K = K.copy()
alpha = np.atleast_1d(alpha)
one_alpha = (alpha == alpha[0]).all()
has_sw = isinstance(sample_weight, np.ndarray) \
or sample_weight not in [1.0, None]
if has_sw:
# Unlike other solvers, we need to support sample_weight directly
# because K might be a pre-computed kernel.
sw = np.sqrt(np.atleast_1d(sample_weight))
y = y * sw[:, np.newaxis]
K *= np.outer(sw, sw)
if one_alpha:
# Only one penalty, we can solve multi-target problems in one time.
K.flat[::n_samples + 1] += alpha[0]
try:
# Note: we must use overwrite_a=False in order to be able to
# use the fall-back solution below in case a LinAlgError
# is raised
dual_coef = linalg.solve(K, y, sym_pos=True,
overwrite_a=False)
except np.linalg.LinAlgError:
warnings.warn("Singular matrix in solving dual problem. Using "
"least-squares solution instead.")
dual_coef = linalg.lstsq(K, y)[0]
# K is expensive to compute and store in memory so change it back in
# case it was user-given.
K.flat[::n_samples + 1] -= alpha[0]
if has_sw:
dual_coef *= sw[:, np.newaxis]
return dual_coef
else:
# One penalty per target. We need to solve each target separately.
dual_coefs = np.empty([n_targets, n_samples], K.dtype)
for dual_coef, target, current_alpha in zip(dual_coefs, y.T, alpha):
K.flat[::n_samples + 1] += current_alpha
dual_coef[:] = linalg.solve(K, target, sym_pos=True,
overwrite_a=False).ravel()
K.flat[::n_samples + 1] -= current_alpha
if has_sw:
dual_coefs *= sw[np.newaxis, :]
return dual_coefs.T
def _solve_svd(X, y, alpha):
U, s, Vt = linalg.svd(X, full_matrices=False)
idx = s > 1e-15 # same default value as scipy.linalg.pinv
s_nnz = s[idx][:, np.newaxis]
UTy = np.dot(U.T, y)
d = np.zeros((s.size, alpha.size), dtype=X.dtype)
d[idx] = s_nnz / (s_nnz ** 2 + alpha)
d_UT_y = d * UTy
return np.dot(Vt.T, d_UT_y).T
def ridge_regression(X, y, alpha, sample_weight=None, solver='auto',
max_iter=None, tol=1e-3, verbose=0, random_state=None,
return_n_iter=False, return_intercept=False):
"""Solve the ridge equation by the method of normal equations.
Read more in the :ref:`User Guide <ridge_regression>`.
Parameters
----------
X : {array-like, sparse matrix, LinearOperator},
shape = [n_samples, n_features]
Training data
y : array-like, shape = [n_samples] or [n_samples, n_targets]
Target values
alpha : {float, array-like},
shape = [n_targets] if array-like
Regularization strength; must be a positive float. Regularization
improves the conditioning of the problem and reduces the variance of
the estimates. Larger values specify stronger regularization.
Alpha corresponds to ``C^-1`` in other linear models such as
LogisticRegression or LinearSVC. If an array is passed, penalties are
assumed to be specific to the targets. Hence they must correspond in
number.
sample_weight : float or numpy array of shape [n_samples]
Individual weights for each sample. If sample_weight is not None and
solver='auto', the solver will be set to 'cholesky'.
.. versionadded:: 0.17
solver : {'auto', 'svd', 'cholesky', 'lsqr', 'sparse_cg', 'sag', 'saga'}
Solver to use in the computational routines:
- 'auto' chooses the solver automatically based on the type of data.
- 'svd' uses a Singular Value Decomposition of X to compute the Ridge
coefficients. More stable for singular matrices than
'cholesky'.
- 'cholesky' uses the standard scipy.linalg.solve function to
obtain a closed-form solution via a Cholesky decomposition of
dot(X.T, X)
- 'sparse_cg' uses the conjugate gradient solver as found in
scipy.sparse.linalg.cg. As an iterative algorithm, this solver is
more appropriate than 'cholesky' for large-scale data
(possibility to set `tol` and `max_iter`).
- 'lsqr' uses the dedicated regularized least-squares routine
scipy.sparse.linalg.lsqr. It is the fastest but may not be available
in old scipy versions. It also uses an iterative procedure.
- 'sag' uses a Stochastic Average Gradient descent, and 'saga' uses
its improved, unbiased version named SAGA. Both methods also use an
iterative procedure, and are often faster than other solvers when
both n_samples and n_features are large. Note that 'sag' and
'saga' fast convergence is only guaranteed on features with
approximately the same scale. You can preprocess the data with a
scaler from sklearn.preprocessing.
All last five solvers support both dense and sparse data. However, only
'sag' and 'saga' supports sparse input when`fit_intercept` is True.
.. versionadded:: 0.17
Stochastic Average Gradient descent solver.
.. versionadded:: 0.19
SAGA solver.
max_iter : int, optional
Maximum number of iterations for conjugate gradient solver.
For the 'sparse_cg' and 'lsqr' solvers, the default value is determined
by scipy.sparse.linalg. For 'sag' and saga solver, the default value is
1000.
tol : float
Precision of the solution.
verbose : int
Verbosity level. Setting verbose > 0 will display additional
information depending on the solver used.
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator to use when shuffling
the data. If int, random_state is the seed used by the random number
generator; If RandomState instance, random_state is the random number
generator; If None, the random number generator is the RandomState
instance used by `np.random`. Used when ``solver`` == 'sag'.
return_n_iter : boolean, default False
If True, the method also returns `n_iter`, the actual number of
iteration performed by the solver.
.. versionadded:: 0.17
return_intercept : boolean, default False
If True and if X is sparse, the method also returns the intercept,
and the solver is automatically changed to 'sag'. This is only a
temporary fix for fitting the intercept with sparse data. For dense
data, use sklearn.linear_model._preprocess_data before your regression.
.. versionadded:: 0.17
Returns
-------
coef : array, shape = [n_features] or [n_targets, n_features]
Weight vector(s).
n_iter : int, optional
The actual number of iteration performed by the solver.
Only returned if `return_n_iter` is True.
intercept : float or array, shape = [n_targets]
The intercept of the model. Only returned if `return_intercept`
is True and if X is a scipy sparse array.
Notes
-----
This function won't compute the intercept.
"""
if return_intercept and sparse.issparse(X) and solver != 'sag':
if solver != 'auto':
warnings.warn("In Ridge, only 'sag' solver can currently fit the "
"intercept when X is sparse. Solver has been "
"automatically changed into 'sag'.")
solver = 'sag'
_dtype = [np.float64, np.float32]
# SAG needs X and y columns to be C-contiguous and np.float64
if solver in ['sag', 'saga']:
X = check_array(X, accept_sparse=['csr'],
dtype=np.float64, order='C')
y = check_array(y, dtype=np.float64, ensure_2d=False, order='F')
else:
X = check_array(X, accept_sparse=['csr', 'csc', 'coo'],
dtype=_dtype)
y = check_array(y, dtype=X.dtype, ensure_2d=False)
check_consistent_length(X, y)
n_samples, n_features = X.shape
if y.ndim > 2:
raise ValueError("Target y has the wrong shape %s" % str(y.shape))
ravel = False
if y.ndim == 1:
y = y.reshape(-1, 1)
ravel = True
n_samples_, n_targets = y.shape
if n_samples != n_samples_:
raise ValueError("Number of samples in X and y does not correspond:"
" %d != %d" % (n_samples, n_samples_))
has_sw = sample_weight is not None
if solver == 'auto':
# cholesky if it's a dense array and cg in any other case
if not sparse.issparse(X) or has_sw:
solver = 'cholesky'
else:
solver = 'sparse_cg'
elif solver == 'lsqr' and not hasattr(sp_linalg, 'lsqr'):
warnings.warn("""lsqr not available on this machine, falling back
to sparse_cg.""")
solver = 'sparse_cg'
if has_sw:
if np.atleast_1d(sample_weight).ndim > 1:
raise ValueError("Sample weights must be 1D array or scalar")
if solver not in ['sag', 'saga']:
# SAG supports sample_weight directly. For other solvers,
# we implement sample_weight via a simple rescaling.
X, y = _rescale_data(X, y, sample_weight)
# There should be either 1 or n_targets penalties
alpha = np.asarray(alpha, dtype=X.dtype).ravel()
if alpha.size not in [1, n_targets]:
raise ValueError("Number of targets and number of penalties "
"do not correspond: %d != %d"
% (alpha.size, n_targets))
if alpha.size == 1 and n_targets > 1:
alpha = np.repeat(alpha, n_targets)
if solver not in ('sparse_cg', 'cholesky', 'svd', 'lsqr', 'sag', 'saga'):
raise ValueError('Solver %s not understood' % solver)
n_iter = None
if solver == 'sparse_cg':
coef = _solve_sparse_cg(X, y, alpha, max_iter, tol, verbose)
elif solver == 'lsqr':
coef, n_iter = _solve_lsqr(X, y, alpha, max_iter, tol)
elif solver == 'cholesky':
if n_features > n_samples:
K = safe_sparse_dot(X, X.T, dense_output=True)
try:
dual_coef = _solve_cholesky_kernel(K, y, alpha)
coef = safe_sparse_dot(X.T, dual_coef, dense_output=True).T
except linalg.LinAlgError:
# use SVD solver if matrix is singular
solver = 'svd'
else:
try:
coef = _solve_cholesky(X, y, alpha)
except linalg.LinAlgError:
# use SVD solver if matrix is singular
solver = 'svd'
elif solver in ['sag', 'saga']:
# precompute max_squared_sum for all targets
max_squared_sum = row_norms(X, squared=True).max()
coef = np.empty((y.shape[1], n_features))
n_iter = np.empty(y.shape[1], dtype=np.int32)
intercept = np.zeros((y.shape[1], ))
for i, (alpha_i, target) in enumerate(zip(alpha, y.T)):
init = {'coef': np.zeros((n_features + int(return_intercept), 1))}
coef_, n_iter_, _ = sag_solver(
X, target.ravel(), sample_weight, 'squared', alpha_i, 0,
max_iter, tol, verbose, random_state, False, max_squared_sum,
init,
is_saga=solver == 'saga')
if return_intercept:
coef[i] = coef_[:-1]
intercept[i] = coef_[-1]
else:
coef[i] = coef_
n_iter[i] = n_iter_
if intercept.shape[0] == 1:
intercept = intercept[0]
coef = np.asarray(coef)
if solver == 'svd':
if sparse.issparse(X):
raise TypeError('SVD solver does not support sparse'
' inputs currently')
coef = _solve_svd(X, y, alpha)
if ravel:
# When y was passed as a 1d-array, we flatten the coefficients.
coef = coef.ravel()
if return_n_iter and return_intercept:
return coef, n_iter, intercept
elif return_intercept:
return coef, intercept
elif return_n_iter:
return coef, n_iter
else:
return coef
class _BaseRidge(six.with_metaclass(ABCMeta, LinearModel)):
@abstractmethod
def __init__(self, alpha=1.0, fit_intercept=True, normalize=False,
copy_X=True, max_iter=None, tol=1e-3, solver="auto",
random_state=None):
self.alpha = alpha
self.fit_intercept = fit_intercept
self.normalize = normalize
self.copy_X = copy_X
self.max_iter = max_iter
self.tol = tol
self.solver = solver
self.random_state = random_state
def fit(self, X, y, sample_weight=None):
if self.solver in ('sag', 'saga'):
_dtype = np.float64
else:
# all other solvers work at both float precision levels
_dtype = [np.float64, np.float32]
X, y = check_X_y(X, y, ['csr', 'csc', 'coo'], dtype=_dtype,
multi_output=True, y_numeric=True)
if ((sample_weight is not None) and
np.atleast_1d(sample_weight).ndim > 1):
raise ValueError("Sample weights must be 1D array or scalar")
X, y, X_offset, y_offset, X_scale = self._preprocess_data(
X, y, self.fit_intercept, self.normalize, self.copy_X,
sample_weight=sample_weight)
# temporary fix for fitting the intercept with sparse data using 'sag'
if sparse.issparse(X) and self.fit_intercept:
self.coef_, self.n_iter_, self.intercept_ = ridge_regression(
X, y, alpha=self.alpha, sample_weight=sample_weight,
max_iter=self.max_iter, tol=self.tol, solver=self.solver,
random_state=self.random_state, return_n_iter=True,
return_intercept=True)
self.intercept_ += y_offset
else:
self.coef_, self.n_iter_ = ridge_regression(
X, y, alpha=self.alpha, sample_weight=sample_weight,
max_iter=self.max_iter, tol=self.tol, solver=self.solver,
random_state=self.random_state, return_n_iter=True,
return_intercept=False)
self._set_intercept(X_offset, y_offset, X_scale)
return self
class Ridge(_BaseRidge, RegressorMixin):
"""Linear least squares with l2 regularization.
This model solves a regression model where the loss function is
the linear least squares function and regularization is given by
the l2-norm. Also known as Ridge Regression or Tikhonov regularization.
This estimator has built-in support for multi-variate regression
(i.e., when y is a 2d-array of shape [n_samples, n_targets]).
Read more in the :ref:`User Guide <ridge_regression>`.
Parameters
----------
alpha : {float, array-like}, shape (n_targets)
Regularization strength; must be a positive float. Regularization
improves the conditioning of the problem and reduces the variance of
the estimates. Larger values specify stronger regularization.
Alpha corresponds to ``C^-1`` in other linear models such as
LogisticRegression or LinearSVC. If an array is passed, penalties are
assumed to be specific to the targets. Hence they must correspond in
number.
fit_intercept : boolean
Whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
copy_X : boolean, optional, default True
If True, X will be copied; else, it may be overwritten.
max_iter : int, optional
Maximum number of iterations for conjugate gradient solver.
For 'sparse_cg' and 'lsqr' solvers, the default value is determined
by scipy.sparse.linalg. For 'sag' solver, the default value is 1000.
tol : float
Precision of the solution.
solver : {'auto', 'svd', 'cholesky', 'lsqr', 'sparse_cg', 'sag', 'saga'}
Solver to use in the computational routines:
- 'auto' chooses the solver automatically based on the type of data.
- 'svd' uses a Singular Value Decomposition of X to compute the Ridge
coefficients. More stable for singular matrices than
'cholesky'.
- 'cholesky' uses the standard scipy.linalg.solve function to
obtain a closed-form solution.
- 'sparse_cg' uses the conjugate gradient solver as found in
scipy.sparse.linalg.cg. As an iterative algorithm, this solver is
more appropriate than 'cholesky' for large-scale data
(possibility to set `tol` and `max_iter`).
- 'lsqr' uses the dedicated regularized least-squares routine
scipy.sparse.linalg.lsqr. It is the fastest but may not be available
in old scipy versions. It also uses an iterative procedure.
- 'sag' uses a Stochastic Average Gradient descent, and 'saga' uses
its improved, unbiased version named SAGA. Both methods also use an
iterative procedure, and are often faster than other solvers when
both n_samples and n_features are large. Note that 'sag' and
'saga' fast convergence is only guaranteed on features with
approximately the same scale. You can preprocess the data with a
scaler from sklearn.preprocessing.
All last five solvers support both dense and sparse data. However,
only 'sag' and 'saga' supports sparse input when `fit_intercept` is
True.
.. versionadded:: 0.17
Stochastic Average Gradient descent solver.
.. versionadded:: 0.19
SAGA solver.
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator to use when shuffling
the data. If int, random_state is the seed used by the random number
generator; If RandomState instance, random_state is the random number
generator; If None, the random number generator is the RandomState
instance used by `np.random`. Used when ``solver`` == 'sag'.
.. versionadded:: 0.17
*random_state* to support Stochastic Average Gradient.
Attributes
----------
coef_ : array, shape (n_features,) or (n_targets, n_features)
Weight vector(s).
intercept_ : float | array, shape = (n_targets,)
Independent term in decision function. Set to 0.0 if
``fit_intercept = False``.
n_iter_ : array or None, shape (n_targets,)
Actual number of iterations for each target. Available only for
sag and lsqr solvers. Other solvers will return None.
.. versionadded:: 0.17
See also
--------
RidgeClassifier, RidgeCV, :class:`sklearn.kernel_ridge.KernelRidge`
Examples
--------
>>> from sklearn.linear_model import Ridge
>>> import numpy as np
>>> n_samples, n_features = 10, 5
>>> np.random.seed(0)
>>> y = np.random.randn(n_samples)
>>> X = np.random.randn(n_samples, n_features)
>>> clf = Ridge(alpha=1.0)
>>> clf.fit(X, y) # doctest: +NORMALIZE_WHITESPACE
Ridge(alpha=1.0, copy_X=True, fit_intercept=True, max_iter=None,
normalize=False, random_state=None, solver='auto', tol=0.001)
"""
def __init__(self, alpha=1.0, fit_intercept=True, normalize=False,
copy_X=True, max_iter=None, tol=1e-3, solver="auto",
random_state=None):
super(Ridge, self).__init__(alpha=alpha, fit_intercept=fit_intercept,
normalize=normalize, copy_X=copy_X,
max_iter=max_iter, tol=tol, solver=solver,
random_state=random_state)
def fit(self, X, y, sample_weight=None):
"""Fit Ridge regression model
Parameters
----------
X : {array-like, sparse matrix}, shape = [n_samples, n_features]
Training data
y : array-like, shape = [n_samples] or [n_samples, n_targets]
Target values
sample_weight : float or numpy array of shape [n_samples]
Individual weights for each sample
Returns
-------
self : returns an instance of self.
"""
return super(Ridge, self).fit(X, y, sample_weight=sample_weight)
class RidgeClassifier(LinearClassifierMixin, _BaseRidge):
"""Classifier using Ridge regression.
Read more in the :ref:`User Guide <ridge_regression>`.
Parameters
----------
alpha : float
Regularization strength; must be a positive float. Regularization
improves the conditioning of the problem and reduces the variance of
the estimates. Larger values specify stronger regularization.
Alpha corresponds to ``C^-1`` in other linear models such as
LogisticRegression or LinearSVC.
fit_intercept : boolean
Whether to calculate the intercept for this model. If set to false, no
intercept will be used in calculations (e.g. data is expected to be
already centered).
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
copy_X : boolean, optional, default True
If True, X will be copied; else, it may be overwritten.
max_iter : int, optional
Maximum number of iterations for conjugate gradient solver.
The default value is determined by scipy.sparse.linalg.
tol : float
Precision of the solution.
class_weight : dict or 'balanced', optional
Weights associated with classes in the form ``{class_label: weight}``.
If not given, all classes are supposed to have weight one.
The "balanced" mode uses the values of y to automatically adjust
weights inversely proportional to class frequencies in the input data
as ``n_samples / (n_classes * np.bincount(y))``
solver : {'auto', 'svd', 'cholesky', 'lsqr', 'sparse_cg', 'sag', 'saga'}
Solver to use in the computational routines:
- 'auto' chooses the solver automatically based on the type of data.
- 'svd' uses a Singular Value Decomposition of X to compute the Ridge
coefficients. More stable for singular matrices than
'cholesky'.
- 'cholesky' uses the standard scipy.linalg.solve function to
obtain a closed-form solution.
- 'sparse_cg' uses the conjugate gradient solver as found in
scipy.sparse.linalg.cg. As an iterative algorithm, this solver is
more appropriate than 'cholesky' for large-scale data
(possibility to set `tol` and `max_iter`).
- 'lsqr' uses the dedicated regularized least-squares routine
scipy.sparse.linalg.lsqr. It is the fastest but may not be available
in old scipy versions. It also uses an iterative procedure.
- 'sag' uses a Stochastic Average Gradient descent, and 'saga' uses
its unbiased and more flexible version named SAGA. Both methods
use an iterative procedure, and are often faster than other solvers
when both n_samples and n_features are large. Note that 'sag' and
'saga' fast convergence is only guaranteed on features with
approximately the same scale. You can preprocess the data with a
scaler from sklearn.preprocessing.
.. versionadded:: 0.17
Stochastic Average Gradient descent solver.
.. versionadded:: 0.19
SAGA solver.
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator to use when shuffling
the data. If int, random_state is the seed used by the random number
generator; If RandomState instance, random_state is the random number
generator; If None, the random number generator is the RandomState
instance used by `np.random`. Used when ``solver`` == 'sag'.
Attributes
----------
coef_ : array, shape (n_features,) or (n_classes, n_features)
Weight vector(s).
intercept_ : float | array, shape = (n_targets,)
Independent term in decision function. Set to 0.0 if
``fit_intercept = False``.
n_iter_ : array or None, shape (n_targets,)
Actual number of iterations for each target. Available only for
sag and lsqr solvers. Other solvers will return None.
See also
--------
Ridge, RidgeClassifierCV
Notes
-----
For multi-class classification, n_class classifiers are trained in
a one-versus-all approach. Concretely, this is implemented by taking
advantage of the multi-variate response support in Ridge.
"""
def __init__(self, alpha=1.0, fit_intercept=True, normalize=False,
copy_X=True, max_iter=None, tol=1e-3, class_weight=None,
solver="auto", random_state=None):
super(RidgeClassifier, self).__init__(
alpha=alpha, fit_intercept=fit_intercept, normalize=normalize,
copy_X=copy_X, max_iter=max_iter, tol=tol, solver=solver,
random_state=random_state)
self.class_weight = class_weight
def fit(self, X, y, sample_weight=None):
"""Fit Ridge regression model.
Parameters
----------
X : {array-like, sparse matrix}, shape = [n_samples,n_features]
Training data
y : array-like, shape = [n_samples]
Target values
sample_weight : float or numpy array of shape (n_samples,)
Sample weight.
.. versionadded:: 0.17
*sample_weight* support to Classifier.
Returns
-------
self : returns an instance of self.
"""
self._label_binarizer = LabelBinarizer(pos_label=1, neg_label=-1)
Y = self._label_binarizer.fit_transform(y)
if not self._label_binarizer.y_type_.startswith('multilabel'):
y = column_or_1d(y, warn=True)
else:
# we don't (yet) support multi-label classification in Ridge
raise ValueError(
"%s doesn't support multi-label classification" % (
self.__class__.__name__))
if self.class_weight:
if sample_weight is None:
sample_weight = 1.
# modify the sample weights with the corresponding class weight
sample_weight = (sample_weight *
compute_sample_weight(self.class_weight, y))
super(RidgeClassifier, self).fit(X, Y, sample_weight=sample_weight)
return self
@property
def classes_(self):
return self._label_binarizer.classes_
class _RidgeGCV(LinearModel):
"""Ridge regression with built-in Generalized Cross-Validation
It allows efficient Leave-One-Out cross-validation.
This class is not intended to be used directly. Use RidgeCV instead.
Notes
-----
We want to solve (K + alpha*Id)c = y,
where K = X X^T is the kernel matrix.
Let G = (K + alpha*Id)^-1.
Dual solution: c = Gy
Primal solution: w = X^T c
Compute eigendecomposition K = Q V Q^T.
Then G = Q (V + alpha*Id)^-1 Q^T,
where (V + alpha*Id) is diagonal.
It is thus inexpensive to inverse for many alphas.
Let loov be the vector of prediction values for each example
when the model was fitted with all examples but this example.
loov = (KGY - diag(KG)Y) / diag(I-KG)
Let looe be the vector of prediction errors for each example
when the model was fitted with all examples but this example.
looe = y - loov = c / diag(G)
References
----------
http://cbcl.mit.edu/projects/cbcl/publications/ps/MIT-CSAIL-TR-2007-025.pdf
http://www.mit.edu/~9.520/spring07/Classes/rlsslides.pdf
"""
def __init__(self, alphas=(0.1, 1.0, 10.0),
fit_intercept=True, normalize=False,
scoring=None, copy_X=True,
gcv_mode=None, store_cv_values=False):
self.alphas = np.asarray(alphas)
self.fit_intercept = fit_intercept
self.normalize = normalize
self.scoring = scoring
self.copy_X = copy_X
self.gcv_mode = gcv_mode
self.store_cv_values = store_cv_values
def _pre_compute(self, X, y, centered_kernel=True):
# even if X is very sparse, K is usually very dense
K = safe_sparse_dot(X, X.T, dense_output=True)
# the following emulates an additional constant regressor
# corresponding to fit_intercept=True
# but this is done only when the features have been centered
if centered_kernel:
K += np.ones_like(K)
v, Q = linalg.eigh(K)
QT_y = np.dot(Q.T, y)
return v, Q, QT_y
def _decomp_diag(self, v_prime, Q):
# compute diagonal of the matrix: dot(Q, dot(diag(v_prime), Q^T))
return (v_prime * Q ** 2).sum(axis=-1)
def _diag_dot(self, D, B):
# compute dot(diag(D), B)
if len(B.shape) > 1:
# handle case where B is > 1-d
D = D[(slice(None), ) + (np.newaxis, ) * (len(B.shape) - 1)]
return D * B
def _errors_and_values_helper(self, alpha, y, v, Q, QT_y):
"""Helper function to avoid code duplication between self._errors and
self._values.
Notes
-----
We don't construct matrix G, instead compute action on y & diagonal.
"""
w = 1. / (v + alpha)
constant_column = np.var(Q, 0) < 1.e-12
# detect constant columns
w[constant_column] = 0 # cancel the regularization for the intercept
c = np.dot(Q, self._diag_dot(w, QT_y))
G_diag = self._decomp_diag(w, Q)
# handle case where y is 2-d
if len(y.shape) != 1:
G_diag = G_diag[:, np.newaxis]
return G_diag, c
def _errors(self, alpha, y, v, Q, QT_y):
G_diag, c = self._errors_and_values_helper(alpha, y, v, Q, QT_y)
return (c / G_diag) ** 2, c
def _values(self, alpha, y, v, Q, QT_y):
G_diag, c = self._errors_and_values_helper(alpha, y, v, Q, QT_y)
return y - (c / G_diag), c
def _pre_compute_svd(self, X, y, centered_kernel=True):
if sparse.issparse(X):
raise TypeError("SVD not supported for sparse matrices")
if centered_kernel:
X = np.hstack((X, np.ones((X.shape[0], 1))))
# to emulate fit_intercept=True situation, add a column on ones
# Note that by centering, the other columns are orthogonal to that one
U, s, _ = linalg.svd(X, full_matrices=0)
v = s ** 2
UT_y = np.dot(U.T, y)
return v, U, UT_y
def _errors_and_values_svd_helper(self, alpha, y, v, U, UT_y):
"""Helper function to avoid code duplication between self._errors_svd
and self._values_svd.
"""
constant_column = np.var(U, 0) < 1.e-12
# detect columns colinear to ones
w = ((v + alpha) ** -1) - (alpha ** -1)
w[constant_column] = - (alpha ** -1)
# cancel the regularization for the intercept
c = np.dot(U, self._diag_dot(w, UT_y)) + (alpha ** -1) * y
G_diag = self._decomp_diag(w, U) + (alpha ** -1)
if len(y.shape) != 1:
# handle case where y is 2-d
G_diag = G_diag[:, np.newaxis]
return G_diag, c
def _errors_svd(self, alpha, y, v, U, UT_y):
G_diag, c = self._errors_and_values_svd_helper(alpha, y, v, U, UT_y)
return (c / G_diag) ** 2, c
def _values_svd(self, alpha, y, v, U, UT_y):
G_diag, c = self._errors_and_values_svd_helper(alpha, y, v, U, UT_y)
return y - (c / G_diag), c
def fit(self, X, y, sample_weight=None):
"""Fit Ridge regression model
Parameters
----------
X : {array-like, sparse matrix}, shape = [n_samples, n_features]
Training data
y : array-like, shape = [n_samples] or [n_samples, n_targets]
Target values. Will be cast to X's dtype if necessary
sample_weight : float or array-like of shape [n_samples]
Sample weight
Returns
-------
self : Returns self.
"""
X, y = check_X_y(X, y, ['csr', 'csc', 'coo'], dtype=np.float64,
multi_output=True, y_numeric=True)
if sample_weight is not None and not isinstance(sample_weight, float):
sample_weight = check_array(sample_weight, ensure_2d=False)
n_samples, n_features = X.shape
X, y, X_offset, y_offset, X_scale = LinearModel._preprocess_data(
X, y, self.fit_intercept, self.normalize, self.copy_X,
sample_weight=sample_weight)
gcv_mode = self.gcv_mode
with_sw = len(np.shape(sample_weight))
if gcv_mode is None or gcv_mode == 'auto':
if sparse.issparse(X) or n_features > n_samples or with_sw:
gcv_mode = 'eigen'
else:
gcv_mode = 'svd'
elif gcv_mode == "svd" and with_sw:
# FIXME non-uniform sample weights not yet supported
warnings.warn("non-uniform sample weights unsupported for svd, "
"forcing usage of eigen")
gcv_mode = 'eigen'
if gcv_mode == 'eigen':
_pre_compute = self._pre_compute
_errors = self._errors
_values = self._values
elif gcv_mode == 'svd':
# assert n_samples >= n_features
_pre_compute = self._pre_compute_svd
_errors = self._errors_svd
_values = self._values_svd
else:
raise ValueError('bad gcv_mode "%s"' % gcv_mode)
if sample_weight is not None:
X, y = _rescale_data(X, y, sample_weight)
centered_kernel = not sparse.issparse(X) and self.fit_intercept
v, Q, QT_y = _pre_compute(X, y, centered_kernel)
n_y = 1 if len(y.shape) == 1 else y.shape[1]
cv_values = np.zeros((n_samples * n_y, len(self.alphas)))
C = []
scorer = check_scoring(self, scoring=self.scoring, allow_none=True)
error = scorer is None
for i, alpha in enumerate(self.alphas):
if error:
out, c = _errors(alpha, y, v, Q, QT_y)
else:
out, c = _values(alpha, y, v, Q, QT_y)
cv_values[:, i] = out.ravel()
C.append(c)
if error:
best = cv_values.mean(axis=0).argmin()
else:
# The scorer want an object that will make the predictions but
# they are already computed efficiently by _RidgeGCV. This
# identity_estimator will just return them
def identity_estimator():
pass
identity_estimator.decision_function = lambda y_predict: y_predict
identity_estimator.predict = lambda y_predict: y_predict
out = [scorer(identity_estimator, y.ravel(), cv_values[:, i])
for i in range(len(self.alphas))]
best = np.argmax(out)
self.alpha_ = self.alphas[best]
self.dual_coef_ = C[best]
self.coef_ = safe_sparse_dot(self.dual_coef_.T, X)
self._set_intercept(X_offset, y_offset, X_scale)
if self.store_cv_values:
if len(y.shape) == 1:
cv_values_shape = n_samples, len(self.alphas)
else:
cv_values_shape = n_samples, n_y, len(self.alphas)
self.cv_values_ = cv_values.reshape(cv_values_shape)
return self
class _BaseRidgeCV(LinearModel):
def __init__(self, alphas=(0.1, 1.0, 10.0),
fit_intercept=True, normalize=False, scoring=None,
cv=None, gcv_mode=None,
store_cv_values=False):
self.alphas = alphas
self.fit_intercept = fit_intercept
self.normalize = normalize
self.scoring = scoring
self.cv = cv
self.gcv_mode = gcv_mode
self.store_cv_values = store_cv_values
def fit(self, X, y, sample_weight=None):
"""Fit Ridge regression model
Parameters
----------
X : array-like, shape = [n_samples, n_features]
Training data
y : array-like, shape = [n_samples] or [n_samples, n_targets]
Target values. Will be cast to X's dtype if necessary
sample_weight : float or array-like of shape [n_samples]
Sample weight
Returns
-------
self : Returns self.
"""
if self.cv is None:
estimator = _RidgeGCV(self.alphas,
fit_intercept=self.fit_intercept,
normalize=self.normalize,
scoring=self.scoring,
gcv_mode=self.gcv_mode,
store_cv_values=self.store_cv_values)
estimator.fit(X, y, sample_weight=sample_weight)
self.alpha_ = estimator.alpha_
if self.store_cv_values:
self.cv_values_ = estimator.cv_values_
else:
if self.store_cv_values:
raise ValueError("cv!=None and store_cv_values=True "
" are incompatible")
parameters = {'alpha': self.alphas}
gs = GridSearchCV(Ridge(fit_intercept=self.fit_intercept,
normalize=self.normalize),
parameters, cv=self.cv, scoring=self.scoring)
gs.fit(X, y, sample_weight=sample_weight)
estimator = gs.best_estimator_
self.alpha_ = gs.best_estimator_.alpha
self.coef_ = estimator.coef_
self.intercept_ = estimator.intercept_
return self
class RidgeCV(_BaseRidgeCV, RegressorMixin):
"""Ridge regression with built-in cross-validation.
By default, it performs Generalized Cross-Validation, which is a form of
efficient Leave-One-Out cross-validation.
Read more in the :ref:`User Guide <ridge_regression>`.
Parameters
----------
alphas : numpy array of shape [n_alphas]
Array of alpha values to try.
Regularization strength; must be a positive float. Regularization
improves the conditioning of the problem and reduces the variance of
the estimates. Larger values specify stronger regularization.
Alpha corresponds to ``C^-1`` in other linear models such as
LogisticRegression or LinearSVC.
fit_intercept : boolean
Whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
scoring : string, callable or None, optional, default: None
A string (see model evaluation documentation) or
a scorer callable object / function with signature
``scorer(estimator, X, y)``.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the efficient Leave-One-Out cross-validation
- integer, to specify the number of folds.
- An object to be used as a cross-validation generator.
- An iterable yielding train/test splits.
For integer/None inputs, if ``y`` is binary or multiclass,
:class:`sklearn.model_selection.StratifiedKFold` is used, else,
:class:`sklearn.model_selection.KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
gcv_mode : {None, 'auto', 'svd', eigen'}, optional
Flag indicating which strategy to use when performing
Generalized Cross-Validation. Options are::
'auto' : use svd if n_samples > n_features or when X is a sparse
matrix, otherwise use eigen
'svd' : force computation via singular value decomposition of X
(does not work for sparse matrices)
'eigen' : force computation via eigendecomposition of X^T X
The 'auto' mode is the default and is intended to pick the cheaper
option of the two depending upon the shape and format of the training
data.
store_cv_values : boolean, default=False
Flag indicating if the cross-validation values corresponding to
each alpha should be stored in the `cv_values_` attribute (see
below). This flag is only compatible with `cv=None` (i.e. using
Generalized Cross-Validation).
Attributes
----------
cv_values_ : array, shape = [n_samples, n_alphas] or \
shape = [n_samples, n_targets, n_alphas], optional
Cross-validation values for each alpha (if `store_cv_values=True` and \
`cv=None`). After `fit()` has been called, this attribute will \
contain the mean squared errors (by default) or the values of the \
`{loss,score}_func` function (if provided in the constructor).
coef_ : array, shape = [n_features] or [n_targets, n_features]
Weight vector(s).
intercept_ : float | array, shape = (n_targets,)
Independent term in decision function. Set to 0.0 if
``fit_intercept = False``.
alpha_ : float
Estimated regularization parameter.
See also
--------
Ridge: Ridge regression
RidgeClassifier: Ridge classifier
RidgeClassifierCV: Ridge classifier with built-in cross validation
"""
pass
class RidgeClassifierCV(LinearClassifierMixin, _BaseRidgeCV):
"""Ridge classifier with built-in cross-validation.
By default, it performs Generalized Cross-Validation, which is a form of
efficient Leave-One-Out cross-validation. Currently, only the n_features >
n_samples case is handled efficiently.
Read more in the :ref:`User Guide <ridge_regression>`.
Parameters
----------
alphas : numpy array of shape [n_alphas]
Array of alpha values to try.
Regularization strength; must be a positive float. Regularization
improves the conditioning of the problem and reduces the variance of
the estimates. Larger values specify stronger regularization.
Alpha corresponds to ``C^-1`` in other linear models such as
LogisticRegression or LinearSVC.
fit_intercept : boolean
Whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
scoring : string, callable or None, optional, default: None
A string (see model evaluation documentation) or
a scorer callable object / function with signature
``scorer(estimator, X, y)``.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the efficient Leave-One-Out cross-validation
- integer, to specify the number of folds.
- An object to be used as a cross-validation generator.
- An iterable yielding train/test splits.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
class_weight : dict or 'balanced', optional
Weights associated with classes in the form ``{class_label: weight}``.
If not given, all classes are supposed to have weight one.
The "balanced" mode uses the values of y to automatically adjust
weights inversely proportional to class frequencies in the input data
as ``n_samples / (n_classes * np.bincount(y))``
Attributes
----------
cv_values_ : array, shape = [n_samples, n_alphas] or \
shape = [n_samples, n_responses, n_alphas], optional
Cross-validation values for each alpha (if `store_cv_values=True` and
`cv=None`). After `fit()` has been called, this attribute will contain \
the mean squared errors (by default) or the values of the \
`{loss,score}_func` function (if provided in the constructor).
coef_ : array, shape = [n_features] or [n_targets, n_features]
Weight vector(s).
intercept_ : float | array, shape = (n_targets,)
Independent term in decision function. Set to 0.0 if
``fit_intercept = False``.
alpha_ : float
Estimated regularization parameter
See also
--------
Ridge: Ridge regression
RidgeClassifier: Ridge classifier
RidgeCV: Ridge regression with built-in cross validation
Notes
-----
For multi-class classification, n_class classifiers are trained in
a one-versus-all approach. Concretely, this is implemented by taking
advantage of the multi-variate response support in Ridge.
"""
def __init__(self, alphas=(0.1, 1.0, 10.0), fit_intercept=True,
normalize=False, scoring=None, cv=None, class_weight=None):
super(RidgeClassifierCV, self).__init__(
alphas=alphas, fit_intercept=fit_intercept, normalize=normalize,
scoring=scoring, cv=cv)
self.class_weight = class_weight
def fit(self, X, y, sample_weight=None):
"""Fit the ridge classifier.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Training vectors, where n_samples is the number of samples
and n_features is the number of features.
y : array-like, shape (n_samples,)
Target values. Will be cast to X's dtype if necessary
sample_weight : float or numpy array of shape (n_samples,)
Sample weight.
Returns
-------
self : object
Returns self.
"""
self._label_binarizer = LabelBinarizer(pos_label=1, neg_label=-1)
Y = self._label_binarizer.fit_transform(y)
if not self._label_binarizer.y_type_.startswith('multilabel'):
y = column_or_1d(y, warn=True)
if self.class_weight:
if sample_weight is None:
sample_weight = 1.
# modify the sample weights with the corresponding class weight
sample_weight = (sample_weight *
compute_sample_weight(self.class_weight, y))
_BaseRidgeCV.fit(self, X, Y, sample_weight=sample_weight)
return self
@property
def classes_(self):
return self._label_binarizer.classes_
| 52,900 | 37.642075 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/setup.py | import os
from os.path import join
import numpy
from sklearn._build_utils import get_blas_info
def configuration(parent_package='', top_path=None):
from numpy.distutils.misc_util import Configuration
config = Configuration('linear_model', parent_package, top_path)
cblas_libs, blas_info = get_blas_info()
if os.name == 'posix':
cblas_libs.append('m')
config.add_extension('cd_fast', sources=['cd_fast.pyx'],
libraries=cblas_libs,
include_dirs=[join('..', 'src', 'cblas'),
numpy.get_include(),
blas_info.pop('include_dirs', [])],
extra_compile_args=blas_info.pop('extra_compile_args',
[]), **blas_info)
config.add_extension('sgd_fast',
sources=['sgd_fast.pyx'],
include_dirs=[join('..', 'src', 'cblas'),
numpy.get_include(),
blas_info.pop('include_dirs', [])],
libraries=cblas_libs,
extra_compile_args=blas_info.pop('extra_compile_args',
[]),
**blas_info)
config.add_extension('sag_fast',
sources=['sag_fast.pyx'],
include_dirs=numpy.get_include())
# add other directories
config.add_subpackage('tests')
return config
if __name__ == '__main__':
from numpy.distutils.core import setup
setup(**configuration(top_path='').todict())
| 1,719 | 34.102041 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/bayes.py | """
Various bayesian regression
"""
from __future__ import print_function
# Authors: V. Michel, F. Pedregosa, A. Gramfort
# License: BSD 3 clause
from math import log
import numpy as np
from scipy import linalg
from scipy.linalg import pinvh
from .base import LinearModel
from ..base import RegressorMixin
from ..utils.extmath import fast_logdet
from ..utils import check_X_y
###############################################################################
# BayesianRidge regression
class BayesianRidge(LinearModel, RegressorMixin):
"""Bayesian ridge regression
Fit a Bayesian ridge model and optimize the regularization parameters
lambda (precision of the weights) and alpha (precision of the noise).
Read more in the :ref:`User Guide <bayesian_regression>`.
Parameters
----------
n_iter : int, optional
Maximum number of iterations. Default is 300.
tol : float, optional
Stop the algorithm if w has converged. Default is 1.e-3.
alpha_1 : float, optional
Hyper-parameter : shape parameter for the Gamma distribution prior
over the alpha parameter. Default is 1.e-6
alpha_2 : float, optional
Hyper-parameter : inverse scale parameter (rate parameter) for the
Gamma distribution prior over the alpha parameter.
Default is 1.e-6.
lambda_1 : float, optional
Hyper-parameter : shape parameter for the Gamma distribution prior
over the lambda parameter. Default is 1.e-6.
lambda_2 : float, optional
Hyper-parameter : inverse scale parameter (rate parameter) for the
Gamma distribution prior over the lambda parameter.
Default is 1.e-6
compute_score : boolean, optional
If True, compute the objective function at each step of the model.
Default is False
fit_intercept : boolean, optional
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
Default is True.
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
copy_X : boolean, optional, default True
If True, X will be copied; else, it may be overwritten.
verbose : boolean, optional, default False
Verbose mode when fitting the model.
Attributes
----------
coef_ : array, shape = (n_features)
Coefficients of the regression model (mean of distribution)
alpha_ : float
estimated precision of the noise.
lambda_ : float
estimated precision of the weights.
sigma_ : array, shape = (n_features, n_features)
estimated variance-covariance matrix of the weights
scores_ : float
if computed, value of the objective function (to be maximized)
Examples
--------
>>> from sklearn import linear_model
>>> clf = linear_model.BayesianRidge()
>>> clf.fit([[0,0], [1, 1], [2, 2]], [0, 1, 2])
... # doctest: +NORMALIZE_WHITESPACE
BayesianRidge(alpha_1=1e-06, alpha_2=1e-06, compute_score=False,
copy_X=True, fit_intercept=True, lambda_1=1e-06, lambda_2=1e-06,
n_iter=300, normalize=False, tol=0.001, verbose=False)
>>> clf.predict([[1, 1]])
array([ 1.])
Notes
-----
For an example, see :ref:`examples/linear_model/plot_bayesian_ridge.py
<sphx_glr_auto_examples_linear_model_plot_bayesian_ridge.py>`.
References
----------
D. J. C. MacKay, Bayesian Interpolation, Computation and Neural Systems,
Vol. 4, No. 3, 1992.
R. Salakhutdinov, Lecture notes on Statistical Machine Learning,
http://www.utstat.toronto.edu/~rsalakhu/sta4273/notes/Lecture2.pdf#page=15
Their beta is our ``self.alpha_``
Their alpha is our ``self.lambda_``
"""
def __init__(self, n_iter=300, tol=1.e-3, alpha_1=1.e-6, alpha_2=1.e-6,
lambda_1=1.e-6, lambda_2=1.e-6, compute_score=False,
fit_intercept=True, normalize=False, copy_X=True,
verbose=False):
self.n_iter = n_iter
self.tol = tol
self.alpha_1 = alpha_1
self.alpha_2 = alpha_2
self.lambda_1 = lambda_1
self.lambda_2 = lambda_2
self.compute_score = compute_score
self.fit_intercept = fit_intercept
self.normalize = normalize
self.copy_X = copy_X
self.verbose = verbose
def fit(self, X, y):
"""Fit the model
Parameters
----------
X : numpy array of shape [n_samples,n_features]
Training data
y : numpy array of shape [n_samples]
Target values. Will be cast to X's dtype if necessary
Returns
-------
self : returns an instance of self.
"""
X, y = check_X_y(X, y, dtype=np.float64, y_numeric=True)
X, y, X_offset_, y_offset_, X_scale_ = self._preprocess_data(
X, y, self.fit_intercept, self.normalize, self.copy_X)
self.X_offset_ = X_offset_
self.X_scale_ = X_scale_
n_samples, n_features = X.shape
# Initialization of the values of the parameters
alpha_ = 1. / np.var(y)
lambda_ = 1.
verbose = self.verbose
lambda_1 = self.lambda_1
lambda_2 = self.lambda_2
alpha_1 = self.alpha_1
alpha_2 = self.alpha_2
self.scores_ = list()
coef_old_ = None
XT_y = np.dot(X.T, y)
U, S, Vh = linalg.svd(X, full_matrices=False)
eigen_vals_ = S ** 2
# Convergence loop of the bayesian ridge regression
for iter_ in range(self.n_iter):
# Compute mu and sigma
# sigma_ = lambda_ / alpha_ * np.eye(n_features) + np.dot(X.T, X)
# coef_ = sigma_^-1 * XT * y
if n_samples > n_features:
coef_ = np.dot(Vh.T,
Vh / (eigen_vals_ +
lambda_ / alpha_)[:, np.newaxis])
coef_ = np.dot(coef_, XT_y)
if self.compute_score:
logdet_sigma_ = - np.sum(
np.log(lambda_ + alpha_ * eigen_vals_))
else:
coef_ = np.dot(X.T, np.dot(
U / (eigen_vals_ + lambda_ / alpha_)[None, :], U.T))
coef_ = np.dot(coef_, y)
if self.compute_score:
logdet_sigma_ = lambda_ * np.ones(n_features)
logdet_sigma_[:n_samples] += alpha_ * eigen_vals_
logdet_sigma_ = - np.sum(np.log(logdet_sigma_))
# Preserve the alpha and lambda values that were used to
# calculate the final coefficients
self.alpha_ = alpha_
self.lambda_ = lambda_
# Update alpha and lambda
rmse_ = np.sum((y - np.dot(X, coef_)) ** 2)
gamma_ = (np.sum((alpha_ * eigen_vals_) /
(lambda_ + alpha_ * eigen_vals_)))
lambda_ = ((gamma_ + 2 * lambda_1) /
(np.sum(coef_ ** 2) + 2 * lambda_2))
alpha_ = ((n_samples - gamma_ + 2 * alpha_1) /
(rmse_ + 2 * alpha_2))
# Compute the objective function
if self.compute_score:
s = lambda_1 * log(lambda_) - lambda_2 * lambda_
s += alpha_1 * log(alpha_) - alpha_2 * alpha_
s += 0.5 * (n_features * log(lambda_) +
n_samples * log(alpha_) -
alpha_ * rmse_ -
(lambda_ * np.sum(coef_ ** 2)) -
logdet_sigma_ -
n_samples * log(2 * np.pi))
self.scores_.append(s)
# Check for convergence
if iter_ != 0 and np.sum(np.abs(coef_old_ - coef_)) < self.tol:
if verbose:
print("Convergence after ", str(iter_), " iterations")
break
coef_old_ = np.copy(coef_)
self.coef_ = coef_
sigma_ = np.dot(Vh.T,
Vh / (eigen_vals_ + lambda_ / alpha_)[:, np.newaxis])
self.sigma_ = (1. / alpha_) * sigma_
self._set_intercept(X_offset_, y_offset_, X_scale_)
return self
def predict(self, X, return_std=False):
"""Predict using the linear model.
In addition to the mean of the predictive distribution, also its
standard deviation can be returned.
Parameters
----------
X : {array-like, sparse matrix}, shape = (n_samples, n_features)
Samples.
return_std : boolean, optional
Whether to return the standard deviation of posterior prediction.
Returns
-------
y_mean : array, shape = (n_samples,)
Mean of predictive distribution of query points.
y_std : array, shape = (n_samples,)
Standard deviation of predictive distribution of query points.
"""
y_mean = self._decision_function(X)
if return_std is False:
return y_mean
else:
if self.normalize:
X = (X - self.X_offset_) / self.X_scale_
sigmas_squared_data = (np.dot(X, self.sigma_) * X).sum(axis=1)
y_std = np.sqrt(sigmas_squared_data + (1. / self.alpha_))
return y_mean, y_std
###############################################################################
# ARD (Automatic Relevance Determination) regression
class ARDRegression(LinearModel, RegressorMixin):
"""Bayesian ARD regression.
Fit the weights of a regression model, using an ARD prior. The weights of
the regression model are assumed to be in Gaussian distributions.
Also estimate the parameters lambda (precisions of the distributions of the
weights) and alpha (precision of the distribution of the noise).
The estimation is done by an iterative procedures (Evidence Maximization)
Read more in the :ref:`User Guide <bayesian_regression>`.
Parameters
----------
n_iter : int, optional
Maximum number of iterations. Default is 300
tol : float, optional
Stop the algorithm if w has converged. Default is 1.e-3.
alpha_1 : float, optional
Hyper-parameter : shape parameter for the Gamma distribution prior
over the alpha parameter. Default is 1.e-6.
alpha_2 : float, optional
Hyper-parameter : inverse scale parameter (rate parameter) for the
Gamma distribution prior over the alpha parameter. Default is 1.e-6.
lambda_1 : float, optional
Hyper-parameter : shape parameter for the Gamma distribution prior
over the lambda parameter. Default is 1.e-6.
lambda_2 : float, optional
Hyper-parameter : inverse scale parameter (rate parameter) for the
Gamma distribution prior over the lambda parameter. Default is 1.e-6.
compute_score : boolean, optional
If True, compute the objective function at each step of the model.
Default is False.
threshold_lambda : float, optional
threshold for removing (pruning) weights with high precision from
the computation. Default is 1.e+4.
fit_intercept : boolean, optional
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
Default is True.
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
copy_X : boolean, optional, default True.
If True, X will be copied; else, it may be overwritten.
verbose : boolean, optional, default False
Verbose mode when fitting the model.
Attributes
----------
coef_ : array, shape = (n_features)
Coefficients of the regression model (mean of distribution)
alpha_ : float
estimated precision of the noise.
lambda_ : array, shape = (n_features)
estimated precisions of the weights.
sigma_ : array, shape = (n_features, n_features)
estimated variance-covariance matrix of the weights
scores_ : float
if computed, value of the objective function (to be maximized)
Examples
--------
>>> from sklearn import linear_model
>>> clf = linear_model.ARDRegression()
>>> clf.fit([[0,0], [1, 1], [2, 2]], [0, 1, 2])
... # doctest: +NORMALIZE_WHITESPACE
ARDRegression(alpha_1=1e-06, alpha_2=1e-06, compute_score=False,
copy_X=True, fit_intercept=True, lambda_1=1e-06, lambda_2=1e-06,
n_iter=300, normalize=False, threshold_lambda=10000.0, tol=0.001,
verbose=False)
>>> clf.predict([[1, 1]])
array([ 1.])
Notes
-----
For an example, see :ref:`examples/linear_model/plot_ard.py
<sphx_glr_auto_examples_linear_model_plot_ard.py>`.
References
----------
D. J. C. MacKay, Bayesian nonlinear modeling for the prediction
competition, ASHRAE Transactions, 1994.
R. Salakhutdinov, Lecture notes on Statistical Machine Learning,
http://www.utstat.toronto.edu/~rsalakhu/sta4273/notes/Lecture2.pdf#page=15
Their beta is our ``self.alpha_``
Their alpha is our ``self.lambda_``
ARD is a little different than the slide: only dimensions/features for
which ``self.lambda_ < self.threshold_lambda`` are kept and the rest are
discarded.
"""
def __init__(self, n_iter=300, tol=1.e-3, alpha_1=1.e-6, alpha_2=1.e-6,
lambda_1=1.e-6, lambda_2=1.e-6, compute_score=False,
threshold_lambda=1.e+4, fit_intercept=True, normalize=False,
copy_X=True, verbose=False):
self.n_iter = n_iter
self.tol = tol
self.fit_intercept = fit_intercept
self.normalize = normalize
self.alpha_1 = alpha_1
self.alpha_2 = alpha_2
self.lambda_1 = lambda_1
self.lambda_2 = lambda_2
self.compute_score = compute_score
self.threshold_lambda = threshold_lambda
self.copy_X = copy_X
self.verbose = verbose
def fit(self, X, y):
"""Fit the ARDRegression model according to the given training data
and parameters.
Iterative procedure to maximize the evidence
Parameters
----------
X : array-like, shape = [n_samples, n_features]
Training vector, where n_samples in the number of samples and
n_features is the number of features.
y : array, shape = [n_samples]
Target values (integers). Will be cast to X's dtype if necessary
Returns
-------
self : returns an instance of self.
"""
X, y = check_X_y(X, y, dtype=np.float64, y_numeric=True)
n_samples, n_features = X.shape
coef_ = np.zeros(n_features)
X, y, X_offset_, y_offset_, X_scale_ = self._preprocess_data(
X, y, self.fit_intercept, self.normalize, self.copy_X)
# Launch the convergence loop
keep_lambda = np.ones(n_features, dtype=bool)
lambda_1 = self.lambda_1
lambda_2 = self.lambda_2
alpha_1 = self.alpha_1
alpha_2 = self.alpha_2
verbose = self.verbose
# Initialization of the values of the parameters
alpha_ = 1. / np.var(y)
lambda_ = np.ones(n_features)
self.scores_ = list()
coef_old_ = None
# Iterative procedure of ARDRegression
for iter_ in range(self.n_iter):
# Compute mu and sigma (using Woodbury matrix identity)
sigma_ = pinvh(np.eye(n_samples) / alpha_ +
np.dot(X[:, keep_lambda] *
np.reshape(1. / lambda_[keep_lambda], [1, -1]),
X[:, keep_lambda].T))
sigma_ = np.dot(sigma_, X[:, keep_lambda] *
np.reshape(1. / lambda_[keep_lambda], [1, -1]))
sigma_ = - np.dot(np.reshape(1. / lambda_[keep_lambda], [-1, 1]) *
X[:, keep_lambda].T, sigma_)
sigma_.flat[::(sigma_.shape[1] + 1)] += 1. / lambda_[keep_lambda]
coef_[keep_lambda] = alpha_ * np.dot(
sigma_, np.dot(X[:, keep_lambda].T, y))
# Update alpha and lambda
rmse_ = np.sum((y - np.dot(X, coef_)) ** 2)
gamma_ = 1. - lambda_[keep_lambda] * np.diag(sigma_)
lambda_[keep_lambda] = ((gamma_ + 2. * lambda_1) /
((coef_[keep_lambda]) ** 2 +
2. * lambda_2))
alpha_ = ((n_samples - gamma_.sum() + 2. * alpha_1) /
(rmse_ + 2. * alpha_2))
# Prune the weights with a precision over a threshold
keep_lambda = lambda_ < self.threshold_lambda
coef_[~keep_lambda] = 0
# Compute the objective function
if self.compute_score:
s = (lambda_1 * np.log(lambda_) - lambda_2 * lambda_).sum()
s += alpha_1 * log(alpha_) - alpha_2 * alpha_
s += 0.5 * (fast_logdet(sigma_) + n_samples * log(alpha_) +
np.sum(np.log(lambda_)))
s -= 0.5 * (alpha_ * rmse_ + (lambda_ * coef_ ** 2).sum())
self.scores_.append(s)
# Check for convergence
if iter_ > 0 and np.sum(np.abs(coef_old_ - coef_)) < self.tol:
if verbose:
print("Converged after %s iterations" % iter_)
break
coef_old_ = np.copy(coef_)
self.coef_ = coef_
self.alpha_ = alpha_
self.sigma_ = sigma_
self.lambda_ = lambda_
self._set_intercept(X_offset_, y_offset_, X_scale_)
return self
def predict(self, X, return_std=False):
"""Predict using the linear model.
In addition to the mean of the predictive distribution, also its
standard deviation can be returned.
Parameters
----------
X : {array-like, sparse matrix}, shape = (n_samples, n_features)
Samples.
return_std : boolean, optional
Whether to return the standard deviation of posterior prediction.
Returns
-------
y_mean : array, shape = (n_samples,)
Mean of predictive distribution of query points.
y_std : array, shape = (n_samples,)
Standard deviation of predictive distribution of query points.
"""
y_mean = self._decision_function(X)
if return_std is False:
return y_mean
else:
if self.normalize:
X = (X - self.X_offset_) / self.X_scale_
X = X[:, self.lambda_ < self.threshold_lambda]
sigmas_squared_data = (np.dot(X, self.sigma_) * X).sum(axis=1)
y_std = np.sqrt(sigmas_squared_data + (1. / self.alpha_))
return y_mean, y_std
| 19,750 | 35.848881 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/huber.py | # Authors: Manoj Kumar [email protected]
# License: BSD 3 clause
import numpy as np
from scipy import optimize, sparse
from ..base import BaseEstimator, RegressorMixin
from .base import LinearModel
from ..utils import check_X_y
from ..utils import check_consistent_length
from ..utils import axis0_safe_slice
from ..utils.extmath import safe_sparse_dot
def _huber_loss_and_gradient(w, X, y, epsilon, alpha, sample_weight=None):
"""Returns the Huber loss and the gradient.
Parameters
----------
w : ndarray, shape (n_features + 1,) or (n_features + 2,)
Feature vector.
w[:n_features] gives the coefficients
w[-1] gives the scale factor and if the intercept is fit w[-2]
gives the intercept factor.
X : ndarray, shape (n_samples, n_features)
Input data.
y : ndarray, shape (n_samples,)
Target vector.
epsilon : float
Robustness of the Huber estimator.
alpha : float
Regularization parameter.
sample_weight : ndarray, shape (n_samples,), optional
Weight assigned to each sample.
Returns
-------
loss : float
Huber loss.
gradient : ndarray, shape (len(w))
Returns the derivative of the Huber loss with respect to each
coefficient, intercept and the scale as a vector.
"""
X_is_sparse = sparse.issparse(X)
_, n_features = X.shape
fit_intercept = (n_features + 2 == w.shape[0])
if fit_intercept:
intercept = w[-2]
sigma = w[-1]
w = w[:n_features]
n_samples = np.sum(sample_weight)
# Calculate the values where |y - X'w -c / sigma| > epsilon
# The values above this threshold are outliers.
linear_loss = y - safe_sparse_dot(X, w)
if fit_intercept:
linear_loss -= intercept
abs_linear_loss = np.abs(linear_loss)
outliers_mask = abs_linear_loss > epsilon * sigma
# Calculate the linear loss due to the outliers.
# This is equal to (2 * M * |y - X'w -c / sigma| - M**2) * sigma
outliers = abs_linear_loss[outliers_mask]
num_outliers = np.count_nonzero(outliers_mask)
n_non_outliers = X.shape[0] - num_outliers
# n_sq_outliers includes the weight give to the outliers while
# num_outliers is just the number of outliers.
outliers_sw = sample_weight[outliers_mask]
n_sw_outliers = np.sum(outliers_sw)
outlier_loss = (2. * epsilon * np.sum(outliers_sw * outliers) -
sigma * n_sw_outliers * epsilon ** 2)
# Calculate the quadratic loss due to the non-outliers.-
# This is equal to |(y - X'w - c)**2 / sigma**2| * sigma
non_outliers = linear_loss[~outliers_mask]
weighted_non_outliers = sample_weight[~outliers_mask] * non_outliers
weighted_loss = np.dot(weighted_non_outliers.T, non_outliers)
squared_loss = weighted_loss / sigma
if fit_intercept:
grad = np.zeros(n_features + 2)
else:
grad = np.zeros(n_features + 1)
# Gradient due to the squared loss.
X_non_outliers = -axis0_safe_slice(X, ~outliers_mask, n_non_outliers)
grad[:n_features] = (
2. / sigma * safe_sparse_dot(weighted_non_outliers, X_non_outliers))
# Gradient due to the linear loss.
signed_outliers = np.ones_like(outliers)
signed_outliers_mask = linear_loss[outliers_mask] < 0
signed_outliers[signed_outliers_mask] = -1.0
X_outliers = axis0_safe_slice(X, outliers_mask, num_outliers)
sw_outliers = sample_weight[outliers_mask] * signed_outliers
grad[:n_features] -= 2. * epsilon * (
safe_sparse_dot(sw_outliers, X_outliers))
# Gradient due to the penalty.
grad[:n_features] += alpha * 2. * w
# Gradient due to sigma.
grad[-1] = n_samples
grad[-1] -= n_sw_outliers * epsilon ** 2
grad[-1] -= squared_loss / sigma
# Gradient due to the intercept.
if fit_intercept:
grad[-2] = -2. * np.sum(weighted_non_outliers) / sigma
grad[-2] -= 2. * epsilon * np.sum(sw_outliers)
loss = n_samples * sigma + squared_loss + outlier_loss
loss += alpha * np.dot(w, w)
return loss, grad
class HuberRegressor(LinearModel, RegressorMixin, BaseEstimator):
"""Linear regression model that is robust to outliers.
The Huber Regressor optimizes the squared loss for the samples where
``|(y - X'w) / sigma| < epsilon`` and the absolute loss for the samples
where ``|(y - X'w) / sigma| > epsilon``, where w and sigma are parameters
to be optimized. The parameter sigma makes sure that if y is scaled up
or down by a certain factor, one does not need to rescale epsilon to
achieve the same robustness. Note that this does not take into account
the fact that the different features of X may be of different scales.
This makes sure that the loss function is not heavily influenced by the
outliers while not completely ignoring their effect.
Read more in the :ref:`User Guide <huber_regression>`
.. versionadded:: 0.18
Parameters
----------
epsilon : float, greater than 1.0, default 1.35
The parameter epsilon controls the number of samples that should be
classified as outliers. The smaller the epsilon, the more robust it is
to outliers.
max_iter : int, default 100
Maximum number of iterations that scipy.optimize.fmin_l_bfgs_b
should run for.
alpha : float, default 0.0001
Regularization parameter.
warm_start : bool, default False
This is useful if the stored attributes of a previously used model
has to be reused. If set to False, then the coefficients will
be rewritten for every call to fit.
fit_intercept : bool, default True
Whether or not to fit the intercept. This can be set to False
if the data is already centered around the origin.
tol : float, default 1e-5
The iteration will stop when
``max{|proj g_i | i = 1, ..., n}`` <= ``tol``
where pg_i is the i-th component of the projected gradient.
Attributes
----------
coef_ : array, shape (n_features,)
Features got by optimizing the Huber loss.
intercept_ : float
Bias.
scale_ : float
The value by which ``|y - X'w - c|`` is scaled down.
n_iter_ : int
Number of iterations that fmin_l_bfgs_b has run for.
Not available if SciPy version is 0.9 and below.
outliers_ : array, shape (n_samples,)
A boolean mask which is set to True where the samples are identified
as outliers.
References
----------
.. [1] Peter J. Huber, Elvezio M. Ronchetti, Robust Statistics
Concomitant scale estimates, pg 172
.. [2] Art B. Owen (2006), A robust hybrid of lasso and ridge regression.
http://statweb.stanford.edu/~owen/reports/hhu.pdf
"""
def __init__(self, epsilon=1.35, max_iter=100, alpha=0.0001,
warm_start=False, fit_intercept=True, tol=1e-05):
self.epsilon = epsilon
self.max_iter = max_iter
self.alpha = alpha
self.warm_start = warm_start
self.fit_intercept = fit_intercept
self.tol = tol
def fit(self, X, y, sample_weight=None):
"""Fit the model according to the given training data.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Training vector, where n_samples in the number of samples and
n_features is the number of features.
y : array-like, shape (n_samples,)
Target vector relative to X.
sample_weight : array-like, shape (n_samples,)
Weight given to each sample.
Returns
-------
self : object
Returns self.
"""
X, y = check_X_y(
X, y, copy=False, accept_sparse=['csr'], y_numeric=True)
if sample_weight is not None:
sample_weight = np.array(sample_weight)
check_consistent_length(y, sample_weight)
else:
sample_weight = np.ones_like(y)
if self.epsilon < 1.0:
raise ValueError(
"epsilon should be greater than or equal to 1.0, got %f"
% self.epsilon)
if self.warm_start and hasattr(self, 'coef_'):
parameters = np.concatenate(
(self.coef_, [self.intercept_, self.scale_]))
else:
if self.fit_intercept:
parameters = np.zeros(X.shape[1] + 2)
else:
parameters = np.zeros(X.shape[1] + 1)
# Make sure to initialize the scale parameter to a strictly
# positive value:
parameters[-1] = 1
# Sigma or the scale factor should be non-negative.
# Setting it to be zero might cause undefined bounds hence we set it
# to a value close to zero.
bounds = np.tile([-np.inf, np.inf], (parameters.shape[0], 1))
bounds[-1][0] = np.finfo(np.float64).eps * 10
# Type Error caused in old versions of SciPy because of no
# maxiter argument ( <= 0.9).
try:
parameters, f, dict_ = optimize.fmin_l_bfgs_b(
_huber_loss_and_gradient, parameters,
args=(X, y, self.epsilon, self.alpha, sample_weight),
maxiter=self.max_iter, pgtol=self.tol, bounds=bounds,
iprint=0)
except TypeError:
parameters, f, dict_ = optimize.fmin_l_bfgs_b(
_huber_loss_and_gradient, parameters,
args=(X, y, self.epsilon, self.alpha, sample_weight),
bounds=bounds)
if dict_['warnflag'] == 2:
raise ValueError("HuberRegressor convergence failed:"
" l-BFGS-b solver terminated with %s"
% dict_['task'].decode('ascii'))
self.n_iter_ = dict_.get('nit', None)
self.scale_ = parameters[-1]
if self.fit_intercept:
self.intercept_ = parameters[-2]
else:
self.intercept_ = 0.0
self.coef_ = parameters[:X.shape[1]]
residual = np.abs(
y - safe_sparse_dot(X, self.coef_) - self.intercept_)
self.outliers_ = residual > self.scale_ * self.epsilon
return self
| 10,265 | 34.770035 | 78 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/sag.py | """Solvers for Ridge and LogisticRegression using SAG algorithm"""
# Authors: Tom Dupre la Tour <[email protected]>
#
# License: BSD 3 clause
import warnings
import numpy as np
from .base import make_dataset
from .sag_fast import sag
from ..exceptions import ConvergenceWarning
from ..utils import check_array
from ..utils.extmath import row_norms
def get_auto_step_size(max_squared_sum, alpha_scaled, loss, fit_intercept,
n_samples=None,
is_saga=False):
"""Compute automatic step size for SAG solver
The step size is set to 1 / (alpha_scaled + L + fit_intercept) where L is
the max sum of squares for over all samples.
Parameters
----------
max_squared_sum : float
Maximum squared sum of X over samples.
alpha_scaled : float
Constant that multiplies the regularization term, scaled by
1. / n_samples, the number of samples.
loss : string, in {"log", "squared"}
The loss function used in SAG solver.
fit_intercept : bool
Specifies if a constant (a.k.a. bias or intercept) will be
added to the decision function.
n_samples : int, optional
Number of rows in X. Useful if is_saga=True.
is_saga : boolean, optional
Whether to return step size for the SAGA algorithm or the SAG
algorithm.
Returns
-------
step_size : float
Step size used in SAG solver.
References
----------
Schmidt, M., Roux, N. L., & Bach, F. (2013).
Minimizing finite sums with the stochastic average gradient
https://hal.inria.fr/hal-00860051/document
Defazio, A., Bach F. & Lacoste-Julien S. (2014).
SAGA: A Fast Incremental Gradient Method With Support
for Non-Strongly Convex Composite Objectives
https://arxiv.org/abs/1407.0202
"""
if loss in ('log', 'multinomial'):
L = (0.25 * (max_squared_sum + int(fit_intercept)) + alpha_scaled)
elif loss == 'squared':
# inverse Lipschitz constant for squared loss
L = max_squared_sum + int(fit_intercept) + alpha_scaled
else:
raise ValueError("Unknown loss function for SAG solver, got %s "
"instead of 'log' or 'squared'" % loss)
if is_saga:
# SAGA theoretical step size is 1/3L or 1 / (2 * (L + mu n))
# See Defazio et al. 2014
mun = min(2 * n_samples * alpha_scaled, L)
step = 1. / (2 * L + mun)
else:
# SAG theoretical step size is 1/16L but it is recommended to use 1 / L
# see http://www.birs.ca//workshops//2014/14w5003/files/schmidt.pdf,
# slide 65
step = 1. / L
return step
def sag_solver(X, y, sample_weight=None, loss='log', alpha=1., beta=0.,
max_iter=1000, tol=0.001, verbose=0, random_state=None,
check_input=True, max_squared_sum=None,
warm_start_mem=None,
is_saga=False):
"""SAG solver for Ridge and LogisticRegression
SAG stands for Stochastic Average Gradient: the gradient of the loss is
estimated each sample at a time and the model is updated along the way with
a constant learning rate.
IMPORTANT NOTE: 'sag' solver converges faster on columns that are on the
same scale. You can normalize the data by using
sklearn.preprocessing.StandardScaler on your data before passing it to the
fit method.
This implementation works with data represented as dense numpy arrays or
sparse scipy arrays of floating point values for the features. It will
fit the data according to squared loss or log loss.
The regularizer is a penalty added to the loss function that shrinks model
parameters towards the zero vector using the squared euclidean norm L2.
.. versionadded:: 0.17
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data
y : numpy array, shape (n_samples,)
Target values. With loss='multinomial', y must be label encoded
(see preprocessing.LabelEncoder).
sample_weight : array-like, shape (n_samples,), optional
Weights applied to individual samples (1. for unweighted).
loss : 'log' | 'squared' | 'multinomial'
Loss function that will be optimized:
-'log' is the binary logistic loss, as used in LogisticRegression.
-'squared' is the squared loss, as used in Ridge.
-'multinomial' is the multinomial logistic loss, as used in
LogisticRegression.
.. versionadded:: 0.18
*loss='multinomial'*
alpha : float, optional
Constant that multiplies the regularization term. Defaults to 1.
max_iter : int, optional
The max number of passes over the training data if the stopping
criteria is not reached. Defaults to 1000.
tol : double, optional
The stopping criteria for the weights. The iterations will stop when
max(change in weights) / max(weights) < tol. Defaults to .001
verbose : integer, optional
The verbosity level.
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator to use when shuffling
the data. If int, random_state is the seed used by the random number
generator; If RandomState instance, random_state is the random number
generator; If None, the random number generator is the RandomState
instance used by `np.random`.
check_input : bool, default True
If False, the input arrays X and y will not be checked.
max_squared_sum : float, default None
Maximum squared sum of X over samples. If None, it will be computed,
going through all the samples. The value should be precomputed
to speed up cross validation.
warm_start_mem : dict, optional
The initialization parameters used for warm starting. Warm starting is
currently used in LogisticRegression but not in Ridge.
It contains:
- 'coef': the weight vector, with the intercept in last line
if the intercept is fitted.
- 'gradient_memory': the scalar gradient for all seen samples.
- 'sum_gradient': the sum of gradient over all seen samples,
for each feature.
- 'intercept_sum_gradient': the sum of gradient over all seen
samples, for the intercept.
- 'seen': array of boolean describing the seen samples.
- 'num_seen': the number of seen samples.
is_saga : boolean, optional
Whether to use the SAGA algorithm or the SAG algorithm. SAGA behaves
better in the first epochs, and allow for l1 regularisation.
Returns
-------
coef_ : array, shape (n_features)
Weight vector.
n_iter_ : int
The number of full pass on all samples.
warm_start_mem : dict
Contains a 'coef' key with the fitted result, and possibly the
fitted intercept at the end of the array. Contains also other keys
used for warm starting.
Examples
--------
>>> import numpy as np
>>> from sklearn import linear_model
>>> n_samples, n_features = 10, 5
>>> np.random.seed(0)
>>> X = np.random.randn(n_samples, n_features)
>>> y = np.random.randn(n_samples)
>>> clf = linear_model.Ridge(solver='sag')
>>> clf.fit(X, y)
... #doctest: +NORMALIZE_WHITESPACE
Ridge(alpha=1.0, copy_X=True, fit_intercept=True, max_iter=None,
normalize=False, random_state=None, solver='sag', tol=0.001)
>>> X = np.array([[-1, -1], [-2, -1], [1, 1], [2, 1]])
>>> y = np.array([1, 1, 2, 2])
>>> clf = linear_model.LogisticRegression(solver='sag')
>>> clf.fit(X, y)
... #doctest: +NORMALIZE_WHITESPACE
LogisticRegression(C=1.0, class_weight=None, dual=False,
fit_intercept=True, intercept_scaling=1, max_iter=100,
multi_class='ovr', n_jobs=1, penalty='l2', random_state=None,
solver='sag', tol=0.0001, verbose=0, warm_start=False)
References
----------
Schmidt, M., Roux, N. L., & Bach, F. (2013).
Minimizing finite sums with the stochastic average gradient
https://hal.inria.fr/hal-00860051/document
Defazio, A., Bach F. & Lacoste-Julien S. (2014).
SAGA: A Fast Incremental Gradient Method With Support
for Non-Strongly Convex Composite Objectives
https://arxiv.org/abs/1407.0202
See also
--------
Ridge, SGDRegressor, ElasticNet, Lasso, SVR, and
LogisticRegression, SGDClassifier, LinearSVC, Perceptron
"""
if warm_start_mem is None:
warm_start_mem = {}
# Ridge default max_iter is None
if max_iter is None:
max_iter = 1000
if check_input:
X = check_array(X, dtype=np.float64, accept_sparse='csr', order='C')
y = check_array(y, dtype=np.float64, ensure_2d=False, order='C')
n_samples, n_features = X.shape[0], X.shape[1]
# As in SGD, the alpha is scaled by n_samples.
alpha_scaled = float(alpha) / n_samples
beta_scaled = float(beta) / n_samples
# if loss == 'multinomial', y should be label encoded.
n_classes = int(y.max()) + 1 if loss == 'multinomial' else 1
# initialization
if sample_weight is None:
sample_weight = np.ones(n_samples, dtype=np.float64, order='C')
if 'coef' in warm_start_mem.keys():
coef_init = warm_start_mem['coef']
else:
# assume fit_intercept is False
coef_init = np.zeros((n_features, n_classes), dtype=np.float64,
order='C')
# coef_init contains possibly the intercept_init at the end.
# Note that Ridge centers the data before fitting, so fit_intercept=False.
fit_intercept = coef_init.shape[0] == (n_features + 1)
if fit_intercept:
intercept_init = coef_init[-1, :]
coef_init = coef_init[:-1, :]
else:
intercept_init = np.zeros(n_classes, dtype=np.float64)
if 'intercept_sum_gradient' in warm_start_mem.keys():
intercept_sum_gradient = warm_start_mem['intercept_sum_gradient']
else:
intercept_sum_gradient = np.zeros(n_classes, dtype=np.float64)
if 'gradient_memory' in warm_start_mem.keys():
gradient_memory_init = warm_start_mem['gradient_memory']
else:
gradient_memory_init = np.zeros((n_samples, n_classes),
dtype=np.float64, order='C')
if 'sum_gradient' in warm_start_mem.keys():
sum_gradient_init = warm_start_mem['sum_gradient']
else:
sum_gradient_init = np.zeros((n_features, n_classes),
dtype=np.float64, order='C')
if 'seen' in warm_start_mem.keys():
seen_init = warm_start_mem['seen']
else:
seen_init = np.zeros(n_samples, dtype=np.int32, order='C')
if 'num_seen' in warm_start_mem.keys():
num_seen_init = warm_start_mem['num_seen']
else:
num_seen_init = 0
dataset, intercept_decay = make_dataset(X, y, sample_weight, random_state)
if max_squared_sum is None:
max_squared_sum = row_norms(X, squared=True).max()
step_size = get_auto_step_size(max_squared_sum, alpha_scaled, loss,
fit_intercept, n_samples=n_samples,
is_saga=is_saga)
if step_size * alpha_scaled == 1:
raise ZeroDivisionError("Current sag implementation does not handle "
"the case step_size * alpha_scaled == 1")
num_seen, n_iter_ = sag(dataset, coef_init,
intercept_init, n_samples,
n_features, n_classes, tol,
max_iter,
loss,
step_size, alpha_scaled,
beta_scaled,
sum_gradient_init,
gradient_memory_init,
seen_init,
num_seen_init,
fit_intercept,
intercept_sum_gradient,
intercept_decay,
is_saga,
verbose)
if n_iter_ == max_iter:
warnings.warn("The max_iter was reached which means "
"the coef_ did not converge", ConvergenceWarning)
if fit_intercept:
coef_init = np.vstack((coef_init, intercept_init))
warm_start_mem = {'coef': coef_init, 'sum_gradient': sum_gradient_init,
'intercept_sum_gradient': intercept_sum_gradient,
'gradient_memory': gradient_memory_init,
'seen': seen_init, 'num_seen': num_seen}
if loss == 'multinomial':
coef_ = coef_init.T
else:
coef_ = coef_init[:, 0]
return coef_, n_iter_, warm_start_mem
| 12,959 | 36.894737 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/coordinate_descent.py | # Author: Alexandre Gramfort <[email protected]>
# Fabian Pedregosa <[email protected]>
# Olivier Grisel <[email protected]>
# Gael Varoquaux <[email protected]>
#
# License: BSD 3 clause
import sys
import warnings
from abc import ABCMeta, abstractmethod
import numpy as np
from scipy import sparse
from .base import LinearModel, _pre_fit
from ..base import RegressorMixin
from .base import _preprocess_data
from ..utils import check_array, check_X_y
from ..utils.validation import check_random_state
from ..model_selection import check_cv
from ..externals.joblib import Parallel, delayed
from ..externals import six
from ..externals.six.moves import xrange
from ..utils.extmath import safe_sparse_dot
from ..utils.validation import check_is_fitted
from ..utils.validation import column_or_1d
from ..exceptions import ConvergenceWarning
from . import cd_fast
###############################################################################
# Paths functions
def _alpha_grid(X, y, Xy=None, l1_ratio=1.0, fit_intercept=True,
eps=1e-3, n_alphas=100, normalize=False, copy_X=True):
""" Compute the grid of alpha values for elastic net parameter search
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data. Pass directly as Fortran-contiguous data to avoid
unnecessary memory duplication
y : ndarray, shape (n_samples,)
Target values
Xy : array-like, optional
Xy = np.dot(X.T, y) that can be precomputed.
l1_ratio : float
The elastic net mixing parameter, with ``0 < l1_ratio <= 1``.
For ``l1_ratio = 0`` the penalty is an L2 penalty. (currently not
supported) ``For l1_ratio = 1`` it is an L1 penalty. For
``0 < l1_ratio <1``, the penalty is a combination of L1 and L2.
eps : float, optional
Length of the path. ``eps=1e-3`` means that
``alpha_min / alpha_max = 1e-3``
n_alphas : int, optional
Number of alphas along the regularization path
fit_intercept : boolean, default True
Whether to fit an intercept or not
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
copy_X : boolean, optional, default True
If ``True``, X will be copied; else, it may be overwritten.
"""
if l1_ratio == 0:
raise ValueError("Automatic alpha grid generation is not supported for"
" l1_ratio=0. Please supply a grid by providing "
"your estimator with the appropriate `alphas=` "
"argument.")
n_samples = len(y)
sparse_center = False
if Xy is None:
X_sparse = sparse.isspmatrix(X)
sparse_center = X_sparse and (fit_intercept or normalize)
X = check_array(X, 'csc',
copy=(copy_X and fit_intercept and not X_sparse))
if not X_sparse:
# X can be touched inplace thanks to the above line
X, y, _, _, _ = _preprocess_data(X, y, fit_intercept,
normalize, copy=False)
Xy = safe_sparse_dot(X.T, y, dense_output=True)
if sparse_center:
# Workaround to find alpha_max for sparse matrices.
# since we should not destroy the sparsity of such matrices.
_, _, X_offset, _, X_scale = _preprocess_data(X, y, fit_intercept,
normalize,
return_mean=True)
mean_dot = X_offset * np.sum(y)
if Xy.ndim == 1:
Xy = Xy[:, np.newaxis]
if sparse_center:
if fit_intercept:
Xy -= mean_dot[:, np.newaxis]
if normalize:
Xy /= X_scale[:, np.newaxis]
alpha_max = (np.sqrt(np.sum(Xy ** 2, axis=1)).max() /
(n_samples * l1_ratio))
if alpha_max <= np.finfo(float).resolution:
alphas = np.empty(n_alphas)
alphas.fill(np.finfo(float).resolution)
return alphas
return np.logspace(np.log10(alpha_max * eps), np.log10(alpha_max),
num=n_alphas)[::-1]
def lasso_path(X, y, eps=1e-3, n_alphas=100, alphas=None,
precompute='auto', Xy=None, copy_X=True, coef_init=None,
verbose=False, return_n_iter=False, positive=False, **params):
"""Compute Lasso path with coordinate descent
The Lasso optimization function varies for mono and multi-outputs.
For mono-output tasks it is::
(1 / (2 * n_samples)) * ||y - Xw||^2_2 + alpha * ||w||_1
For multi-output tasks it is::
(1 / (2 * n_samples)) * ||Y - XW||^2_Fro + alpha * ||W||_21
Where::
||W||_21 = \sum_i \sqrt{\sum_j w_{ij}^2}
i.e. the sum of norm of each row.
Read more in the :ref:`User Guide <lasso>`.
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data. Pass directly as Fortran-contiguous data to avoid
unnecessary memory duplication. If ``y`` is mono-output then ``X``
can be sparse.
y : ndarray, shape (n_samples,), or (n_samples, n_outputs)
Target values
eps : float, optional
Length of the path. ``eps=1e-3`` means that
``alpha_min / alpha_max = 1e-3``
n_alphas : int, optional
Number of alphas along the regularization path
alphas : ndarray, optional
List of alphas where to compute the models.
If ``None`` alphas are set automatically
precompute : True | False | 'auto' | array-like
Whether to use a precomputed Gram matrix to speed up
calculations. If set to ``'auto'`` let us decide. The Gram
matrix can also be passed as argument.
Xy : array-like, optional
Xy = np.dot(X.T, y) that can be precomputed. It is useful
only when the Gram matrix is precomputed.
copy_X : boolean, optional, default True
If ``True``, X will be copied; else, it may be overwritten.
coef_init : array, shape (n_features, ) | None
The initial values of the coefficients.
verbose : bool or integer
Amount of verbosity.
return_n_iter : bool
whether to return the number of iterations or not.
positive : bool, default False
If set to True, forces coefficients to be positive.
(Only allowed when ``y.ndim == 1``).
**params : kwargs
keyword arguments passed to the coordinate descent solver.
Returns
-------
alphas : array, shape (n_alphas,)
The alphas along the path where models are computed.
coefs : array, shape (n_features, n_alphas) or \
(n_outputs, n_features, n_alphas)
Coefficients along the path.
dual_gaps : array, shape (n_alphas,)
The dual gaps at the end of the optimization for each alpha.
n_iters : array-like, shape (n_alphas,)
The number of iterations taken by the coordinate descent optimizer to
reach the specified tolerance for each alpha.
Notes
-----
For an example, see
:ref:`examples/linear_model/plot_lasso_coordinate_descent_path.py
<sphx_glr_auto_examples_linear_model_plot_lasso_coordinate_descent_path.py>`.
To avoid unnecessary memory duplication the X argument of the fit method
should be directly passed as a Fortran-contiguous numpy array.
Note that in certain cases, the Lars solver may be significantly
faster to implement this functionality. In particular, linear
interpolation can be used to retrieve model coefficients between the
values output by lars_path
Examples
---------
Comparing lasso_path and lars_path with interpolation:
>>> X = np.array([[1, 2, 3.1], [2.3, 5.4, 4.3]]).T
>>> y = np.array([1, 2, 3.1])
>>> # Use lasso_path to compute a coefficient path
>>> _, coef_path, _ = lasso_path(X, y, alphas=[5., 1., .5])
>>> print(coef_path)
[[ 0. 0. 0.46874778]
[ 0.2159048 0.4425765 0.23689075]]
>>> # Now use lars_path and 1D linear interpolation to compute the
>>> # same path
>>> from sklearn.linear_model import lars_path
>>> alphas, active, coef_path_lars = lars_path(X, y, method='lasso')
>>> from scipy import interpolate
>>> coef_path_continuous = interpolate.interp1d(alphas[::-1],
... coef_path_lars[:, ::-1])
>>> print(coef_path_continuous([5., 1., .5]))
[[ 0. 0. 0.46915237]
[ 0.2159048 0.4425765 0.23668876]]
See also
--------
lars_path
Lasso
LassoLars
LassoCV
LassoLarsCV
sklearn.decomposition.sparse_encode
"""
return enet_path(X, y, l1_ratio=1., eps=eps, n_alphas=n_alphas,
alphas=alphas, precompute=precompute, Xy=Xy,
copy_X=copy_X, coef_init=coef_init, verbose=verbose,
positive=positive, return_n_iter=return_n_iter, **params)
def enet_path(X, y, l1_ratio=0.5, eps=1e-3, n_alphas=100, alphas=None,
precompute='auto', Xy=None, copy_X=True, coef_init=None,
verbose=False, return_n_iter=False, positive=False,
check_input=True, **params):
"""Compute elastic net path with coordinate descent
The elastic net optimization function varies for mono and multi-outputs.
For mono-output tasks it is::
1 / (2 * n_samples) * ||y - Xw||^2_2
+ alpha * l1_ratio * ||w||_1
+ 0.5 * alpha * (1 - l1_ratio) * ||w||^2_2
For multi-output tasks it is::
(1 / (2 * n_samples)) * ||Y - XW||^Fro_2
+ alpha * l1_ratio * ||W||_21
+ 0.5 * alpha * (1 - l1_ratio) * ||W||_Fro^2
Where::
||W||_21 = \sum_i \sqrt{\sum_j w_{ij}^2}
i.e. the sum of norm of each row.
Read more in the :ref:`User Guide <elastic_net>`.
Parameters
----------
X : {array-like}, shape (n_samples, n_features)
Training data. Pass directly as Fortran-contiguous data to avoid
unnecessary memory duplication. If ``y`` is mono-output then ``X``
can be sparse.
y : ndarray, shape (n_samples,) or (n_samples, n_outputs)
Target values
l1_ratio : float, optional
float between 0 and 1 passed to elastic net (scaling between
l1 and l2 penalties). ``l1_ratio=1`` corresponds to the Lasso
eps : float
Length of the path. ``eps=1e-3`` means that
``alpha_min / alpha_max = 1e-3``
n_alphas : int, optional
Number of alphas along the regularization path
alphas : ndarray, optional
List of alphas where to compute the models.
If None alphas are set automatically
precompute : True | False | 'auto' | array-like
Whether to use a precomputed Gram matrix to speed up
calculations. If set to ``'auto'`` let us decide. The Gram
matrix can also be passed as argument.
Xy : array-like, optional
Xy = np.dot(X.T, y) that can be precomputed. It is useful
only when the Gram matrix is precomputed.
copy_X : boolean, optional, default True
If ``True``, X will be copied; else, it may be overwritten.
coef_init : array, shape (n_features, ) | None
The initial values of the coefficients.
verbose : bool or integer
Amount of verbosity.
return_n_iter : bool
whether to return the number of iterations or not.
positive : bool, default False
If set to True, forces coefficients to be positive.
(Only allowed when ``y.ndim == 1``).
check_input : bool, default True
Skip input validation checks, including the Gram matrix when provided
assuming there are handled by the caller when check_input=False.
**params : kwargs
keyword arguments passed to the coordinate descent solver.
Returns
-------
alphas : array, shape (n_alphas,)
The alphas along the path where models are computed.
coefs : array, shape (n_features, n_alphas) or \
(n_outputs, n_features, n_alphas)
Coefficients along the path.
dual_gaps : array, shape (n_alphas,)
The dual gaps at the end of the optimization for each alpha.
n_iters : array-like, shape (n_alphas,)
The number of iterations taken by the coordinate descent optimizer to
reach the specified tolerance for each alpha.
(Is returned when ``return_n_iter`` is set to True).
Notes
-----
For an example, see
:ref:`examples/linear_model/plot_lasso_coordinate_descent_path.py
<sphx_glr_auto_examples_linear_model_plot_lasso_coordinate_descent_path.py>`.
See also
--------
MultiTaskElasticNet
MultiTaskElasticNetCV
ElasticNet
ElasticNetCV
"""
# We expect X and y to be already Fortran ordered when bypassing
# checks
if check_input:
X = check_array(X, 'csc', dtype=[np.float64, np.float32],
order='F', copy=copy_X)
y = check_array(y, 'csc', dtype=X.dtype.type, order='F', copy=False,
ensure_2d=False)
if Xy is not None:
# Xy should be a 1d contiguous array or a 2D C ordered array
Xy = check_array(Xy, dtype=X.dtype.type, order='C', copy=False,
ensure_2d=False)
n_samples, n_features = X.shape
multi_output = False
if y.ndim != 1:
multi_output = True
_, n_outputs = y.shape
if multi_output and positive:
raise ValueError('positive=True is not allowed for multi-output'
' (y.ndim != 1)')
# MultiTaskElasticNet does not support sparse matrices
if not multi_output and sparse.isspmatrix(X):
if 'X_offset' in params:
# As sparse matrices are not actually centered we need this
# to be passed to the CD solver.
X_sparse_scaling = params['X_offset'] / params['X_scale']
X_sparse_scaling = np.asarray(X_sparse_scaling, dtype=X.dtype)
else:
X_sparse_scaling = np.zeros(n_features, dtype=X.dtype)
# X should be normalized and fit already if function is called
# from ElasticNet.fit
if check_input:
X, y, X_offset, y_offset, X_scale, precompute, Xy = \
_pre_fit(X, y, Xy, precompute, normalize=False,
fit_intercept=False, copy=False)
if alphas is None:
# No need to normalize of fit_intercept: it has been done
# above
alphas = _alpha_grid(X, y, Xy=Xy, l1_ratio=l1_ratio,
fit_intercept=False, eps=eps, n_alphas=n_alphas,
normalize=False, copy_X=False)
else:
alphas = np.sort(alphas)[::-1] # make sure alphas are properly ordered
n_alphas = len(alphas)
tol = params.get('tol', 1e-4)
max_iter = params.get('max_iter', 1000)
dual_gaps = np.empty(n_alphas)
n_iters = []
rng = check_random_state(params.get('random_state', None))
selection = params.get('selection', 'cyclic')
if selection not in ['random', 'cyclic']:
raise ValueError("selection should be either random or cyclic.")
random = (selection == 'random')
if not multi_output:
coefs = np.empty((n_features, n_alphas), dtype=X.dtype)
else:
coefs = np.empty((n_outputs, n_features, n_alphas),
dtype=X.dtype)
if coef_init is None:
coef_ = np.asfortranarray(np.zeros(coefs.shape[:-1], dtype=X.dtype))
else:
coef_ = np.asfortranarray(coef_init, dtype=X.dtype)
for i, alpha in enumerate(alphas):
l1_reg = alpha * l1_ratio * n_samples
l2_reg = alpha * (1.0 - l1_ratio) * n_samples
if not multi_output and sparse.isspmatrix(X):
model = cd_fast.sparse_enet_coordinate_descent(
coef_, l1_reg, l2_reg, X.data, X.indices,
X.indptr, y, X_sparse_scaling,
max_iter, tol, rng, random, positive)
elif multi_output:
model = cd_fast.enet_coordinate_descent_multi_task(
coef_, l1_reg, l2_reg, X, y, max_iter, tol, rng, random)
elif isinstance(precompute, np.ndarray):
# We expect precompute to be already Fortran ordered when bypassing
# checks
if check_input:
precompute = check_array(precompute, dtype=X.dtype.type,
order='C')
model = cd_fast.enet_coordinate_descent_gram(
coef_, l1_reg, l2_reg, precompute, Xy, y, max_iter,
tol, rng, random, positive)
elif precompute is False:
model = cd_fast.enet_coordinate_descent(
coef_, l1_reg, l2_reg, X, y, max_iter, tol, rng, random,
positive)
else:
raise ValueError("Precompute should be one of True, False, "
"'auto' or array-like. Got %r" % precompute)
coef_, dual_gap_, eps_, n_iter_ = model
coefs[..., i] = coef_
dual_gaps[i] = dual_gap_
n_iters.append(n_iter_)
if dual_gap_ > eps_:
warnings.warn('Objective did not converge.' +
' You might want' +
' to increase the number of iterations.' +
' Fitting data with very small alpha' +
' may cause precision problems.',
ConvergenceWarning)
if verbose:
if verbose > 2:
print(model)
elif verbose > 1:
print('Path: %03i out of %03i' % (i, n_alphas))
else:
sys.stderr.write('.')
if return_n_iter:
return alphas, coefs, dual_gaps, n_iters
return alphas, coefs, dual_gaps
###############################################################################
# ElasticNet model
class ElasticNet(LinearModel, RegressorMixin):
"""Linear regression with combined L1 and L2 priors as regularizer.
Minimizes the objective function::
1 / (2 * n_samples) * ||y - Xw||^2_2
+ alpha * l1_ratio * ||w||_1
+ 0.5 * alpha * (1 - l1_ratio) * ||w||^2_2
If you are interested in controlling the L1 and L2 penalty
separately, keep in mind that this is equivalent to::
a * L1 + b * L2
where::
alpha = a + b and l1_ratio = a / (a + b)
The parameter l1_ratio corresponds to alpha in the glmnet R package while
alpha corresponds to the lambda parameter in glmnet. Specifically, l1_ratio
= 1 is the lasso penalty. Currently, l1_ratio <= 0.01 is not reliable,
unless you supply your own sequence of alpha.
Read more in the :ref:`User Guide <elastic_net>`.
Parameters
----------
alpha : float, optional
Constant that multiplies the penalty terms. Defaults to 1.0.
See the notes for the exact mathematical meaning of this
parameter.``alpha = 0`` is equivalent to an ordinary least square,
solved by the :class:`LinearRegression` object. For numerical
reasons, using ``alpha = 0`` with the ``Lasso`` object is not advised.
Given this, you should use the :class:`LinearRegression` object.
l1_ratio : float
The ElasticNet mixing parameter, with ``0 <= l1_ratio <= 1``. For
``l1_ratio = 0`` the penalty is an L2 penalty. ``For l1_ratio = 1`` it
is an L1 penalty. For ``0 < l1_ratio < 1``, the penalty is a
combination of L1 and L2.
fit_intercept : bool
Whether the intercept should be estimated or not. If ``False``, the
data is assumed to be already centered.
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
precompute : True | False | array-like
Whether to use a precomputed Gram matrix to speed up
calculations. The Gram matrix can also be passed as argument.
For sparse input this option is always ``True`` to preserve sparsity.
max_iter : int, optional
The maximum number of iterations
copy_X : boolean, optional, default True
If ``True``, X will be copied; else, it may be overwritten.
tol : float, optional
The tolerance for the optimization: if the updates are
smaller than ``tol``, the optimization code checks the
dual gap for optimality and continues until it is smaller
than ``tol``.
warm_start : bool, optional
When set to ``True``, reuse the solution of the previous call to fit as
initialization, otherwise, just erase the previous solution.
positive : bool, optional
When set to ``True``, forces the coefficients to be positive.
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator that selects a random
feature to update. If int, random_state is the seed used by the random
number generator; If RandomState instance, random_state is the random
number generator; If None, the random number generator is the
RandomState instance used by `np.random`. Used when ``selection`` ==
'random'.
selection : str, default 'cyclic'
If set to 'random', a random coefficient is updated every iteration
rather than looping over features sequentially by default. This
(setting to 'random') often leads to significantly faster convergence
especially when tol is higher than 1e-4.
Attributes
----------
coef_ : array, shape (n_features,) | (n_targets, n_features)
parameter vector (w in the cost function formula)
sparse_coef_ : scipy.sparse matrix, shape (n_features, 1) | \
(n_targets, n_features)
``sparse_coef_`` is a readonly property derived from ``coef_``
intercept_ : float | array, shape (n_targets,)
independent term in decision function.
n_iter_ : array-like, shape (n_targets,)
number of iterations run by the coordinate descent solver to reach
the specified tolerance.
Examples
--------
>>> from sklearn.linear_model import ElasticNet
>>> from sklearn.datasets import make_regression
>>>
>>> X, y = make_regression(n_features=2, random_state=0)
>>> regr = ElasticNet(random_state=0)
>>> regr.fit(X, y)
ElasticNet(alpha=1.0, copy_X=True, fit_intercept=True, l1_ratio=0.5,
max_iter=1000, normalize=False, positive=False, precompute=False,
random_state=0, selection='cyclic', tol=0.0001, warm_start=False)
>>> print(regr.coef_) # doctest: +ELLIPSIS
[ 18.83816048 64.55968825]
>>> print(regr.intercept_) # doctest: +ELLIPSIS
1.45126075617
>>> print(regr.predict([[0, 0]])) # doctest: +ELLIPSIS
[ 1.45126076]
Notes
-----
To avoid unnecessary memory duplication the X argument of the fit method
should be directly passed as a Fortran-contiguous numpy array.
See also
--------
SGDRegressor: implements elastic net regression with incremental training.
SGDClassifier: implements logistic regression with elastic net penalty
(``SGDClassifier(loss="log", penalty="elasticnet")``).
"""
path = staticmethod(enet_path)
def __init__(self, alpha=1.0, l1_ratio=0.5, fit_intercept=True,
normalize=False, precompute=False, max_iter=1000,
copy_X=True, tol=1e-4, warm_start=False, positive=False,
random_state=None, selection='cyclic'):
self.alpha = alpha
self.l1_ratio = l1_ratio
self.fit_intercept = fit_intercept
self.normalize = normalize
self.precompute = precompute
self.max_iter = max_iter
self.copy_X = copy_X
self.tol = tol
self.warm_start = warm_start
self.positive = positive
self.random_state = random_state
self.selection = selection
def fit(self, X, y, check_input=True):
"""Fit model with coordinate descent.
Parameters
-----------
X : ndarray or scipy.sparse matrix, (n_samples, n_features)
Data
y : ndarray, shape (n_samples,) or (n_samples, n_targets)
Target. Will be cast to X's dtype if necessary
check_input : boolean, (default=True)
Allow to bypass several input checking.
Don't use this parameter unless you know what you do.
Notes
-----
Coordinate descent is an algorithm that considers each column of
data at a time hence it will automatically convert the X input
as a Fortran-contiguous numpy array if necessary.
To avoid memory re-allocation it is advised to allocate the
initial data in memory directly using that format.
"""
if self.alpha == 0:
warnings.warn("With alpha=0, this algorithm does not converge "
"well. You are advised to use the LinearRegression "
"estimator", stacklevel=2)
if isinstance(self.precompute, six.string_types):
raise ValueError('precompute should be one of True, False or'
' array-like. Got %r' % self.precompute)
# We expect X and y to be float64 or float32 Fortran ordered arrays
# when bypassing checks
if check_input:
X, y = check_X_y(X, y, accept_sparse='csc',
order='F', dtype=[np.float64, np.float32],
copy=self.copy_X and self.fit_intercept,
multi_output=True, y_numeric=True)
y = check_array(y, order='F', copy=False, dtype=X.dtype.type,
ensure_2d=False)
X, y, X_offset, y_offset, X_scale, precompute, Xy = \
_pre_fit(X, y, None, self.precompute, self.normalize,
self.fit_intercept, copy=False)
if y.ndim == 1:
y = y[:, np.newaxis]
if Xy is not None and Xy.ndim == 1:
Xy = Xy[:, np.newaxis]
n_samples, n_features = X.shape
n_targets = y.shape[1]
if self.selection not in ['cyclic', 'random']:
raise ValueError("selection should be either random or cyclic.")
if not self.warm_start or not hasattr(self, "coef_"):
coef_ = np.zeros((n_targets, n_features), dtype=X.dtype,
order='F')
else:
coef_ = self.coef_
if coef_.ndim == 1:
coef_ = coef_[np.newaxis, :]
dual_gaps_ = np.zeros(n_targets, dtype=X.dtype)
self.n_iter_ = []
for k in xrange(n_targets):
if Xy is not None:
this_Xy = Xy[:, k]
else:
this_Xy = None
_, this_coef, this_dual_gap, this_iter = \
self.path(X, y[:, k],
l1_ratio=self.l1_ratio, eps=None,
n_alphas=None, alphas=[self.alpha],
precompute=precompute, Xy=this_Xy,
fit_intercept=False, normalize=False, copy_X=True,
verbose=False, tol=self.tol, positive=self.positive,
X_offset=X_offset, X_scale=X_scale, return_n_iter=True,
coef_init=coef_[k], max_iter=self.max_iter,
random_state=self.random_state,
selection=self.selection,
check_input=False)
coef_[k] = this_coef[:, 0]
dual_gaps_[k] = this_dual_gap[0]
self.n_iter_.append(this_iter[0])
if n_targets == 1:
self.n_iter_ = self.n_iter_[0]
self.coef_, self.dual_gap_ = map(np.squeeze, [coef_, dual_gaps_])
self._set_intercept(X_offset, y_offset, X_scale)
# workaround since _set_intercept will cast self.coef_ into X.dtype
self.coef_ = np.asarray(self.coef_, dtype=X.dtype)
# return self for chaining fit and predict calls
return self
@property
def sparse_coef_(self):
""" sparse representation of the fitted ``coef_`` """
return sparse.csr_matrix(self.coef_)
def _decision_function(self, X):
"""Decision function of the linear model
Parameters
----------
X : numpy array or scipy.sparse matrix of shape (n_samples, n_features)
Returns
-------
T : array, shape (n_samples,)
The predicted decision function
"""
check_is_fitted(self, 'n_iter_')
if sparse.isspmatrix(X):
return safe_sparse_dot(X, self.coef_.T,
dense_output=True) + self.intercept_
else:
return super(ElasticNet, self)._decision_function(X)
###############################################################################
# Lasso model
class Lasso(ElasticNet):
"""Linear Model trained with L1 prior as regularizer (aka the Lasso)
The optimization objective for Lasso is::
(1 / (2 * n_samples)) * ||y - Xw||^2_2 + alpha * ||w||_1
Technically the Lasso model is optimizing the same objective function as
the Elastic Net with ``l1_ratio=1.0`` (no L2 penalty).
Read more in the :ref:`User Guide <lasso>`.
Parameters
----------
alpha : float, optional
Constant that multiplies the L1 term. Defaults to 1.0.
``alpha = 0`` is equivalent to an ordinary least square, solved
by the :class:`LinearRegression` object. For numerical
reasons, using ``alpha = 0`` with the ``Lasso`` object is not advised.
Given this, you should use the :class:`LinearRegression` object.
fit_intercept : boolean
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
precompute : True | False | array-like, default=False
Whether to use a precomputed Gram matrix to speed up
calculations. If set to ``'auto'`` let us decide. The Gram
matrix can also be passed as argument. For sparse input
this option is always ``True`` to preserve sparsity.
copy_X : boolean, optional, default True
If ``True``, X will be copied; else, it may be overwritten.
max_iter : int, optional
The maximum number of iterations
tol : float, optional
The tolerance for the optimization: if the updates are
smaller than ``tol``, the optimization code checks the
dual gap for optimality and continues until it is smaller
than ``tol``.
warm_start : bool, optional
When set to True, reuse the solution of the previous call to fit as
initialization, otherwise, just erase the previous solution.
positive : bool, optional
When set to ``True``, forces the coefficients to be positive.
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator that selects a random
feature to update. If int, random_state is the seed used by the random
number generator; If RandomState instance, random_state is the random
number generator; If None, the random number generator is the
RandomState instance used by `np.random`. Used when ``selection`` ==
'random'.
selection : str, default 'cyclic'
If set to 'random', a random coefficient is updated every iteration
rather than looping over features sequentially by default. This
(setting to 'random') often leads to significantly faster convergence
especially when tol is higher than 1e-4.
Attributes
----------
coef_ : array, shape (n_features,) | (n_targets, n_features)
parameter vector (w in the cost function formula)
sparse_coef_ : scipy.sparse matrix, shape (n_features, 1) | \
(n_targets, n_features)
``sparse_coef_`` is a readonly property derived from ``coef_``
intercept_ : float | array, shape (n_targets,)
independent term in decision function.
n_iter_ : int | array-like, shape (n_targets,)
number of iterations run by the coordinate descent solver to reach
the specified tolerance.
Examples
--------
>>> from sklearn import linear_model
>>> clf = linear_model.Lasso(alpha=0.1)
>>> clf.fit([[0,0], [1, 1], [2, 2]], [0, 1, 2])
Lasso(alpha=0.1, copy_X=True, fit_intercept=True, max_iter=1000,
normalize=False, positive=False, precompute=False, random_state=None,
selection='cyclic', tol=0.0001, warm_start=False)
>>> print(clf.coef_)
[ 0.85 0. ]
>>> print(clf.intercept_)
0.15
See also
--------
lars_path
lasso_path
LassoLars
LassoCV
LassoLarsCV
sklearn.decomposition.sparse_encode
Notes
-----
The algorithm used to fit the model is coordinate descent.
To avoid unnecessary memory duplication the X argument of the fit method
should be directly passed as a Fortran-contiguous numpy array.
"""
path = staticmethod(enet_path)
def __init__(self, alpha=1.0, fit_intercept=True, normalize=False,
precompute=False, copy_X=True, max_iter=1000,
tol=1e-4, warm_start=False, positive=False,
random_state=None, selection='cyclic'):
super(Lasso, self).__init__(
alpha=alpha, l1_ratio=1.0, fit_intercept=fit_intercept,
normalize=normalize, precompute=precompute, copy_X=copy_X,
max_iter=max_iter, tol=tol, warm_start=warm_start,
positive=positive, random_state=random_state,
selection=selection)
###############################################################################
# Functions for CV with paths functions
def _path_residuals(X, y, train, test, path, path_params, alphas=None,
l1_ratio=1, X_order=None, dtype=None):
"""Returns the MSE for the models computed by 'path'
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data.
y : array-like, shape (n_samples,) or (n_samples, n_targets)
Target values
train : list of indices
The indices of the train set
test : list of indices
The indices of the test set
path : callable
function returning a list of models on the path. See
enet_path for an example of signature
path_params : dictionary
Parameters passed to the path function
alphas : array-like, optional
Array of float that is used for cross-validation. If not
provided, computed using 'path'
l1_ratio : float, optional
float between 0 and 1 passed to ElasticNet (scaling between
l1 and l2 penalties). For ``l1_ratio = 0`` the penalty is an
L2 penalty. For ``l1_ratio = 1`` it is an L1 penalty. For ``0
< l1_ratio < 1``, the penalty is a combination of L1 and L2
X_order : {'F', 'C', or None}, optional
The order of the arrays expected by the path function to
avoid memory copies
dtype : a numpy dtype or None
The dtype of the arrays expected by the path function to
avoid memory copies
"""
X_train = X[train]
y_train = y[train]
X_test = X[test]
y_test = y[test]
fit_intercept = path_params['fit_intercept']
normalize = path_params['normalize']
if y.ndim == 1:
precompute = path_params['precompute']
else:
# No Gram variant of multi-task exists right now.
# Fall back to default enet_multitask
precompute = False
X_train, y_train, X_offset, y_offset, X_scale, precompute, Xy = \
_pre_fit(X_train, y_train, None, precompute, normalize, fit_intercept,
copy=False)
path_params = path_params.copy()
path_params['Xy'] = Xy
path_params['X_offset'] = X_offset
path_params['X_scale'] = X_scale
path_params['precompute'] = precompute
path_params['copy_X'] = False
path_params['alphas'] = alphas
if 'l1_ratio' in path_params:
path_params['l1_ratio'] = l1_ratio
# Do the ordering and type casting here, as if it is done in the path,
# X is copied and a reference is kept here
X_train = check_array(X_train, 'csc', dtype=dtype, order=X_order)
alphas, coefs, _ = path(X_train, y_train, **path_params)
del X_train, y_train
if y.ndim == 1:
# Doing this so that it becomes coherent with multioutput.
coefs = coefs[np.newaxis, :, :]
y_offset = np.atleast_1d(y_offset)
y_test = y_test[:, np.newaxis]
if normalize:
nonzeros = np.flatnonzero(X_scale)
coefs[:, nonzeros] /= X_scale[nonzeros][:, np.newaxis]
intercepts = y_offset[:, np.newaxis] - np.dot(X_offset, coefs)
if sparse.issparse(X_test):
n_order, n_features, n_alphas = coefs.shape
# Work around for sparse matrices since coefs is a 3-D numpy array.
coefs_feature_major = np.rollaxis(coefs, 1)
feature_2d = np.reshape(coefs_feature_major, (n_features, -1))
X_test_coefs = safe_sparse_dot(X_test, feature_2d)
X_test_coefs = X_test_coefs.reshape(X_test.shape[0], n_order, -1)
else:
X_test_coefs = safe_sparse_dot(X_test, coefs)
residues = X_test_coefs - y_test[:, :, np.newaxis]
residues += intercepts
this_mses = ((residues ** 2).mean(axis=0)).mean(axis=0)
return this_mses
class LinearModelCV(six.with_metaclass(ABCMeta, LinearModel)):
"""Base class for iterative model fitting along a regularization path"""
@abstractmethod
def __init__(self, eps=1e-3, n_alphas=100, alphas=None, fit_intercept=True,
normalize=False, precompute='auto', max_iter=1000, tol=1e-4,
copy_X=True, cv=None, verbose=False, n_jobs=1,
positive=False, random_state=None, selection='cyclic'):
self.eps = eps
self.n_alphas = n_alphas
self.alphas = alphas
self.fit_intercept = fit_intercept
self.normalize = normalize
self.precompute = precompute
self.max_iter = max_iter
self.tol = tol
self.copy_X = copy_X
self.cv = cv
self.verbose = verbose
self.n_jobs = n_jobs
self.positive = positive
self.random_state = random_state
self.selection = selection
def fit(self, X, y):
"""Fit linear model with coordinate descent
Fit is on grid of alphas and best alpha estimated by cross-validation.
Parameters
----------
X : {array-like}, shape (n_samples, n_features)
Training data. Pass directly as Fortran-contiguous data
to avoid unnecessary memory duplication. If y is mono-output,
X can be sparse.
y : array-like, shape (n_samples,) or (n_samples, n_targets)
Target values
"""
y = check_array(y, copy=False, dtype=[np.float64, np.float32],
ensure_2d=False)
if y.shape[0] == 0:
raise ValueError("y has 0 samples: %r" % y)
if hasattr(self, 'l1_ratio'):
model_str = 'ElasticNet'
else:
model_str = 'Lasso'
if isinstance(self, ElasticNetCV) or isinstance(self, LassoCV):
if model_str == 'ElasticNet':
model = ElasticNet()
else:
model = Lasso()
if y.ndim > 1 and y.shape[1] > 1:
raise ValueError("For multi-task outputs, use "
"MultiTask%sCV" % (model_str))
y = column_or_1d(y, warn=True)
else:
if sparse.isspmatrix(X):
raise TypeError("X should be dense but a sparse matrix was"
"passed")
elif y.ndim == 1:
raise ValueError("For mono-task outputs, use "
"%sCV" % (model_str))
if model_str == 'ElasticNet':
model = MultiTaskElasticNet()
else:
model = MultiTaskLasso()
if self.selection not in ["random", "cyclic"]:
raise ValueError("selection should be either random or cyclic.")
# This makes sure that there is no duplication in memory.
# Dealing right with copy_X is important in the following:
# Multiple functions touch X and subsamples of X and can induce a
# lot of duplication of memory
copy_X = self.copy_X and self.fit_intercept
if isinstance(X, np.ndarray) or sparse.isspmatrix(X):
# Keep a reference to X
reference_to_old_X = X
# Let us not impose fortran ordering so far: it is
# not useful for the cross-validation loop and will be done
# by the model fitting itself
X = check_array(X, 'csc', copy=False)
if sparse.isspmatrix(X):
if (hasattr(reference_to_old_X, "data") and
not np.may_share_memory(reference_to_old_X.data, X.data)):
# X is a sparse matrix and has been copied
copy_X = False
elif not np.may_share_memory(reference_to_old_X, X):
# X has been copied
copy_X = False
del reference_to_old_X
else:
X = check_array(X, 'csc', dtype=[np.float64, np.float32],
order='F', copy=copy_X)
copy_X = False
if X.shape[0] != y.shape[0]:
raise ValueError("X and y have inconsistent dimensions (%d != %d)"
% (X.shape[0], y.shape[0]))
# All LinearModelCV parameters except 'cv' are acceptable
path_params = self.get_params()
if 'l1_ratio' in path_params:
l1_ratios = np.atleast_1d(path_params['l1_ratio'])
# For the first path, we need to set l1_ratio
path_params['l1_ratio'] = l1_ratios[0]
else:
l1_ratios = [1, ]
path_params.pop('cv', None)
path_params.pop('n_jobs', None)
alphas = self.alphas
n_l1_ratio = len(l1_ratios)
if alphas is None:
alphas = []
for l1_ratio in l1_ratios:
alphas.append(_alpha_grid(
X, y, l1_ratio=l1_ratio,
fit_intercept=self.fit_intercept,
eps=self.eps, n_alphas=self.n_alphas,
normalize=self.normalize,
copy_X=self.copy_X))
else:
# Making sure alphas is properly ordered.
alphas = np.tile(np.sort(alphas)[::-1], (n_l1_ratio, 1))
# We want n_alphas to be the number of alphas used for each l1_ratio.
n_alphas = len(alphas[0])
path_params.update({'n_alphas': n_alphas})
path_params['copy_X'] = copy_X
# We are not computing in parallel, we can modify X
# inplace in the folds
if not (self.n_jobs == 1 or self.n_jobs is None):
path_params['copy_X'] = False
# init cross-validation generator
cv = check_cv(self.cv)
# Compute path for all folds and compute MSE to get the best alpha
folds = list(cv.split(X, y))
best_mse = np.inf
# We do a double for loop folded in one, in order to be able to
# iterate in parallel on l1_ratio and folds
jobs = (delayed(_path_residuals)(X, y, train, test, self.path,
path_params, alphas=this_alphas,
l1_ratio=this_l1_ratio, X_order='F',
dtype=X.dtype.type)
for this_l1_ratio, this_alphas in zip(l1_ratios, alphas)
for train, test in folds)
mse_paths = Parallel(n_jobs=self.n_jobs, verbose=self.verbose,
backend="threading")(jobs)
mse_paths = np.reshape(mse_paths, (n_l1_ratio, len(folds), -1))
mean_mse = np.mean(mse_paths, axis=1)
self.mse_path_ = np.squeeze(np.rollaxis(mse_paths, 2, 1))
for l1_ratio, l1_alphas, mse_alphas in zip(l1_ratios, alphas,
mean_mse):
i_best_alpha = np.argmin(mse_alphas)
this_best_mse = mse_alphas[i_best_alpha]
if this_best_mse < best_mse:
best_alpha = l1_alphas[i_best_alpha]
best_l1_ratio = l1_ratio
best_mse = this_best_mse
self.l1_ratio_ = best_l1_ratio
self.alpha_ = best_alpha
if self.alphas is None:
self.alphas_ = np.asarray(alphas)
if n_l1_ratio == 1:
self.alphas_ = self.alphas_[0]
# Remove duplicate alphas in case alphas is provided.
else:
self.alphas_ = np.asarray(alphas[0])
# Refit the model with the parameters selected
common_params = dict((name, value)
for name, value in self.get_params().items()
if name in model.get_params())
model.set_params(**common_params)
model.alpha = best_alpha
model.l1_ratio = best_l1_ratio
model.copy_X = copy_X
model.precompute = False
model.fit(X, y)
if not hasattr(self, 'l1_ratio'):
del self.l1_ratio_
self.coef_ = model.coef_
self.intercept_ = model.intercept_
self.dual_gap_ = model.dual_gap_
self.n_iter_ = model.n_iter_
return self
class LassoCV(LinearModelCV, RegressorMixin):
"""Lasso linear model with iterative fitting along a regularization path
The best model is selected by cross-validation.
The optimization objective for Lasso is::
(1 / (2 * n_samples)) * ||y - Xw||^2_2 + alpha * ||w||_1
Read more in the :ref:`User Guide <lasso>`.
Parameters
----------
eps : float, optional
Length of the path. ``eps=1e-3`` means that
``alpha_min / alpha_max = 1e-3``.
n_alphas : int, optional
Number of alphas along the regularization path
alphas : numpy array, optional
List of alphas where to compute the models.
If ``None`` alphas are set automatically
fit_intercept : boolean, default True
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
precompute : True | False | 'auto' | array-like
Whether to use a precomputed Gram matrix to speed up
calculations. If set to ``'auto'`` let us decide. The Gram
matrix can also be passed as argument.
max_iter : int, optional
The maximum number of iterations
tol : float, optional
The tolerance for the optimization: if the updates are
smaller than ``tol``, the optimization code checks the
dual gap for optimality and continues until it is smaller
than ``tol``.
copy_X : boolean, optional, default True
If ``True``, X will be copied; else, it may be overwritten.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross-validation,
- integer, to specify the number of folds.
- An object to be used as a cross-validation generator.
- An iterable yielding train/test splits.
For integer/None inputs, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
verbose : bool or integer
Amount of verbosity.
n_jobs : integer, optional
Number of CPUs to use during the cross validation. If ``-1``, use
all the CPUs.
positive : bool, optional
If positive, restrict regression coefficients to be positive
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator that selects a random
feature to update. If int, random_state is the seed used by the random
number generator; If RandomState instance, random_state is the random
number generator; If None, the random number generator is the
RandomState instance used by `np.random`. Used when ``selection`` ==
'random'.
selection : str, default 'cyclic'
If set to 'random', a random coefficient is updated every iteration
rather than looping over features sequentially by default. This
(setting to 'random') often leads to significantly faster convergence
especially when tol is higher than 1e-4.
Attributes
----------
alpha_ : float
The amount of penalization chosen by cross validation
coef_ : array, shape (n_features,) | (n_targets, n_features)
parameter vector (w in the cost function formula)
intercept_ : float | array, shape (n_targets,)
independent term in decision function.
mse_path_ : array, shape (n_alphas, n_folds)
mean square error for the test set on each fold, varying alpha
alphas_ : numpy array, shape (n_alphas,)
The grid of alphas used for fitting
dual_gap_ : ndarray, shape ()
The dual gap at the end of the optimization for the optimal alpha
(``alpha_``).
n_iter_ : int
number of iterations run by the coordinate descent solver to reach
the specified tolerance for the optimal alpha.
Notes
-----
For an example, see
:ref:`examples/linear_model/plot_lasso_model_selection.py
<sphx_glr_auto_examples_linear_model_plot_lasso_model_selection.py>`.
To avoid unnecessary memory duplication the X argument of the fit method
should be directly passed as a Fortran-contiguous numpy array.
See also
--------
lars_path
lasso_path
LassoLars
Lasso
LassoLarsCV
"""
path = staticmethod(lasso_path)
def __init__(self, eps=1e-3, n_alphas=100, alphas=None, fit_intercept=True,
normalize=False, precompute='auto', max_iter=1000, tol=1e-4,
copy_X=True, cv=None, verbose=False, n_jobs=1,
positive=False, random_state=None, selection='cyclic'):
super(LassoCV, self).__init__(
eps=eps, n_alphas=n_alphas, alphas=alphas,
fit_intercept=fit_intercept, normalize=normalize,
precompute=precompute, max_iter=max_iter, tol=tol, copy_X=copy_X,
cv=cv, verbose=verbose, n_jobs=n_jobs, positive=positive,
random_state=random_state, selection=selection)
class ElasticNetCV(LinearModelCV, RegressorMixin):
"""Elastic Net model with iterative fitting along a regularization path
The best model is selected by cross-validation.
Read more in the :ref:`User Guide <elastic_net>`.
Parameters
----------
l1_ratio : float or array of floats, optional
float between 0 and 1 passed to ElasticNet (scaling between
l1 and l2 penalties). For ``l1_ratio = 0``
the penalty is an L2 penalty. For ``l1_ratio = 1`` it is an L1 penalty.
For ``0 < l1_ratio < 1``, the penalty is a combination of L1 and L2
This parameter can be a list, in which case the different
values are tested by cross-validation and the one giving the best
prediction score is used. Note that a good choice of list of
values for l1_ratio is often to put more values close to 1
(i.e. Lasso) and less close to 0 (i.e. Ridge), as in ``[.1, .5, .7,
.9, .95, .99, 1]``
eps : float, optional
Length of the path. ``eps=1e-3`` means that
``alpha_min / alpha_max = 1e-3``.
n_alphas : int, optional
Number of alphas along the regularization path, used for each l1_ratio.
alphas : numpy array, optional
List of alphas where to compute the models.
If None alphas are set automatically
fit_intercept : boolean
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
precompute : True | False | 'auto' | array-like
Whether to use a precomputed Gram matrix to speed up
calculations. If set to ``'auto'`` let us decide. The Gram
matrix can also be passed as argument.
max_iter : int, optional
The maximum number of iterations
tol : float, optional
The tolerance for the optimization: if the updates are
smaller than ``tol``, the optimization code checks the
dual gap for optimality and continues until it is smaller
than ``tol``.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross-validation,
- integer, to specify the number of folds.
- An object to be used as a cross-validation generator.
- An iterable yielding train/test splits.
For integer/None inputs, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
copy_X : boolean, optional, default True
If ``True``, X will be copied; else, it may be overwritten.
verbose : bool or integer
Amount of verbosity.
n_jobs : integer, optional
Number of CPUs to use during the cross validation. If ``-1``, use
all the CPUs.
positive : bool, optional
When set to ``True``, forces the coefficients to be positive.
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator that selects a random
feature to update. If int, random_state is the seed used by the random
number generator; If RandomState instance, random_state is the random
number generator; If None, the random number generator is the
RandomState instance used by `np.random`. Used when ``selection`` ==
'random'.
selection : str, default 'cyclic'
If set to 'random', a random coefficient is updated every iteration
rather than looping over features sequentially by default. This
(setting to 'random') often leads to significantly faster convergence
especially when tol is higher than 1e-4.
Attributes
----------
alpha_ : float
The amount of penalization chosen by cross validation
l1_ratio_ : float
The compromise between l1 and l2 penalization chosen by
cross validation
coef_ : array, shape (n_features,) | (n_targets, n_features)
Parameter vector (w in the cost function formula),
intercept_ : float | array, shape (n_targets, n_features)
Independent term in the decision function.
mse_path_ : array, shape (n_l1_ratio, n_alpha, n_folds)
Mean square error for the test set on each fold, varying l1_ratio and
alpha.
alphas_ : numpy array, shape (n_alphas,) or (n_l1_ratio, n_alphas)
The grid of alphas used for fitting, for each l1_ratio.
n_iter_ : int
number of iterations run by the coordinate descent solver to reach
the specified tolerance for the optimal alpha.
Examples
--------
>>> from sklearn.linear_model import ElasticNetCV
>>> from sklearn.datasets import make_regression
>>>
>>> X, y = make_regression(n_features=2, random_state=0)
>>> regr = ElasticNetCV(cv=5, random_state=0)
>>> regr.fit(X, y)
ElasticNetCV(alphas=None, copy_X=True, cv=5, eps=0.001, fit_intercept=True,
l1_ratio=0.5, max_iter=1000, n_alphas=100, n_jobs=1,
normalize=False, positive=False, precompute='auto', random_state=0,
selection='cyclic', tol=0.0001, verbose=0)
>>> print(regr.alpha_) # doctest: +ELLIPSIS
0.19947279427
>>> print(regr.intercept_) # doctest: +ELLIPSIS
0.398882965428
>>> print(regr.predict([[0, 0]])) # doctest: +ELLIPSIS
[ 0.39888297]
Notes
-----
For an example, see
:ref:`examples/linear_model/plot_lasso_model_selection.py
<sphx_glr_auto_examples_linear_model_plot_lasso_model_selection.py>`.
To avoid unnecessary memory duplication the X argument of the fit method
should be directly passed as a Fortran-contiguous numpy array.
The parameter l1_ratio corresponds to alpha in the glmnet R package
while alpha corresponds to the lambda parameter in glmnet.
More specifically, the optimization objective is::
1 / (2 * n_samples) * ||y - Xw||^2_2
+ alpha * l1_ratio * ||w||_1
+ 0.5 * alpha * (1 - l1_ratio) * ||w||^2_2
If you are interested in controlling the L1 and L2 penalty
separately, keep in mind that this is equivalent to::
a * L1 + b * L2
for::
alpha = a + b and l1_ratio = a / (a + b).
See also
--------
enet_path
ElasticNet
"""
path = staticmethod(enet_path)
def __init__(self, l1_ratio=0.5, eps=1e-3, n_alphas=100, alphas=None,
fit_intercept=True, normalize=False, precompute='auto',
max_iter=1000, tol=1e-4, cv=None, copy_X=True,
verbose=0, n_jobs=1, positive=False, random_state=None,
selection='cyclic'):
self.l1_ratio = l1_ratio
self.eps = eps
self.n_alphas = n_alphas
self.alphas = alphas
self.fit_intercept = fit_intercept
self.normalize = normalize
self.precompute = precompute
self.max_iter = max_iter
self.tol = tol
self.cv = cv
self.copy_X = copy_X
self.verbose = verbose
self.n_jobs = n_jobs
self.positive = positive
self.random_state = random_state
self.selection = selection
###############################################################################
# Multi Task ElasticNet and Lasso models (with joint feature selection)
class MultiTaskElasticNet(Lasso):
"""Multi-task ElasticNet model trained with L1/L2 mixed-norm as regularizer
The optimization objective for MultiTaskElasticNet is::
(1 / (2 * n_samples)) * ||Y - XW||^Fro_2
+ alpha * l1_ratio * ||W||_21
+ 0.5 * alpha * (1 - l1_ratio) * ||W||_Fro^2
Where::
||W||_21 = \sum_i \sqrt{\sum_j w_{ij}^2}
i.e. the sum of norm of each row.
Read more in the :ref:`User Guide <multi_task_elastic_net>`.
Parameters
----------
alpha : float, optional
Constant that multiplies the L1/L2 term. Defaults to 1.0
l1_ratio : float
The ElasticNet mixing parameter, with 0 < l1_ratio <= 1.
For l1_ratio = 1 the penalty is an L1/L2 penalty. For l1_ratio = 0 it
is an L2 penalty.
For ``0 < l1_ratio < 1``, the penalty is a combination of L1/L2 and L2.
fit_intercept : boolean
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
copy_X : boolean, optional, default True
If ``True``, X will be copied; else, it may be overwritten.
max_iter : int, optional
The maximum number of iterations
tol : float, optional
The tolerance for the optimization: if the updates are
smaller than ``tol``, the optimization code checks the
dual gap for optimality and continues until it is smaller
than ``tol``.
warm_start : bool, optional
When set to ``True``, reuse the solution of the previous call to fit as
initialization, otherwise, just erase the previous solution.
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator that selects a random
feature to update. If int, random_state is the seed used by the random
number generator; If RandomState instance, random_state is the random
number generator; If None, the random number generator is the
RandomState instance used by `np.random`. Used when ``selection`` ==
'random'.
selection : str, default 'cyclic'
If set to 'random', a random coefficient is updated every iteration
rather than looping over features sequentially by default. This
(setting to 'random') often leads to significantly faster convergence
especially when tol is higher than 1e-4.
Attributes
----------
intercept_ : array, shape (n_tasks,)
Independent term in decision function.
coef_ : array, shape (n_tasks, n_features)
Parameter vector (W in the cost function formula). If a 1D y is \
passed in at fit (non multi-task usage), ``coef_`` is then a 1D array.
Note that ``coef_`` stores the transpose of ``W``, ``W.T``.
n_iter_ : int
number of iterations run by the coordinate descent solver to reach
the specified tolerance.
Examples
--------
>>> from sklearn import linear_model
>>> clf = linear_model.MultiTaskElasticNet(alpha=0.1)
>>> clf.fit([[0,0], [1, 1], [2, 2]], [[0, 0], [1, 1], [2, 2]])
... #doctest: +NORMALIZE_WHITESPACE
MultiTaskElasticNet(alpha=0.1, copy_X=True, fit_intercept=True,
l1_ratio=0.5, max_iter=1000, normalize=False, random_state=None,
selection='cyclic', tol=0.0001, warm_start=False)
>>> print(clf.coef_)
[[ 0.45663524 0.45612256]
[ 0.45663524 0.45612256]]
>>> print(clf.intercept_)
[ 0.0872422 0.0872422]
See also
--------
ElasticNet, MultiTaskLasso
Notes
-----
The algorithm used to fit the model is coordinate descent.
To avoid unnecessary memory duplication the X argument of the fit method
should be directly passed as a Fortran-contiguous numpy array.
"""
def __init__(self, alpha=1.0, l1_ratio=0.5, fit_intercept=True,
normalize=False, copy_X=True, max_iter=1000, tol=1e-4,
warm_start=False, random_state=None, selection='cyclic'):
self.l1_ratio = l1_ratio
self.alpha = alpha
self.fit_intercept = fit_intercept
self.normalize = normalize
self.max_iter = max_iter
self.copy_X = copy_X
self.tol = tol
self.warm_start = warm_start
self.random_state = random_state
self.selection = selection
def fit(self, X, y):
"""Fit MultiTaskElasticNet model with coordinate descent
Parameters
-----------
X : ndarray, shape (n_samples, n_features)
Data
y : ndarray, shape (n_samples, n_tasks)
Target. Will be cast to X's dtype if necessary
Notes
-----
Coordinate descent is an algorithm that considers each column of
data at a time hence it will automatically convert the X input
as a Fortran-contiguous numpy array if necessary.
To avoid memory re-allocation it is advised to allocate the
initial data in memory directly using that format.
"""
X = check_array(X, dtype=[np.float64, np.float32], order='F',
copy=self.copy_X and self.fit_intercept)
y = check_array(y, dtype=X.dtype.type, ensure_2d=False)
if hasattr(self, 'l1_ratio'):
model_str = 'ElasticNet'
else:
model_str = 'Lasso'
if y.ndim == 1:
raise ValueError("For mono-task outputs, use %s" % model_str)
n_samples, n_features = X.shape
_, n_tasks = y.shape
if n_samples != y.shape[0]:
raise ValueError("X and y have inconsistent dimensions (%d != %d)"
% (n_samples, y.shape[0]))
X, y, X_offset, y_offset, X_scale = _preprocess_data(
X, y, self.fit_intercept, self.normalize, copy=False)
if not self.warm_start or self.coef_ is None:
self.coef_ = np.zeros((n_tasks, n_features), dtype=X.dtype.type,
order='F')
l1_reg = self.alpha * self.l1_ratio * n_samples
l2_reg = self.alpha * (1.0 - self.l1_ratio) * n_samples
self.coef_ = np.asfortranarray(self.coef_) # coef contiguous in memory
if self.selection not in ['random', 'cyclic']:
raise ValueError("selection should be either random or cyclic.")
random = (self.selection == 'random')
self.coef_, self.dual_gap_, self.eps_, self.n_iter_ = \
cd_fast.enet_coordinate_descent_multi_task(
self.coef_, l1_reg, l2_reg, X, y, self.max_iter, self.tol,
check_random_state(self.random_state), random)
self._set_intercept(X_offset, y_offset, X_scale)
if self.dual_gap_ > self.eps_:
warnings.warn('Objective did not converge, you might want'
' to increase the number of iterations',
ConvergenceWarning)
# return self for chaining fit and predict calls
return self
class MultiTaskLasso(MultiTaskElasticNet):
"""Multi-task Lasso model trained with L1/L2 mixed-norm as regularizer
The optimization objective for Lasso is::
(1 / (2 * n_samples)) * ||Y - XW||^2_Fro + alpha * ||W||_21
Where::
||W||_21 = \sum_i \sqrt{\sum_j w_{ij}^2}
i.e. the sum of norm of each row.
Read more in the :ref:`User Guide <multi_task_lasso>`.
Parameters
----------
alpha : float, optional
Constant that multiplies the L1/L2 term. Defaults to 1.0
fit_intercept : boolean
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
copy_X : boolean, optional, default True
If ``True``, X will be copied; else, it may be overwritten.
max_iter : int, optional
The maximum number of iterations
tol : float, optional
The tolerance for the optimization: if the updates are
smaller than ``tol``, the optimization code checks the
dual gap for optimality and continues until it is smaller
than ``tol``.
warm_start : bool, optional
When set to ``True``, reuse the solution of the previous call to fit as
initialization, otherwise, just erase the previous solution.
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator that selects a random
feature to update. If int, random_state is the seed used by the random
number generator; If RandomState instance, random_state is the random
number generator; If None, the random number generator is the
RandomState instance used by `np.random`. Used when ``selection`` ==
'random'.
selection : str, default 'cyclic'
If set to 'random', a random coefficient is updated every iteration
rather than looping over features sequentially by default. This
(setting to 'random') often leads to significantly faster convergence
especially when tol is higher than 1e-4
Attributes
----------
coef_ : array, shape (n_tasks, n_features)
Parameter vector (W in the cost function formula).
Note that ``coef_`` stores the transpose of ``W``, ``W.T``.
intercept_ : array, shape (n_tasks,)
independent term in decision function.
n_iter_ : int
number of iterations run by the coordinate descent solver to reach
the specified tolerance.
Examples
--------
>>> from sklearn import linear_model
>>> clf = linear_model.MultiTaskLasso(alpha=0.1)
>>> clf.fit([[0,0], [1, 1], [2, 2]], [[0, 0], [1, 1], [2, 2]])
MultiTaskLasso(alpha=0.1, copy_X=True, fit_intercept=True, max_iter=1000,
normalize=False, random_state=None, selection='cyclic', tol=0.0001,
warm_start=False)
>>> print(clf.coef_)
[[ 0.89393398 0. ]
[ 0.89393398 0. ]]
>>> print(clf.intercept_)
[ 0.10606602 0.10606602]
See also
--------
Lasso, MultiTaskElasticNet
Notes
-----
The algorithm used to fit the model is coordinate descent.
To avoid unnecessary memory duplication the X argument of the fit method
should be directly passed as a Fortran-contiguous numpy array.
"""
def __init__(self, alpha=1.0, fit_intercept=True, normalize=False,
copy_X=True, max_iter=1000, tol=1e-4, warm_start=False,
random_state=None, selection='cyclic'):
self.alpha = alpha
self.fit_intercept = fit_intercept
self.normalize = normalize
self.max_iter = max_iter
self.copy_X = copy_X
self.tol = tol
self.warm_start = warm_start
self.l1_ratio = 1.0
self.random_state = random_state
self.selection = selection
class MultiTaskElasticNetCV(LinearModelCV, RegressorMixin):
"""Multi-task L1/L2 ElasticNet with built-in cross-validation.
The optimization objective for MultiTaskElasticNet is::
(1 / (2 * n_samples)) * ||Y - XW||^Fro_2
+ alpha * l1_ratio * ||W||_21
+ 0.5 * alpha * (1 - l1_ratio) * ||W||_Fro^2
Where::
||W||_21 = \sum_i \sqrt{\sum_j w_{ij}^2}
i.e. the sum of norm of each row.
Read more in the :ref:`User Guide <multi_task_elastic_net>`.
Parameters
----------
l1_ratio : float or array of floats
The ElasticNet mixing parameter, with 0 < l1_ratio <= 1.
For l1_ratio = 1 the penalty is an L1/L2 penalty. For l1_ratio = 0 it
is an L2 penalty.
For ``0 < l1_ratio < 1``, the penalty is a combination of L1/L2 and L2.
This parameter can be a list, in which case the different
values are tested by cross-validation and the one giving the best
prediction score is used. Note that a good choice of list of
values for l1_ratio is often to put more values close to 1
(i.e. Lasso) and less close to 0 (i.e. Ridge), as in ``[.1, .5, .7,
.9, .95, .99, 1]``
eps : float, optional
Length of the path. ``eps=1e-3`` means that
``alpha_min / alpha_max = 1e-3``.
n_alphas : int, optional
Number of alphas along the regularization path
alphas : array-like, optional
List of alphas where to compute the models.
If not provided, set automatically.
fit_intercept : boolean
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
max_iter : int, optional
The maximum number of iterations
tol : float, optional
The tolerance for the optimization: if the updates are
smaller than ``tol``, the optimization code checks the
dual gap for optimality and continues until it is smaller
than ``tol``.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross-validation,
- integer, to specify the number of folds.
- An object to be used as a cross-validation generator.
- An iterable yielding train/test splits.
For integer/None inputs, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
copy_X : boolean, optional, default True
If ``True``, X will be copied; else, it may be overwritten.
verbose : bool or integer
Amount of verbosity.
n_jobs : integer, optional
Number of CPUs to use during the cross validation. If ``-1``, use
all the CPUs. Note that this is used only if multiple values for
l1_ratio are given.
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator that selects a random
feature to update. If int, random_state is the seed used by the random
number generator; If RandomState instance, random_state is the random
number generator; If None, the random number generator is the
RandomState instance used by `np.random`. Used when ``selection`` ==
'random'.
selection : str, default 'cyclic'
If set to 'random', a random coefficient is updated every iteration
rather than looping over features sequentially by default. This
(setting to 'random') often leads to significantly faster convergence
especially when tol is higher than 1e-4.
Attributes
----------
intercept_ : array, shape (n_tasks,)
Independent term in decision function.
coef_ : array, shape (n_tasks, n_features)
Parameter vector (W in the cost function formula).
Note that ``coef_`` stores the transpose of ``W``, ``W.T``.
alpha_ : float
The amount of penalization chosen by cross validation
mse_path_ : array, shape (n_alphas, n_folds) or \
(n_l1_ratio, n_alphas, n_folds)
mean square error for the test set on each fold, varying alpha
alphas_ : numpy array, shape (n_alphas,) or (n_l1_ratio, n_alphas)
The grid of alphas used for fitting, for each l1_ratio
l1_ratio_ : float
best l1_ratio obtained by cross-validation.
n_iter_ : int
number of iterations run by the coordinate descent solver to reach
the specified tolerance for the optimal alpha.
Examples
--------
>>> from sklearn import linear_model
>>> clf = linear_model.MultiTaskElasticNetCV()
>>> clf.fit([[0,0], [1, 1], [2, 2]],
... [[0, 0], [1, 1], [2, 2]])
... #doctest: +NORMALIZE_WHITESPACE
MultiTaskElasticNetCV(alphas=None, copy_X=True, cv=None, eps=0.001,
fit_intercept=True, l1_ratio=0.5, max_iter=1000, n_alphas=100,
n_jobs=1, normalize=False, random_state=None, selection='cyclic',
tol=0.0001, verbose=0)
>>> print(clf.coef_)
[[ 0.52875032 0.46958558]
[ 0.52875032 0.46958558]]
>>> print(clf.intercept_)
[ 0.00166409 0.00166409]
See also
--------
MultiTaskElasticNet
ElasticNetCV
MultiTaskLassoCV
Notes
-----
The algorithm used to fit the model is coordinate descent.
To avoid unnecessary memory duplication the X argument of the fit method
should be directly passed as a Fortran-contiguous numpy array.
"""
path = staticmethod(enet_path)
def __init__(self, l1_ratio=0.5, eps=1e-3, n_alphas=100, alphas=None,
fit_intercept=True, normalize=False,
max_iter=1000, tol=1e-4, cv=None, copy_X=True,
verbose=0, n_jobs=1, random_state=None, selection='cyclic'):
self.l1_ratio = l1_ratio
self.eps = eps
self.n_alphas = n_alphas
self.alphas = alphas
self.fit_intercept = fit_intercept
self.normalize = normalize
self.max_iter = max_iter
self.tol = tol
self.cv = cv
self.copy_X = copy_X
self.verbose = verbose
self.n_jobs = n_jobs
self.random_state = random_state
self.selection = selection
class MultiTaskLassoCV(LinearModelCV, RegressorMixin):
"""Multi-task L1/L2 Lasso with built-in cross-validation.
The optimization objective for MultiTaskLasso is::
(1 / (2 * n_samples)) * ||Y - XW||^Fro_2 + alpha * ||W||_21
Where::
||W||_21 = \sum_i \sqrt{\sum_j w_{ij}^2}
i.e. the sum of norm of each row.
Read more in the :ref:`User Guide <multi_task_lasso>`.
Parameters
----------
eps : float, optional
Length of the path. ``eps=1e-3`` means that
``alpha_min / alpha_max = 1e-3``.
n_alphas : int, optional
Number of alphas along the regularization path
alphas : array-like, optional
List of alphas where to compute the models.
If not provided, set automatically.
fit_intercept : boolean
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
normalize : boolean, optional, default False
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
max_iter : int, optional
The maximum number of iterations.
tol : float, optional
The tolerance for the optimization: if the updates are
smaller than ``tol``, the optimization code checks the
dual gap for optimality and continues until it is smaller
than ``tol``.
copy_X : boolean, optional, default True
If ``True``, X will be copied; else, it may be overwritten.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross-validation,
- integer, to specify the number of folds.
- An object to be used as a cross-validation generator.
- An iterable yielding train/test splits.
For integer/None inputs, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
verbose : bool or integer
Amount of verbosity.
n_jobs : integer, optional
Number of CPUs to use during the cross validation. If ``-1``, use
all the CPUs. Note that this is used only if multiple values for
l1_ratio are given.
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator that selects a random
feature to update. If int, random_state is the seed used by the random
number generator; If RandomState instance, random_state is the random
number generator; If None, the random number generator is the
RandomState instance used by `np.random`. Used when ``selection`` ==
'random'
selection : str, default 'cyclic'
If set to 'random', a random coefficient is updated every iteration
rather than looping over features sequentially by default. This
(setting to 'random') often leads to significantly faster convergence
especially when tol is higher than 1e-4.
Attributes
----------
intercept_ : array, shape (n_tasks,)
Independent term in decision function.
coef_ : array, shape (n_tasks, n_features)
Parameter vector (W in the cost function formula).
Note that ``coef_`` stores the transpose of ``W``, ``W.T``.
alpha_ : float
The amount of penalization chosen by cross validation
mse_path_ : array, shape (n_alphas, n_folds)
mean square error for the test set on each fold, varying alpha
alphas_ : numpy array, shape (n_alphas,)
The grid of alphas used for fitting.
n_iter_ : int
number of iterations run by the coordinate descent solver to reach
the specified tolerance for the optimal alpha.
See also
--------
MultiTaskElasticNet
ElasticNetCV
MultiTaskElasticNetCV
Notes
-----
The algorithm used to fit the model is coordinate descent.
To avoid unnecessary memory duplication the X argument of the fit method
should be directly passed as a Fortran-contiguous numpy array.
"""
path = staticmethod(lasso_path)
def __init__(self, eps=1e-3, n_alphas=100, alphas=None, fit_intercept=True,
normalize=False, max_iter=1000, tol=1e-4, copy_X=True,
cv=None, verbose=False, n_jobs=1, random_state=None,
selection='cyclic'):
super(MultiTaskLassoCV, self).__init__(
eps=eps, n_alphas=n_alphas, alphas=alphas,
fit_intercept=fit_intercept, normalize=normalize,
max_iter=max_iter, tol=tol, copy_X=copy_X,
cv=cv, verbose=verbose, n_jobs=n_jobs, random_state=random_state,
selection=selection)
| 84,453 | 37.09382 | 81 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/least_angle.py | """
Least Angle Regression algorithm. See the documentation on the
Generalized Linear Model for a complete discussion.
"""
from __future__ import print_function
# Author: Fabian Pedregosa <[email protected]>
# Alexandre Gramfort <[email protected]>
# Gael Varoquaux
#
# License: BSD 3 clause
from math import log
import sys
import warnings
import numpy as np
from scipy import linalg, interpolate
from scipy.linalg.lapack import get_lapack_funcs
from .base import LinearModel
from ..base import RegressorMixin
from ..utils import arrayfuncs, as_float_array, check_X_y, deprecated
from ..model_selection import check_cv
from ..exceptions import ConvergenceWarning
from ..externals.joblib import Parallel, delayed
from ..externals.six.moves import xrange
from ..externals.six import string_types
solve_triangular_args = {'check_finite': False}
def lars_path(X, y, Xy=None, Gram=None, max_iter=500,
alpha_min=0, method='lar', copy_X=True,
eps=np.finfo(np.float).eps,
copy_Gram=True, verbose=0, return_path=True,
return_n_iter=False, positive=False):
"""Compute Least Angle Regression or Lasso path using LARS algorithm [1]
The optimization objective for the case method='lasso' is::
(1 / (2 * n_samples)) * ||y - Xw||^2_2 + alpha * ||w||_1
in the case of method='lars', the objective function is only known in
the form of an implicit equation (see discussion in [1])
Read more in the :ref:`User Guide <least_angle_regression>`.
Parameters
-----------
X : array, shape: (n_samples, n_features)
Input data.
y : array, shape: (n_samples)
Input targets.
Xy : array-like, shape (n_samples,) or (n_samples, n_targets), \
optional
Xy = np.dot(X.T, y) that can be precomputed. It is useful
only when the Gram matrix is precomputed.
Gram : None, 'auto', array, shape: (n_features, n_features), optional
Precomputed Gram matrix (X' * X), if ``'auto'``, the Gram
matrix is precomputed from the given X, if there are more samples
than features.
max_iter : integer, optional (default=500)
Maximum number of iterations to perform, set to infinity for no limit.
alpha_min : float, optional (default=0)
Minimum correlation along the path. It corresponds to the
regularization parameter alpha parameter in the Lasso.
method : {'lar', 'lasso'}, optional (default='lar')
Specifies the returned model. Select ``'lar'`` for Least Angle
Regression, ``'lasso'`` for the Lasso.
copy_X : bool, optional (default=True)
If ``False``, ``X`` is overwritten.
eps : float, optional (default=``np.finfo(np.float).eps``)
The machine-precision regularization in the computation of the
Cholesky diagonal factors. Increase this for very ill-conditioned
systems.
copy_Gram : bool, optional (default=True)
If ``False``, ``Gram`` is overwritten.
verbose : int (default=0)
Controls output verbosity.
return_path : bool, optional (default=True)
If ``return_path==True`` returns the entire path, else returns only the
last point of the path.
return_n_iter : bool, optional (default=False)
Whether to return the number of iterations.
positive : boolean (default=False)
Restrict coefficients to be >= 0.
When using this option together with method 'lasso' the model
coefficients will not converge to the ordinary-least-squares solution
for small values of alpha (neither will they when using method 'lar'
..). Only coefficients up to the smallest alpha value
(``alphas_[alphas_ > 0.].min()`` when fit_path=True) reached by the
stepwise Lars-Lasso algorithm are typically in congruence with the
solution of the coordinate descent lasso_path function.
Returns
--------
alphas : array, shape: [n_alphas + 1]
Maximum of covariances (in absolute value) at each iteration.
``n_alphas`` is either ``max_iter``, ``n_features`` or the
number of nodes in the path with ``alpha >= alpha_min``, whichever
is smaller.
active : array, shape [n_alphas]
Indices of active variables at the end of the path.
coefs : array, shape (n_features, n_alphas + 1)
Coefficients along the path
n_iter : int
Number of iterations run. Returned only if return_n_iter is set
to True.
See also
--------
lasso_path
LassoLars
Lars
LassoLarsCV
LarsCV
sklearn.decomposition.sparse_encode
References
----------
.. [1] "Least Angle Regression", Effron et al.
http://statweb.stanford.edu/~tibs/ftp/lars.pdf
.. [2] `Wikipedia entry on the Least-angle regression
<https://en.wikipedia.org/wiki/Least-angle_regression>`_
.. [3] `Wikipedia entry on the Lasso
<https://en.wikipedia.org/wiki/Lasso_(statistics)>`_
"""
n_features = X.shape[1]
n_samples = y.size
max_features = min(max_iter, n_features)
if return_path:
coefs = np.zeros((max_features + 1, n_features))
alphas = np.zeros(max_features + 1)
else:
coef, prev_coef = np.zeros(n_features), np.zeros(n_features)
alpha, prev_alpha = np.array([0.]), np.array([0.]) # better ideas?
n_iter, n_active = 0, 0
active, indices = list(), np.arange(n_features)
# holds the sign of covariance
sign_active = np.empty(max_features, dtype=np.int8)
drop = False
# will hold the cholesky factorization. Only lower part is
# referenced.
# We are initializing this to "zeros" and not empty, because
# it is passed to scipy linalg functions and thus if it has NaNs,
# even if they are in the upper part that it not used, we
# get errors raised.
# Once we support only scipy > 0.12 we can use check_finite=False and
# go back to "empty"
L = np.zeros((max_features, max_features), dtype=X.dtype)
swap, nrm2 = linalg.get_blas_funcs(('swap', 'nrm2'), (X,))
solve_cholesky, = get_lapack_funcs(('potrs',), (X,))
if Gram is None or Gram is False:
Gram = None
if copy_X:
# force copy. setting the array to be fortran-ordered
# speeds up the calculation of the (partial) Gram matrix
# and allows to easily swap columns
X = X.copy('F')
elif isinstance(Gram, string_types) and Gram == 'auto' or Gram is True:
if Gram is True or X.shape[0] > X.shape[1]:
Gram = np.dot(X.T, X)
else:
Gram = None
elif copy_Gram:
Gram = Gram.copy()
if Xy is None:
Cov = np.dot(X.T, y)
else:
Cov = Xy.copy()
if verbose:
if verbose > 1:
print("Step\t\tAdded\t\tDropped\t\tActive set size\t\tC")
else:
sys.stdout.write('.')
sys.stdout.flush()
tiny32 = np.finfo(np.float32).tiny # to avoid division by 0 warning
equality_tolerance = np.finfo(np.float32).eps
while True:
if Cov.size:
if positive:
C_idx = np.argmax(Cov)
else:
C_idx = np.argmax(np.abs(Cov))
C_ = Cov[C_idx]
if positive:
C = C_
else:
C = np.fabs(C_)
else:
C = 0.
if return_path:
alpha = alphas[n_iter, np.newaxis]
coef = coefs[n_iter]
prev_alpha = alphas[n_iter - 1, np.newaxis]
prev_coef = coefs[n_iter - 1]
alpha[0] = C / n_samples
if alpha[0] <= alpha_min + equality_tolerance: # early stopping
if abs(alpha[0] - alpha_min) > equality_tolerance:
# interpolation factor 0 <= ss < 1
if n_iter > 0:
# In the first iteration, all alphas are zero, the formula
# below would make ss a NaN
ss = ((prev_alpha[0] - alpha_min) /
(prev_alpha[0] - alpha[0]))
coef[:] = prev_coef + ss * (coef - prev_coef)
alpha[0] = alpha_min
if return_path:
coefs[n_iter] = coef
break
if n_iter >= max_iter or n_active >= n_features:
break
if not drop:
##########################################################
# Append x_j to the Cholesky factorization of (Xa * Xa') #
# #
# ( L 0 ) #
# L -> ( ) , where L * w = Xa' x_j #
# ( w z ) and z = ||x_j|| #
# #
##########################################################
if positive:
sign_active[n_active] = np.ones_like(C_)
else:
sign_active[n_active] = np.sign(C_)
m, n = n_active, C_idx + n_active
Cov[C_idx], Cov[0] = swap(Cov[C_idx], Cov[0])
indices[n], indices[m] = indices[m], indices[n]
Cov_not_shortened = Cov
Cov = Cov[1:] # remove Cov[0]
if Gram is None:
X.T[n], X.T[m] = swap(X.T[n], X.T[m])
c = nrm2(X.T[n_active]) ** 2
L[n_active, :n_active] = \
np.dot(X.T[n_active], X.T[:n_active].T)
else:
# swap does only work inplace if matrix is fortran
# contiguous ...
Gram[m], Gram[n] = swap(Gram[m], Gram[n])
Gram[:, m], Gram[:, n] = swap(Gram[:, m], Gram[:, n])
c = Gram[n_active, n_active]
L[n_active, :n_active] = Gram[n_active, :n_active]
# Update the cholesky decomposition for the Gram matrix
if n_active:
linalg.solve_triangular(L[:n_active, :n_active],
L[n_active, :n_active],
trans=0, lower=1,
overwrite_b=True,
**solve_triangular_args)
v = np.dot(L[n_active, :n_active], L[n_active, :n_active])
diag = max(np.sqrt(np.abs(c - v)), eps)
L[n_active, n_active] = diag
if diag < 1e-7:
# The system is becoming too ill-conditioned.
# We have degenerate vectors in our active set.
# We'll 'drop for good' the last regressor added.
# Note: this case is very rare. It is no longer triggered by
# the test suite. The `equality_tolerance` margin added in 0.16
# to get early stopping to work consistently on all versions of
# Python including 32 bit Python under Windows seems to make it
# very difficult to trigger the 'drop for good' strategy.
warnings.warn('Regressors in active set degenerate. '
'Dropping a regressor, after %i iterations, '
'i.e. alpha=%.3e, '
'with an active set of %i regressors, and '
'the smallest cholesky pivot element being %.3e.'
' Reduce max_iter or increase eps parameters.'
% (n_iter, alpha, n_active, diag),
ConvergenceWarning)
# XXX: need to figure a 'drop for good' way
Cov = Cov_not_shortened
Cov[0] = 0
Cov[C_idx], Cov[0] = swap(Cov[C_idx], Cov[0])
continue
active.append(indices[n_active])
n_active += 1
if verbose > 1:
print("%s\t\t%s\t\t%s\t\t%s\t\t%s" % (n_iter, active[-1], '',
n_active, C))
if method == 'lasso' and n_iter > 0 and prev_alpha[0] < alpha[0]:
# alpha is increasing. This is because the updates of Cov are
# bringing in too much numerical error that is greater than
# than the remaining correlation with the
# regressors. Time to bail out
warnings.warn('Early stopping the lars path, as the residues '
'are small and the current value of alpha is no '
'longer well controlled. %i iterations, alpha=%.3e, '
'previous alpha=%.3e, with an active set of %i '
'regressors.'
% (n_iter, alpha, prev_alpha, n_active),
ConvergenceWarning)
break
# least squares solution
least_squares, info = solve_cholesky(L[:n_active, :n_active],
sign_active[:n_active],
lower=True)
if least_squares.size == 1 and least_squares == 0:
# This happens because sign_active[:n_active] = 0
least_squares[...] = 1
AA = 1.
else:
# is this really needed ?
AA = 1. / np.sqrt(np.sum(least_squares * sign_active[:n_active]))
if not np.isfinite(AA):
# L is too ill-conditioned
i = 0
L_ = L[:n_active, :n_active].copy()
while not np.isfinite(AA):
L_.flat[::n_active + 1] += (2 ** i) * eps
least_squares, info = solve_cholesky(
L_, sign_active[:n_active], lower=True)
tmp = max(np.sum(least_squares * sign_active[:n_active]),
eps)
AA = 1. / np.sqrt(tmp)
i += 1
least_squares *= AA
if Gram is None:
# equiangular direction of variables in the active set
eq_dir = np.dot(X.T[:n_active].T, least_squares)
# correlation between each unactive variables and
# eqiangular vector
corr_eq_dir = np.dot(X.T[n_active:], eq_dir)
else:
# if huge number of features, this takes 50% of time, I
# think could be avoided if we just update it using an
# orthogonal (QR) decomposition of X
corr_eq_dir = np.dot(Gram[:n_active, n_active:].T,
least_squares)
g1 = arrayfuncs.min_pos((C - Cov) / (AA - corr_eq_dir + tiny32))
if positive:
gamma_ = min(g1, C / AA)
else:
g2 = arrayfuncs.min_pos((C + Cov) / (AA + corr_eq_dir + tiny32))
gamma_ = min(g1, g2, C / AA)
# TODO: better names for these variables: z
drop = False
z = -coef[active] / (least_squares + tiny32)
z_pos = arrayfuncs.min_pos(z)
if z_pos < gamma_:
# some coefficients have changed sign
idx = np.where(z == z_pos)[0][::-1]
# update the sign, important for LAR
sign_active[idx] = -sign_active[idx]
if method == 'lasso':
gamma_ = z_pos
drop = True
n_iter += 1
if return_path:
if n_iter >= coefs.shape[0]:
del coef, alpha, prev_alpha, prev_coef
# resize the coefs and alphas array
add_features = 2 * max(1, (max_features - n_active))
coefs = np.resize(coefs, (n_iter + add_features, n_features))
coefs[-add_features:] = 0
alphas = np.resize(alphas, n_iter + add_features)
alphas[-add_features:] = 0
coef = coefs[n_iter]
prev_coef = coefs[n_iter - 1]
alpha = alphas[n_iter, np.newaxis]
prev_alpha = alphas[n_iter - 1, np.newaxis]
else:
# mimic the effect of incrementing n_iter on the array references
prev_coef = coef
prev_alpha[0] = alpha[0]
coef = np.zeros_like(coef)
coef[active] = prev_coef[active] + gamma_ * least_squares
# update correlations
Cov -= gamma_ * corr_eq_dir
# See if any coefficient has changed sign
if drop and method == 'lasso':
# handle the case when idx is not length of 1
[arrayfuncs.cholesky_delete(L[:n_active, :n_active], ii) for ii in
idx]
n_active -= 1
m, n = idx, n_active
# handle the case when idx is not length of 1
drop_idx = [active.pop(ii) for ii in idx]
if Gram is None:
# propagate dropped variable
for ii in idx:
for i in range(ii, n_active):
X.T[i], X.T[i + 1] = swap(X.T[i], X.T[i + 1])
# yeah this is stupid
indices[i], indices[i + 1] = indices[i + 1], indices[i]
# TODO: this could be updated
residual = y - np.dot(X[:, :n_active], coef[active])
temp = np.dot(X.T[n_active], residual)
Cov = np.r_[temp, Cov]
else:
for ii in idx:
for i in range(ii, n_active):
indices[i], indices[i + 1] = indices[i + 1], indices[i]
Gram[i], Gram[i + 1] = swap(Gram[i], Gram[i + 1])
Gram[:, i], Gram[:, i + 1] = swap(Gram[:, i],
Gram[:, i + 1])
# Cov_n = Cov_j + x_j * X + increment(betas) TODO:
# will this still work with multiple drops ?
# recompute covariance. Probably could be done better
# wrong as Xy is not swapped with the rest of variables
# TODO: this could be updated
residual = y - np.dot(X, coef)
temp = np.dot(X.T[drop_idx], residual)
Cov = np.r_[temp, Cov]
sign_active = np.delete(sign_active, idx)
sign_active = np.append(sign_active, 0.) # just to maintain size
if verbose > 1:
print("%s\t\t%s\t\t%s\t\t%s\t\t%s" % (n_iter, '', drop_idx,
n_active, abs(temp)))
if return_path:
# resize coefs in case of early stop
alphas = alphas[:n_iter + 1]
coefs = coefs[:n_iter + 1]
if return_n_iter:
return alphas, active, coefs.T, n_iter
else:
return alphas, active, coefs.T
else:
if return_n_iter:
return alpha, active, coef, n_iter
else:
return alpha, active, coef
###############################################################################
# Estimator classes
class Lars(LinearModel, RegressorMixin):
"""Least Angle Regression model a.k.a. LAR
Read more in the :ref:`User Guide <least_angle_regression>`.
Parameters
----------
fit_intercept : boolean
Whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
verbose : boolean or integer, optional
Sets the verbosity amount
normalize : boolean, optional, default True
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
precompute : True | False | 'auto' | array-like
Whether to use a precomputed Gram matrix to speed up
calculations. If set to ``'auto'`` let us decide. The Gram
matrix can also be passed as argument.
n_nonzero_coefs : int, optional
Target number of non-zero coefficients. Use ``np.inf`` for no limit.
eps : float, optional
The machine-precision regularization in the computation of the
Cholesky diagonal factors. Increase this for very ill-conditioned
systems. Unlike the ``tol`` parameter in some iterative
optimization-based algorithms, this parameter does not control
the tolerance of the optimization.
copy_X : boolean, optional, default True
If ``True``, X will be copied; else, it may be overwritten.
fit_path : boolean
If True the full path is stored in the ``coef_path_`` attribute.
If you compute the solution for a large problem or many targets,
setting ``fit_path`` to ``False`` will lead to a speedup, especially
with a small alpha.
positive : boolean (default=False)
Restrict coefficients to be >= 0. Be aware that you might want to
remove fit_intercept which is set True by default.
Attributes
----------
alphas_ : array, shape (n_alphas + 1,) | list of n_targets such arrays
Maximum of covariances (in absolute value) at each iteration. \
``n_alphas`` is either ``n_nonzero_coefs`` or ``n_features``, \
whichever is smaller.
active_ : list, length = n_alphas | list of n_targets such lists
Indices of active variables at the end of the path.
coef_path_ : array, shape (n_features, n_alphas + 1) \
| list of n_targets such arrays
The varying values of the coefficients along the path. It is not
present if the ``fit_path`` parameter is ``False``.
coef_ : array, shape (n_features,) or (n_targets, n_features)
Parameter vector (w in the formulation formula).
intercept_ : float | array, shape (n_targets,)
Independent term in decision function.
n_iter_ : array-like or int
The number of iterations taken by lars_path to find the
grid of alphas for each target.
Examples
--------
>>> from sklearn import linear_model
>>> reg = linear_model.Lars(n_nonzero_coefs=1)
>>> reg.fit([[-1, 1], [0, 0], [1, 1]], [-1.1111, 0, -1.1111])
... # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
Lars(copy_X=True, eps=..., fit_intercept=True, fit_path=True,
n_nonzero_coefs=1, normalize=True, positive=False, precompute='auto',
verbose=False)
>>> print(reg.coef_) # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
[ 0. -1.11...]
See also
--------
lars_path, LarsCV
sklearn.decomposition.sparse_encode
"""
method = 'lar'
def __init__(self, fit_intercept=True, verbose=False, normalize=True,
precompute='auto', n_nonzero_coefs=500,
eps=np.finfo(np.float).eps, copy_X=True, fit_path=True,
positive=False):
self.fit_intercept = fit_intercept
self.verbose = verbose
self.normalize = normalize
self.precompute = precompute
self.n_nonzero_coefs = n_nonzero_coefs
self.positive = positive
self.eps = eps
self.copy_X = copy_X
self.fit_path = fit_path
def _get_gram(self, precompute, X, y):
if (not hasattr(precompute, '__array__')) and (
(precompute is True) or
(precompute == 'auto' and X.shape[0] > X.shape[1]) or
(precompute == 'auto' and y.shape[1] > 1)):
precompute = np.dot(X.T, X)
return precompute
def _fit(self, X, y, max_iter, alpha, fit_path, Xy=None):
"""Auxiliary method to fit the model using X, y as training data"""
n_features = X.shape[1]
X, y, X_offset, y_offset, X_scale = self._preprocess_data(X, y,
self.fit_intercept,
self.normalize,
self.copy_X)
if y.ndim == 1:
y = y[:, np.newaxis]
n_targets = y.shape[1]
Gram = self._get_gram(self.precompute, X, y)
self.alphas_ = []
self.n_iter_ = []
self.coef_ = np.empty((n_targets, n_features))
if fit_path:
self.active_ = []
self.coef_path_ = []
for k in xrange(n_targets):
this_Xy = None if Xy is None else Xy[:, k]
alphas, active, coef_path, n_iter_ = lars_path(
X, y[:, k], Gram=Gram, Xy=this_Xy, copy_X=self.copy_X,
copy_Gram=True, alpha_min=alpha, method=self.method,
verbose=max(0, self.verbose - 1), max_iter=max_iter,
eps=self.eps, return_path=True,
return_n_iter=True, positive=self.positive)
self.alphas_.append(alphas)
self.active_.append(active)
self.n_iter_.append(n_iter_)
self.coef_path_.append(coef_path)
self.coef_[k] = coef_path[:, -1]
if n_targets == 1:
self.alphas_, self.active_, self.coef_path_, self.coef_ = [
a[0] for a in (self.alphas_, self.active_, self.coef_path_,
self.coef_)]
self.n_iter_ = self.n_iter_[0]
else:
for k in xrange(n_targets):
this_Xy = None if Xy is None else Xy[:, k]
alphas, _, self.coef_[k], n_iter_ = lars_path(
X, y[:, k], Gram=Gram, Xy=this_Xy, copy_X=self.copy_X,
copy_Gram=True, alpha_min=alpha, method=self.method,
verbose=max(0, self.verbose - 1), max_iter=max_iter,
eps=self.eps, return_path=False, return_n_iter=True,
positive=self.positive)
self.alphas_.append(alphas)
self.n_iter_.append(n_iter_)
if n_targets == 1:
self.alphas_ = self.alphas_[0]
self.n_iter_ = self.n_iter_[0]
self._set_intercept(X_offset, y_offset, X_scale)
return self
def fit(self, X, y, Xy=None):
"""Fit the model using X, y as training data.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Training data.
y : array-like, shape (n_samples,) or (n_samples, n_targets)
Target values.
Xy : array-like, shape (n_samples,) or (n_samples, n_targets), \
optional
Xy = np.dot(X.T, y) that can be precomputed. It is useful
only when the Gram matrix is precomputed.
Returns
-------
self : object
returns an instance of self.
"""
X, y = check_X_y(X, y, y_numeric=True, multi_output=True)
alpha = getattr(self, 'alpha', 0.)
if hasattr(self, 'n_nonzero_coefs'):
alpha = 0. # n_nonzero_coefs parametrization takes priority
max_iter = self.n_nonzero_coefs
else:
max_iter = self.max_iter
self._fit(X, y, max_iter=max_iter, alpha=alpha, fit_path=self.fit_path,
Xy=Xy)
return self
class LassoLars(Lars):
"""Lasso model fit with Least Angle Regression a.k.a. Lars
It is a Linear Model trained with an L1 prior as regularizer.
The optimization objective for Lasso is::
(1 / (2 * n_samples)) * ||y - Xw||^2_2 + alpha * ||w||_1
Read more in the :ref:`User Guide <least_angle_regression>`.
Parameters
----------
alpha : float
Constant that multiplies the penalty term. Defaults to 1.0.
``alpha = 0`` is equivalent to an ordinary least square, solved
by :class:`LinearRegression`. For numerical reasons, using
``alpha = 0`` with the LassoLars object is not advised and you
should prefer the LinearRegression object.
fit_intercept : boolean
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
verbose : boolean or integer, optional
Sets the verbosity amount
normalize : boolean, optional, default True
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
precompute : True | False | 'auto' | array-like
Whether to use a precomputed Gram matrix to speed up
calculations. If set to ``'auto'`` let us decide. The Gram
matrix can also be passed as argument.
max_iter : integer, optional
Maximum number of iterations to perform.
eps : float, optional
The machine-precision regularization in the computation of the
Cholesky diagonal factors. Increase this for very ill-conditioned
systems. Unlike the ``tol`` parameter in some iterative
optimization-based algorithms, this parameter does not control
the tolerance of the optimization.
copy_X : boolean, optional, default True
If True, X will be copied; else, it may be overwritten.
fit_path : boolean
If ``True`` the full path is stored in the ``coef_path_`` attribute.
If you compute the solution for a large problem or many targets,
setting ``fit_path`` to ``False`` will lead to a speedup, especially
with a small alpha.
positive : boolean (default=False)
Restrict coefficients to be >= 0. Be aware that you might want to
remove fit_intercept which is set True by default.
Under the positive restriction the model coefficients will not converge
to the ordinary-least-squares solution for small values of alpha.
Only coefficients up to the smallest alpha value (``alphas_[alphas_ >
0.].min()`` when fit_path=True) reached by the stepwise Lars-Lasso
algorithm are typically in congruence with the solution of the
coordinate descent Lasso estimator.
Attributes
----------
alphas_ : array, shape (n_alphas + 1,) | list of n_targets such arrays
Maximum of covariances (in absolute value) at each iteration. \
``n_alphas`` is either ``max_iter``, ``n_features``, or the number of \
nodes in the path with correlation greater than ``alpha``, whichever \
is smaller.
active_ : list, length = n_alphas | list of n_targets such lists
Indices of active variables at the end of the path.
coef_path_ : array, shape (n_features, n_alphas + 1) or list
If a list is passed it's expected to be one of n_targets such arrays.
The varying values of the coefficients along the path. It is not
present if the ``fit_path`` parameter is ``False``.
coef_ : array, shape (n_features,) or (n_targets, n_features)
Parameter vector (w in the formulation formula).
intercept_ : float | array, shape (n_targets,)
Independent term in decision function.
n_iter_ : array-like or int.
The number of iterations taken by lars_path to find the
grid of alphas for each target.
Examples
--------
>>> from sklearn import linear_model
>>> reg = linear_model.LassoLars(alpha=0.01)
>>> reg.fit([[-1, 1], [0, 0], [1, 1]], [-1, 0, -1])
... # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
LassoLars(alpha=0.01, copy_X=True, eps=..., fit_intercept=True,
fit_path=True, max_iter=500, normalize=True, positive=False,
precompute='auto', verbose=False)
>>> print(reg.coef_) # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
[ 0. -0.963257...]
See also
--------
lars_path
lasso_path
Lasso
LassoCV
LassoLarsCV
sklearn.decomposition.sparse_encode
"""
method = 'lasso'
def __init__(self, alpha=1.0, fit_intercept=True, verbose=False,
normalize=True, precompute='auto', max_iter=500,
eps=np.finfo(np.float).eps, copy_X=True, fit_path=True,
positive=False):
self.alpha = alpha
self.fit_intercept = fit_intercept
self.max_iter = max_iter
self.verbose = verbose
self.normalize = normalize
self.positive = positive
self.precompute = precompute
self.copy_X = copy_X
self.eps = eps
self.fit_path = fit_path
###############################################################################
# Cross-validated estimator classes
def _check_copy_and_writeable(array, copy=False):
if copy or not array.flags.writeable:
return array.copy()
return array
def _lars_path_residues(X_train, y_train, X_test, y_test, Gram=None,
copy=True, method='lars', verbose=False,
fit_intercept=True, normalize=True, max_iter=500,
eps=np.finfo(np.float).eps, positive=False):
"""Compute the residues on left-out data for a full LARS path
Parameters
-----------
X_train : array, shape (n_samples, n_features)
The data to fit the LARS on
y_train : array, shape (n_samples)
The target variable to fit LARS on
X_test : array, shape (n_samples, n_features)
The data to compute the residues on
y_test : array, shape (n_samples)
The target variable to compute the residues on
Gram : None, 'auto', array, shape: (n_features, n_features), optional
Precomputed Gram matrix (X' * X), if ``'auto'``, the Gram
matrix is precomputed from the given X, if there are more samples
than features
copy : boolean, optional
Whether X_train, X_test, y_train and y_test should be copied;
if False, they may be overwritten.
method : 'lar' | 'lasso'
Specifies the returned model. Select ``'lar'`` for Least Angle
Regression, ``'lasso'`` for the Lasso.
verbose : integer, optional
Sets the amount of verbosity
fit_intercept : boolean
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
positive : boolean (default=False)
Restrict coefficients to be >= 0. Be aware that you might want to
remove fit_intercept which is set True by default.
See reservations for using this option in combination with method
'lasso' for expected small values of alpha in the doc of LassoLarsCV
and LassoLarsIC.
normalize : boolean, optional, default True
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
max_iter : integer, optional
Maximum number of iterations to perform.
eps : float, optional
The machine-precision regularization in the computation of the
Cholesky diagonal factors. Increase this for very ill-conditioned
systems. Unlike the ``tol`` parameter in some iterative
optimization-based algorithms, this parameter does not control
the tolerance of the optimization.
Returns
--------
alphas : array, shape (n_alphas,)
Maximum of covariances (in absolute value) at each iteration.
``n_alphas`` is either ``max_iter`` or ``n_features``, whichever
is smaller.
active : list
Indices of active variables at the end of the path.
coefs : array, shape (n_features, n_alphas)
Coefficients along the path
residues : array, shape (n_alphas, n_samples)
Residues of the prediction on the test data
"""
X_train = _check_copy_and_writeable(X_train, copy)
y_train = _check_copy_and_writeable(y_train, copy)
X_test = _check_copy_and_writeable(X_test, copy)
y_test = _check_copy_and_writeable(y_test, copy)
if fit_intercept:
X_mean = X_train.mean(axis=0)
X_train -= X_mean
X_test -= X_mean
y_mean = y_train.mean(axis=0)
y_train = as_float_array(y_train, copy=False)
y_train -= y_mean
y_test = as_float_array(y_test, copy=False)
y_test -= y_mean
if normalize:
norms = np.sqrt(np.sum(X_train ** 2, axis=0))
nonzeros = np.flatnonzero(norms)
X_train[:, nonzeros] /= norms[nonzeros]
alphas, active, coefs = lars_path(
X_train, y_train, Gram=Gram, copy_X=False, copy_Gram=False,
method=method, verbose=max(0, verbose - 1), max_iter=max_iter, eps=eps,
positive=positive)
if normalize:
coefs[nonzeros] /= norms[nonzeros][:, np.newaxis]
residues = np.dot(X_test, coefs) - y_test[:, np.newaxis]
return alphas, active, coefs, residues.T
class LarsCV(Lars):
"""Cross-validated Least Angle Regression model
Read more in the :ref:`User Guide <least_angle_regression>`.
Parameters
----------
fit_intercept : boolean
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
verbose : boolean or integer, optional
Sets the verbosity amount
max_iter : integer, optional
Maximum number of iterations to perform.
normalize : boolean, optional, default True
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
precompute : True | False | 'auto' | array-like
Whether to use a precomputed Gram matrix to speed up
calculations. If set to ``'auto'`` let us decide. The Gram matrix
cannot be passed as argument since we will use only subsets of X.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross-validation,
- integer, to specify the number of folds.
- An object to be used as a cross-validation generator.
- An iterable yielding train/test splits.
For integer/None inputs, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
max_n_alphas : integer, optional
The maximum number of points on the path used to compute the
residuals in the cross-validation
n_jobs : integer, optional
Number of CPUs to use during the cross validation. If ``-1``, use
all the CPUs
eps : float, optional
The machine-precision regularization in the computation of the
Cholesky diagonal factors. Increase this for very ill-conditioned
systems.
copy_X : boolean, optional, default True
If ``True``, X will be copied; else, it may be overwritten.
positive : boolean (default=False)
Restrict coefficients to be >= 0. Be aware that you might want to
remove fit_intercept which is set True by default.
Attributes
----------
coef_ : array, shape (n_features,)
parameter vector (w in the formulation formula)
intercept_ : float
independent term in decision function
coef_path_ : array, shape (n_features, n_alphas)
the varying values of the coefficients along the path
alpha_ : float
the estimated regularization parameter alpha
alphas_ : array, shape (n_alphas,)
the different values of alpha along the path
cv_alphas_ : array, shape (n_cv_alphas,)
all the values of alpha along the path for the different folds
mse_path_ : array, shape (n_folds, n_cv_alphas)
the mean square error on left-out for each fold along the path
(alpha values given by ``cv_alphas``)
n_iter_ : array-like or int
the number of iterations run by Lars with the optimal alpha.
See also
--------
lars_path, LassoLars, LassoLarsCV
"""
method = 'lar'
def __init__(self, fit_intercept=True, verbose=False, max_iter=500,
normalize=True, precompute='auto', cv=None,
max_n_alphas=1000, n_jobs=1, eps=np.finfo(np.float).eps,
copy_X=True, positive=False):
self.max_iter = max_iter
self.cv = cv
self.max_n_alphas = max_n_alphas
self.n_jobs = n_jobs
super(LarsCV, self).__init__(fit_intercept=fit_intercept,
verbose=verbose, normalize=normalize,
precompute=precompute,
n_nonzero_coefs=500,
eps=eps, copy_X=copy_X, fit_path=True,
positive=positive)
def fit(self, X, y):
"""Fit the model using X, y as training data.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Training data.
y : array-like, shape (n_samples,)
Target values.
Returns
-------
self : object
returns an instance of self.
"""
X, y = check_X_y(X, y, y_numeric=True)
X = as_float_array(X, copy=self.copy_X)
y = as_float_array(y, copy=self.copy_X)
# init cross-validation generator
cv = check_cv(self.cv, classifier=False)
# As we use cross-validation, the Gram matrix is not precomputed here
Gram = self.precompute
if hasattr(Gram, '__array__'):
warnings.warn("Parameter 'precompute' cannot be an array in "
"%s. Automatically switch to 'auto' instead."
% self.__class__.__name__)
Gram = 'auto'
cv_paths = Parallel(n_jobs=self.n_jobs, verbose=self.verbose)(
delayed(_lars_path_residues)(
X[train], y[train], X[test], y[test], Gram=Gram, copy=False,
method=self.method, verbose=max(0, self.verbose - 1),
normalize=self.normalize, fit_intercept=self.fit_intercept,
max_iter=self.max_iter, eps=self.eps, positive=self.positive)
for train, test in cv.split(X, y))
all_alphas = np.concatenate(list(zip(*cv_paths))[0])
# Unique also sorts
all_alphas = np.unique(all_alphas)
# Take at most max_n_alphas values
stride = int(max(1, int(len(all_alphas) / float(self.max_n_alphas))))
all_alphas = all_alphas[::stride]
mse_path = np.empty((len(all_alphas), len(cv_paths)))
for index, (alphas, active, coefs, residues) in enumerate(cv_paths):
alphas = alphas[::-1]
residues = residues[::-1]
if alphas[0] != 0:
alphas = np.r_[0, alphas]
residues = np.r_[residues[0, np.newaxis], residues]
if alphas[-1] != all_alphas[-1]:
alphas = np.r_[alphas, all_alphas[-1]]
residues = np.r_[residues, residues[-1, np.newaxis]]
this_residues = interpolate.interp1d(alphas,
residues,
axis=0)(all_alphas)
this_residues **= 2
mse_path[:, index] = np.mean(this_residues, axis=-1)
mask = np.all(np.isfinite(mse_path), axis=-1)
all_alphas = all_alphas[mask]
mse_path = mse_path[mask]
# Select the alpha that minimizes left-out error
i_best_alpha = np.argmin(mse_path.mean(axis=-1))
best_alpha = all_alphas[i_best_alpha]
# Store our parameters
self.alpha_ = best_alpha
self.cv_alphas_ = all_alphas
self.mse_path_ = mse_path
# Now compute the full model
# it will call a lasso internally when self if LassoLarsCV
# as self.method == 'lasso'
self._fit(X, y, max_iter=self.max_iter, alpha=best_alpha,
Xy=None, fit_path=True)
return self
@property
@deprecated("Attribute alpha is deprecated in 0.19 and "
"will be removed in 0.21. See ``alpha_`` instead")
def alpha(self):
# impedance matching for the above Lars.fit (should not be documented)
return self.alpha_
@property
@deprecated("Attribute ``cv_mse_path_`` is deprecated in 0.18 and "
"will be removed in 0.20. Use ``mse_path_`` instead")
def cv_mse_path_(self):
return self.mse_path_
class LassoLarsCV(LarsCV):
"""Cross-validated Lasso, using the LARS algorithm
The optimization objective for Lasso is::
(1 / (2 * n_samples)) * ||y - Xw||^2_2 + alpha * ||w||_1
Read more in the :ref:`User Guide <least_angle_regression>`.
Parameters
----------
fit_intercept : boolean
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
verbose : boolean or integer, optional
Sets the verbosity amount
max_iter : integer, optional
Maximum number of iterations to perform.
normalize : boolean, optional, default True
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
precompute : True | False | 'auto'
Whether to use a precomputed Gram matrix to speed up
calculations. If set to ``'auto'`` let us decide. The Gram matrix
cannot be passed as argument since we will use only subsets of X.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross-validation,
- integer, to specify the number of folds.
- An object to be used as a cross-validation generator.
- An iterable yielding train/test splits.
For integer/None inputs, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
max_n_alphas : integer, optional
The maximum number of points on the path used to compute the
residuals in the cross-validation
n_jobs : integer, optional
Number of CPUs to use during the cross validation. If ``-1``, use
all the CPUs
eps : float, optional
The machine-precision regularization in the computation of the
Cholesky diagonal factors. Increase this for very ill-conditioned
systems.
copy_X : boolean, optional, default True
If True, X will be copied; else, it may be overwritten.
positive : boolean (default=False)
Restrict coefficients to be >= 0. Be aware that you might want to
remove fit_intercept which is set True by default.
Under the positive restriction the model coefficients do not converge
to the ordinary-least-squares solution for small values of alpha.
Only coefficients up to the smallest alpha value (``alphas_[alphas_ >
0.].min()`` when fit_path=True) reached by the stepwise Lars-Lasso
algorithm are typically in congruence with the solution of the
coordinate descent Lasso estimator.
As a consequence using LassoLarsCV only makes sense for problems where
a sparse solution is expected and/or reached.
Attributes
----------
coef_ : array, shape (n_features,)
parameter vector (w in the formulation formula)
intercept_ : float
independent term in decision function.
coef_path_ : array, shape (n_features, n_alphas)
the varying values of the coefficients along the path
alpha_ : float
the estimated regularization parameter alpha
alphas_ : array, shape (n_alphas,)
the different values of alpha along the path
cv_alphas_ : array, shape (n_cv_alphas,)
all the values of alpha along the path for the different folds
mse_path_ : array, shape (n_folds, n_cv_alphas)
the mean square error on left-out for each fold along the path
(alpha values given by ``cv_alphas``)
n_iter_ : array-like or int
the number of iterations run by Lars with the optimal alpha.
Notes
-----
The object solves the same problem as the LassoCV object. However,
unlike the LassoCV, it find the relevant alphas values by itself.
In general, because of this property, it will be more stable.
However, it is more fragile to heavily multicollinear datasets.
It is more efficient than the LassoCV if only a small number of
features are selected compared to the total number, for instance if
there are very few samples compared to the number of features.
See also
--------
lars_path, LassoLars, LarsCV, LassoCV
"""
method = 'lasso'
def __init__(self, fit_intercept=True, verbose=False, max_iter=500,
normalize=True, precompute='auto', cv=None,
max_n_alphas=1000, n_jobs=1, eps=np.finfo(np.float).eps,
copy_X=True, positive=False):
self.fit_intercept = fit_intercept
self.verbose = verbose
self.max_iter = max_iter
self.normalize = normalize
self.precompute = precompute
self.cv = cv
self.max_n_alphas = max_n_alphas
self.n_jobs = n_jobs
self.eps = eps
self.copy_X = copy_X
self.positive = positive
# XXX : we don't use super(LarsCV, self).__init__
# to avoid setting n_nonzero_coefs
class LassoLarsIC(LassoLars):
"""Lasso model fit with Lars using BIC or AIC for model selection
The optimization objective for Lasso is::
(1 / (2 * n_samples)) * ||y - Xw||^2_2 + alpha * ||w||_1
AIC is the Akaike information criterion and BIC is the Bayes
Information criterion. Such criteria are useful to select the value
of the regularization parameter by making a trade-off between the
goodness of fit and the complexity of the model. A good model should
explain well the data while being simple.
Read more in the :ref:`User Guide <least_angle_regression>`.
Parameters
----------
criterion : 'bic' | 'aic'
The type of criterion to use.
fit_intercept : boolean
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
verbose : boolean or integer, optional
Sets the verbosity amount
normalize : boolean, optional, default True
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
precompute : True | False | 'auto' | array-like
Whether to use a precomputed Gram matrix to speed up
calculations. If set to ``'auto'`` let us decide. The Gram
matrix can also be passed as argument.
max_iter : integer, optional
Maximum number of iterations to perform. Can be used for
early stopping.
eps : float, optional
The machine-precision regularization in the computation of the
Cholesky diagonal factors. Increase this for very ill-conditioned
systems. Unlike the ``tol`` parameter in some iterative
optimization-based algorithms, this parameter does not control
the tolerance of the optimization.
copy_X : boolean, optional, default True
If True, X will be copied; else, it may be overwritten.
positive : boolean (default=False)
Restrict coefficients to be >= 0. Be aware that you might want to
remove fit_intercept which is set True by default.
Under the positive restriction the model coefficients do not converge
to the ordinary-least-squares solution for small values of alpha.
Only coefficients up to the smallest alpha value (``alphas_[alphas_ >
0.].min()`` when fit_path=True) reached by the stepwise Lars-Lasso
algorithm are typically in congruence with the solution of the
coordinate descent Lasso estimator.
As a consequence using LassoLarsIC only makes sense for problems where
a sparse solution is expected and/or reached.
Attributes
----------
coef_ : array, shape (n_features,)
parameter vector (w in the formulation formula)
intercept_ : float
independent term in decision function.
alpha_ : float
the alpha parameter chosen by the information criterion
n_iter_ : int
number of iterations run by lars_path to find the grid of
alphas.
criterion_ : array, shape (n_alphas,)
The value of the information criteria ('aic', 'bic') across all
alphas. The alpha which has the smallest information criterion is
chosen. This value is larger by a factor of ``n_samples`` compared to
Eqns. 2.15 and 2.16 in (Zou et al, 2007).
Examples
--------
>>> from sklearn import linear_model
>>> reg = linear_model.LassoLarsIC(criterion='bic')
>>> reg.fit([[-1, 1], [0, 0], [1, 1]], [-1.1111, 0, -1.1111])
... # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
LassoLarsIC(copy_X=True, criterion='bic', eps=..., fit_intercept=True,
max_iter=500, normalize=True, positive=False, precompute='auto',
verbose=False)
>>> print(reg.coef_) # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
[ 0. -1.11...]
Notes
-----
The estimation of the number of degrees of freedom is given by:
"On the degrees of freedom of the lasso"
Hui Zou, Trevor Hastie, and Robert Tibshirani
Ann. Statist. Volume 35, Number 5 (2007), 2173-2192.
https://en.wikipedia.org/wiki/Akaike_information_criterion
https://en.wikipedia.org/wiki/Bayesian_information_criterion
See also
--------
lars_path, LassoLars, LassoLarsCV
"""
def __init__(self, criterion='aic', fit_intercept=True, verbose=False,
normalize=True, precompute='auto', max_iter=500,
eps=np.finfo(np.float).eps, copy_X=True, positive=False):
self.criterion = criterion
self.fit_intercept = fit_intercept
self.positive = positive
self.max_iter = max_iter
self.verbose = verbose
self.normalize = normalize
self.copy_X = copy_X
self.precompute = precompute
self.eps = eps
self.fit_path = True
def fit(self, X, y, copy_X=True):
"""Fit the model using X, y as training data.
Parameters
----------
X : array-like, shape (n_samples, n_features)
training data.
y : array-like, shape (n_samples,)
target values. Will be cast to X's dtype if necessary
copy_X : boolean, optional, default True
If ``True``, X will be copied; else, it may be overwritten.
Returns
-------
self : object
returns an instance of self.
"""
X, y = check_X_y(X, y, y_numeric=True)
X, y, Xmean, ymean, Xstd = LinearModel._preprocess_data(
X, y, self.fit_intercept, self.normalize, self.copy_X)
max_iter = self.max_iter
Gram = self.precompute
alphas_, active_, coef_path_, self.n_iter_ = lars_path(
X, y, Gram=Gram, copy_X=copy_X, copy_Gram=True, alpha_min=0.0,
method='lasso', verbose=self.verbose, max_iter=max_iter,
eps=self.eps, return_n_iter=True, positive=self.positive)
n_samples = X.shape[0]
if self.criterion == 'aic':
K = 2 # AIC
elif self.criterion == 'bic':
K = log(n_samples) # BIC
else:
raise ValueError('criterion should be either bic or aic')
R = y[:, np.newaxis] - np.dot(X, coef_path_) # residuals
mean_squared_error = np.mean(R ** 2, axis=0)
sigma2 = np.var(y)
df = np.zeros(coef_path_.shape[1], dtype=np.int) # Degrees of freedom
for k, coef in enumerate(coef_path_.T):
mask = np.abs(coef) > np.finfo(coef.dtype).eps
if not np.any(mask):
continue
# get the number of degrees of freedom equal to:
# Xc = X[:, mask]
# Trace(Xc * inv(Xc.T, Xc) * Xc.T) ie the number of non-zero coefs
df[k] = np.sum(mask)
self.alphas_ = alphas_
eps64 = np.finfo('float64').eps
self.criterion_ = (n_samples * mean_squared_error / (sigma2 + eps64) +
K * df) # Eqns. 2.15--16 in (Zou et al, 2007)
n_best = np.argmin(self.criterion_)
self.alpha_ = alphas_[n_best]
self.coef_ = coef_path_[:, n_best]
self._set_intercept(Xmean, ymean, Xstd)
return self
| 58,438 | 37.472021 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/randomized_l1.py | """
Randomized Lasso/Logistic: feature selection based on Lasso and
sparse Logistic Regression
"""
# Author: Gael Varoquaux, Alexandre Gramfort
#
# License: BSD 3 clause
import warnings
import itertools
from abc import ABCMeta, abstractmethod
import numpy as np
from scipy.sparse import issparse
from scipy import sparse
from scipy.interpolate import interp1d
from .base import _preprocess_data
from ..base import BaseEstimator
from ..externals import six
from ..externals.joblib import Memory, Parallel, delayed
from ..feature_selection.base import SelectorMixin
from ..utils import (as_float_array, check_random_state, check_X_y, safe_mask,
deprecated)
from ..utils.validation import check_is_fitted
from .least_angle import lars_path, LassoLarsIC
from .logistic import LogisticRegression
from ..exceptions import ConvergenceWarning
###############################################################################
# Randomized linear model: feature selection
def _resample_model(estimator_func, X, y, scaling=.5, n_resampling=200,
n_jobs=1, verbose=False, pre_dispatch='3*n_jobs',
random_state=None, sample_fraction=.75, **params):
random_state = check_random_state(random_state)
# We are generating 1 - weights, and not weights
n_samples, n_features = X.shape
if not (0 < scaling < 1):
raise ValueError(
"'scaling' should be between 0 and 1. Got %r instead." % scaling)
scaling = 1. - scaling
scores_ = 0.0
for active_set in Parallel(n_jobs=n_jobs, verbose=verbose,
pre_dispatch=pre_dispatch)(
delayed(estimator_func)(
X, y, weights=scaling * random_state.randint(
0, 2, size=(n_features,)),
mask=(random_state.rand(n_samples) < sample_fraction),
verbose=max(0, verbose - 1),
**params)
for _ in range(n_resampling)):
scores_ += active_set
scores_ /= n_resampling
return scores_
@deprecated("The class BaseRandomizedLinearModel is deprecated in 0.19"
" and will be removed in 0.21.")
class BaseRandomizedLinearModel(six.with_metaclass(ABCMeta, BaseEstimator,
SelectorMixin)):
"""Base class to implement randomized linear models for feature selection
This implements the strategy by Meinshausen and Buhlman:
stability selection with randomized sampling, and random re-weighting of
the penalty.
"""
@abstractmethod
def __init__(self):
pass
_preprocess_data = staticmethod(_preprocess_data)
def fit(self, X, y):
"""Fit the model using X, y as training data.
Parameters
----------
X : array-like, shape = [n_samples, n_features]
Training data.
y : array-like, shape = [n_samples]
Target values. Will be cast to X's dtype if necessary
Returns
-------
self : object
Returns an instance of self.
"""
X, y = check_X_y(X, y, ['csr', 'csc'], y_numeric=True,
ensure_min_samples=2, estimator=self)
X = as_float_array(X, copy=False)
n_samples, n_features = X.shape
X, y, X_offset, y_offset, X_scale = \
self._preprocess_data(X, y, self.fit_intercept, self.normalize)
estimator_func, params = self._make_estimator_and_params(X, y)
memory = self.memory
if memory is None:
memory = Memory(cachedir=None, verbose=0)
elif isinstance(memory, six.string_types):
memory = Memory(cachedir=memory, verbose=0)
elif not isinstance(memory, Memory):
raise ValueError("'memory' should either be a string or"
" a sklearn.externals.joblib.Memory"
" instance, got 'memory={!r}' instead.".format(
type(memory)))
scores_ = memory.cache(
_resample_model, ignore=['verbose', 'n_jobs', 'pre_dispatch']
)(
estimator_func, X, y,
scaling=self.scaling, n_resampling=self.n_resampling,
n_jobs=self.n_jobs, verbose=self.verbose,
pre_dispatch=self.pre_dispatch, random_state=self.random_state,
sample_fraction=self.sample_fraction, **params)
if scores_.ndim == 1:
scores_ = scores_[:, np.newaxis]
self.all_scores_ = scores_
self.scores_ = np.max(self.all_scores_, axis=1)
return self
def _make_estimator_and_params(self, X, y):
"""Return the parameters passed to the estimator"""
raise NotImplementedError
def _get_support_mask(self):
"""Get the boolean mask indicating which features are selected.
Returns
-------
support : boolean array of shape [# input features]
An element is True iff its corresponding feature is selected
for retention.
"""
check_is_fitted(self, 'scores_')
return self.scores_ > self.selection_threshold
###############################################################################
# Randomized lasso: regression settings
def _randomized_lasso(X, y, weights, mask, alpha=1., verbose=False,
precompute=False, eps=np.finfo(np.float).eps,
max_iter=500):
X = X[safe_mask(X, mask)]
y = y[mask]
# Center X and y to avoid fit the intercept
X -= X.mean(axis=0)
y -= y.mean()
alpha = np.atleast_1d(np.asarray(alpha, dtype=np.float64))
X = (1 - weights) * X
with warnings.catch_warnings():
warnings.simplefilter('ignore', ConvergenceWarning)
alphas_, _, coef_ = lars_path(X, y,
Gram=precompute, copy_X=False,
copy_Gram=False, alpha_min=np.min(alpha),
method='lasso', verbose=verbose,
max_iter=max_iter, eps=eps)
if len(alpha) > 1:
if len(alphas_) > 1: # np.min(alpha) < alpha_min
interpolator = interp1d(alphas_[::-1], coef_[:, ::-1],
bounds_error=False, fill_value=0.)
scores = (interpolator(alpha) != 0.0)
else:
scores = np.zeros((X.shape[1], len(alpha)), dtype=np.bool)
else:
scores = coef_[:, -1] != 0.0
return scores
@deprecated("The class RandomizedLasso is deprecated in 0.19"
" and will be removed in 0.21.")
class RandomizedLasso(BaseRandomizedLinearModel):
"""Randomized Lasso.
Randomized Lasso works by subsampling the training data and
computing a Lasso estimate where the penalty of a random subset of
coefficients has been scaled. By performing this double
randomization several times, the method assigns high scores to
features that are repeatedly selected across randomizations. This
is known as stability selection. In short, features selected more
often are considered good features.
Parameters
----------
alpha : float, 'aic', or 'bic', optional
The regularization parameter alpha parameter in the Lasso.
Warning: this is not the alpha parameter in the stability selection
article which is scaling.
scaling : float, optional
The s parameter used to randomly scale the penalty of different
features.
Should be between 0 and 1.
sample_fraction : float, optional
The fraction of samples to be used in each randomized design.
Should be between 0 and 1. If 1, all samples are used.
n_resampling : int, optional
Number of randomized models.
selection_threshold : float, optional
The score above which features should be selected.
fit_intercept : boolean, optional
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
verbose : boolean or integer, optional
Sets the verbosity amount
normalize : boolean, optional, default True
If True, the regressors X will be normalized before regression.
This parameter is ignored when `fit_intercept` is set to False.
When the regressors are normalized, note that this makes the
hyperparameters learned more robust and almost independent of
the number of samples. The same property is not valid for
standardized data. However, if you wish to standardize, please
use `preprocessing.StandardScaler` before calling `fit` on an
estimator with `normalize=False`.
precompute : True | False | 'auto' | array-like
Whether to use a precomputed Gram matrix to speed up calculations.
If set to 'auto' let us decide.
The Gram matrix can also be passed as argument, but it will be used
only for the selection of parameter alpha, if alpha is 'aic' or 'bic'.
max_iter : integer, optional
Maximum number of iterations to perform in the Lars algorithm.
eps : float, optional
The machine-precision regularization in the computation of the
Cholesky diagonal factors. Increase this for very ill-conditioned
systems. Unlike the 'tol' parameter in some iterative
optimization-based algorithms, this parameter does not control
the tolerance of the optimization.
random_state : int, RandomState instance or None, optional (default=None)
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
n_jobs : integer, optional
Number of CPUs to use during the resampling. If '-1', use
all the CPUs
pre_dispatch : int, or string, optional
Controls the number of jobs that get dispatched during parallel
execution. Reducing this number can be useful to avoid an
explosion of memory consumption when more jobs get dispatched
than CPUs can process. This parameter can be:
- None, in which case all the jobs are immediately
created and spawned. Use this for lightweight and
fast-running jobs, to avoid delays due to on-demand
spawning of the jobs
- An int, giving the exact number of total jobs that are
spawned
- A string, giving an expression as a function of n_jobs,
as in '2*n_jobs'
memory : None, str or object with the joblib.Memory interface, optional \
(default=None)
Used for internal caching. By default, no caching is done.
If a string is given, it is the path to the caching directory.
Attributes
----------
scores_ : array, shape = [n_features]
Feature scores between 0 and 1.
all_scores_ : array, shape = [n_features, n_reg_parameter]
Feature scores between 0 and 1 for all values of the regularization \
parameter. The reference article suggests ``scores_`` is the max of \
``all_scores_``.
Examples
--------
>>> from sklearn.linear_model import RandomizedLasso
>>> randomized_lasso = RandomizedLasso()
References
----------
Stability selection
Nicolai Meinshausen, Peter Buhlmann
Journal of the Royal Statistical Society: Series B
Volume 72, Issue 4, pages 417-473, September 2010
DOI: 10.1111/j.1467-9868.2010.00740.x
See also
--------
RandomizedLogisticRegression, Lasso, ElasticNet
"""
def __init__(self, alpha='aic', scaling=.5, sample_fraction=.75,
n_resampling=200, selection_threshold=.25,
fit_intercept=True, verbose=False,
normalize=True, precompute='auto',
max_iter=500,
eps=np.finfo(np.float).eps, random_state=None,
n_jobs=1, pre_dispatch='3*n_jobs',
memory=None):
self.alpha = alpha
self.scaling = scaling
self.sample_fraction = sample_fraction
self.n_resampling = n_resampling
self.fit_intercept = fit_intercept
self.max_iter = max_iter
self.verbose = verbose
self.normalize = normalize
self.precompute = precompute
self.eps = eps
self.random_state = random_state
self.n_jobs = n_jobs
self.selection_threshold = selection_threshold
self.pre_dispatch = pre_dispatch
self.memory = memory
def _make_estimator_and_params(self, X, y):
alpha = self.alpha
if isinstance(alpha, six.string_types) and alpha in ('aic', 'bic'):
model = LassoLarsIC(precompute=self.precompute,
criterion=self.alpha,
max_iter=self.max_iter,
eps=self.eps)
model.fit(X, y)
self.alpha_ = alpha = model.alpha_
precompute = self.precompute
# A precomputed Gram array is useless, since _randomized_lasso
# change X a each iteration
if hasattr(precompute, '__array__'):
precompute = 'auto'
assert precompute in (True, False, None, 'auto')
return _randomized_lasso, dict(alpha=alpha, max_iter=self.max_iter,
eps=self.eps,
precompute=precompute)
###############################################################################
# Randomized logistic: classification settings
def _randomized_logistic(X, y, weights, mask, C=1., verbose=False,
fit_intercept=True, tol=1e-3):
X = X[safe_mask(X, mask)]
y = y[mask]
if issparse(X):
size = len(weights)
weight_dia = sparse.dia_matrix((1 - weights, 0), (size, size))
X = X * weight_dia
else:
X *= (1 - weights)
C = np.atleast_1d(np.asarray(C, dtype=np.float64))
if C.ndim > 1:
raise ValueError("C should be 1-dimensional array-like, "
"but got a {}-dimensional array-like instead: {}."
.format(C.ndim, C))
scores = np.zeros((X.shape[1], len(C)), dtype=np.bool)
for this_C, this_scores in zip(C, scores.T):
# XXX : would be great to do it with a warm_start ...
clf = LogisticRegression(C=this_C, tol=tol, penalty='l1', dual=False,
fit_intercept=fit_intercept)
clf.fit(X, y)
this_scores[:] = np.any(
np.abs(clf.coef_) > 10 * np.finfo(np.float).eps, axis=0)
return scores
@deprecated("The class RandomizedLogisticRegression is deprecated in 0.19"
" and will be removed in 0.21.")
class RandomizedLogisticRegression(BaseRandomizedLinearModel):
"""Randomized Logistic Regression
Randomized Logistic Regression works by subsampling the training
data and fitting a L1-penalized LogisticRegression model where the
penalty of a random subset of coefficients has been scaled. By
performing this double randomization several times, the method
assigns high scores to features that are repeatedly selected across
randomizations. This is known as stability selection. In short,
features selected more often are considered good features.
Parameters
----------
C : float or array-like of shape [n_reg_parameter], optional, default=1
The regularization parameter C in the LogisticRegression.
When C is an array, fit will take each regularization parameter in C
one by one for LogisticRegression and store results for each one
in ``all_scores_``, where columns and rows represent corresponding
reg_parameters and features.
scaling : float, optional, default=0.5
The s parameter used to randomly scale the penalty of different
features.
Should be between 0 and 1.
sample_fraction : float, optional, default=0.75
The fraction of samples to be used in each randomized design.
Should be between 0 and 1. If 1, all samples are used.
n_resampling : int, optional, default=200
Number of randomized models.
selection_threshold : float, optional, default=0.25
The score above which features should be selected.
tol : float, optional, default=1e-3
tolerance for stopping criteria of LogisticRegression
fit_intercept : boolean, optional, default=True
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
verbose : boolean or integer, optional
Sets the verbosity amount
normalize : boolean, optional, default True
If True, the regressors X will be normalized before regression.
This parameter is ignored when `fit_intercept` is set to False.
When the regressors are normalized, note that this makes the
hyperparameters learnt more robust and almost independent of the number
of samples. The same property is not valid for standardized data.
However, if you wish to standardize, please use
`preprocessing.StandardScaler` before calling `fit` on an estimator
with `normalize=False`.
random_state : int, RandomState instance or None, optional (default=None)
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
n_jobs : integer, optional
Number of CPUs to use during the resampling. If '-1', use
all the CPUs
pre_dispatch : int, or string, optional
Controls the number of jobs that get dispatched during parallel
execution. Reducing this number can be useful to avoid an
explosion of memory consumption when more jobs get dispatched
than CPUs can process. This parameter can be:
- None, in which case all the jobs are immediately
created and spawned. Use this for lightweight and
fast-running jobs, to avoid delays due to on-demand
spawning of the jobs
- An int, giving the exact number of total jobs that are
spawned
- A string, giving an expression as a function of n_jobs,
as in '2*n_jobs'
memory : None, str or object with the joblib.Memory interface, optional \
(default=None)
Used for internal caching. By default, no caching is done.
If a string is given, it is the path to the caching directory.
Attributes
----------
scores_ : array, shape = [n_features]
Feature scores between 0 and 1.
all_scores_ : array, shape = [n_features, n_reg_parameter]
Feature scores between 0 and 1 for all values of the regularization \
parameter. The reference article suggests ``scores_`` is the max \
of ``all_scores_``.
Examples
--------
>>> from sklearn.linear_model import RandomizedLogisticRegression
>>> randomized_logistic = RandomizedLogisticRegression()
References
----------
Stability selection
Nicolai Meinshausen, Peter Buhlmann
Journal of the Royal Statistical Society: Series B
Volume 72, Issue 4, pages 417-473, September 2010
DOI: 10.1111/j.1467-9868.2010.00740.x
See also
--------
RandomizedLasso, LogisticRegression
"""
def __init__(self, C=1, scaling=.5, sample_fraction=.75,
n_resampling=200,
selection_threshold=.25, tol=1e-3,
fit_intercept=True, verbose=False,
normalize=True,
random_state=None,
n_jobs=1, pre_dispatch='3*n_jobs',
memory=None):
self.C = C
self.scaling = scaling
self.sample_fraction = sample_fraction
self.n_resampling = n_resampling
self.fit_intercept = fit_intercept
self.verbose = verbose
self.normalize = normalize
self.tol = tol
self.random_state = random_state
self.n_jobs = n_jobs
self.selection_threshold = selection_threshold
self.pre_dispatch = pre_dispatch
self.memory = memory
def _make_estimator_and_params(self, X, y):
params = dict(C=self.C, tol=self.tol,
fit_intercept=self.fit_intercept)
return _randomized_logistic, params
def _preprocess_data(self, X, y, fit_intercept, normalize=False):
"""Center the data in X but not in y"""
X, _, X_offset, _, X_scale = _preprocess_data(X, y, fit_intercept,
normalize=normalize)
return X, y, X_offset, y, X_scale
###############################################################################
# Stability paths
def _lasso_stability_path(X, y, mask, weights, eps):
"Inner loop of lasso_stability_path"
X = X * weights[np.newaxis, :]
X = X[safe_mask(X, mask), :]
y = y[mask]
alpha_max = np.max(np.abs(np.dot(X.T, y))) / X.shape[0]
alpha_min = eps * alpha_max # set for early stopping in path
with warnings.catch_warnings():
warnings.simplefilter('ignore', ConvergenceWarning)
alphas, _, coefs = lars_path(X, y, method='lasso', verbose=False,
alpha_min=alpha_min)
# Scale alpha by alpha_max
alphas /= alphas[0]
# Sort alphas in ascending order
alphas = alphas[::-1]
coefs = coefs[:, ::-1]
# Get rid of the alphas that are too small
mask = alphas >= eps
# We also want to keep the first one: it should be close to the OLS
# solution
mask[0] = True
alphas = alphas[mask]
coefs = coefs[:, mask]
return alphas, coefs
@deprecated("The function lasso_stability_path is deprecated in 0.19"
" and will be removed in 0.21.")
def lasso_stability_path(X, y, scaling=0.5, random_state=None,
n_resampling=200, n_grid=100,
sample_fraction=0.75,
eps=4 * np.finfo(np.float).eps, n_jobs=1,
verbose=False):
"""Stability path based on randomized Lasso estimates
Parameters
----------
X : array-like, shape = [n_samples, n_features]
training data.
y : array-like, shape = [n_samples]
target values.
scaling : float, optional, default=0.5
The alpha parameter in the stability selection article used to
randomly scale the features. Should be between 0 and 1.
random_state : int, RandomState instance or None, optional, default=None
The generator used to randomize the design. If int, random_state is
the seed used by the random number generator; If RandomState instance,
random_state is the random number generator; If None, the random number
generator is the RandomState instance used by `np.random`.
n_resampling : int, optional, default=200
Number of randomized models.
n_grid : int, optional, default=100
Number of grid points. The path is linearly reinterpolated
on a grid between 0 and 1 before computing the scores.
sample_fraction : float, optional, default=0.75
The fraction of samples to be used in each randomized design.
Should be between 0 and 1. If 1, all samples are used.
eps : float, optional
Smallest value of alpha / alpha_max considered
n_jobs : integer, optional
Number of CPUs to use during the resampling. If '-1', use
all the CPUs
verbose : boolean or integer, optional
Sets the verbosity amount
Returns
-------
alphas_grid : array, shape ~ [n_grid]
The grid points between 0 and 1: alpha/alpha_max
scores_path : array, shape = [n_features, n_grid]
The scores for each feature along the path.
"""
X, y = check_X_y(X, y, accept_sparse=['csr', 'csc', 'coo'])
rng = check_random_state(random_state)
if not (0 < scaling < 1):
raise ValueError("Parameter 'scaling' should be between 0 and 1."
" Got %r instead." % scaling)
n_samples, n_features = X.shape
paths = Parallel(n_jobs=n_jobs, verbose=verbose)(
delayed(_lasso_stability_path)(
X, y, mask=rng.rand(n_samples) < sample_fraction,
weights=1. - scaling * rng.randint(0, 2, size=(n_features,)),
eps=eps)
for k in range(n_resampling))
all_alphas = sorted(list(set(itertools.chain(*[p[0] for p in paths]))))
# Take approximately n_grid values
stride = int(max(1, int(len(all_alphas) / float(n_grid))))
all_alphas = all_alphas[::stride]
if not all_alphas[-1] == 1:
all_alphas.append(1.)
all_alphas = np.array(all_alphas)
scores_path = np.zeros((n_features, len(all_alphas)))
for alphas, coefs in paths:
if alphas[0] != 0:
alphas = np.r_[0, alphas]
coefs = np.c_[np.ones((n_features, 1)), coefs]
if alphas[-1] != all_alphas[-1]:
alphas = np.r_[alphas, all_alphas[-1]]
coefs = np.c_[coefs, np.zeros((n_features, 1))]
scores_path += (interp1d(alphas, coefs,
kind='nearest', bounds_error=False,
fill_value=0, axis=-1)(all_alphas) != 0)
scores_path /= n_resampling
return all_alphas, scores_path
| 25,868 | 37.959337 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/theil_sen.py | # -*- coding: utf-8 -*-
"""
A Theil-Sen Estimator for Multiple Linear Regression Model
"""
# Author: Florian Wilhelm <[email protected]>
#
# License: BSD 3 clause
from __future__ import division, print_function, absolute_import
import warnings
from itertools import combinations
import numpy as np
from scipy import linalg
from scipy.special import binom
from scipy.linalg.lapack import get_lapack_funcs
from .base import LinearModel
from ..base import RegressorMixin
from ..utils import check_random_state
from ..utils import check_X_y, _get_n_jobs
from ..externals.joblib import Parallel, delayed
from ..externals.six.moves import xrange as range
from ..exceptions import ConvergenceWarning
_EPSILON = np.finfo(np.double).eps
def _modified_weiszfeld_step(X, x_old):
"""Modified Weiszfeld step.
This function defines one iteration step in order to approximate the
spatial median (L1 median). It is a form of an iteratively re-weighted
least squares method.
Parameters
----------
X : array, shape = [n_samples, n_features]
Training vector, where n_samples is the number of samples and
n_features is the number of features.
x_old : array, shape = [n_features]
Current start vector.
Returns
-------
x_new : array, shape = [n_features]
New iteration step.
References
----------
- On Computation of Spatial Median for Robust Data Mining, 2005
T. Kärkkäinen and S. Äyrämö
http://users.jyu.fi/~samiayr/pdf/ayramo_eurogen05.pdf
"""
diff = X - x_old
diff_norm = np.sqrt(np.sum(diff ** 2, axis=1))
mask = diff_norm >= _EPSILON
# x_old equals one of our samples
is_x_old_in_X = int(mask.sum() < X.shape[0])
diff = diff[mask]
diff_norm = diff_norm[mask][:, np.newaxis]
quotient_norm = linalg.norm(np.sum(diff / diff_norm, axis=0))
if quotient_norm > _EPSILON: # to avoid division by zero
new_direction = (np.sum(X[mask, :] / diff_norm, axis=0)
/ np.sum(1 / diff_norm, axis=0))
else:
new_direction = 1.
quotient_norm = 1.
return (max(0., 1. - is_x_old_in_X / quotient_norm) * new_direction
+ min(1., is_x_old_in_X / quotient_norm) * x_old)
def _spatial_median(X, max_iter=300, tol=1.e-3):
"""Spatial median (L1 median).
The spatial median is member of a class of so-called M-estimators which
are defined by an optimization problem. Given a number of p points in an
n-dimensional space, the point x minimizing the sum of all distances to the
p other points is called spatial median.
Parameters
----------
X : array, shape = [n_samples, n_features]
Training vector, where n_samples is the number of samples and
n_features is the number of features.
max_iter : int, optional
Maximum number of iterations. Default is 300.
tol : float, optional
Stop the algorithm if spatial_median has converged. Default is 1.e-3.
Returns
-------
spatial_median : array, shape = [n_features]
Spatial median.
n_iter : int
Number of iterations needed.
References
----------
- On Computation of Spatial Median for Robust Data Mining, 2005
T. Kärkkäinen and S. Äyrämö
http://users.jyu.fi/~samiayr/pdf/ayramo_eurogen05.pdf
"""
if X.shape[1] == 1:
return 1, np.median(X.ravel())
tol **= 2 # We are computing the tol on the squared norm
spatial_median_old = np.mean(X, axis=0)
for n_iter in range(max_iter):
spatial_median = _modified_weiszfeld_step(X, spatial_median_old)
if np.sum((spatial_median_old - spatial_median) ** 2) < tol:
break
else:
spatial_median_old = spatial_median
else:
warnings.warn("Maximum number of iterations {max_iter} reached in "
"spatial median for TheilSen regressor."
"".format(max_iter=max_iter), ConvergenceWarning)
return n_iter, spatial_median
def _breakdown_point(n_samples, n_subsamples):
"""Approximation of the breakdown point.
Parameters
----------
n_samples : int
Number of samples.
n_subsamples : int
Number of subsamples to consider.
Returns
-------
breakdown_point : float
Approximation of breakdown point.
"""
return 1 - (0.5 ** (1 / n_subsamples) * (n_samples - n_subsamples + 1) +
n_subsamples - 1) / n_samples
def _lstsq(X, y, indices, fit_intercept):
"""Least Squares Estimator for TheilSenRegressor class.
This function calculates the least squares method on a subset of rows of X
and y defined by the indices array. Optionally, an intercept column is
added if intercept is set to true.
Parameters
----------
X : array, shape = [n_samples, n_features]
Design matrix, where n_samples is the number of samples and
n_features is the number of features.
y : array, shape = [n_samples]
Target vector, where n_samples is the number of samples.
indices : array, shape = [n_subpopulation, n_subsamples]
Indices of all subsamples with respect to the chosen subpopulation.
fit_intercept : bool
Fit intercept or not.
Returns
-------
weights : array, shape = [n_subpopulation, n_features + intercept]
Solution matrix of n_subpopulation solved least square problems.
"""
fit_intercept = int(fit_intercept)
n_features = X.shape[1] + fit_intercept
n_subsamples = indices.shape[1]
weights = np.empty((indices.shape[0], n_features))
X_subpopulation = np.ones((n_subsamples, n_features))
# gelss need to pad y_subpopulation to be of the max dim of X_subpopulation
y_subpopulation = np.zeros((max(n_subsamples, n_features)))
lstsq, = get_lapack_funcs(('gelss',), (X_subpopulation, y_subpopulation))
for index, subset in enumerate(indices):
X_subpopulation[:, fit_intercept:] = X[subset, :]
y_subpopulation[:n_subsamples] = y[subset]
weights[index] = lstsq(X_subpopulation,
y_subpopulation)[1][:n_features]
return weights
class TheilSenRegressor(LinearModel, RegressorMixin):
"""Theil-Sen Estimator: robust multivariate regression model.
The algorithm calculates least square solutions on subsets with size
n_subsamples of the samples in X. Any value of n_subsamples between the
number of features and samples leads to an estimator with a compromise
between robustness and efficiency. Since the number of least square
solutions is "n_samples choose n_subsamples", it can be extremely large
and can therefore be limited with max_subpopulation. If this limit is
reached, the subsets are chosen randomly. In a final step, the spatial
median (or L1 median) is calculated of all least square solutions.
Read more in the :ref:`User Guide <theil_sen_regression>`.
Parameters
----------
fit_intercept : boolean, optional, default True
Whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations.
copy_X : boolean, optional, default True
If True, X will be copied; else, it may be overwritten.
max_subpopulation : int, optional, default 1e4
Instead of computing with a set of cardinality 'n choose k', where n is
the number of samples and k is the number of subsamples (at least
number of features), consider only a stochastic subpopulation of a
given maximal size if 'n choose k' is larger than max_subpopulation.
For other than small problem sizes this parameter will determine
memory usage and runtime if n_subsamples is not changed.
n_subsamples : int, optional, default None
Number of samples to calculate the parameters. This is at least the
number of features (plus 1 if fit_intercept=True) and the number of
samples as a maximum. A lower number leads to a higher breakdown
point and a low efficiency while a high number leads to a low
breakdown point and a high efficiency. If None, take the
minimum number of subsamples leading to maximal robustness.
If n_subsamples is set to n_samples, Theil-Sen is identical to least
squares.
max_iter : int, optional, default 300
Maximum number of iterations for the calculation of spatial median.
tol : float, optional, default 1.e-3
Tolerance when calculating spatial median.
random_state : int, RandomState instance or None, optional, default None
A random number generator instance to define the state of the random
permutations generator. If int, random_state is the seed used by the
random number generator; If RandomState instance, random_state is the
random number generator; If None, the random number generator is the
RandomState instance used by `np.random`.
n_jobs : integer, optional, default 1
Number of CPUs to use during the cross validation. If ``-1``, use
all the CPUs.
verbose : boolean, optional, default False
Verbose mode when fitting the model.
Attributes
----------
coef_ : array, shape = (n_features)
Coefficients of the regression model (median of distribution).
intercept_ : float
Estimated intercept of regression model.
breakdown_ : float
Approximated breakdown point.
n_iter_ : int
Number of iterations needed for the spatial median.
n_subpopulation_ : int
Number of combinations taken into account from 'n choose k', where n is
the number of samples and k is the number of subsamples.
References
----------
- Theil-Sen Estimators in a Multiple Linear Regression Model, 2009
Xin Dang, Hanxiang Peng, Xueqin Wang and Heping Zhang
http://home.olemiss.edu/~xdang/papers/MTSE.pdf
"""
def __init__(self, fit_intercept=True, copy_X=True,
max_subpopulation=1e4, n_subsamples=None, max_iter=300,
tol=1.e-3, random_state=None, n_jobs=1, verbose=False):
self.fit_intercept = fit_intercept
self.copy_X = copy_X
self.max_subpopulation = int(max_subpopulation)
self.n_subsamples = n_subsamples
self.max_iter = max_iter
self.tol = tol
self.random_state = random_state
self.n_jobs = n_jobs
self.verbose = verbose
def _check_subparams(self, n_samples, n_features):
n_subsamples = self.n_subsamples
if self.fit_intercept:
n_dim = n_features + 1
else:
n_dim = n_features
if n_subsamples is not None:
if n_subsamples > n_samples:
raise ValueError("Invalid parameter since n_subsamples > "
"n_samples ({0} > {1}).".format(n_subsamples,
n_samples))
if n_samples >= n_features:
if n_dim > n_subsamples:
plus_1 = "+1" if self.fit_intercept else ""
raise ValueError("Invalid parameter since n_features{0} "
"> n_subsamples ({1} > {2})."
"".format(plus_1, n_dim, n_samples))
else: # if n_samples < n_features
if n_subsamples != n_samples:
raise ValueError("Invalid parameter since n_subsamples != "
"n_samples ({0} != {1}) while n_samples "
"< n_features.".format(n_subsamples,
n_samples))
else:
n_subsamples = min(n_dim, n_samples)
if self.max_subpopulation <= 0:
raise ValueError("Subpopulation must be strictly positive "
"({0} <= 0).".format(self.max_subpopulation))
all_combinations = max(1, np.rint(binom(n_samples, n_subsamples)))
n_subpopulation = int(min(self.max_subpopulation, all_combinations))
return n_subsamples, n_subpopulation
def fit(self, X, y):
"""Fit linear model.
Parameters
----------
X : numpy array of shape [n_samples, n_features]
Training data
y : numpy array of shape [n_samples]
Target values
Returns
-------
self : returns an instance of self.
"""
random_state = check_random_state(self.random_state)
X, y = check_X_y(X, y, y_numeric=True)
n_samples, n_features = X.shape
n_subsamples, self.n_subpopulation_ = self._check_subparams(n_samples,
n_features)
self.breakdown_ = _breakdown_point(n_samples, n_subsamples)
if self.verbose:
print("Breakdown point: {0}".format(self.breakdown_))
print("Number of samples: {0}".format(n_samples))
tol_outliers = int(self.breakdown_ * n_samples)
print("Tolerable outliers: {0}".format(tol_outliers))
print("Number of subpopulations: {0}".format(
self.n_subpopulation_))
# Determine indices of subpopulation
if np.rint(binom(n_samples, n_subsamples)) <= self.max_subpopulation:
indices = list(combinations(range(n_samples), n_subsamples))
else:
indices = [random_state.choice(n_samples, size=n_subsamples,
replace=False)
for _ in range(self.n_subpopulation_)]
n_jobs = _get_n_jobs(self.n_jobs)
index_list = np.array_split(indices, n_jobs)
weights = Parallel(n_jobs=n_jobs,
verbose=self.verbose)(
delayed(_lstsq)(X, y, index_list[job], self.fit_intercept)
for job in range(n_jobs))
weights = np.vstack(weights)
self.n_iter_, coefs = _spatial_median(weights,
max_iter=self.max_iter,
tol=self.tol)
if self.fit_intercept:
self.intercept_ = coefs[0]
self.coef_ = coefs[1:]
else:
self.intercept_ = 0.
self.coef_ = coefs
return self
| 14,493 | 36.164103 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/__init__.py | """
The :mod:`sklearn.linear_model` module implements generalized linear models. It
includes Ridge regression, Bayesian Regression, Lasso and Elastic Net
estimators computed with Least Angle Regression and coordinate descent. It also
implements Stochastic Gradient Descent related algorithms.
"""
# See http://scikit-learn.sourceforge.net/modules/sgd.html and
# http://scikit-learn.sourceforge.net/modules/linear_model.html for
# complete documentation.
from .base import LinearRegression
from .bayes import BayesianRidge, ARDRegression
from .least_angle import (Lars, LassoLars, lars_path, LarsCV, LassoLarsCV,
LassoLarsIC)
from .coordinate_descent import (Lasso, ElasticNet, LassoCV, ElasticNetCV,
lasso_path, enet_path, MultiTaskLasso,
MultiTaskElasticNet, MultiTaskElasticNetCV,
MultiTaskLassoCV)
from .huber import HuberRegressor
from .sgd_fast import Hinge, Log, ModifiedHuber, SquaredLoss, Huber
from .stochastic_gradient import SGDClassifier, SGDRegressor
from .ridge import (Ridge, RidgeCV, RidgeClassifier, RidgeClassifierCV,
ridge_regression)
from .logistic import (LogisticRegression, LogisticRegressionCV,
logistic_regression_path)
from .omp import (orthogonal_mp, orthogonal_mp_gram, OrthogonalMatchingPursuit,
OrthogonalMatchingPursuitCV)
from .passive_aggressive import PassiveAggressiveClassifier
from .passive_aggressive import PassiveAggressiveRegressor
from .perceptron import Perceptron
from .randomized_l1 import (RandomizedLasso, RandomizedLogisticRegression,
lasso_stability_path)
from .ransac import RANSACRegressor
from .theil_sen import TheilSenRegressor
__all__ = ['ARDRegression',
'BayesianRidge',
'ElasticNet',
'ElasticNetCV',
'Hinge',
'Huber',
'HuberRegressor',
'Lars',
'LarsCV',
'Lasso',
'LassoCV',
'LassoLars',
'LassoLarsCV',
'LassoLarsIC',
'LinearRegression',
'Log',
'LogisticRegression',
'LogisticRegressionCV',
'ModifiedHuber',
'MultiTaskElasticNet',
'MultiTaskElasticNetCV',
'MultiTaskLasso',
'MultiTaskLassoCV',
'OrthogonalMatchingPursuit',
'OrthogonalMatchingPursuitCV',
'PassiveAggressiveClassifier',
'PassiveAggressiveRegressor',
'Perceptron',
'RandomizedLasso',
'RandomizedLogisticRegression',
'Ridge',
'RidgeCV',
'RidgeClassifier',
'RidgeClassifierCV',
'SGDClassifier',
'SGDRegressor',
'SquaredLoss',
'TheilSenRegressor',
'enet_path',
'lars_path',
'lasso_path',
'lasso_stability_path',
'logistic_regression_path',
'orthogonal_mp',
'orthogonal_mp_gram',
'ridge_regression',
'RANSACRegressor']
| 3,161 | 35.344828 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/omp.py | """Orthogonal matching pursuit algorithms
"""
# Author: Vlad Niculae
#
# License: BSD 3 clause
import warnings
import numpy as np
from scipy import linalg
from scipy.linalg.lapack import get_lapack_funcs
from .base import LinearModel, _pre_fit
from ..base import RegressorMixin
from ..utils import as_float_array, check_array, check_X_y
from ..model_selection import check_cv
from ..externals.joblib import Parallel, delayed
solve_triangular_args = {'check_finite': False}
premature = """ Orthogonal matching pursuit ended prematurely due to linear
dependence in the dictionary. The requested precision might not have been met.
"""
def _cholesky_omp(X, y, n_nonzero_coefs, tol=None, copy_X=True,
return_path=False):
"""Orthogonal Matching Pursuit step using the Cholesky decomposition.
Parameters
----------
X : array, shape (n_samples, n_features)
Input dictionary. Columns are assumed to have unit norm.
y : array, shape (n_samples,)
Input targets
n_nonzero_coefs : int
Targeted number of non-zero elements
tol : float
Targeted squared error, if not None overrides n_nonzero_coefs.
copy_X : bool, optional
Whether the design matrix X must be copied by the algorithm. A false
value is only helpful if X is already Fortran-ordered, otherwise a
copy is made anyway.
return_path : bool, optional. Default: False
Whether to return every value of the nonzero coefficients along the
forward path. Useful for cross-validation.
Returns
-------
gamma : array, shape (n_nonzero_coefs,)
Non-zero elements of the solution
idx : array, shape (n_nonzero_coefs,)
Indices of the positions of the elements in gamma within the solution
vector
coef : array, shape (n_features, n_nonzero_coefs)
The first k values of column k correspond to the coefficient value
for the active features at that step. The lower left triangle contains
garbage. Only returned if ``return_path=True``.
n_active : int
Number of active features at convergence.
"""
if copy_X:
X = X.copy('F')
else: # even if we are allowed to overwrite, still copy it if bad order
X = np.asfortranarray(X)
min_float = np.finfo(X.dtype).eps
nrm2, swap = linalg.get_blas_funcs(('nrm2', 'swap'), (X,))
potrs, = get_lapack_funcs(('potrs',), (X,))
alpha = np.dot(X.T, y)
residual = y
gamma = np.empty(0)
n_active = 0
indices = np.arange(X.shape[1]) # keeping track of swapping
max_features = X.shape[1] if tol is not None else n_nonzero_coefs
if solve_triangular_args:
# new scipy, don't need to initialize because check_finite=False
L = np.empty((max_features, max_features), dtype=X.dtype)
else:
# old scipy, we need the garbage upper triangle to be non-Inf
L = np.zeros((max_features, max_features), dtype=X.dtype)
L[0, 0] = 1.
if return_path:
coefs = np.empty_like(L)
while True:
lam = np.argmax(np.abs(np.dot(X.T, residual)))
if lam < n_active or alpha[lam] ** 2 < min_float:
# atom already selected or inner product too small
warnings.warn(premature, RuntimeWarning, stacklevel=2)
break
if n_active > 0:
# Updates the Cholesky decomposition of X' X
L[n_active, :n_active] = np.dot(X[:, :n_active].T, X[:, lam])
linalg.solve_triangular(L[:n_active, :n_active],
L[n_active, :n_active],
trans=0, lower=1,
overwrite_b=True,
**solve_triangular_args)
v = nrm2(L[n_active, :n_active]) ** 2
if 1 - v <= min_float: # selected atoms are dependent
warnings.warn(premature, RuntimeWarning, stacklevel=2)
break
L[n_active, n_active] = np.sqrt(1 - v)
X.T[n_active], X.T[lam] = swap(X.T[n_active], X.T[lam])
alpha[n_active], alpha[lam] = alpha[lam], alpha[n_active]
indices[n_active], indices[lam] = indices[lam], indices[n_active]
n_active += 1
# solves LL'x = y as a composition of two triangular systems
gamma, _ = potrs(L[:n_active, :n_active], alpha[:n_active], lower=True,
overwrite_b=False)
if return_path:
coefs[:n_active, n_active - 1] = gamma
residual = y - np.dot(X[:, :n_active], gamma)
if tol is not None and nrm2(residual) ** 2 <= tol:
break
elif n_active == max_features:
break
if return_path:
return gamma, indices[:n_active], coefs[:, :n_active], n_active
else:
return gamma, indices[:n_active], n_active
def _gram_omp(Gram, Xy, n_nonzero_coefs, tol_0=None, tol=None,
copy_Gram=True, copy_Xy=True, return_path=False):
"""Orthogonal Matching Pursuit step on a precomputed Gram matrix.
This function uses the Cholesky decomposition method.
Parameters
----------
Gram : array, shape (n_features, n_features)
Gram matrix of the input data matrix
Xy : array, shape (n_features,)
Input targets
n_nonzero_coefs : int
Targeted number of non-zero elements
tol_0 : float
Squared norm of y, required if tol is not None.
tol : float
Targeted squared error, if not None overrides n_nonzero_coefs.
copy_Gram : bool, optional
Whether the gram matrix must be copied by the algorithm. A false
value is only helpful if it is already Fortran-ordered, otherwise a
copy is made anyway.
copy_Xy : bool, optional
Whether the covariance vector Xy must be copied by the algorithm.
If False, it may be overwritten.
return_path : bool, optional. Default: False
Whether to return every value of the nonzero coefficients along the
forward path. Useful for cross-validation.
Returns
-------
gamma : array, shape (n_nonzero_coefs,)
Non-zero elements of the solution
idx : array, shape (n_nonzero_coefs,)
Indices of the positions of the elements in gamma within the solution
vector
coefs : array, shape (n_features, n_nonzero_coefs)
The first k values of column k correspond to the coefficient value
for the active features at that step. The lower left triangle contains
garbage. Only returned if ``return_path=True``.
n_active : int
Number of active features at convergence.
"""
Gram = Gram.copy('F') if copy_Gram else np.asfortranarray(Gram)
if copy_Xy:
Xy = Xy.copy()
min_float = np.finfo(Gram.dtype).eps
nrm2, swap = linalg.get_blas_funcs(('nrm2', 'swap'), (Gram,))
potrs, = get_lapack_funcs(('potrs',), (Gram,))
indices = np.arange(len(Gram)) # keeping track of swapping
alpha = Xy
tol_curr = tol_0
delta = 0
gamma = np.empty(0)
n_active = 0
max_features = len(Gram) if tol is not None else n_nonzero_coefs
if solve_triangular_args:
# new scipy, don't need to initialize because check_finite=False
L = np.empty((max_features, max_features), dtype=Gram.dtype)
else:
# old scipy, we need the garbage upper triangle to be non-Inf
L = np.zeros((max_features, max_features), dtype=Gram.dtype)
L[0, 0] = 1.
if return_path:
coefs = np.empty_like(L)
while True:
lam = np.argmax(np.abs(alpha))
if lam < n_active or alpha[lam] ** 2 < min_float:
# selected same atom twice, or inner product too small
warnings.warn(premature, RuntimeWarning, stacklevel=3)
break
if n_active > 0:
L[n_active, :n_active] = Gram[lam, :n_active]
linalg.solve_triangular(L[:n_active, :n_active],
L[n_active, :n_active],
trans=0, lower=1,
overwrite_b=True,
**solve_triangular_args)
v = nrm2(L[n_active, :n_active]) ** 2
if 1 - v <= min_float: # selected atoms are dependent
warnings.warn(premature, RuntimeWarning, stacklevel=3)
break
L[n_active, n_active] = np.sqrt(1 - v)
Gram[n_active], Gram[lam] = swap(Gram[n_active], Gram[lam])
Gram.T[n_active], Gram.T[lam] = swap(Gram.T[n_active], Gram.T[lam])
indices[n_active], indices[lam] = indices[lam], indices[n_active]
Xy[n_active], Xy[lam] = Xy[lam], Xy[n_active]
n_active += 1
# solves LL'x = y as a composition of two triangular systems
gamma, _ = potrs(L[:n_active, :n_active], Xy[:n_active], lower=True,
overwrite_b=False)
if return_path:
coefs[:n_active, n_active - 1] = gamma
beta = np.dot(Gram[:, :n_active], gamma)
alpha = Xy - beta
if tol is not None:
tol_curr += delta
delta = np.inner(gamma, beta[:n_active])
tol_curr -= delta
if abs(tol_curr) <= tol:
break
elif n_active == max_features:
break
if return_path:
return gamma, indices[:n_active], coefs[:, :n_active], n_active
else:
return gamma, indices[:n_active], n_active
def orthogonal_mp(X, y, n_nonzero_coefs=None, tol=None, precompute=False,
copy_X=True, return_path=False,
return_n_iter=False):
"""Orthogonal Matching Pursuit (OMP)
Solves n_targets Orthogonal Matching Pursuit problems.
An instance of the problem has the form:
When parametrized by the number of non-zero coefficients using
`n_nonzero_coefs`:
argmin ||y - X\gamma||^2 subject to ||\gamma||_0 <= n_{nonzero coefs}
When parametrized by error using the parameter `tol`:
argmin ||\gamma||_0 subject to ||y - X\gamma||^2 <= tol
Read more in the :ref:`User Guide <omp>`.
Parameters
----------
X : array, shape (n_samples, n_features)
Input data. Columns are assumed to have unit norm.
y : array, shape (n_samples,) or (n_samples, n_targets)
Input targets
n_nonzero_coefs : int
Desired number of non-zero entries in the solution. If None (by
default) this value is set to 10% of n_features.
tol : float
Maximum norm of the residual. If not None, overrides n_nonzero_coefs.
precompute : {True, False, 'auto'},
Whether to perform precomputations. Improves performance when n_targets
or n_samples is very large.
copy_X : bool, optional
Whether the design matrix X must be copied by the algorithm. A false
value is only helpful if X is already Fortran-ordered, otherwise a
copy is made anyway.
return_path : bool, optional. Default: False
Whether to return every value of the nonzero coefficients along the
forward path. Useful for cross-validation.
return_n_iter : bool, optional default False
Whether or not to return the number of iterations.
Returns
-------
coef : array, shape (n_features,) or (n_features, n_targets)
Coefficients of the OMP solution. If `return_path=True`, this contains
the whole coefficient path. In this case its shape is
(n_features, n_features) or (n_features, n_targets, n_features) and
iterating over the last axis yields coefficients in increasing order
of active features.
n_iters : array-like or int
Number of active features across every target. Returned only if
`return_n_iter` is set to True.
See also
--------
OrthogonalMatchingPursuit
orthogonal_mp_gram
lars_path
decomposition.sparse_encode
Notes
-----
Orthogonal matching pursuit was introduced in S. Mallat, Z. Zhang,
Matching pursuits with time-frequency dictionaries, IEEE Transactions on
Signal Processing, Vol. 41, No. 12. (December 1993), pp. 3397-3415.
(http://blanche.polytechnique.fr/~mallat/papiers/MallatPursuit93.pdf)
This implementation is based on Rubinstein, R., Zibulevsky, M. and Elad,
M., Efficient Implementation of the K-SVD Algorithm using Batch Orthogonal
Matching Pursuit Technical Report - CS Technion, April 2008.
http://www.cs.technion.ac.il/~ronrubin/Publications/KSVD-OMP-v2.pdf
"""
X = check_array(X, order='F', copy=copy_X)
copy_X = False
if y.ndim == 1:
y = y.reshape(-1, 1)
y = check_array(y)
if y.shape[1] > 1: # subsequent targets will be affected
copy_X = True
if n_nonzero_coefs is None and tol is None:
# default for n_nonzero_coefs is 0.1 * n_features
# but at least one.
n_nonzero_coefs = max(int(0.1 * X.shape[1]), 1)
if tol is not None and tol < 0:
raise ValueError("Epsilon cannot be negative")
if tol is None and n_nonzero_coefs <= 0:
raise ValueError("The number of atoms must be positive")
if tol is None and n_nonzero_coefs > X.shape[1]:
raise ValueError("The number of atoms cannot be more than the number "
"of features")
if precompute == 'auto':
precompute = X.shape[0] > X.shape[1]
if precompute:
G = np.dot(X.T, X)
G = np.asfortranarray(G)
Xy = np.dot(X.T, y)
if tol is not None:
norms_squared = np.sum((y ** 2), axis=0)
else:
norms_squared = None
return orthogonal_mp_gram(G, Xy, n_nonzero_coefs, tol, norms_squared,
copy_Gram=copy_X, copy_Xy=False,
return_path=return_path)
if return_path:
coef = np.zeros((X.shape[1], y.shape[1], X.shape[1]))
else:
coef = np.zeros((X.shape[1], y.shape[1]))
n_iters = []
for k in range(y.shape[1]):
out = _cholesky_omp(
X, y[:, k], n_nonzero_coefs, tol,
copy_X=copy_X, return_path=return_path)
if return_path:
_, idx, coefs, n_iter = out
coef = coef[:, :, :len(idx)]
for n_active, x in enumerate(coefs.T):
coef[idx[:n_active + 1], k, n_active] = x[:n_active + 1]
else:
x, idx, n_iter = out
coef[idx, k] = x
n_iters.append(n_iter)
if y.shape[1] == 1:
n_iters = n_iters[0]
if return_n_iter:
return np.squeeze(coef), n_iters
else:
return np.squeeze(coef)
def orthogonal_mp_gram(Gram, Xy, n_nonzero_coefs=None, tol=None,
norms_squared=None, copy_Gram=True,
copy_Xy=True, return_path=False,
return_n_iter=False):
"""Gram Orthogonal Matching Pursuit (OMP)
Solves n_targets Orthogonal Matching Pursuit problems using only
the Gram matrix X.T * X and the product X.T * y.
Read more in the :ref:`User Guide <omp>`.
Parameters
----------
Gram : array, shape (n_features, n_features)
Gram matrix of the input data: X.T * X
Xy : array, shape (n_features,) or (n_features, n_targets)
Input targets multiplied by X: X.T * y
n_nonzero_coefs : int
Desired number of non-zero entries in the solution. If None (by
default) this value is set to 10% of n_features.
tol : float
Maximum norm of the residual. If not None, overrides n_nonzero_coefs.
norms_squared : array-like, shape (n_targets,)
Squared L2 norms of the lines of y. Required if tol is not None.
copy_Gram : bool, optional
Whether the gram matrix must be copied by the algorithm. A false
value is only helpful if it is already Fortran-ordered, otherwise a
copy is made anyway.
copy_Xy : bool, optional
Whether the covariance vector Xy must be copied by the algorithm.
If False, it may be overwritten.
return_path : bool, optional. Default: False
Whether to return every value of the nonzero coefficients along the
forward path. Useful for cross-validation.
return_n_iter : bool, optional default False
Whether or not to return the number of iterations.
Returns
-------
coef : array, shape (n_features,) or (n_features, n_targets)
Coefficients of the OMP solution. If `return_path=True`, this contains
the whole coefficient path. In this case its shape is
(n_features, n_features) or (n_features, n_targets, n_features) and
iterating over the last axis yields coefficients in increasing order
of active features.
n_iters : array-like or int
Number of active features across every target. Returned only if
`return_n_iter` is set to True.
See also
--------
OrthogonalMatchingPursuit
orthogonal_mp
lars_path
decomposition.sparse_encode
Notes
-----
Orthogonal matching pursuit was introduced in G. Mallat, Z. Zhang,
Matching pursuits with time-frequency dictionaries, IEEE Transactions on
Signal Processing, Vol. 41, No. 12. (December 1993), pp. 3397-3415.
(http://blanche.polytechnique.fr/~mallat/papiers/MallatPursuit93.pdf)
This implementation is based on Rubinstein, R., Zibulevsky, M. and Elad,
M., Efficient Implementation of the K-SVD Algorithm using Batch Orthogonal
Matching Pursuit Technical Report - CS Technion, April 2008.
http://www.cs.technion.ac.il/~ronrubin/Publications/KSVD-OMP-v2.pdf
"""
Gram = check_array(Gram, order='F', copy=copy_Gram)
Xy = np.asarray(Xy)
if Xy.ndim > 1 and Xy.shape[1] > 1:
# or subsequent target will be affected
copy_Gram = True
if Xy.ndim == 1:
Xy = Xy[:, np.newaxis]
if tol is not None:
norms_squared = [norms_squared]
if n_nonzero_coefs is None and tol is None:
n_nonzero_coefs = int(0.1 * len(Gram))
if tol is not None and norms_squared is None:
raise ValueError('Gram OMP needs the precomputed norms in order '
'to evaluate the error sum of squares.')
if tol is not None and tol < 0:
raise ValueError("Epsilon cannot be negative")
if tol is None and n_nonzero_coefs <= 0:
raise ValueError("The number of atoms must be positive")
if tol is None and n_nonzero_coefs > len(Gram):
raise ValueError("The number of atoms cannot be more than the number "
"of features")
if return_path:
coef = np.zeros((len(Gram), Xy.shape[1], len(Gram)))
else:
coef = np.zeros((len(Gram), Xy.shape[1]))
n_iters = []
for k in range(Xy.shape[1]):
out = _gram_omp(
Gram, Xy[:, k], n_nonzero_coefs,
norms_squared[k] if tol is not None else None, tol,
copy_Gram=copy_Gram, copy_Xy=copy_Xy,
return_path=return_path)
if return_path:
_, idx, coefs, n_iter = out
coef = coef[:, :, :len(idx)]
for n_active, x in enumerate(coefs.T):
coef[idx[:n_active + 1], k, n_active] = x[:n_active + 1]
else:
x, idx, n_iter = out
coef[idx, k] = x
n_iters.append(n_iter)
if Xy.shape[1] == 1:
n_iters = n_iters[0]
if return_n_iter:
return np.squeeze(coef), n_iters
else:
return np.squeeze(coef)
class OrthogonalMatchingPursuit(LinearModel, RegressorMixin):
"""Orthogonal Matching Pursuit model (OMP)
Read more in the :ref:`User Guide <omp>`.
Parameters
----------
n_nonzero_coefs : int, optional
Desired number of non-zero entries in the solution. If None (by
default) this value is set to 10% of n_features.
tol : float, optional
Maximum norm of the residual. If not None, overrides n_nonzero_coefs.
fit_intercept : boolean, optional
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
normalize : boolean, optional, default True
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
precompute : {True, False, 'auto'}, default 'auto'
Whether to use a precomputed Gram and Xy matrix to speed up
calculations. Improves performance when `n_targets` or `n_samples` is
very large. Note that if you already have such matrices, you can pass
them directly to the fit method.
Attributes
----------
coef_ : array, shape (n_features,) or (n_targets, n_features)
parameter vector (w in the formula)
intercept_ : float or array, shape (n_targets,)
independent term in decision function.
n_iter_ : int or array-like
Number of active features across every target.
Notes
-----
Orthogonal matching pursuit was introduced in G. Mallat, Z. Zhang,
Matching pursuits with time-frequency dictionaries, IEEE Transactions on
Signal Processing, Vol. 41, No. 12. (December 1993), pp. 3397-3415.
(http://blanche.polytechnique.fr/~mallat/papiers/MallatPursuit93.pdf)
This implementation is based on Rubinstein, R., Zibulevsky, M. and Elad,
M., Efficient Implementation of the K-SVD Algorithm using Batch Orthogonal
Matching Pursuit Technical Report - CS Technion, April 2008.
http://www.cs.technion.ac.il/~ronrubin/Publications/KSVD-OMP-v2.pdf
See also
--------
orthogonal_mp
orthogonal_mp_gram
lars_path
Lars
LassoLars
decomposition.sparse_encode
"""
def __init__(self, n_nonzero_coefs=None, tol=None, fit_intercept=True,
normalize=True, precompute='auto'):
self.n_nonzero_coefs = n_nonzero_coefs
self.tol = tol
self.fit_intercept = fit_intercept
self.normalize = normalize
self.precompute = precompute
def fit(self, X, y):
"""Fit the model using X, y as training data.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Training data.
y : array-like, shape (n_samples,) or (n_samples, n_targets)
Target values. Will be cast to X's dtype if necessary
Returns
-------
self : object
returns an instance of self.
"""
X, y = check_X_y(X, y, multi_output=True, y_numeric=True)
n_features = X.shape[1]
X, y, X_offset, y_offset, X_scale, Gram, Xy = \
_pre_fit(X, y, None, self.precompute, self.normalize,
self.fit_intercept, copy=True)
if y.ndim == 1:
y = y[:, np.newaxis]
if self.n_nonzero_coefs is None and self.tol is None:
# default for n_nonzero_coefs is 0.1 * n_features
# but at least one.
self.n_nonzero_coefs_ = max(int(0.1 * n_features), 1)
else:
self.n_nonzero_coefs_ = self.n_nonzero_coefs
if Gram is False:
coef_, self.n_iter_ = orthogonal_mp(
X, y, self.n_nonzero_coefs_, self.tol,
precompute=False, copy_X=True,
return_n_iter=True)
else:
norms_sq = np.sum(y ** 2, axis=0) if self.tol is not None else None
coef_, self.n_iter_ = orthogonal_mp_gram(
Gram, Xy=Xy, n_nonzero_coefs=self.n_nonzero_coefs_,
tol=self.tol, norms_squared=norms_sq,
copy_Gram=True, copy_Xy=True,
return_n_iter=True)
self.coef_ = coef_.T
self._set_intercept(X_offset, y_offset, X_scale)
return self
def _omp_path_residues(X_train, y_train, X_test, y_test, copy=True,
fit_intercept=True, normalize=True, max_iter=100):
"""Compute the residues on left-out data for a full LARS path
Parameters
-----------
X_train : array, shape (n_samples, n_features)
The data to fit the LARS on
y_train : array, shape (n_samples)
The target variable to fit LARS on
X_test : array, shape (n_samples, n_features)
The data to compute the residues on
y_test : array, shape (n_samples)
The target variable to compute the residues on
copy : boolean, optional
Whether X_train, X_test, y_train and y_test should be copied. If
False, they may be overwritten.
fit_intercept : boolean
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
normalize : boolean, optional, default True
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
max_iter : integer, optional
Maximum numbers of iterations to perform, therefore maximum features
to include. 100 by default.
Returns
-------
residues : array, shape (n_samples, max_features)
Residues of the prediction on the test data
"""
if copy:
X_train = X_train.copy()
y_train = y_train.copy()
X_test = X_test.copy()
y_test = y_test.copy()
if fit_intercept:
X_mean = X_train.mean(axis=0)
X_train -= X_mean
X_test -= X_mean
y_mean = y_train.mean(axis=0)
y_train = as_float_array(y_train, copy=False)
y_train -= y_mean
y_test = as_float_array(y_test, copy=False)
y_test -= y_mean
if normalize:
norms = np.sqrt(np.sum(X_train ** 2, axis=0))
nonzeros = np.flatnonzero(norms)
X_train[:, nonzeros] /= norms[nonzeros]
coefs = orthogonal_mp(X_train, y_train, n_nonzero_coefs=max_iter, tol=None,
precompute=False, copy_X=False,
return_path=True)
if coefs.ndim == 1:
coefs = coefs[:, np.newaxis]
if normalize:
coefs[nonzeros] /= norms[nonzeros][:, np.newaxis]
return np.dot(coefs.T, X_test.T) - y_test
class OrthogonalMatchingPursuitCV(LinearModel, RegressorMixin):
"""Cross-validated Orthogonal Matching Pursuit model (OMP)
Read more in the :ref:`User Guide <omp>`.
Parameters
----------
copy : bool, optional
Whether the design matrix X must be copied by the algorithm. A false
value is only helpful if X is already Fortran-ordered, otherwise a
copy is made anyway.
fit_intercept : boolean, optional
whether to calculate the intercept for this model. If set
to false, no intercept will be used in calculations
(e.g. data is expected to be already centered).
normalize : boolean, optional, default True
This parameter is ignored when ``fit_intercept`` is set to False.
If True, the regressors X will be normalized before regression by
subtracting the mean and dividing by the l2-norm.
If you wish to standardize, please use
:class:`sklearn.preprocessing.StandardScaler` before calling ``fit``
on an estimator with ``normalize=False``.
max_iter : integer, optional
Maximum numbers of iterations to perform, therefore maximum features
to include. 10% of ``n_features`` but at least 5 if available.
cv : int, cross-validation generator or an iterable, optional
Determines the cross-validation splitting strategy.
Possible inputs for cv are:
- None, to use the default 3-fold cross-validation,
- integer, to specify the number of folds.
- An object to be used as a cross-validation generator.
- An iterable yielding train/test splits.
For integer/None inputs, :class:`KFold` is used.
Refer :ref:`User Guide <cross_validation>` for the various
cross-validation strategies that can be used here.
n_jobs : integer, optional
Number of CPUs to use during the cross validation. If ``-1``, use
all the CPUs
verbose : boolean or integer, optional
Sets the verbosity amount
Attributes
----------
intercept_ : float or array, shape (n_targets,)
Independent term in decision function.
coef_ : array, shape (n_features,) or (n_targets, n_features)
Parameter vector (w in the problem formulation).
n_nonzero_coefs_ : int
Estimated number of non-zero coefficients giving the best mean squared
error over the cross-validation folds.
n_iter_ : int or array-like
Number of active features across every target for the model refit with
the best hyperparameters got by cross-validating across all folds.
See also
--------
orthogonal_mp
orthogonal_mp_gram
lars_path
Lars
LassoLars
OrthogonalMatchingPursuit
LarsCV
LassoLarsCV
decomposition.sparse_encode
"""
def __init__(self, copy=True, fit_intercept=True, normalize=True,
max_iter=None, cv=None, n_jobs=1, verbose=False):
self.copy = copy
self.fit_intercept = fit_intercept
self.normalize = normalize
self.max_iter = max_iter
self.cv = cv
self.n_jobs = n_jobs
self.verbose = verbose
def fit(self, X, y):
"""Fit the model using X, y as training data.
Parameters
----------
X : array-like, shape [n_samples, n_features]
Training data.
y : array-like, shape [n_samples]
Target values. Will be cast to X's dtype if necessary
Returns
-------
self : object
returns an instance of self.
"""
X, y = check_X_y(X, y, y_numeric=True, ensure_min_features=2,
estimator=self)
X = as_float_array(X, copy=False, force_all_finite=False)
cv = check_cv(self.cv, classifier=False)
max_iter = (min(max(int(0.1 * X.shape[1]), 5), X.shape[1])
if not self.max_iter
else self.max_iter)
cv_paths = Parallel(n_jobs=self.n_jobs, verbose=self.verbose)(
delayed(_omp_path_residues)(
X[train], y[train], X[test], y[test], self.copy,
self.fit_intercept, self.normalize, max_iter)
for train, test in cv.split(X))
min_early_stop = min(fold.shape[0] for fold in cv_paths)
mse_folds = np.array([(fold[:min_early_stop] ** 2).mean(axis=1)
for fold in cv_paths])
best_n_nonzero_coefs = np.argmin(mse_folds.mean(axis=0)) + 1
self.n_nonzero_coefs_ = best_n_nonzero_coefs
omp = OrthogonalMatchingPursuit(n_nonzero_coefs=best_n_nonzero_coefs,
fit_intercept=self.fit_intercept,
normalize=self.normalize)
omp.fit(X, y)
self.coef_ = omp.coef_
self.intercept_ = omp.intercept_
self.n_iter_ = omp.n_iter_
return self
| 31,718 | 35.416762 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/stochastic_gradient.py | # Authors: Peter Prettenhofer <[email protected]> (main author)
# Mathieu Blondel (partial_fit support)
#
# License: BSD 3 clause
"""Classification and regression using Stochastic Gradient Descent (SGD)."""
import numpy as np
import warnings
from abc import ABCMeta, abstractmethod
from ..externals.joblib import Parallel, delayed
from .base import LinearClassifierMixin, SparseCoefMixin
from .base import make_dataset
from ..base import BaseEstimator, RegressorMixin
from ..utils import check_array, check_random_state, check_X_y
from ..utils.extmath import safe_sparse_dot
from ..utils.multiclass import _check_partial_fit_first_call
from ..utils.validation import check_is_fitted
from ..exceptions import ConvergenceWarning
from ..externals import six
from .sgd_fast import plain_sgd, average_sgd
from ..utils import compute_class_weight
from ..utils import deprecated
from .sgd_fast import Hinge
from .sgd_fast import SquaredHinge
from .sgd_fast import Log
from .sgd_fast import ModifiedHuber
from .sgd_fast import SquaredLoss
from .sgd_fast import Huber
from .sgd_fast import EpsilonInsensitive
from .sgd_fast import SquaredEpsilonInsensitive
LEARNING_RATE_TYPES = {"constant": 1, "optimal": 2, "invscaling": 3,
"pa1": 4, "pa2": 5}
PENALTY_TYPES = {"none": 0, "l2": 2, "l1": 1, "elasticnet": 3}
DEFAULT_EPSILON = 0.1
# Default value of ``epsilon`` parameter.
class BaseSGD(six.with_metaclass(ABCMeta, BaseEstimator, SparseCoefMixin)):
"""Base class for SGD classification and regression."""
def __init__(self, loss, penalty='l2', alpha=0.0001, C=1.0,
l1_ratio=0.15, fit_intercept=True, max_iter=None, tol=None,
shuffle=True, verbose=0, epsilon=0.1, random_state=None,
learning_rate="optimal", eta0=0.0, power_t=0.5,
warm_start=False, average=False, n_iter=None):
self.loss = loss
self.penalty = penalty
self.learning_rate = learning_rate
self.epsilon = epsilon
self.alpha = alpha
self.C = C
self.l1_ratio = l1_ratio
self.fit_intercept = fit_intercept
self.shuffle = shuffle
self.random_state = random_state
self.verbose = verbose
self.eta0 = eta0
self.power_t = power_t
self.warm_start = warm_start
self.average = average
self.n_iter = n_iter
self.max_iter = max_iter
self.tol = tol
# current tests expect init to do parameter validation
# but we are not allowed to set attributes
self._validate_params(set_max_iter=False)
def set_params(self, *args, **kwargs):
super(BaseSGD, self).set_params(*args, **kwargs)
self._validate_params(set_max_iter=False)
return self
@abstractmethod
def fit(self, X, y):
"""Fit model."""
def _validate_params(self, set_max_iter=True):
"""Validate input params. """
if not isinstance(self.shuffle, bool):
raise ValueError("shuffle must be either True or False")
if self.max_iter is not None and self.max_iter <= 0:
raise ValueError("max_iter must be > zero. Got %f" % self.max_iter)
if not (0.0 <= self.l1_ratio <= 1.0):
raise ValueError("l1_ratio must be in [0, 1]")
if self.alpha < 0.0:
raise ValueError("alpha must be >= 0")
if self.learning_rate in ("constant", "invscaling"):
if self.eta0 <= 0.0:
raise ValueError("eta0 must be > 0")
if self.learning_rate == "optimal" and self.alpha == 0:
raise ValueError("alpha must be > 0 since "
"learning_rate is 'optimal'. alpha is used "
"to compute the optimal learning rate.")
# raises ValueError if not registered
self._get_penalty_type(self.penalty)
self._get_learning_rate_type(self.learning_rate)
if self.loss not in self.loss_functions:
raise ValueError("The loss %s is not supported. " % self.loss)
if not set_max_iter:
return
# n_iter deprecation, set self._max_iter, self._tol
self._tol = self.tol
if self.n_iter is not None:
warnings.warn("n_iter parameter is deprecated in 0.19 and will be"
" removed in 0.21. Use max_iter and tol instead.",
DeprecationWarning)
# Same behavior as before 0.19
max_iter = self.n_iter
self._tol = None
elif self.tol is None and self.max_iter is None:
warnings.warn(
"max_iter and tol parameters have been added in %s in 0.19. If"
" both are left unset, they default to max_iter=5 and tol=None"
". If tol is not None, max_iter defaults to max_iter=1000. "
"From 0.21, default max_iter will be 1000, "
"and default tol will be 1e-3." % type(self), FutureWarning)
# Before 0.19, default was n_iter=5
max_iter = 5
else:
max_iter = self.max_iter if self.max_iter is not None else 1000
self._max_iter = max_iter
def _get_loss_function(self, loss):
"""Get concrete ``LossFunction`` object for str ``loss``. """
try:
loss_ = self.loss_functions[loss]
loss_class, args = loss_[0], loss_[1:]
if loss in ('huber', 'epsilon_insensitive',
'squared_epsilon_insensitive'):
args = (self.epsilon, )
return loss_class(*args)
except KeyError:
raise ValueError("The loss %s is not supported. " % loss)
def _get_learning_rate_type(self, learning_rate):
try:
return LEARNING_RATE_TYPES[learning_rate]
except KeyError:
raise ValueError("learning rate %s "
"is not supported. " % learning_rate)
def _get_penalty_type(self, penalty):
penalty = str(penalty).lower()
try:
return PENALTY_TYPES[penalty]
except KeyError:
raise ValueError("Penalty %s is not supported. " % penalty)
def _validate_sample_weight(self, sample_weight, n_samples):
"""Set the sample weight array."""
if sample_weight is None:
# uniform sample weights
sample_weight = np.ones(n_samples, dtype=np.float64, order='C')
else:
# user-provided array
sample_weight = np.asarray(sample_weight, dtype=np.float64,
order="C")
if sample_weight.shape[0] != n_samples:
raise ValueError("Shapes of X and sample_weight do not match.")
return sample_weight
def _allocate_parameter_mem(self, n_classes, n_features, coef_init=None,
intercept_init=None):
"""Allocate mem for parameters; initialize if provided."""
if n_classes > 2:
# allocate coef_ for multi-class
if coef_init is not None:
coef_init = np.asarray(coef_init, order="C")
if coef_init.shape != (n_classes, n_features):
raise ValueError("Provided ``coef_`` does not match "
"dataset. ")
self.coef_ = coef_init
else:
self.coef_ = np.zeros((n_classes, n_features),
dtype=np.float64, order="C")
# allocate intercept_ for multi-class
if intercept_init is not None:
intercept_init = np.asarray(intercept_init, order="C")
if intercept_init.shape != (n_classes, ):
raise ValueError("Provided intercept_init "
"does not match dataset.")
self.intercept_ = intercept_init
else:
self.intercept_ = np.zeros(n_classes, dtype=np.float64,
order="C")
else:
# allocate coef_ for binary problem
if coef_init is not None:
coef_init = np.asarray(coef_init, dtype=np.float64,
order="C")
coef_init = coef_init.ravel()
if coef_init.shape != (n_features,):
raise ValueError("Provided coef_init does not "
"match dataset.")
self.coef_ = coef_init
else:
self.coef_ = np.zeros(n_features,
dtype=np.float64,
order="C")
# allocate intercept_ for binary problem
if intercept_init is not None:
intercept_init = np.asarray(intercept_init, dtype=np.float64)
if intercept_init.shape != (1,) and intercept_init.shape != ():
raise ValueError("Provided intercept_init "
"does not match dataset.")
self.intercept_ = intercept_init.reshape(1,)
else:
self.intercept_ = np.zeros(1, dtype=np.float64, order="C")
# initialize average parameters
if self.average > 0:
self.standard_coef_ = self.coef_
self.standard_intercept_ = self.intercept_
self.average_coef_ = np.zeros(self.coef_.shape,
dtype=np.float64,
order="C")
self.average_intercept_ = np.zeros(self.standard_intercept_.shape,
dtype=np.float64,
order="C")
def _prepare_fit_binary(est, y, i):
"""Initialization for fit_binary.
Returns y, coef, intercept.
"""
y_i = np.ones(y.shape, dtype=np.float64, order="C")
y_i[y != est.classes_[i]] = -1.0
average_intercept = 0
average_coef = None
if len(est.classes_) == 2:
if not est.average:
coef = est.coef_.ravel()
intercept = est.intercept_[0]
else:
coef = est.standard_coef_.ravel()
intercept = est.standard_intercept_[0]
average_coef = est.average_coef_.ravel()
average_intercept = est.average_intercept_[0]
else:
if not est.average:
coef = est.coef_[i]
intercept = est.intercept_[i]
else:
coef = est.standard_coef_[i]
intercept = est.standard_intercept_[i]
average_coef = est.average_coef_[i]
average_intercept = est.average_intercept_[i]
return y_i, coef, intercept, average_coef, average_intercept
def fit_binary(est, i, X, y, alpha, C, learning_rate, max_iter,
pos_weight, neg_weight, sample_weight):
"""Fit a single binary classifier.
The i'th class is considered the "positive" class.
"""
# if average is not true, average_coef, and average_intercept will be
# unused
y_i, coef, intercept, average_coef, average_intercept = \
_prepare_fit_binary(est, y, i)
assert y_i.shape[0] == y.shape[0] == sample_weight.shape[0]
dataset, intercept_decay = make_dataset(X, y_i, sample_weight)
penalty_type = est._get_penalty_type(est.penalty)
learning_rate_type = est._get_learning_rate_type(learning_rate)
# XXX should have random_state_!
random_state = check_random_state(est.random_state)
# numpy mtrand expects a C long which is a signed 32 bit integer under
# Windows
seed = random_state.randint(0, np.iinfo(np.int32).max)
tol = est.tol if est.tol is not None else -np.inf
if not est.average:
return plain_sgd(coef, intercept, est.loss_function_,
penalty_type, alpha, C, est.l1_ratio,
dataset, max_iter, tol, int(est.fit_intercept),
int(est.verbose), int(est.shuffle), seed,
pos_weight, neg_weight,
learning_rate_type, est.eta0,
est.power_t, est.t_, intercept_decay)
else:
standard_coef, standard_intercept, average_coef, average_intercept, \
n_iter_ = average_sgd(coef, intercept, average_coef,
average_intercept, est.loss_function_,
penalty_type, alpha, C, est.l1_ratio,
dataset, max_iter, tol,
int(est.fit_intercept), int(est.verbose),
int(est.shuffle), seed, pos_weight,
neg_weight, learning_rate_type, est.eta0,
est.power_t, est.t_, intercept_decay,
est.average)
if len(est.classes_) == 2:
est.average_intercept_[0] = average_intercept
else:
est.average_intercept_[i] = average_intercept
return standard_coef, standard_intercept, n_iter_
class BaseSGDClassifier(six.with_metaclass(ABCMeta, BaseSGD,
LinearClassifierMixin)):
loss_functions = {
"hinge": (Hinge, 1.0),
"squared_hinge": (SquaredHinge, 1.0),
"perceptron": (Hinge, 0.0),
"log": (Log, ),
"modified_huber": (ModifiedHuber, ),
"squared_loss": (SquaredLoss, ),
"huber": (Huber, DEFAULT_EPSILON),
"epsilon_insensitive": (EpsilonInsensitive, DEFAULT_EPSILON),
"squared_epsilon_insensitive": (SquaredEpsilonInsensitive,
DEFAULT_EPSILON),
}
@abstractmethod
def __init__(self, loss="hinge", penalty='l2', alpha=0.0001,
l1_ratio=0.15, fit_intercept=True, max_iter=None, tol=None,
shuffle=True, verbose=0, epsilon=DEFAULT_EPSILON, n_jobs=1,
random_state=None, learning_rate="optimal", eta0=0.0,
power_t=0.5, class_weight=None, warm_start=False,
average=False, n_iter=None):
super(BaseSGDClassifier, self).__init__(loss=loss, penalty=penalty,
alpha=alpha, l1_ratio=l1_ratio,
fit_intercept=fit_intercept,
max_iter=max_iter, tol=tol,
shuffle=shuffle,
verbose=verbose,
epsilon=epsilon,
random_state=random_state,
learning_rate=learning_rate,
eta0=eta0, power_t=power_t,
warm_start=warm_start,
average=average,
n_iter=n_iter)
self.class_weight = class_weight
self.n_jobs = int(n_jobs)
@property
@deprecated("Attribute loss_function was deprecated in version 0.19 and "
"will be removed in 0.21. Use ``loss_function_`` instead")
def loss_function(self):
return self.loss_function_
def _partial_fit(self, X, y, alpha, C,
loss, learning_rate, max_iter,
classes, sample_weight,
coef_init, intercept_init):
X, y = check_X_y(X, y, 'csr', dtype=np.float64, order="C")
n_samples, n_features = X.shape
_check_partial_fit_first_call(self, classes)
n_classes = self.classes_.shape[0]
# Allocate datastructures from input arguments
self._expanded_class_weight = compute_class_weight(self.class_weight,
self.classes_, y)
sample_weight = self._validate_sample_weight(sample_weight, n_samples)
if getattr(self, "coef_", None) is None or coef_init is not None:
self._allocate_parameter_mem(n_classes, n_features,
coef_init, intercept_init)
elif n_features != self.coef_.shape[-1]:
raise ValueError("Number of features %d does not match previous "
"data %d." % (n_features, self.coef_.shape[-1]))
self.loss_function_ = self._get_loss_function(loss)
if not hasattr(self, "t_"):
self.t_ = 1.0
# delegate to concrete training procedure
if n_classes > 2:
self._fit_multiclass(X, y, alpha=alpha, C=C,
learning_rate=learning_rate,
sample_weight=sample_weight,
max_iter=max_iter)
elif n_classes == 2:
self._fit_binary(X, y, alpha=alpha, C=C,
learning_rate=learning_rate,
sample_weight=sample_weight,
max_iter=max_iter)
else:
raise ValueError("The number of class labels must be "
"greater than one.")
return self
def _fit(self, X, y, alpha, C, loss, learning_rate, coef_init=None,
intercept_init=None, sample_weight=None):
self._validate_params()
if hasattr(self, "classes_"):
self.classes_ = None
X, y = check_X_y(X, y, 'csr', dtype=np.float64, order="C")
n_samples, n_features = X.shape
# labels can be encoded as float, int, or string literals
# np.unique sorts in asc order; largest class id is positive class
classes = np.unique(y)
if self.warm_start and hasattr(self, "coef_"):
if coef_init is None:
coef_init = self.coef_
if intercept_init is None:
intercept_init = self.intercept_
else:
self.coef_ = None
self.intercept_ = None
if self.average > 0:
self.standard_coef_ = self.coef_
self.standard_intercept_ = self.intercept_
self.average_coef_ = None
self.average_intercept_ = None
# Clear iteration count for multiple call to fit.
self.t_ = 1.0
self._partial_fit(X, y, alpha, C, loss, learning_rate, self._max_iter,
classes, sample_weight, coef_init, intercept_init)
if (self._tol is not None and self._tol > -np.inf
and self.n_iter_ == self._max_iter):
warnings.warn("Maximum number of iteration reached before "
"convergence. Consider increasing max_iter to "
"improve the fit.",
ConvergenceWarning)
return self
def _fit_binary(self, X, y, alpha, C, sample_weight,
learning_rate, max_iter):
"""Fit a binary classifier on X and y. """
coef, intercept, n_iter_ = fit_binary(self, 1, X, y, alpha, C,
learning_rate, max_iter,
self._expanded_class_weight[1],
self._expanded_class_weight[0],
sample_weight)
self.t_ += n_iter_ * X.shape[0]
self.n_iter_ = n_iter_
# need to be 2d
if self.average > 0:
if self.average <= self.t_ - 1:
self.coef_ = self.average_coef_.reshape(1, -1)
self.intercept_ = self.average_intercept_
else:
self.coef_ = self.standard_coef_.reshape(1, -1)
self.standard_intercept_ = np.atleast_1d(intercept)
self.intercept_ = self.standard_intercept_
else:
self.coef_ = coef.reshape(1, -1)
# intercept is a float, need to convert it to an array of length 1
self.intercept_ = np.atleast_1d(intercept)
def _fit_multiclass(self, X, y, alpha, C, learning_rate,
sample_weight, max_iter):
"""Fit a multi-class classifier by combining binary classifiers
Each binary classifier predicts one class versus all others. This
strategy is called OVA: One Versus All.
"""
# Use joblib to fit OvA in parallel.
result = Parallel(n_jobs=self.n_jobs, backend="threading",
verbose=self.verbose)(
delayed(fit_binary)(self, i, X, y, alpha, C, learning_rate,
max_iter, self._expanded_class_weight[i],
1., sample_weight)
for i in range(len(self.classes_)))
# take the maximum of n_iter_ over every binary fit
n_iter_ = 0.
for i, (_, intercept, n_iter_i) in enumerate(result):
self.intercept_[i] = intercept
n_iter_ = max(n_iter_, n_iter_i)
self.t_ += n_iter_ * X.shape[0]
self.n_iter_ = n_iter_
if self.average > 0:
if self.average <= self.t_ - 1.0:
self.coef_ = self.average_coef_
self.intercept_ = self.average_intercept_
else:
self.coef_ = self.standard_coef_
self.standard_intercept_ = np.atleast_1d(self.intercept_)
self.intercept_ = self.standard_intercept_
def partial_fit(self, X, y, classes=None, sample_weight=None):
"""Fit linear model with Stochastic Gradient Descent.
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Subset of the training data
y : numpy array, shape (n_samples,)
Subset of the target values
classes : array, shape (n_classes,)
Classes across all calls to partial_fit.
Can be obtained by via `np.unique(y_all)`, where y_all is the
target vector of the entire dataset.
This argument is required for the first call to partial_fit
and can be omitted in the subsequent calls.
Note that y doesn't need to contain all labels in `classes`.
sample_weight : array-like, shape (n_samples,), optional
Weights applied to individual samples.
If not provided, uniform weights are assumed.
Returns
-------
self : returns an instance of self.
"""
self._validate_params()
if self.class_weight in ['balanced']:
raise ValueError("class_weight '{0}' is not supported for "
"partial_fit. In order to use 'balanced' weights,"
" use compute_class_weight('{0}', classes, y). "
"In place of y you can us a large enough sample "
"of the full training set target to properly "
"estimate the class frequency distributions. "
"Pass the resulting weights as the class_weight "
"parameter.".format(self.class_weight))
return self._partial_fit(X, y, alpha=self.alpha, C=1.0, loss=self.loss,
learning_rate=self.learning_rate, max_iter=1,
classes=classes, sample_weight=sample_weight,
coef_init=None, intercept_init=None)
def fit(self, X, y, coef_init=None, intercept_init=None,
sample_weight=None):
"""Fit linear model with Stochastic Gradient Descent.
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data
y : numpy array, shape (n_samples,)
Target values
coef_init : array, shape (n_classes, n_features)
The initial coefficients to warm-start the optimization.
intercept_init : array, shape (n_classes,)
The initial intercept to warm-start the optimization.
sample_weight : array-like, shape (n_samples,), optional
Weights applied to individual samples.
If not provided, uniform weights are assumed. These weights will
be multiplied with class_weight (passed through the
constructor) if class_weight is specified
Returns
-------
self : returns an instance of self.
"""
return self._fit(X, y, alpha=self.alpha, C=1.0,
loss=self.loss, learning_rate=self.learning_rate,
coef_init=coef_init, intercept_init=intercept_init,
sample_weight=sample_weight)
class SGDClassifier(BaseSGDClassifier):
"""Linear classifiers (SVM, logistic regression, a.o.) with SGD training.
This estimator implements regularized linear models with stochastic
gradient descent (SGD) learning: the gradient of the loss is estimated
each sample at a time and the model is updated along the way with a
decreasing strength schedule (aka learning rate). SGD allows minibatch
(online/out-of-core) learning, see the partial_fit method.
For best results using the default learning rate schedule, the data should
have zero mean and unit variance.
This implementation works with data represented as dense or sparse arrays
of floating point values for the features. The model it fits can be
controlled with the loss parameter; by default, it fits a linear support
vector machine (SVM).
The regularizer is a penalty added to the loss function that shrinks model
parameters towards the zero vector using either the squared euclidean norm
L2 or the absolute norm L1 or a combination of both (Elastic Net). If the
parameter update crosses the 0.0 value because of the regularizer, the
update is truncated to 0.0 to allow for learning sparse models and achieve
online feature selection.
Read more in the :ref:`User Guide <sgd>`.
Parameters
----------
loss : str, default: 'hinge'
The loss function to be used. Defaults to 'hinge', which gives a
linear SVM.
The possible options are 'hinge', 'log', 'modified_huber',
'squared_hinge', 'perceptron', or a regression loss: 'squared_loss',
'huber', 'epsilon_insensitive', or 'squared_epsilon_insensitive'.
The 'log' loss gives logistic regression, a probabilistic classifier.
'modified_huber' is another smooth loss that brings tolerance to
outliers as well as probability estimates.
'squared_hinge' is like hinge but is quadratically penalized.
'perceptron' is the linear loss used by the perceptron algorithm.
The other losses are designed for regression but can be useful in
classification as well; see SGDRegressor for a description.
penalty : str, 'none', 'l2', 'l1', or 'elasticnet'
The penalty (aka regularization term) to be used. Defaults to 'l2'
which is the standard regularizer for linear SVM models. 'l1' and
'elasticnet' might bring sparsity to the model (feature selection)
not achievable with 'l2'.
alpha : float
Constant that multiplies the regularization term. Defaults to 0.0001
Also used to compute learning_rate when set to 'optimal'.
l1_ratio : float
The Elastic Net mixing parameter, with 0 <= l1_ratio <= 1.
l1_ratio=0 corresponds to L2 penalty, l1_ratio=1 to L1.
Defaults to 0.15.
fit_intercept : bool
Whether the intercept should be estimated or not. If False, the
data is assumed to be already centered. Defaults to True.
max_iter : int, optional
The maximum number of passes over the training data (aka epochs).
It only impacts the behavior in the ``fit`` method, and not the
`partial_fit`.
Defaults to 5. Defaults to 1000 from 0.21, or if tol is not None.
.. versionadded:: 0.19
tol : float or None, optional
The stopping criterion. If it is not None, the iterations will stop
when (loss > previous_loss - tol). Defaults to None.
Defaults to 1e-3 from 0.21.
.. versionadded:: 0.19
shuffle : bool, optional
Whether or not the training data should be shuffled after each epoch.
Defaults to True.
verbose : integer, optional
The verbosity level
epsilon : float
Epsilon in the epsilon-insensitive loss functions; only if `loss` is
'huber', 'epsilon_insensitive', or 'squared_epsilon_insensitive'.
For 'huber', determines the threshold at which it becomes less
important to get the prediction exactly right.
For epsilon-insensitive, any differences between the current prediction
and the correct label are ignored if they are less than this threshold.
n_jobs : integer, optional
The number of CPUs to use to do the OVA (One Versus All, for
multi-class problems) computation. -1 means 'all CPUs'. Defaults
to 1.
random_state : int, RandomState instance or None, optional (default=None)
The seed of the pseudo random number generator to use when shuffling
the data. If int, random_state is the seed used by the random number
generator; If RandomState instance, random_state is the random number
generator; If None, the random number generator is the RandomState
instance used by `np.random`.
learning_rate : string, optional
The learning rate schedule:
- 'constant': eta = eta0
- 'optimal': eta = 1.0 / (alpha * (t + t0)) [default]
- 'invscaling': eta = eta0 / pow(t, power_t)
where t0 is chosen by a heuristic proposed by Leon Bottou.
eta0 : double
The initial learning rate for the 'constant' or 'invscaling'
schedules. The default value is 0.0 as eta0 is not used by the
default schedule 'optimal'.
power_t : double
The exponent for inverse scaling learning rate [default 0.5].
class_weight : dict, {class_label: weight} or "balanced" or None, optional
Preset for the class_weight fit parameter.
Weights associated with classes. If not given, all classes
are supposed to have weight one.
The "balanced" mode uses the values of y to automatically adjust
weights inversely proportional to class frequencies in the input data
as ``n_samples / (n_classes * np.bincount(y))``
warm_start : bool, optional
When set to True, reuse the solution of the previous call to fit as
initialization, otherwise, just erase the previous solution.
average : bool or int, optional
When set to True, computes the averaged SGD weights and stores the
result in the ``coef_`` attribute. If set to an int greater than 1,
averaging will begin once the total number of samples seen reaches
average. So ``average=10`` will begin averaging after seeing 10
samples.
n_iter : int, optional
The number of passes over the training data (aka epochs).
Defaults to None. Deprecated, will be removed in 0.21.
.. versionchanged:: 0.19
Deprecated
Attributes
----------
coef_ : array, shape (1, n_features) if n_classes == 2 else (n_classes,\
n_features)
Weights assigned to the features.
intercept_ : array, shape (1,) if n_classes == 2 else (n_classes,)
Constants in decision function.
n_iter_ : int
The actual number of iterations to reach the stopping criterion.
For multiclass fits, it is the maximum over every binary fit.
loss_function_ : concrete ``LossFunction``
Examples
--------
>>> import numpy as np
>>> from sklearn import linear_model
>>> X = np.array([[-1, -1], [-2, -1], [1, 1], [2, 1]])
>>> Y = np.array([1, 1, 2, 2])
>>> clf = linear_model.SGDClassifier()
>>> clf.fit(X, Y)
... #doctest: +NORMALIZE_WHITESPACE
SGDClassifier(alpha=0.0001, average=False, class_weight=None, epsilon=0.1,
eta0=0.0, fit_intercept=True, l1_ratio=0.15,
learning_rate='optimal', loss='hinge', max_iter=None, n_iter=None,
n_jobs=1, penalty='l2', power_t=0.5, random_state=None,
shuffle=True, tol=None, verbose=0, warm_start=False)
>>> print(clf.predict([[-0.8, -1]]))
[1]
See also
--------
LinearSVC, LogisticRegression, Perceptron
"""
def __init__(self, loss="hinge", penalty='l2', alpha=0.0001, l1_ratio=0.15,
fit_intercept=True, max_iter=None, tol=None, shuffle=True,
verbose=0, epsilon=DEFAULT_EPSILON, n_jobs=1,
random_state=None, learning_rate="optimal", eta0=0.0,
power_t=0.5, class_weight=None, warm_start=False,
average=False, n_iter=None):
super(SGDClassifier, self).__init__(
loss=loss, penalty=penalty, alpha=alpha, l1_ratio=l1_ratio,
fit_intercept=fit_intercept, max_iter=max_iter, tol=tol,
shuffle=shuffle, verbose=verbose, epsilon=epsilon, n_jobs=n_jobs,
random_state=random_state, learning_rate=learning_rate, eta0=eta0,
power_t=power_t, class_weight=class_weight, warm_start=warm_start,
average=average, n_iter=n_iter)
def _check_proba(self):
check_is_fitted(self, "t_")
if self.loss not in ("log", "modified_huber"):
raise AttributeError("probability estimates are not available for"
" loss=%r" % self.loss)
@property
def predict_proba(self):
"""Probability estimates.
This method is only available for log loss and modified Huber loss.
Multiclass probability estimates are derived from binary (one-vs.-rest)
estimates by simple normalization, as recommended by Zadrozny and
Elkan.
Binary probability estimates for loss="modified_huber" are given by
(clip(decision_function(X), -1, 1) + 1) / 2. For other loss functions
it is necessary to perform proper probability calibration by wrapping
the classifier with
:class:`sklearn.calibration.CalibratedClassifierCV` instead.
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Returns
-------
array, shape (n_samples, n_classes)
Returns the probability of the sample for each class in the model,
where classes are ordered as they are in `self.classes_`.
References
----------
Zadrozny and Elkan, "Transforming classifier scores into multiclass
probability estimates", SIGKDD'02,
http://www.research.ibm.com/people/z/zadrozny/kdd2002-Transf.pdf
The justification for the formula in the loss="modified_huber"
case is in the appendix B in:
http://jmlr.csail.mit.edu/papers/volume2/zhang02c/zhang02c.pdf
"""
self._check_proba()
return self._predict_proba
def _predict_proba(self, X):
if self.loss == "log":
return self._predict_proba_lr(X)
elif self.loss == "modified_huber":
binary = (len(self.classes_) == 2)
scores = self.decision_function(X)
if binary:
prob2 = np.ones((scores.shape[0], 2))
prob = prob2[:, 1]
else:
prob = scores
np.clip(scores, -1, 1, prob)
prob += 1.
prob /= 2.
if binary:
prob2[:, 0] -= prob
prob = prob2
else:
# the above might assign zero to all classes, which doesn't
# normalize neatly; work around this to produce uniform
# probabilities
prob_sum = prob.sum(axis=1)
all_zero = (prob_sum == 0)
if np.any(all_zero):
prob[all_zero, :] = 1
prob_sum[all_zero] = len(self.classes_)
# normalize
prob /= prob_sum.reshape((prob.shape[0], -1))
return prob
else:
raise NotImplementedError("predict_(log_)proba only supported when"
" loss='log' or loss='modified_huber' "
"(%r given)" % self.loss)
@property
def predict_log_proba(self):
"""Log of probability estimates.
This method is only available for log loss and modified Huber loss.
When loss="modified_huber", probability estimates may be hard zeros
and ones, so taking the logarithm is not possible.
See ``predict_proba`` for details.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Returns
-------
T : array-like, shape (n_samples, n_classes)
Returns the log-probability of the sample for each class in the
model, where classes are ordered as they are in
`self.classes_`.
"""
self._check_proba()
return self._predict_log_proba
def _predict_log_proba(self, X):
return np.log(self.predict_proba(X))
class BaseSGDRegressor(BaseSGD, RegressorMixin):
loss_functions = {
"squared_loss": (SquaredLoss, ),
"huber": (Huber, DEFAULT_EPSILON),
"epsilon_insensitive": (EpsilonInsensitive, DEFAULT_EPSILON),
"squared_epsilon_insensitive": (SquaredEpsilonInsensitive,
DEFAULT_EPSILON),
}
@abstractmethod
def __init__(self, loss="squared_loss", penalty="l2", alpha=0.0001,
l1_ratio=0.15, fit_intercept=True, max_iter=None, tol=None,
shuffle=True, verbose=0, epsilon=DEFAULT_EPSILON,
random_state=None, learning_rate="invscaling", eta0=0.01,
power_t=0.25, warm_start=False, average=False, n_iter=None):
super(BaseSGDRegressor, self).__init__(loss=loss, penalty=penalty,
alpha=alpha, l1_ratio=l1_ratio,
fit_intercept=fit_intercept,
max_iter=max_iter, tol=tol,
shuffle=shuffle,
verbose=verbose,
epsilon=epsilon,
random_state=random_state,
learning_rate=learning_rate,
eta0=eta0, power_t=power_t,
warm_start=warm_start,
average=average,
n_iter=n_iter)
def _partial_fit(self, X, y, alpha, C, loss, learning_rate,
max_iter, sample_weight, coef_init, intercept_init):
X, y = check_X_y(X, y, "csr", copy=False, order='C', dtype=np.float64)
y = y.astype(np.float64, copy=False)
n_samples, n_features = X.shape
# Allocate datastructures from input arguments
sample_weight = self._validate_sample_weight(sample_weight, n_samples)
if getattr(self, "coef_", None) is None:
self._allocate_parameter_mem(1, n_features,
coef_init, intercept_init)
elif n_features != self.coef_.shape[-1]:
raise ValueError("Number of features %d does not match previous "
"data %d." % (n_features, self.coef_.shape[-1]))
if self.average > 0 and getattr(self, "average_coef_", None) is None:
self.average_coef_ = np.zeros(n_features,
dtype=np.float64,
order="C")
self.average_intercept_ = np.zeros(1,
dtype=np.float64,
order="C")
self._fit_regressor(X, y, alpha, C, loss, learning_rate,
sample_weight, max_iter)
return self
def partial_fit(self, X, y, sample_weight=None):
"""Fit linear model with Stochastic Gradient Descent.
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Subset of training data
y : numpy array of shape (n_samples,)
Subset of target values
sample_weight : array-like, shape (n_samples,), optional
Weights applied to individual samples.
If not provided, uniform weights are assumed.
Returns
-------
self : returns an instance of self.
"""
self._validate_params()
return self._partial_fit(X, y, self.alpha, C=1.0,
loss=self.loss,
learning_rate=self.learning_rate, max_iter=1,
sample_weight=sample_weight, coef_init=None,
intercept_init=None)
def _fit(self, X, y, alpha, C, loss, learning_rate, coef_init=None,
intercept_init=None, sample_weight=None):
self._validate_params()
if self.warm_start and getattr(self, "coef_", None) is not None:
if coef_init is None:
coef_init = self.coef_
if intercept_init is None:
intercept_init = self.intercept_
else:
self.coef_ = None
self.intercept_ = None
if self.average > 0:
self.standard_intercept_ = self.intercept_
self.standard_coef_ = self.coef_
self.average_coef_ = None
self.average_intercept_ = None
# Clear iteration count for multiple call to fit.
self.t_ = 1.0
self._partial_fit(X, y, alpha, C, loss, learning_rate,
self._max_iter, sample_weight, coef_init,
intercept_init)
if (self._tol is not None and self._tol > -np.inf
and self.n_iter_ == self._max_iter):
warnings.warn("Maximum number of iteration reached before "
"convergence. Consider increasing max_iter to "
"improve the fit.",
ConvergenceWarning)
return self
def fit(self, X, y, coef_init=None, intercept_init=None,
sample_weight=None):
"""Fit linear model with Stochastic Gradient Descent.
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Training data
y : numpy array, shape (n_samples,)
Target values
coef_init : array, shape (n_features,)
The initial coefficients to warm-start the optimization.
intercept_init : array, shape (1,)
The initial intercept to warm-start the optimization.
sample_weight : array-like, shape (n_samples,), optional
Weights applied to individual samples (1. for unweighted).
Returns
-------
self : returns an instance of self.
"""
return self._fit(X, y, alpha=self.alpha, C=1.0,
loss=self.loss, learning_rate=self.learning_rate,
coef_init=coef_init,
intercept_init=intercept_init,
sample_weight=sample_weight)
def _decision_function(self, X):
"""Predict using the linear model
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Returns
-------
array, shape (n_samples,)
Predicted target values per element in X.
"""
check_is_fitted(self, ["t_", "coef_", "intercept_"], all_or_any=all)
X = check_array(X, accept_sparse='csr')
scores = safe_sparse_dot(X, self.coef_.T,
dense_output=True) + self.intercept_
return scores.ravel()
def predict(self, X):
"""Predict using the linear model
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples, n_features)
Returns
-------
array, shape (n_samples,)
Predicted target values per element in X.
"""
return self._decision_function(X)
def _fit_regressor(self, X, y, alpha, C, loss, learning_rate,
sample_weight, max_iter):
dataset, intercept_decay = make_dataset(X, y, sample_weight)
loss_function = self._get_loss_function(loss)
penalty_type = self._get_penalty_type(self.penalty)
learning_rate_type = self._get_learning_rate_type(learning_rate)
if not hasattr(self, "t_"):
self.t_ = 1.0
random_state = check_random_state(self.random_state)
# numpy mtrand expects a C long which is a signed 32 bit integer under
# Windows
seed = random_state.randint(0, np.iinfo(np.int32).max)
tol = self._tol if self._tol is not None else -np.inf
if self.average > 0:
self.standard_coef_, self.standard_intercept_, \
self.average_coef_, self.average_intercept_, self.n_iter_ =\
average_sgd(self.standard_coef_,
self.standard_intercept_[0],
self.average_coef_,
self.average_intercept_[0],
loss_function,
penalty_type,
alpha, C,
self.l1_ratio,
dataset,
max_iter, tol,
int(self.fit_intercept),
int(self.verbose),
int(self.shuffle),
seed,
1.0, 1.0,
learning_rate_type,
self.eta0, self.power_t, self.t_,
intercept_decay, self.average)
self.average_intercept_ = np.atleast_1d(self.average_intercept_)
self.standard_intercept_ = np.atleast_1d(self.standard_intercept_)
self.t_ += self.n_iter_ * X.shape[0]
if self.average <= self.t_ - 1.0:
self.coef_ = self.average_coef_
self.intercept_ = self.average_intercept_
else:
self.coef_ = self.standard_coef_
self.intercept_ = self.standard_intercept_
else:
self.coef_, self.intercept_, self.n_iter_ = \
plain_sgd(self.coef_,
self.intercept_[0],
loss_function,
penalty_type,
alpha, C,
self.l1_ratio,
dataset,
max_iter, tol,
int(self.fit_intercept),
int(self.verbose),
int(self.shuffle),
seed,
1.0, 1.0,
learning_rate_type,
self.eta0, self.power_t, self.t_,
intercept_decay)
self.t_ += self.n_iter_ * X.shape[0]
self.intercept_ = np.atleast_1d(self.intercept_)
class SGDRegressor(BaseSGDRegressor):
"""Linear model fitted by minimizing a regularized empirical loss with SGD
SGD stands for Stochastic Gradient Descent: the gradient of the loss is
estimated each sample at a time and the model is updated along the way with
a decreasing strength schedule (aka learning rate).
The regularizer is a penalty added to the loss function that shrinks model
parameters towards the zero vector using either the squared euclidean norm
L2 or the absolute norm L1 or a combination of both (Elastic Net). If the
parameter update crosses the 0.0 value because of the regularizer, the
update is truncated to 0.0 to allow for learning sparse models and achieve
online feature selection.
This implementation works with data represented as dense numpy arrays of
floating point values for the features.
Read more in the :ref:`User Guide <sgd>`.
Parameters
----------
loss : str, default: 'squared_loss'
The loss function to be used. The possible values are 'squared_loss',
'huber', 'epsilon_insensitive', or 'squared_epsilon_insensitive'
The 'squared_loss' refers to the ordinary least squares fit.
'huber' modifies 'squared_loss' to focus less on getting outliers
correct by switching from squared to linear loss past a distance of
epsilon. 'epsilon_insensitive' ignores errors less than epsilon and is
linear past that; this is the loss function used in SVR.
'squared_epsilon_insensitive' is the same but becomes squared loss past
a tolerance of epsilon.
penalty : str, 'none', 'l2', 'l1', or 'elasticnet'
The penalty (aka regularization term) to be used. Defaults to 'l2'
which is the standard regularizer for linear SVM models. 'l1' and
'elasticnet' might bring sparsity to the model (feature selection)
not achievable with 'l2'.
alpha : float
Constant that multiplies the regularization term. Defaults to 0.0001
Also used to compute learning_rate when set to 'optimal'.
l1_ratio : float
The Elastic Net mixing parameter, with 0 <= l1_ratio <= 1.
l1_ratio=0 corresponds to L2 penalty, l1_ratio=1 to L1.
Defaults to 0.15.
fit_intercept : bool
Whether the intercept should be estimated or not. If False, the
data is assumed to be already centered. Defaults to True.
max_iter : int, optional
The maximum number of passes over the training data (aka epochs).
It only impacts the behavior in the ``fit`` method, and not the
`partial_fit`.
Defaults to 5. Defaults to 1000 from 0.21, or if tol is not None.
.. versionadded:: 0.19
tol : float or None, optional
The stopping criterion. If it is not None, the iterations will stop
when (loss > previous_loss - tol). Defaults to None.
Defaults to 1e-3 from 0.21.
.. versionadded:: 0.19
shuffle : bool, optional
Whether or not the training data should be shuffled after each epoch.
Defaults to True.
verbose : integer, optional
The verbosity level.
epsilon : float
Epsilon in the epsilon-insensitive loss functions; only if `loss` is
'huber', 'epsilon_insensitive', or 'squared_epsilon_insensitive'.
For 'huber', determines the threshold at which it becomes less
important to get the prediction exactly right.
For epsilon-insensitive, any differences between the current prediction
and the correct label are ignored if they are less than this threshold.
random_state : int, RandomState instance or None, optional (default=None)
The seed of the pseudo random number generator to use when shuffling
the data. If int, random_state is the seed used by the random number
generator; If RandomState instance, random_state is the random number
generator; If None, the random number generator is the RandomState
instance used by `np.random`.
learning_rate : string, optional
The learning rate schedule:
- 'constant': eta = eta0
- 'optimal': eta = 1.0 / (alpha * (t + t0)) [default]
- 'invscaling': eta = eta0 / pow(t, power_t)
where t0 is chosen by a heuristic proposed by Leon Bottou.
eta0 : double, optional
The initial learning rate [default 0.01].
power_t : double, optional
The exponent for inverse scaling learning rate [default 0.25].
warm_start : bool, optional
When set to True, reuse the solution of the previous call to fit as
initialization, otherwise, just erase the previous solution.
average : bool or int, optional
When set to True, computes the averaged SGD weights and stores the
result in the ``coef_`` attribute. If set to an int greater than 1,
averaging will begin once the total number of samples seen reaches
average. So ``average=10`` will begin averaging after seeing 10
samples.
n_iter : int, optional
The number of passes over the training data (aka epochs).
Defaults to None. Deprecated, will be removed in 0.21.
.. versionchanged:: 0.19
Deprecated
Attributes
----------
coef_ : array, shape (n_features,)
Weights assigned to the features.
intercept_ : array, shape (1,)
The intercept term.
average_coef_ : array, shape (n_features,)
Averaged weights assigned to the features.
average_intercept_ : array, shape (1,)
The averaged intercept term.
n_iter_ : int
The actual number of iterations to reach the stopping criterion.
Examples
--------
>>> import numpy as np
>>> from sklearn import linear_model
>>> n_samples, n_features = 10, 5
>>> np.random.seed(0)
>>> y = np.random.randn(n_samples)
>>> X = np.random.randn(n_samples, n_features)
>>> clf = linear_model.SGDRegressor()
>>> clf.fit(X, y)
... #doctest: +NORMALIZE_WHITESPACE
SGDRegressor(alpha=0.0001, average=False, epsilon=0.1, eta0=0.01,
fit_intercept=True, l1_ratio=0.15, learning_rate='invscaling',
loss='squared_loss', max_iter=None, n_iter=None, penalty='l2',
power_t=0.25, random_state=None, shuffle=True, tol=None,
verbose=0, warm_start=False)
See also
--------
Ridge, ElasticNet, Lasso, SVR
"""
def __init__(self, loss="squared_loss", penalty="l2", alpha=0.0001,
l1_ratio=0.15, fit_intercept=True, max_iter=None, tol=None,
shuffle=True, verbose=0, epsilon=DEFAULT_EPSILON,
random_state=None, learning_rate="invscaling", eta0=0.01,
power_t=0.25, warm_start=False, average=False, n_iter=None):
super(SGDRegressor, self).__init__(loss=loss, penalty=penalty,
alpha=alpha, l1_ratio=l1_ratio,
fit_intercept=fit_intercept,
max_iter=max_iter, tol=tol,
shuffle=shuffle,
verbose=verbose,
epsilon=epsilon,
random_state=random_state,
learning_rate=learning_rate,
eta0=eta0, power_t=power_t,
warm_start=warm_start,
average=average, n_iter=n_iter)
| 55,745 | 40.477679 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/perceptron.py | # Author: Mathieu Blondel
# License: BSD 3 clause
from .stochastic_gradient import BaseSGDClassifier
class Perceptron(BaseSGDClassifier):
"""Perceptron
Read more in the :ref:`User Guide <perceptron>`.
Parameters
----------
penalty : None, 'l2' or 'l1' or 'elasticnet'
The penalty (aka regularization term) to be used. Defaults to None.
alpha : float
Constant that multiplies the regularization term if regularization is
used. Defaults to 0.0001
fit_intercept : bool
Whether the intercept should be estimated or not. If False, the
data is assumed to be already centered. Defaults to True.
max_iter : int, optional
The maximum number of passes over the training data (aka epochs).
It only impacts the behavior in the ``fit`` method, and not the
`partial_fit`.
Defaults to 5. Defaults to 1000 from 0.21, or if tol is not None.
.. versionadded:: 0.19
tol : float or None, optional
The stopping criterion. If it is not None, the iterations will stop
when (loss > previous_loss - tol). Defaults to None.
Defaults to 1e-3 from 0.21.
.. versionadded:: 0.19
shuffle : bool, optional, default True
Whether or not the training data should be shuffled after each epoch.
verbose : integer, optional
The verbosity level
eta0 : double
Constant by which the updates are multiplied. Defaults to 1.
n_jobs : integer, optional
The number of CPUs to use to do the OVA (One Versus All, for
multi-class problems) computation. -1 means 'all CPUs'. Defaults
to 1.
random_state : int, RandomState instance or None, optional, default None
The seed of the pseudo random number generator to use when shuffling
the data. If int, random_state is the seed used by the random number
generator; If RandomState instance, random_state is the random number
generator; If None, the random number generator is the RandomState
instance used by `np.random`.
class_weight : dict, {class_label: weight} or "balanced" or None, optional
Preset for the class_weight fit parameter.
Weights associated with classes. If not given, all classes
are supposed to have weight one.
The "balanced" mode uses the values of y to automatically adjust
weights inversely proportional to class frequencies in the input data
as ``n_samples / (n_classes * np.bincount(y))``
warm_start : bool, optional
When set to True, reuse the solution of the previous call to fit as
initialization, otherwise, just erase the previous solution.
n_iter : int, optional
The number of passes over the training data (aka epochs).
Defaults to None. Deprecated, will be removed in 0.21.
.. versionchanged:: 0.19
Deprecated
Attributes
----------
coef_ : array, shape = [1, n_features] if n_classes == 2 else [n_classes,\
n_features]
Weights assigned to the features.
intercept_ : array, shape = [1] if n_classes == 2 else [n_classes]
Constants in decision function.
n_iter_ : int
The actual number of iterations to reach the stopping criterion.
For multiclass fits, it is the maximum over every binary fit.
Notes
-----
`Perceptron` and `SGDClassifier` share the same underlying implementation.
In fact, `Perceptron()` is equivalent to `SGDClassifier(loss="perceptron",
eta0=1, learning_rate="constant", penalty=None)`.
See also
--------
SGDClassifier
References
----------
https://en.wikipedia.org/wiki/Perceptron and references therein.
"""
def __init__(self, penalty=None, alpha=0.0001, fit_intercept=True,
max_iter=None, tol=None, shuffle=True, verbose=0, eta0=1.0,
n_jobs=1, random_state=0, class_weight=None,
warm_start=False, n_iter=None):
super(Perceptron, self).__init__(loss="perceptron",
penalty=penalty,
alpha=alpha, l1_ratio=0,
fit_intercept=fit_intercept,
max_iter=max_iter,
tol=tol,
shuffle=shuffle,
verbose=verbose,
random_state=random_state,
learning_rate="constant",
eta0=eta0,
power_t=0.5,
warm_start=warm_start,
class_weight=class_weight,
n_jobs=n_jobs,
n_iter=n_iter)
| 4,995 | 36.56391 | 78 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_sag.py | # Authors: Danny Sullivan <[email protected]>
# Tom Dupre la Tour <[email protected]>
#
# License: BSD 3 clause
import math
import numpy as np
import scipy.sparse as sp
from sklearn.linear_model.sag import get_auto_step_size
from sklearn.linear_model.sag_fast import _multinomial_grad_loss_all_samples
from sklearn.linear_model import LogisticRegression, Ridge
from sklearn.linear_model.base import make_dataset
from sklearn.linear_model.logistic import _multinomial_loss_grad
from sklearn.utils.fixes import logsumexp
from sklearn.utils.extmath import row_norms
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_raise_message
from sklearn.utils.testing import ignore_warnings
from sklearn.utils import compute_class_weight
from sklearn.utils import check_random_state
from sklearn.preprocessing import LabelEncoder, LabelBinarizer
from sklearn.datasets import make_blobs, load_iris
from sklearn.base import clone
iris = load_iris()
# this is used for sag classification
def log_dloss(p, y):
z = p * y
# approximately equal and saves the computation of the log
if z > 18.0:
return math.exp(-z) * -y
if z < -18.0:
return -y
return -y / (math.exp(z) + 1.0)
def log_loss(p, y):
return np.mean(np.log(1. + np.exp(-y * p)))
# this is used for sag regression
def squared_dloss(p, y):
return p - y
def squared_loss(p, y):
return np.mean(0.5 * (p - y) * (p - y))
# function for measuring the log loss
def get_pobj(w, alpha, myX, myy, loss):
w = w.ravel()
pred = np.dot(myX, w)
p = loss(pred, myy)
p += alpha * w.dot(w) / 2.
return p
def sag(X, y, step_size, alpha, n_iter=1, dloss=None, sparse=False,
sample_weight=None, fit_intercept=True, saga=False):
n_samples, n_features = X.shape[0], X.shape[1]
weights = np.zeros(X.shape[1])
sum_gradient = np.zeros(X.shape[1])
gradient_memory = np.zeros((n_samples, n_features))
intercept = 0.0
intercept_sum_gradient = 0.0
intercept_gradient_memory = np.zeros(n_samples)
rng = np.random.RandomState(77)
decay = 1.0
seen = set()
# sparse data has a fixed decay of .01
if sparse:
decay = .01
for epoch in range(n_iter):
for k in range(n_samples):
idx = int(rng.rand(1) * n_samples)
# idx = k
entry = X[idx]
seen.add(idx)
p = np.dot(entry, weights) + intercept
gradient = dloss(p, y[idx])
if sample_weight is not None:
gradient *= sample_weight[idx]
update = entry * gradient + alpha * weights
gradient_correction = update - gradient_memory[idx]
sum_gradient += gradient_correction
gradient_memory[idx] = update
if saga:
weights -= (gradient_correction *
step_size * (1 - 1. / len(seen)))
if fit_intercept:
gradient_correction = (gradient -
intercept_gradient_memory[idx])
intercept_gradient_memory[idx] = gradient
intercept_sum_gradient += gradient_correction
gradient_correction *= step_size * (1. - 1. / len(seen))
if saga:
intercept -= (step_size * intercept_sum_gradient /
len(seen) * decay) + gradient_correction
else:
intercept -= (step_size * intercept_sum_gradient /
len(seen) * decay)
weights -= step_size * sum_gradient / len(seen)
return weights, intercept
def sag_sparse(X, y, step_size, alpha, n_iter=1,
dloss=None, sample_weight=None, sparse=False,
fit_intercept=True, saga=False):
if step_size * alpha == 1.:
raise ZeroDivisionError("Sparse sag does not handle the case "
"step_size * alpha == 1")
n_samples, n_features = X.shape[0], X.shape[1]
weights = np.zeros(n_features)
sum_gradient = np.zeros(n_features)
last_updated = np.zeros(n_features, dtype=np.int)
gradient_memory = np.zeros(n_samples)
rng = np.random.RandomState(77)
intercept = 0.0
intercept_sum_gradient = 0.0
wscale = 1.0
decay = 1.0
seen = set()
c_sum = np.zeros(n_iter * n_samples)
# sparse data has a fixed decay of .01
if sparse:
decay = .01
counter = 0
for epoch in range(n_iter):
for k in range(n_samples):
# idx = k
idx = int(rng.rand(1) * n_samples)
entry = X[idx]
seen.add(idx)
if counter >= 1:
for j in range(n_features):
if last_updated[j] == 0:
weights[j] -= c_sum[counter - 1] * sum_gradient[j]
else:
weights[j] -= ((c_sum[counter - 1] -
c_sum[last_updated[j] - 1]) *
sum_gradient[j])
last_updated[j] = counter
p = (wscale * np.dot(entry, weights)) + intercept
gradient = dloss(p, y[idx])
if sample_weight is not None:
gradient *= sample_weight[idx]
update = entry * gradient
gradient_correction = update - (gradient_memory[idx] * entry)
sum_gradient += gradient_correction
if saga:
for j in range(n_features):
weights[j] -= (gradient_correction[j] * step_size *
(1 - 1. / len(seen)) / wscale)
if fit_intercept:
gradient_correction = gradient - gradient_memory[idx]
intercept_sum_gradient += gradient_correction
gradient_correction *= step_size * (1. - 1. / len(seen))
if saga:
intercept -= ((step_size * intercept_sum_gradient /
len(seen) * decay) +
gradient_correction)
else:
intercept -= (step_size * intercept_sum_gradient /
len(seen) * decay)
gradient_memory[idx] = gradient
wscale *= (1.0 - alpha * step_size)
if counter == 0:
c_sum[0] = step_size / (wscale * len(seen))
else:
c_sum[counter] = (c_sum[counter - 1] +
step_size / (wscale * len(seen)))
if counter >= 1 and wscale < 1e-9:
for j in range(n_features):
if last_updated[j] == 0:
weights[j] -= c_sum[counter] * sum_gradient[j]
else:
weights[j] -= ((c_sum[counter] -
c_sum[last_updated[j] - 1]) *
sum_gradient[j])
last_updated[j] = counter + 1
c_sum[counter] = 0
weights *= wscale
wscale = 1.0
counter += 1
for j in range(n_features):
if last_updated[j] == 0:
weights[j] -= c_sum[counter - 1] * sum_gradient[j]
else:
weights[j] -= ((c_sum[counter - 1] -
c_sum[last_updated[j] - 1]) *
sum_gradient[j])
weights *= wscale
return weights, intercept
def get_step_size(X, alpha, fit_intercept, classification=True):
if classification:
return (4.0 / (np.max(np.sum(X * X, axis=1)) +
fit_intercept + 4.0 * alpha))
else:
return 1.0 / (np.max(np.sum(X * X, axis=1)) + fit_intercept + alpha)
@ignore_warnings
def test_classifier_matching():
n_samples = 20
X, y = make_blobs(n_samples=n_samples, centers=2, random_state=0,
cluster_std=0.1)
y[y == 0] = -1
alpha = 1.1
fit_intercept = True
step_size = get_step_size(X, alpha, fit_intercept)
for solver in ['sag', 'saga']:
if solver == 'sag':
n_iter = 80
else:
# SAGA variance w.r.t. stream order is higher
n_iter = 300
clf = LogisticRegression(solver=solver, fit_intercept=fit_intercept,
tol=1e-11, C=1. / alpha / n_samples,
max_iter=n_iter, random_state=10)
clf.fit(X, y)
weights, intercept = sag_sparse(X, y, step_size, alpha, n_iter=n_iter,
dloss=log_dloss,
fit_intercept=fit_intercept,
saga=solver == 'saga')
weights2, intercept2 = sag(X, y, step_size, alpha, n_iter=n_iter,
dloss=log_dloss,
fit_intercept=fit_intercept,
saga=solver == 'saga')
weights = np.atleast_2d(weights)
intercept = np.atleast_1d(intercept)
weights2 = np.atleast_2d(weights2)
intercept2 = np.atleast_1d(intercept2)
assert_array_almost_equal(weights, clf.coef_, decimal=9)
assert_array_almost_equal(intercept, clf.intercept_, decimal=9)
assert_array_almost_equal(weights2, clf.coef_, decimal=9)
assert_array_almost_equal(intercept2, clf.intercept_, decimal=9)
@ignore_warnings
def test_regressor_matching():
n_samples = 10
n_features = 5
rng = np.random.RandomState(10)
X = rng.normal(size=(n_samples, n_features))
true_w = rng.normal(size=n_features)
y = X.dot(true_w)
alpha = 1.
n_iter = 100
fit_intercept = True
step_size = get_step_size(X, alpha, fit_intercept, classification=False)
clf = Ridge(fit_intercept=fit_intercept, tol=.00000000001, solver='sag',
alpha=alpha * n_samples, max_iter=n_iter)
clf.fit(X, y)
weights1, intercept1 = sag_sparse(X, y, step_size, alpha, n_iter=n_iter,
dloss=squared_dloss,
fit_intercept=fit_intercept)
weights2, intercept2 = sag(X, y, step_size, alpha, n_iter=n_iter,
dloss=squared_dloss,
fit_intercept=fit_intercept)
assert_array_almost_equal(weights1, clf.coef_, decimal=10)
assert_array_almost_equal(intercept1, clf.intercept_, decimal=10)
assert_array_almost_equal(weights2, clf.coef_, decimal=10)
assert_array_almost_equal(intercept2, clf.intercept_, decimal=10)
@ignore_warnings
def test_sag_pobj_matches_logistic_regression():
"""tests if the sag pobj matches log reg"""
n_samples = 100
alpha = 1.0
max_iter = 20
X, y = make_blobs(n_samples=n_samples, centers=2, random_state=0,
cluster_std=0.1)
clf1 = LogisticRegression(solver='sag', fit_intercept=False, tol=.0000001,
C=1. / alpha / n_samples, max_iter=max_iter,
random_state=10)
clf2 = clone(clf1)
clf3 = LogisticRegression(fit_intercept=False, tol=.0000001,
C=1. / alpha / n_samples, max_iter=max_iter,
random_state=10)
clf1.fit(X, y)
clf2.fit(sp.csr_matrix(X), y)
clf3.fit(X, y)
pobj1 = get_pobj(clf1.coef_, alpha, X, y, log_loss)
pobj2 = get_pobj(clf2.coef_, alpha, X, y, log_loss)
pobj3 = get_pobj(clf3.coef_, alpha, X, y, log_loss)
assert_array_almost_equal(pobj1, pobj2, decimal=4)
assert_array_almost_equal(pobj2, pobj3, decimal=4)
assert_array_almost_equal(pobj3, pobj1, decimal=4)
@ignore_warnings
def test_sag_pobj_matches_ridge_regression():
"""tests if the sag pobj matches ridge reg"""
n_samples = 100
n_features = 10
alpha = 1.0
n_iter = 100
fit_intercept = False
rng = np.random.RandomState(10)
X = rng.normal(size=(n_samples, n_features))
true_w = rng.normal(size=n_features)
y = X.dot(true_w)
clf1 = Ridge(fit_intercept=fit_intercept, tol=.00000000001, solver='sag',
alpha=alpha, max_iter=n_iter, random_state=42)
clf2 = clone(clf1)
clf3 = Ridge(fit_intercept=fit_intercept, tol=.00001, solver='lsqr',
alpha=alpha, max_iter=n_iter, random_state=42)
clf1.fit(X, y)
clf2.fit(sp.csr_matrix(X), y)
clf3.fit(X, y)
pobj1 = get_pobj(clf1.coef_, alpha, X, y, squared_loss)
pobj2 = get_pobj(clf2.coef_, alpha, X, y, squared_loss)
pobj3 = get_pobj(clf3.coef_, alpha, X, y, squared_loss)
assert_array_almost_equal(pobj1, pobj2, decimal=4)
assert_array_almost_equal(pobj1, pobj3, decimal=4)
assert_array_almost_equal(pobj3, pobj2, decimal=4)
@ignore_warnings
def test_sag_regressor_computed_correctly():
"""tests if the sag regressor is computed correctly"""
alpha = .1
n_features = 10
n_samples = 40
max_iter = 50
tol = .000001
fit_intercept = True
rng = np.random.RandomState(0)
X = rng.normal(size=(n_samples, n_features))
w = rng.normal(size=n_features)
y = np.dot(X, w) + 2.
step_size = get_step_size(X, alpha, fit_intercept, classification=False)
clf1 = Ridge(fit_intercept=fit_intercept, tol=tol, solver='sag',
alpha=alpha * n_samples, max_iter=max_iter)
clf2 = clone(clf1)
clf1.fit(X, y)
clf2.fit(sp.csr_matrix(X), y)
spweights1, spintercept1 = sag_sparse(X, y, step_size, alpha,
n_iter=max_iter,
dloss=squared_dloss,
fit_intercept=fit_intercept)
spweights2, spintercept2 = sag_sparse(X, y, step_size, alpha,
n_iter=max_iter,
dloss=squared_dloss, sparse=True,
fit_intercept=fit_intercept)
assert_array_almost_equal(clf1.coef_.ravel(),
spweights1.ravel(),
decimal=3)
assert_almost_equal(clf1.intercept_, spintercept1, decimal=1)
# TODO: uncomment when sparse Ridge with intercept will be fixed (#4710)
# assert_array_almost_equal(clf2.coef_.ravel(),
# spweights2.ravel(),
# decimal=3)
# assert_almost_equal(clf2.intercept_, spintercept2, decimal=1)'''
@ignore_warnings
def test_get_auto_step_size():
X = np.array([[1, 2, 3], [2, 3, 4], [2, 3, 2]], dtype=np.float64)
alpha = 1.2
fit_intercept = False
# sum the squares of the second sample because that's the largest
max_squared_sum = 4 + 9 + 16
max_squared_sum_ = row_norms(X, squared=True).max()
n_samples = X.shape[0]
assert_almost_equal(max_squared_sum, max_squared_sum_, decimal=4)
for saga in [True, False]:
for fit_intercept in (True, False):
if saga:
L_sqr = (max_squared_sum + alpha + int(fit_intercept))
L_log = (max_squared_sum + 4.0 * alpha +
int(fit_intercept)) / 4.0
mun_sqr = min(2 * n_samples * alpha, L_sqr)
mun_log = min(2 * n_samples * alpha, L_log)
step_size_sqr = 1 / (2 * L_sqr + mun_sqr)
step_size_log = 1 / (2 * L_log + mun_log)
else:
step_size_sqr = 1.0 / (max_squared_sum +
alpha + int(fit_intercept))
step_size_log = 4.0 / (max_squared_sum + 4.0 * alpha +
int(fit_intercept))
step_size_sqr_ = get_auto_step_size(max_squared_sum_, alpha,
"squared",
fit_intercept,
n_samples=n_samples,
is_saga=saga)
step_size_log_ = get_auto_step_size(max_squared_sum_, alpha, "log",
fit_intercept,
n_samples=n_samples,
is_saga=saga)
assert_almost_equal(step_size_sqr, step_size_sqr_, decimal=4)
assert_almost_equal(step_size_log, step_size_log_, decimal=4)
msg = 'Unknown loss function for SAG solver, got wrong instead of'
assert_raise_message(ValueError, msg, get_auto_step_size,
max_squared_sum_, alpha, "wrong", fit_intercept)
@ignore_warnings
def test_sag_regressor():
"""tests if the sag regressor performs well"""
xmin, xmax = -5, 5
n_samples = 20
tol = .001
max_iter = 20
alpha = 0.1
rng = np.random.RandomState(0)
X = np.linspace(xmin, xmax, n_samples).reshape(n_samples, 1)
# simple linear function without noise
y = 0.5 * X.ravel()
clf1 = Ridge(tol=tol, solver='sag', max_iter=max_iter,
alpha=alpha * n_samples)
clf2 = clone(clf1)
clf1.fit(X, y)
clf2.fit(sp.csr_matrix(X), y)
score1 = clf1.score(X, y)
score2 = clf2.score(X, y)
assert_greater(score1, 0.99)
assert_greater(score2, 0.99)
# simple linear function with noise
y = 0.5 * X.ravel() + rng.randn(n_samples, 1).ravel()
clf1 = Ridge(tol=tol, solver='sag', max_iter=max_iter,
alpha=alpha * n_samples)
clf2 = clone(clf1)
clf1.fit(X, y)
clf2.fit(sp.csr_matrix(X), y)
score1 = clf1.score(X, y)
score2 = clf2.score(X, y)
score2 = clf2.score(X, y)
assert_greater(score1, 0.5)
assert_greater(score2, 0.5)
@ignore_warnings
def test_sag_classifier_computed_correctly():
"""tests if the binary classifier is computed correctly"""
alpha = .1
n_samples = 50
n_iter = 50
tol = .00001
fit_intercept = True
X, y = make_blobs(n_samples=n_samples, centers=2, random_state=0,
cluster_std=0.1)
step_size = get_step_size(X, alpha, fit_intercept, classification=True)
classes = np.unique(y)
y_tmp = np.ones(n_samples)
y_tmp[y != classes[1]] = -1
y = y_tmp
clf1 = LogisticRegression(solver='sag', C=1. / alpha / n_samples,
max_iter=n_iter, tol=tol, random_state=77,
fit_intercept=fit_intercept)
clf2 = clone(clf1)
clf1.fit(X, y)
clf2.fit(sp.csr_matrix(X), y)
spweights, spintercept = sag_sparse(X, y, step_size, alpha, n_iter=n_iter,
dloss=log_dloss,
fit_intercept=fit_intercept)
spweights2, spintercept2 = sag_sparse(X, y, step_size, alpha,
n_iter=n_iter,
dloss=log_dloss, sparse=True,
fit_intercept=fit_intercept)
assert_array_almost_equal(clf1.coef_.ravel(),
spweights.ravel(),
decimal=2)
assert_almost_equal(clf1.intercept_, spintercept, decimal=1)
assert_array_almost_equal(clf2.coef_.ravel(),
spweights2.ravel(),
decimal=2)
assert_almost_equal(clf2.intercept_, spintercept2, decimal=1)
@ignore_warnings
def test_sag_multiclass_computed_correctly():
"""tests if the multiclass classifier is computed correctly"""
alpha = .1
n_samples = 20
tol = .00001
max_iter = 40
fit_intercept = True
X, y = make_blobs(n_samples=n_samples, centers=3, random_state=0,
cluster_std=0.1)
step_size = get_step_size(X, alpha, fit_intercept, classification=True)
classes = np.unique(y)
clf1 = LogisticRegression(solver='sag', C=1. / alpha / n_samples,
max_iter=max_iter, tol=tol, random_state=77,
fit_intercept=fit_intercept)
clf2 = clone(clf1)
clf1.fit(X, y)
clf2.fit(sp.csr_matrix(X), y)
coef1 = []
intercept1 = []
coef2 = []
intercept2 = []
for cl in classes:
y_encoded = np.ones(n_samples)
y_encoded[y != cl] = -1
spweights1, spintercept1 = sag_sparse(X, y_encoded, step_size, alpha,
dloss=log_dloss, n_iter=max_iter,
fit_intercept=fit_intercept)
spweights2, spintercept2 = sag_sparse(X, y_encoded, step_size, alpha,
dloss=log_dloss, n_iter=max_iter,
sparse=True,
fit_intercept=fit_intercept)
coef1.append(spweights1)
intercept1.append(spintercept1)
coef2.append(spweights2)
intercept2.append(spintercept2)
coef1 = np.vstack(coef1)
intercept1 = np.array(intercept1)
coef2 = np.vstack(coef2)
intercept2 = np.array(intercept2)
for i, cl in enumerate(classes):
assert_array_almost_equal(clf1.coef_[i].ravel(),
coef1[i].ravel(),
decimal=2)
assert_almost_equal(clf1.intercept_[i], intercept1[i], decimal=1)
assert_array_almost_equal(clf2.coef_[i].ravel(),
coef2[i].ravel(),
decimal=2)
assert_almost_equal(clf2.intercept_[i], intercept2[i], decimal=1)
@ignore_warnings
def test_classifier_results():
"""tests if classifier results match target"""
alpha = .1
n_features = 20
n_samples = 10
tol = .01
max_iter = 200
rng = np.random.RandomState(0)
X = rng.normal(size=(n_samples, n_features))
w = rng.normal(size=n_features)
y = np.dot(X, w)
y = np.sign(y)
clf1 = LogisticRegression(solver='sag', C=1. / alpha / n_samples,
max_iter=max_iter, tol=tol, random_state=77)
clf2 = clone(clf1)
clf1.fit(X, y)
clf2.fit(sp.csr_matrix(X), y)
pred1 = clf1.predict(X)
pred2 = clf2.predict(X)
assert_almost_equal(pred1, y, decimal=12)
assert_almost_equal(pred2, y, decimal=12)
@ignore_warnings
def test_binary_classifier_class_weight():
"""tests binary classifier with classweights for each class"""
alpha = .1
n_samples = 50
n_iter = 20
tol = .00001
fit_intercept = True
X, y = make_blobs(n_samples=n_samples, centers=2, random_state=10,
cluster_std=0.1)
step_size = get_step_size(X, alpha, fit_intercept, classification=True)
classes = np.unique(y)
y_tmp = np.ones(n_samples)
y_tmp[y != classes[1]] = -1
y = y_tmp
class_weight = {1: .45, -1: .55}
clf1 = LogisticRegression(solver='sag', C=1. / alpha / n_samples,
max_iter=n_iter, tol=tol, random_state=77,
fit_intercept=fit_intercept,
class_weight=class_weight)
clf2 = clone(clf1)
clf1.fit(X, y)
clf2.fit(sp.csr_matrix(X), y)
le = LabelEncoder()
class_weight_ = compute_class_weight(class_weight, np.unique(y), y)
sample_weight = class_weight_[le.fit_transform(y)]
spweights, spintercept = sag_sparse(X, y, step_size, alpha, n_iter=n_iter,
dloss=log_dloss,
sample_weight=sample_weight,
fit_intercept=fit_intercept)
spweights2, spintercept2 = sag_sparse(X, y, step_size, alpha,
n_iter=n_iter,
dloss=log_dloss, sparse=True,
sample_weight=sample_weight,
fit_intercept=fit_intercept)
assert_array_almost_equal(clf1.coef_.ravel(),
spweights.ravel(),
decimal=2)
assert_almost_equal(clf1.intercept_, spintercept, decimal=1)
assert_array_almost_equal(clf2.coef_.ravel(),
spweights2.ravel(),
decimal=2)
assert_almost_equal(clf2.intercept_, spintercept2, decimal=1)
@ignore_warnings
def test_multiclass_classifier_class_weight():
"""tests multiclass with classweights for each class"""
alpha = .1
n_samples = 20
tol = .00001
max_iter = 50
class_weight = {0: .45, 1: .55, 2: .75}
fit_intercept = True
X, y = make_blobs(n_samples=n_samples, centers=3, random_state=0,
cluster_std=0.1)
step_size = get_step_size(X, alpha, fit_intercept, classification=True)
classes = np.unique(y)
clf1 = LogisticRegression(solver='sag', C=1. / alpha / n_samples,
max_iter=max_iter, tol=tol, random_state=77,
fit_intercept=fit_intercept,
class_weight=class_weight)
clf2 = clone(clf1)
clf1.fit(X, y)
clf2.fit(sp.csr_matrix(X), y)
le = LabelEncoder()
class_weight_ = compute_class_weight(class_weight, np.unique(y), y)
sample_weight = class_weight_[le.fit_transform(y)]
coef1 = []
intercept1 = []
coef2 = []
intercept2 = []
for cl in classes:
y_encoded = np.ones(n_samples)
y_encoded[y != cl] = -1
spweights1, spintercept1 = sag_sparse(X, y_encoded, step_size, alpha,
n_iter=max_iter, dloss=log_dloss,
sample_weight=sample_weight)
spweights2, spintercept2 = sag_sparse(X, y_encoded, step_size, alpha,
n_iter=max_iter, dloss=log_dloss,
sample_weight=sample_weight,
sparse=True)
coef1.append(spweights1)
intercept1.append(spintercept1)
coef2.append(spweights2)
intercept2.append(spintercept2)
coef1 = np.vstack(coef1)
intercept1 = np.array(intercept1)
coef2 = np.vstack(coef2)
intercept2 = np.array(intercept2)
for i, cl in enumerate(classes):
assert_array_almost_equal(clf1.coef_[i].ravel(),
coef1[i].ravel(),
decimal=2)
assert_almost_equal(clf1.intercept_[i], intercept1[i], decimal=1)
assert_array_almost_equal(clf2.coef_[i].ravel(),
coef2[i].ravel(),
decimal=2)
assert_almost_equal(clf2.intercept_[i], intercept2[i], decimal=1)
def test_classifier_single_class():
"""tests if ValueError is thrown with only one class"""
X = [[1, 2], [3, 4]]
y = [1, 1]
assert_raise_message(ValueError,
"This solver needs samples of at least 2 classes "
"in the data",
LogisticRegression(solver='sag').fit,
X, y)
def test_step_size_alpha_error():
X = [[0, 0], [0, 0]]
y = [1, -1]
fit_intercept = False
alpha = 1.
msg = ("Current sag implementation does not handle the case"
" step_size * alpha_scaled == 1")
clf1 = LogisticRegression(solver='sag', C=1. / alpha,
fit_intercept=fit_intercept)
assert_raise_message(ZeroDivisionError, msg, clf1.fit, X, y)
clf2 = Ridge(fit_intercept=fit_intercept, solver='sag', alpha=alpha)
assert_raise_message(ZeroDivisionError, msg, clf2.fit, X, y)
def test_multinomial_loss():
# test if the multinomial loss and gradient computations are consistent
X, y = iris.data, iris.target.astype(np.float64)
n_samples, n_features = X.shape
n_classes = len(np.unique(y))
rng = check_random_state(42)
weights = rng.randn(n_features, n_classes)
intercept = rng.randn(n_classes)
sample_weights = rng.randn(n_samples)
np.abs(sample_weights, sample_weights)
# compute loss and gradient like in multinomial SAG
dataset, _ = make_dataset(X, y, sample_weights, random_state=42)
loss_1, grad_1 = _multinomial_grad_loss_all_samples(dataset, weights,
intercept, n_samples,
n_features, n_classes)
# compute loss and gradient like in multinomial LogisticRegression
lbin = LabelBinarizer()
Y_bin = lbin.fit_transform(y)
weights_intercept = np.vstack((weights, intercept)).T.ravel()
loss_2, grad_2, _ = _multinomial_loss_grad(weights_intercept, X, Y_bin,
0.0, sample_weights)
grad_2 = grad_2.reshape(n_classes, -1)
grad_2 = grad_2[:, :-1].T
# comparison
assert_array_almost_equal(grad_1, grad_2)
assert_almost_equal(loss_1, loss_2)
def test_multinomial_loss_ground_truth():
# n_samples, n_features, n_classes = 4, 2, 3
n_classes = 3
X = np.array([[1.1, 2.2], [2.2, -4.4], [3.3, -2.2], [1.1, 1.1]])
y = np.array([0, 1, 2, 0])
lbin = LabelBinarizer()
Y_bin = lbin.fit_transform(y)
weights = np.array([[0.1, 0.2, 0.3], [1.1, 1.2, -1.3]])
intercept = np.array([1., 0, -.2])
sample_weights = np.array([0.8, 1, 1, 0.8])
prediction = np.dot(X, weights) + intercept
logsumexp_prediction = logsumexp(prediction, axis=1)
p = prediction - logsumexp_prediction[:, np.newaxis]
loss_1 = -(sample_weights[:, np.newaxis] * p * Y_bin).sum()
diff = sample_weights[:, np.newaxis] * (np.exp(p) - Y_bin)
grad_1 = np.dot(X.T, diff)
weights_intercept = np.vstack((weights, intercept)).T.ravel()
loss_2, grad_2, _ = _multinomial_loss_grad(weights_intercept, X, Y_bin,
0.0, sample_weights)
grad_2 = grad_2.reshape(n_classes, -1)
grad_2 = grad_2[:, :-1].T
assert_almost_equal(loss_1, loss_2)
assert_array_almost_equal(grad_1, grad_2)
# ground truth
loss_gt = 11.680360354325961
grad_gt = np.array([[-0.557487, -1.619151, +2.176638],
[-0.903942, +5.258745, -4.354803]])
assert_almost_equal(loss_1, loss_gt)
assert_array_almost_equal(grad_1, grad_gt)
| 30,671 | 36.088271 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_theil_sen.py | """
Testing for Theil-Sen module (sklearn.linear_model.theil_sen)
"""
# Author: Florian Wilhelm <[email protected]>
# License: BSD 3 clause
from __future__ import division, print_function, absolute_import
import os
import sys
from contextlib import contextmanager
import numpy as np
from numpy.testing import assert_array_equal, assert_array_less
from numpy.testing import assert_array_almost_equal, assert_warns
from scipy.linalg import norm
from scipy.optimize import fmin_bfgs
from sklearn.exceptions import ConvergenceWarning
from sklearn.linear_model import LinearRegression, TheilSenRegressor
from sklearn.linear_model.theil_sen import _spatial_median, _breakdown_point
from sklearn.linear_model.theil_sen import _modified_weiszfeld_step
from sklearn.utils.testing import (
assert_almost_equal, assert_greater, assert_less, raises,
)
@contextmanager
def no_stdout_stderr():
old_stdout = sys.stdout
old_stderr = sys.stderr
with open(os.devnull, 'w') as devnull:
sys.stdout = devnull
sys.stderr = devnull
yield
devnull.flush()
sys.stdout = old_stdout
sys.stderr = old_stderr
def gen_toy_problem_1d(intercept=True):
random_state = np.random.RandomState(0)
# Linear model y = 3*x + N(2, 0.1**2)
w = 3.
if intercept:
c = 2.
n_samples = 50
else:
c = 0.1
n_samples = 100
x = random_state.normal(size=n_samples)
noise = 0.1 * random_state.normal(size=n_samples)
y = w * x + c + noise
# Add some outliers
if intercept:
x[42], y[42] = (-2, 4)
x[43], y[43] = (-2.5, 8)
x[33], y[33] = (2.5, 1)
x[49], y[49] = (2.1, 2)
else:
x[42], y[42] = (-2, 4)
x[43], y[43] = (-2.5, 8)
x[53], y[53] = (2.5, 1)
x[60], y[60] = (2.1, 2)
x[72], y[72] = (1.8, -7)
return x[:, np.newaxis], y, w, c
def gen_toy_problem_2d():
random_state = np.random.RandomState(0)
n_samples = 100
# Linear model y = 5*x_1 + 10*x_2 + N(1, 0.1**2)
X = random_state.normal(size=(n_samples, 2))
w = np.array([5., 10.])
c = 1.
noise = 0.1 * random_state.normal(size=n_samples)
y = np.dot(X, w) + c + noise
# Add some outliers
n_outliers = n_samples // 10
ix = random_state.randint(0, n_samples, size=n_outliers)
y[ix] = 50 * random_state.normal(size=n_outliers)
return X, y, w, c
def gen_toy_problem_4d():
random_state = np.random.RandomState(0)
n_samples = 10000
# Linear model y = 5*x_1 + 10*x_2 + 42*x_3 + 7*x_4 + N(1, 0.1**2)
X = random_state.normal(size=(n_samples, 4))
w = np.array([5., 10., 42., 7.])
c = 1.
noise = 0.1 * random_state.normal(size=n_samples)
y = np.dot(X, w) + c + noise
# Add some outliers
n_outliers = n_samples // 10
ix = random_state.randint(0, n_samples, size=n_outliers)
y[ix] = 50 * random_state.normal(size=n_outliers)
return X, y, w, c
def test_modweiszfeld_step_1d():
X = np.array([1., 2., 3.]).reshape(3, 1)
# Check startvalue is element of X and solution
median = 2.
new_y = _modified_weiszfeld_step(X, median)
assert_array_almost_equal(new_y, median)
# Check startvalue is not the solution
y = 2.5
new_y = _modified_weiszfeld_step(X, y)
assert_array_less(median, new_y)
assert_array_less(new_y, y)
# Check startvalue is not the solution but element of X
y = 3.
new_y = _modified_weiszfeld_step(X, y)
assert_array_less(median, new_y)
assert_array_less(new_y, y)
# Check that a single vector is identity
X = np.array([1., 2., 3.]).reshape(1, 3)
y = X[0, ]
new_y = _modified_weiszfeld_step(X, y)
assert_array_equal(y, new_y)
def test_modweiszfeld_step_2d():
X = np.array([0., 0., 1., 1., 0., 1.]).reshape(3, 2)
y = np.array([0.5, 0.5])
# Check first two iterations
new_y = _modified_weiszfeld_step(X, y)
assert_array_almost_equal(new_y, np.array([1 / 3, 2 / 3]))
new_y = _modified_weiszfeld_step(X, new_y)
assert_array_almost_equal(new_y, np.array([0.2792408, 0.7207592]))
# Check fix point
y = np.array([0.21132505, 0.78867497])
new_y = _modified_weiszfeld_step(X, y)
assert_array_almost_equal(new_y, y)
def test_spatial_median_1d():
X = np.array([1., 2., 3.]).reshape(3, 1)
true_median = 2.
_, median = _spatial_median(X)
assert_array_almost_equal(median, true_median)
# Test larger problem and for exact solution in 1d case
random_state = np.random.RandomState(0)
X = random_state.randint(100, size=(1000, 1))
true_median = np.median(X.ravel())
_, median = _spatial_median(X)
assert_array_equal(median, true_median)
def test_spatial_median_2d():
X = np.array([0., 0., 1., 1., 0., 1.]).reshape(3, 2)
_, median = _spatial_median(X, max_iter=100, tol=1.e-6)
def cost_func(y):
dists = np.array([norm(x - y) for x in X])
return np.sum(dists)
# Check if median is solution of the Fermat-Weber location problem
fermat_weber = fmin_bfgs(cost_func, median, disp=False)
assert_array_almost_equal(median, fermat_weber)
# Check when maximum iteration is exceeded a warning is emitted
assert_warns(ConvergenceWarning, _spatial_median, X, max_iter=30, tol=0.)
def test_theil_sen_1d():
X, y, w, c = gen_toy_problem_1d()
# Check that Least Squares fails
lstq = LinearRegression().fit(X, y)
assert_greater(np.abs(lstq.coef_ - w), 0.9)
# Check that Theil-Sen works
theil_sen = TheilSenRegressor(random_state=0).fit(X, y)
assert_array_almost_equal(theil_sen.coef_, w, 1)
assert_array_almost_equal(theil_sen.intercept_, c, 1)
def test_theil_sen_1d_no_intercept():
X, y, w, c = gen_toy_problem_1d(intercept=False)
# Check that Least Squares fails
lstq = LinearRegression(fit_intercept=False).fit(X, y)
assert_greater(np.abs(lstq.coef_ - w - c), 0.5)
# Check that Theil-Sen works
theil_sen = TheilSenRegressor(fit_intercept=False,
random_state=0).fit(X, y)
assert_array_almost_equal(theil_sen.coef_, w + c, 1)
assert_almost_equal(theil_sen.intercept_, 0.)
def test_theil_sen_2d():
X, y, w, c = gen_toy_problem_2d()
# Check that Least Squares fails
lstq = LinearRegression().fit(X, y)
assert_greater(norm(lstq.coef_ - w), 1.0)
# Check that Theil-Sen works
theil_sen = TheilSenRegressor(max_subpopulation=1e3,
random_state=0).fit(X, y)
assert_array_almost_equal(theil_sen.coef_, w, 1)
assert_array_almost_equal(theil_sen.intercept_, c, 1)
def test_calc_breakdown_point():
bp = _breakdown_point(1e10, 2)
assert_less(np.abs(bp - 1 + 1 / (np.sqrt(2))), 1.e-6)
@raises(ValueError)
def test_checksubparams_negative_subpopulation():
X, y, w, c = gen_toy_problem_1d()
TheilSenRegressor(max_subpopulation=-1, random_state=0).fit(X, y)
@raises(ValueError)
def test_checksubparams_too_few_subsamples():
X, y, w, c = gen_toy_problem_1d()
TheilSenRegressor(n_subsamples=1, random_state=0).fit(X, y)
@raises(ValueError)
def test_checksubparams_too_many_subsamples():
X, y, w, c = gen_toy_problem_1d()
TheilSenRegressor(n_subsamples=101, random_state=0).fit(X, y)
@raises(ValueError)
def test_checksubparams_n_subsamples_if_less_samples_than_features():
random_state = np.random.RandomState(0)
n_samples, n_features = 10, 20
X = random_state.normal(size=(n_samples, n_features))
y = random_state.normal(size=n_samples)
TheilSenRegressor(n_subsamples=9, random_state=0).fit(X, y)
def test_subpopulation():
X, y, w, c = gen_toy_problem_4d()
theil_sen = TheilSenRegressor(max_subpopulation=250,
random_state=0).fit(X, y)
assert_array_almost_equal(theil_sen.coef_, w, 1)
assert_array_almost_equal(theil_sen.intercept_, c, 1)
def test_subsamples():
X, y, w, c = gen_toy_problem_4d()
theil_sen = TheilSenRegressor(n_subsamples=X.shape[0],
random_state=0).fit(X, y)
lstq = LinearRegression().fit(X, y)
# Check for exact the same results as Least Squares
assert_array_almost_equal(theil_sen.coef_, lstq.coef_, 9)
def test_verbosity():
X, y, w, c = gen_toy_problem_1d()
# Check that Theil-Sen can be verbose
with no_stdout_stderr():
TheilSenRegressor(verbose=True, random_state=0).fit(X, y)
TheilSenRegressor(verbose=True,
max_subpopulation=10,
random_state=0).fit(X, y)
def test_theil_sen_parallel():
X, y, w, c = gen_toy_problem_2d()
# Check that Least Squares fails
lstq = LinearRegression().fit(X, y)
assert_greater(norm(lstq.coef_ - w), 1.0)
# Check that Theil-Sen works
theil_sen = TheilSenRegressor(n_jobs=-1,
random_state=0,
max_subpopulation=2e3).fit(X, y)
assert_array_almost_equal(theil_sen.coef_, w, 1)
assert_array_almost_equal(theil_sen.intercept_, c, 1)
def test_less_samples_than_features():
random_state = np.random.RandomState(0)
n_samples, n_features = 10, 20
X = random_state.normal(size=(n_samples, n_features))
y = random_state.normal(size=n_samples)
# Check that Theil-Sen falls back to Least Squares if fit_intercept=False
theil_sen = TheilSenRegressor(fit_intercept=False,
random_state=0).fit(X, y)
lstq = LinearRegression(fit_intercept=False).fit(X, y)
assert_array_almost_equal(theil_sen.coef_, lstq.coef_, 12)
# Check fit_intercept=True case. This will not be equal to the Least
# Squares solution since the intercept is calculated differently.
theil_sen = TheilSenRegressor(fit_intercept=True, random_state=0).fit(X, y)
y_pred = theil_sen.predict(X)
assert_array_almost_equal(y_pred, y, 12)
| 9,939 | 33.634146 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_sgd.py | import pickle
import unittest
import numpy as np
import scipy.sparse as sp
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_less
from sklearn.utils.testing import raises
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_false, assert_true
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_raises_regexp
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import assert_warns_message
from sklearn.utils.testing import assert_no_warnings
from sklearn.utils.testing import ignore_warnings
from sklearn import linear_model, datasets, metrics
from sklearn.base import clone
from sklearn.linear_model import SGDClassifier, SGDRegressor
from sklearn.preprocessing import LabelEncoder, scale, MinMaxScaler
from sklearn.preprocessing import StandardScaler
from sklearn.exceptions import ConvergenceWarning
from sklearn.linear_model import sgd_fast
class SparseSGDClassifier(SGDClassifier):
def fit(self, X, y, *args, **kw):
X = sp.csr_matrix(X)
return super(SparseSGDClassifier, self).fit(X, y, *args, **kw)
def partial_fit(self, X, y, *args, **kw):
X = sp.csr_matrix(X)
return super(SparseSGDClassifier, self).partial_fit(X, y, *args, **kw)
def decision_function(self, X):
X = sp.csr_matrix(X)
return super(SparseSGDClassifier, self).decision_function(X)
def predict_proba(self, X):
X = sp.csr_matrix(X)
return super(SparseSGDClassifier, self).predict_proba(X)
class SparseSGDRegressor(SGDRegressor):
def fit(self, X, y, *args, **kw):
X = sp.csr_matrix(X)
return SGDRegressor.fit(self, X, y, *args, **kw)
def partial_fit(self, X, y, *args, **kw):
X = sp.csr_matrix(X)
return SGDRegressor.partial_fit(self, X, y, *args, **kw)
def decision_function(self, X, *args, **kw):
X = sp.csr_matrix(X)
return SGDRegressor.decision_function(self, X, *args, **kw)
# Test Data
# test sample 1
X = np.array([[-2, -1], [-1, -1], [-1, -2], [1, 1], [1, 2], [2, 1]])
Y = [1, 1, 1, 2, 2, 2]
T = np.array([[-1, -1], [2, 2], [3, 2]])
true_result = [1, 2, 2]
# test sample 2; string class labels
X2 = np.array([[-1, 1], [-0.75, 0.5], [-1.5, 1.5],
[1, 1], [0.75, 0.5], [1.5, 1.5],
[-1, -1], [0, -0.5], [1, -1]])
Y2 = ["one"] * 3 + ["two"] * 3 + ["three"] * 3
T2 = np.array([[-1.5, 0.5], [1, 2], [0, -2]])
true_result2 = ["one", "two", "three"]
# test sample 3
X3 = np.array([[1, 1, 0, 0, 0, 0], [1, 1, 0, 0, 0, 0],
[0, 0, 1, 0, 0, 0], [0, 0, 1, 0, 0, 0],
[0, 0, 0, 0, 1, 1], [0, 0, 0, 0, 1, 1],
[0, 0, 0, 1, 0, 0], [0, 0, 0, 1, 0, 0]])
Y3 = np.array([1, 1, 1, 1, 2, 2, 2, 2])
# test sample 4 - two more or less redundant feature groups
X4 = np.array([[1, 0.9, 0.8, 0, 0, 0], [1, .84, .98, 0, 0, 0],
[1, .96, .88, 0, 0, 0], [1, .91, .99, 0, 0, 0],
[0, 0, 0, .89, .91, 1], [0, 0, 0, .79, .84, 1],
[0, 0, 0, .91, .95, 1], [0, 0, 0, .93, 1, 1]])
Y4 = np.array([1, 1, 1, 1, 2, 2, 2, 2])
iris = datasets.load_iris()
# test sample 5 - test sample 1 as binary classification problem
X5 = np.array([[-2, -1], [-1, -1], [-1, -2], [1, 1], [1, 2], [2, 1]])
Y5 = [1, 1, 1, 2, 2, 2]
true_result5 = [0, 1, 1]
# Classification Test Case
class CommonTest(object):
def factory(self, **kwargs):
if "random_state" not in kwargs:
kwargs["random_state"] = 42
if "tol" not in kwargs:
kwargs["tol"] = None
if "max_iter" not in kwargs:
kwargs["max_iter"] = 5
return self.factory_class(**kwargs)
# a simple implementation of ASGD to use for testing
# uses squared loss to find the gradient
def asgd(self, X, y, eta, alpha, weight_init=None, intercept_init=0.0):
if weight_init is None:
weights = np.zeros(X.shape[1])
else:
weights = weight_init
average_weights = np.zeros(X.shape[1])
intercept = intercept_init
average_intercept = 0.0
decay = 1.0
# sparse data has a fixed decay of .01
if (isinstance(self, SparseSGDClassifierTestCase) or
isinstance(self, SparseSGDRegressorTestCase)):
decay = .01
for i, entry in enumerate(X):
p = np.dot(entry, weights)
p += intercept
gradient = p - y[i]
weights *= 1.0 - (eta * alpha)
weights += -(eta * gradient * entry)
intercept += -(eta * gradient) * decay
average_weights *= i
average_weights += weights
average_weights /= i + 1.0
average_intercept *= i
average_intercept += intercept
average_intercept /= i + 1.0
return average_weights, average_intercept
def _test_warm_start(self, X, Y, lr):
# Test that explicit warm restart...
clf = self.factory(alpha=0.01, eta0=0.01, shuffle=False,
learning_rate=lr)
clf.fit(X, Y)
clf2 = self.factory(alpha=0.001, eta0=0.01, shuffle=False,
learning_rate=lr)
clf2.fit(X, Y,
coef_init=clf.coef_.copy(),
intercept_init=clf.intercept_.copy())
# ... and implicit warm restart are equivalent.
clf3 = self.factory(alpha=0.01, eta0=0.01, shuffle=False,
warm_start=True, learning_rate=lr)
clf3.fit(X, Y)
assert_equal(clf3.t_, clf.t_)
assert_array_almost_equal(clf3.coef_, clf.coef_)
clf3.set_params(alpha=0.001)
clf3.fit(X, Y)
assert_equal(clf3.t_, clf2.t_)
assert_array_almost_equal(clf3.coef_, clf2.coef_)
def test_warm_start_constant(self):
self._test_warm_start(X, Y, "constant")
def test_warm_start_invscaling(self):
self._test_warm_start(X, Y, "invscaling")
def test_warm_start_optimal(self):
self._test_warm_start(X, Y, "optimal")
def test_input_format(self):
# Input format tests.
clf = self.factory(alpha=0.01, shuffle=False)
clf.fit(X, Y)
Y_ = np.array(Y)[:, np.newaxis]
Y_ = np.c_[Y_, Y_]
assert_raises(ValueError, clf.fit, X, Y_)
def test_clone(self):
# Test whether clone works ok.
clf = self.factory(alpha=0.01, penalty='l1')
clf = clone(clf)
clf.set_params(penalty='l2')
clf.fit(X, Y)
clf2 = self.factory(alpha=0.01, penalty='l2')
clf2.fit(X, Y)
assert_array_equal(clf.coef_, clf2.coef_)
def test_plain_has_no_average_attr(self):
clf = self.factory(average=True, eta0=.01)
clf.fit(X, Y)
assert_true(hasattr(clf, 'average_coef_'))
assert_true(hasattr(clf, 'average_intercept_'))
assert_true(hasattr(clf, 'standard_intercept_'))
assert_true(hasattr(clf, 'standard_coef_'))
clf = self.factory()
clf.fit(X, Y)
assert_false(hasattr(clf, 'average_coef_'))
assert_false(hasattr(clf, 'average_intercept_'))
assert_false(hasattr(clf, 'standard_intercept_'))
assert_false(hasattr(clf, 'standard_coef_'))
def test_late_onset_averaging_not_reached(self):
clf1 = self.factory(average=600)
clf2 = self.factory()
for _ in range(100):
if isinstance(clf1, SGDClassifier):
clf1.partial_fit(X, Y, classes=np.unique(Y))
clf2.partial_fit(X, Y, classes=np.unique(Y))
else:
clf1.partial_fit(X, Y)
clf2.partial_fit(X, Y)
assert_array_almost_equal(clf1.coef_, clf2.coef_, decimal=16)
assert_almost_equal(clf1.intercept_, clf2.intercept_, decimal=16)
def test_late_onset_averaging_reached(self):
eta0 = .001
alpha = .0001
Y_encode = np.array(Y)
Y_encode[Y_encode == 1] = -1.0
Y_encode[Y_encode == 2] = 1.0
clf1 = self.factory(average=7, learning_rate="constant",
loss='squared_loss', eta0=eta0,
alpha=alpha, max_iter=2, shuffle=False)
clf2 = self.factory(average=0, learning_rate="constant",
loss='squared_loss', eta0=eta0,
alpha=alpha, max_iter=1, shuffle=False)
clf1.fit(X, Y_encode)
clf2.fit(X, Y_encode)
average_weights, average_intercept = \
self.asgd(X, Y_encode, eta0, alpha,
weight_init=clf2.coef_.ravel(),
intercept_init=clf2.intercept_)
assert_array_almost_equal(clf1.coef_.ravel(),
average_weights.ravel(),
decimal=16)
assert_almost_equal(clf1.intercept_, average_intercept, decimal=16)
@raises(ValueError)
def test_sgd_bad_alpha_for_optimal_learning_rate(self):
# Check whether expected ValueError on bad alpha, i.e. 0
# since alpha is used to compute the optimal learning rate
self.factory(alpha=0, learning_rate="optimal")
class DenseSGDClassifierTestCase(unittest.TestCase, CommonTest):
"""Test suite for the dense representation variant of SGD"""
factory_class = SGDClassifier
def test_sgd(self):
# Check that SGD gives any results :-)
for loss in ("hinge", "squared_hinge", "log", "modified_huber"):
clf = self.factory(penalty='l2', alpha=0.01, fit_intercept=True,
loss=loss, max_iter=10, shuffle=True)
clf.fit(X, Y)
# assert_almost_equal(clf.coef_[0], clf.coef_[1], decimal=7)
assert_array_equal(clf.predict(T), true_result)
@raises(ValueError)
def test_sgd_bad_l1_ratio(self):
# Check whether expected ValueError on bad l1_ratio
self.factory(l1_ratio=1.1)
@raises(ValueError)
def test_sgd_bad_learning_rate_schedule(self):
# Check whether expected ValueError on bad learning_rate
self.factory(learning_rate="<unknown>")
@raises(ValueError)
def test_sgd_bad_eta0(self):
# Check whether expected ValueError on bad eta0
self.factory(eta0=0, learning_rate="constant")
@raises(ValueError)
def test_sgd_bad_alpha(self):
# Check whether expected ValueError on bad alpha
self.factory(alpha=-.1)
@raises(ValueError)
def test_sgd_bad_penalty(self):
# Check whether expected ValueError on bad penalty
self.factory(penalty='foobar', l1_ratio=0.85)
@raises(ValueError)
def test_sgd_bad_loss(self):
# Check whether expected ValueError on bad loss
self.factory(loss="foobar")
@raises(ValueError)
def test_sgd_max_iter_param(self):
# Test parameter validity check
self.factory(max_iter=-10000)
@raises(ValueError)
def test_sgd_shuffle_param(self):
# Test parameter validity check
self.factory(shuffle="false")
@raises(TypeError)
def test_argument_coef(self):
# Checks coef_init not allowed as model argument (only fit)
# Provided coef_ does not match dataset.
self.factory(coef_init=np.zeros((3,))).fit(X, Y)
@raises(ValueError)
def test_provide_coef(self):
# Checks coef_init shape for the warm starts
# Provided coef_ does not match dataset.
self.factory().fit(X, Y, coef_init=np.zeros((3,)))
@raises(ValueError)
def test_set_intercept(self):
# Checks intercept_ shape for the warm starts
# Provided intercept_ does not match dataset.
self.factory().fit(X, Y, intercept_init=np.zeros((3,)))
def test_set_intercept_binary(self):
# Checks intercept_ shape for the warm starts in binary case
self.factory().fit(X5, Y5, intercept_init=0)
def test_average_binary_computed_correctly(self):
# Checks the SGDClassifier correctly computes the average weights
eta = .1
alpha = 2.
n_samples = 20
n_features = 10
rng = np.random.RandomState(0)
X = rng.normal(size=(n_samples, n_features))
w = rng.normal(size=n_features)
clf = self.factory(loss='squared_loss',
learning_rate='constant',
eta0=eta, alpha=alpha,
fit_intercept=True,
max_iter=1, average=True, shuffle=False)
# simple linear function without noise
y = np.dot(X, w)
y = np.sign(y)
clf.fit(X, y)
average_weights, average_intercept = self.asgd(X, y, eta, alpha)
average_weights = average_weights.reshape(1, -1)
assert_array_almost_equal(clf.coef_,
average_weights,
decimal=14)
assert_almost_equal(clf.intercept_, average_intercept, decimal=14)
def test_set_intercept_to_intercept(self):
# Checks intercept_ shape consistency for the warm starts
# Inconsistent intercept_ shape.
clf = self.factory().fit(X5, Y5)
self.factory().fit(X5, Y5, intercept_init=clf.intercept_)
clf = self.factory().fit(X, Y)
self.factory().fit(X, Y, intercept_init=clf.intercept_)
@raises(ValueError)
def test_sgd_at_least_two_labels(self):
# Target must have at least two labels
self.factory(alpha=0.01, max_iter=20).fit(X2, np.ones(9))
def test_partial_fit_weight_class_balanced(self):
# partial_fit with class_weight='balanced' not supported"""
assert_raises_regexp(ValueError,
"class_weight 'balanced' is not supported for "
"partial_fit. In order to use 'balanced' weights, "
"use compute_class_weight\('balanced', classes, y\). "
"In place of y you can us a large enough sample "
"of the full training set target to properly "
"estimate the class frequency distributions. "
"Pass the resulting weights as the class_weight "
"parameter.",
self.factory(class_weight='balanced').partial_fit,
X, Y, classes=np.unique(Y))
def test_sgd_multiclass(self):
# Multi-class test case
clf = self.factory(alpha=0.01, max_iter=20).fit(X2, Y2)
assert_equal(clf.coef_.shape, (3, 2))
assert_equal(clf.intercept_.shape, (3,))
assert_equal(clf.decision_function([[0, 0]]).shape, (1, 3))
pred = clf.predict(T2)
assert_array_equal(pred, true_result2)
def test_sgd_multiclass_average(self):
eta = .001
alpha = .01
# Multi-class average test case
clf = self.factory(loss='squared_loss',
learning_rate='constant',
eta0=eta, alpha=alpha,
fit_intercept=True,
max_iter=1, average=True, shuffle=False)
np_Y2 = np.array(Y2)
clf.fit(X2, np_Y2)
classes = np.unique(np_Y2)
for i, cl in enumerate(classes):
y_i = np.ones(np_Y2.shape[0])
y_i[np_Y2 != cl] = -1
average_coef, average_intercept = self.asgd(X2, y_i, eta, alpha)
assert_array_almost_equal(average_coef, clf.coef_[i], decimal=16)
assert_almost_equal(average_intercept,
clf.intercept_[i],
decimal=16)
def test_sgd_multiclass_with_init_coef(self):
# Multi-class test case
clf = self.factory(alpha=0.01, max_iter=20)
clf.fit(X2, Y2, coef_init=np.zeros((3, 2)),
intercept_init=np.zeros(3))
assert_equal(clf.coef_.shape, (3, 2))
assert_true(clf.intercept_.shape, (3,))
pred = clf.predict(T2)
assert_array_equal(pred, true_result2)
def test_sgd_multiclass_njobs(self):
# Multi-class test case with multi-core support
clf = self.factory(alpha=0.01, max_iter=20, n_jobs=2).fit(X2, Y2)
assert_equal(clf.coef_.shape, (3, 2))
assert_equal(clf.intercept_.shape, (3,))
assert_equal(clf.decision_function([[0, 0]]).shape, (1, 3))
pred = clf.predict(T2)
assert_array_equal(pred, true_result2)
def test_set_coef_multiclass(self):
# Checks coef_init and intercept_init shape for multi-class
# problems
# Provided coef_ does not match dataset
clf = self.factory()
assert_raises(ValueError, clf.fit, X2, Y2, coef_init=np.zeros((2, 2)))
# Provided coef_ does match dataset
clf = self.factory().fit(X2, Y2, coef_init=np.zeros((3, 2)))
# Provided intercept_ does not match dataset
clf = self.factory()
assert_raises(ValueError, clf.fit, X2, Y2,
intercept_init=np.zeros((1,)))
# Provided intercept_ does match dataset.
clf = self.factory().fit(X2, Y2, intercept_init=np.zeros((3,)))
def test_sgd_proba(self):
# Check SGD.predict_proba
# Hinge loss does not allow for conditional prob estimate.
# We cannot use the factory here, because it defines predict_proba
# anyway.
clf = SGDClassifier(loss="hinge", alpha=0.01,
max_iter=10, tol=None).fit(X, Y)
assert_false(hasattr(clf, "predict_proba"))
assert_false(hasattr(clf, "predict_log_proba"))
# log and modified_huber losses can output probability estimates
# binary case
for loss in ["log", "modified_huber"]:
clf = self.factory(loss=loss, alpha=0.01, max_iter=10)
clf.fit(X, Y)
p = clf.predict_proba([[3, 2]])
assert_true(p[0, 1] > 0.5)
p = clf.predict_proba([[-1, -1]])
assert_true(p[0, 1] < 0.5)
p = clf.predict_log_proba([[3, 2]])
assert_true(p[0, 1] > p[0, 0])
p = clf.predict_log_proba([[-1, -1]])
assert_true(p[0, 1] < p[0, 0])
# log loss multiclass probability estimates
clf = self.factory(loss="log", alpha=0.01, max_iter=10).fit(X2, Y2)
d = clf.decision_function([[.1, -.1], [.3, .2]])
p = clf.predict_proba([[.1, -.1], [.3, .2]])
assert_array_equal(np.argmax(p, axis=1), np.argmax(d, axis=1))
assert_almost_equal(p[0].sum(), 1)
assert_true(np.all(p[0] >= 0))
p = clf.predict_proba([[-1, -1]])
d = clf.decision_function([[-1, -1]])
assert_array_equal(np.argsort(p[0]), np.argsort(d[0]))
l = clf.predict_log_proba([[3, 2]])
p = clf.predict_proba([[3, 2]])
assert_array_almost_equal(np.log(p), l)
l = clf.predict_log_proba([[-1, -1]])
p = clf.predict_proba([[-1, -1]])
assert_array_almost_equal(np.log(p), l)
# Modified Huber multiclass probability estimates; requires a separate
# test because the hard zero/one probabilities may destroy the
# ordering present in decision_function output.
clf = self.factory(loss="modified_huber", alpha=0.01, max_iter=10)
clf.fit(X2, Y2)
d = clf.decision_function([[3, 2]])
p = clf.predict_proba([[3, 2]])
if not isinstance(self, SparseSGDClassifierTestCase):
assert_equal(np.argmax(d, axis=1), np.argmax(p, axis=1))
else: # XXX the sparse test gets a different X2 (?)
assert_equal(np.argmin(d, axis=1), np.argmin(p, axis=1))
# the following sample produces decision_function values < -1,
# which would cause naive normalization to fail (see comment
# in SGDClassifier.predict_proba)
x = X.mean(axis=0)
d = clf.decision_function([x])
if np.all(d < -1): # XXX not true in sparse test case (why?)
p = clf.predict_proba([x])
assert_array_almost_equal(p[0], [1 / 3.] * 3)
def test_sgd_l1(self):
# Test L1 regularization
n = len(X4)
rng = np.random.RandomState(13)
idx = np.arange(n)
rng.shuffle(idx)
X = X4[idx, :]
Y = Y4[idx]
clf = self.factory(penalty='l1', alpha=.2, fit_intercept=False,
max_iter=2000, tol=None, shuffle=False)
clf.fit(X, Y)
assert_array_equal(clf.coef_[0, 1:-1], np.zeros((4,)))
pred = clf.predict(X)
assert_array_equal(pred, Y)
# test sparsify with dense inputs
clf.sparsify()
assert_true(sp.issparse(clf.coef_))
pred = clf.predict(X)
assert_array_equal(pred, Y)
# pickle and unpickle with sparse coef_
clf = pickle.loads(pickle.dumps(clf))
assert_true(sp.issparse(clf.coef_))
pred = clf.predict(X)
assert_array_equal(pred, Y)
def test_class_weights(self):
# Test class weights.
X = np.array([[-1.0, -1.0], [-1.0, 0], [-.8, -1.0],
[1.0, 1.0], [1.0, 0.0]])
y = [1, 1, 1, -1, -1]
clf = self.factory(alpha=0.1, max_iter=1000, fit_intercept=False,
class_weight=None)
clf.fit(X, y)
assert_array_equal(clf.predict([[0.2, -1.0]]), np.array([1]))
# we give a small weights to class 1
clf = self.factory(alpha=0.1, max_iter=1000, fit_intercept=False,
class_weight={1: 0.001})
clf.fit(X, y)
# now the hyperplane should rotate clock-wise and
# the prediction on this point should shift
assert_array_equal(clf.predict([[0.2, -1.0]]), np.array([-1]))
def test_equal_class_weight(self):
# Test if equal class weights approx. equals no class weights.
X = [[1, 0], [1, 0], [0, 1], [0, 1]]
y = [0, 0, 1, 1]
clf = self.factory(alpha=0.1, max_iter=1000, class_weight=None)
clf.fit(X, y)
X = [[1, 0], [0, 1]]
y = [0, 1]
clf_weighted = self.factory(alpha=0.1, max_iter=1000,
class_weight={0: 0.5, 1: 0.5})
clf_weighted.fit(X, y)
# should be similar up to some epsilon due to learning rate schedule
assert_almost_equal(clf.coef_, clf_weighted.coef_, decimal=2)
@raises(ValueError)
def test_wrong_class_weight_label(self):
# ValueError due to not existing class label.
clf = self.factory(alpha=0.1, max_iter=1000, class_weight={0: 0.5})
clf.fit(X, Y)
@raises(ValueError)
def test_wrong_class_weight_format(self):
# ValueError due to wrong class_weight argument type.
clf = self.factory(alpha=0.1, max_iter=1000, class_weight=[0.5])
clf.fit(X, Y)
def test_weights_multiplied(self):
# Tests that class_weight and sample_weight are multiplicative
class_weights = {1: .6, 2: .3}
rng = np.random.RandomState(0)
sample_weights = rng.random_sample(Y4.shape[0])
multiplied_together = np.copy(sample_weights)
multiplied_together[Y4 == 1] *= class_weights[1]
multiplied_together[Y4 == 2] *= class_weights[2]
clf1 = self.factory(alpha=0.1, max_iter=20, class_weight=class_weights)
clf2 = self.factory(alpha=0.1, max_iter=20)
clf1.fit(X4, Y4, sample_weight=sample_weights)
clf2.fit(X4, Y4, sample_weight=multiplied_together)
assert_almost_equal(clf1.coef_, clf2.coef_)
def test_balanced_weight(self):
# Test class weights for imbalanced data"""
# compute reference metrics on iris dataset that is quite balanced by
# default
X, y = iris.data, iris.target
X = scale(X)
idx = np.arange(X.shape[0])
rng = np.random.RandomState(6)
rng.shuffle(idx)
X = X[idx]
y = y[idx]
clf = self.factory(alpha=0.0001, max_iter=1000,
class_weight=None, shuffle=False).fit(X, y)
f1 = metrics.f1_score(y, clf.predict(X), average='weighted')
assert_almost_equal(f1, 0.96, decimal=1)
# make the same prediction using balanced class_weight
clf_balanced = self.factory(alpha=0.0001, max_iter=1000,
class_weight="balanced",
shuffle=False).fit(X, y)
f1 = metrics.f1_score(y, clf_balanced.predict(X), average='weighted')
assert_almost_equal(f1, 0.96, decimal=1)
# Make sure that in the balanced case it does not change anything
# to use "balanced"
assert_array_almost_equal(clf.coef_, clf_balanced.coef_, 6)
# build an very very imbalanced dataset out of iris data
X_0 = X[y == 0, :]
y_0 = y[y == 0]
X_imbalanced = np.vstack([X] + [X_0] * 10)
y_imbalanced = np.concatenate([y] + [y_0] * 10)
# fit a model on the imbalanced data without class weight info
clf = self.factory(max_iter=1000, class_weight=None, shuffle=False)
clf.fit(X_imbalanced, y_imbalanced)
y_pred = clf.predict(X)
assert_less(metrics.f1_score(y, y_pred, average='weighted'), 0.96)
# fit a model with balanced class_weight enabled
clf = self.factory(max_iter=1000, class_weight="balanced",
shuffle=False)
clf.fit(X_imbalanced, y_imbalanced)
y_pred = clf.predict(X)
assert_greater(metrics.f1_score(y, y_pred, average='weighted'), 0.96)
def test_sample_weights(self):
# Test weights on individual samples
X = np.array([[-1.0, -1.0], [-1.0, 0], [-.8, -1.0],
[1.0, 1.0], [1.0, 0.0]])
y = [1, 1, 1, -1, -1]
clf = self.factory(alpha=0.1, max_iter=1000, fit_intercept=False)
clf.fit(X, y)
assert_array_equal(clf.predict([[0.2, -1.0]]), np.array([1]))
# we give a small weights to class 1
clf.fit(X, y, sample_weight=[0.001] * 3 + [1] * 2)
# now the hyperplane should rotate clock-wise and
# the prediction on this point should shift
assert_array_equal(clf.predict([[0.2, -1.0]]), np.array([-1]))
@raises(ValueError)
def test_wrong_sample_weights(self):
# Test if ValueError is raised if sample_weight has wrong shape
clf = self.factory(alpha=0.1, max_iter=1000, fit_intercept=False)
# provided sample_weight too long
clf.fit(X, Y, sample_weight=np.arange(7))
@raises(ValueError)
def test_partial_fit_exception(self):
clf = self.factory(alpha=0.01)
# classes was not specified
clf.partial_fit(X3, Y3)
def test_partial_fit_binary(self):
third = X.shape[0] // 3
clf = self.factory(alpha=0.01)
classes = np.unique(Y)
clf.partial_fit(X[:third], Y[:third], classes=classes)
assert_equal(clf.coef_.shape, (1, X.shape[1]))
assert_equal(clf.intercept_.shape, (1,))
assert_equal(clf.decision_function([[0, 0]]).shape, (1, ))
id1 = id(clf.coef_.data)
clf.partial_fit(X[third:], Y[third:])
id2 = id(clf.coef_.data)
# check that coef_ haven't been re-allocated
assert_true(id1, id2)
y_pred = clf.predict(T)
assert_array_equal(y_pred, true_result)
def test_partial_fit_multiclass(self):
third = X2.shape[0] // 3
clf = self.factory(alpha=0.01)
classes = np.unique(Y2)
clf.partial_fit(X2[:third], Y2[:third], classes=classes)
assert_equal(clf.coef_.shape, (3, X2.shape[1]))
assert_equal(clf.intercept_.shape, (3,))
assert_equal(clf.decision_function([[0, 0]]).shape, (1, 3))
id1 = id(clf.coef_.data)
clf.partial_fit(X2[third:], Y2[third:])
id2 = id(clf.coef_.data)
# check that coef_ haven't been re-allocated
assert_true(id1, id2)
def test_partial_fit_multiclass_average(self):
third = X2.shape[0] // 3
clf = self.factory(alpha=0.01, average=X2.shape[0])
classes = np.unique(Y2)
clf.partial_fit(X2[:third], Y2[:third], classes=classes)
assert_equal(clf.coef_.shape, (3, X2.shape[1]))
assert_equal(clf.intercept_.shape, (3,))
clf.partial_fit(X2[third:], Y2[third:])
assert_equal(clf.coef_.shape, (3, X2.shape[1]))
assert_equal(clf.intercept_.shape, (3,))
def test_fit_then_partial_fit(self):
# Partial_fit should work after initial fit in the multiclass case.
# Non-regression test for #2496; fit would previously produce a
# Fortran-ordered coef_ that subsequent partial_fit couldn't handle.
clf = self.factory()
clf.fit(X2, Y2)
clf.partial_fit(X2, Y2) # no exception here
def _test_partial_fit_equal_fit(self, lr):
for X_, Y_, T_ in ((X, Y, T), (X2, Y2, T2)):
clf = self.factory(alpha=0.01, eta0=0.01, max_iter=2,
learning_rate=lr, shuffle=False)
clf.fit(X_, Y_)
y_pred = clf.decision_function(T_)
t = clf.t_
classes = np.unique(Y_)
clf = self.factory(alpha=0.01, eta0=0.01, learning_rate=lr,
shuffle=False)
for i in range(2):
clf.partial_fit(X_, Y_, classes=classes)
y_pred2 = clf.decision_function(T_)
assert_equal(clf.t_, t)
assert_array_almost_equal(y_pred, y_pred2, decimal=2)
def test_partial_fit_equal_fit_constant(self):
self._test_partial_fit_equal_fit("constant")
def test_partial_fit_equal_fit_optimal(self):
self._test_partial_fit_equal_fit("optimal")
def test_partial_fit_equal_fit_invscaling(self):
self._test_partial_fit_equal_fit("invscaling")
def test_regression_losses(self):
clf = self.factory(alpha=0.01, learning_rate="constant",
eta0=0.1, loss="epsilon_insensitive")
clf.fit(X, Y)
assert_equal(1.0, np.mean(clf.predict(X) == Y))
clf = self.factory(alpha=0.01, learning_rate="constant",
eta0=0.1, loss="squared_epsilon_insensitive")
clf.fit(X, Y)
assert_equal(1.0, np.mean(clf.predict(X) == Y))
clf = self.factory(alpha=0.01, loss="huber")
clf.fit(X, Y)
assert_equal(1.0, np.mean(clf.predict(X) == Y))
clf = self.factory(alpha=0.01, learning_rate="constant", eta0=0.01,
loss="squared_loss")
clf.fit(X, Y)
assert_equal(1.0, np.mean(clf.predict(X) == Y))
def test_warm_start_multiclass(self):
self._test_warm_start(X2, Y2, "optimal")
def test_multiple_fit(self):
# Test multiple calls of fit w/ different shaped inputs.
clf = self.factory(alpha=0.01, shuffle=False)
clf.fit(X, Y)
assert_true(hasattr(clf, "coef_"))
# Non-regression test: try fitting with a different label set.
y = [["ham", "spam"][i] for i in LabelEncoder().fit_transform(Y)]
clf.fit(X[:, :-1], y)
class SparseSGDClassifierTestCase(DenseSGDClassifierTestCase):
"""Run exactly the same tests using the sparse representation variant"""
factory_class = SparseSGDClassifier
###############################################################################
# Regression Test Case
class DenseSGDRegressorTestCase(unittest.TestCase, CommonTest):
"""Test suite for the dense representation variant of SGD"""
factory_class = SGDRegressor
def test_sgd(self):
# Check that SGD gives any results.
clf = self.factory(alpha=0.1, max_iter=2,
fit_intercept=False)
clf.fit([[0, 0], [1, 1], [2, 2]], [0, 1, 2])
assert_equal(clf.coef_[0], clf.coef_[1])
@raises(ValueError)
def test_sgd_bad_penalty(self):
# Check whether expected ValueError on bad penalty
self.factory(penalty='foobar', l1_ratio=0.85)
@raises(ValueError)
def test_sgd_bad_loss(self):
# Check whether expected ValueError on bad loss
self.factory(loss="foobar")
def test_sgd_averaged_computed_correctly(self):
# Tests the average regressor matches the naive implementation
eta = .001
alpha = .01
n_samples = 20
n_features = 10
rng = np.random.RandomState(0)
X = rng.normal(size=(n_samples, n_features))
w = rng.normal(size=n_features)
# simple linear function without noise
y = np.dot(X, w)
clf = self.factory(loss='squared_loss',
learning_rate='constant',
eta0=eta, alpha=alpha,
fit_intercept=True,
max_iter=1, average=True, shuffle=False)
clf.fit(X, y)
average_weights, average_intercept = self.asgd(X, y, eta, alpha)
assert_array_almost_equal(clf.coef_,
average_weights,
decimal=16)
assert_almost_equal(clf.intercept_, average_intercept, decimal=16)
def test_sgd_averaged_partial_fit(self):
# Tests whether the partial fit yields the same average as the fit
eta = .001
alpha = .01
n_samples = 20
n_features = 10
rng = np.random.RandomState(0)
X = rng.normal(size=(n_samples, n_features))
w = rng.normal(size=n_features)
# simple linear function without noise
y = np.dot(X, w)
clf = self.factory(loss='squared_loss',
learning_rate='constant',
eta0=eta, alpha=alpha,
fit_intercept=True,
max_iter=1, average=True, shuffle=False)
clf.partial_fit(X[:int(n_samples / 2)][:], y[:int(n_samples / 2)])
clf.partial_fit(X[int(n_samples / 2):][:], y[int(n_samples / 2):])
average_weights, average_intercept = self.asgd(X, y, eta, alpha)
assert_array_almost_equal(clf.coef_,
average_weights,
decimal=16)
assert_almost_equal(clf.intercept_[0], average_intercept, decimal=16)
def test_average_sparse(self):
# Checks the average weights on data with 0s
eta = .001
alpha = .01
clf = self.factory(loss='squared_loss',
learning_rate='constant',
eta0=eta, alpha=alpha,
fit_intercept=True,
max_iter=1, average=True, shuffle=False)
n_samples = Y3.shape[0]
clf.partial_fit(X3[:int(n_samples / 2)][:], Y3[:int(n_samples / 2)])
clf.partial_fit(X3[int(n_samples / 2):][:], Y3[int(n_samples / 2):])
average_weights, average_intercept = self.asgd(X3, Y3, eta, alpha)
assert_array_almost_equal(clf.coef_,
average_weights,
decimal=16)
assert_almost_equal(clf.intercept_, average_intercept, decimal=16)
def test_sgd_least_squares_fit(self):
xmin, xmax = -5, 5
n_samples = 100
rng = np.random.RandomState(0)
X = np.linspace(xmin, xmax, n_samples).reshape(n_samples, 1)
# simple linear function without noise
y = 0.5 * X.ravel()
clf = self.factory(loss='squared_loss', alpha=0.1, max_iter=20,
fit_intercept=False)
clf.fit(X, y)
score = clf.score(X, y)
assert_greater(score, 0.99)
# simple linear function with noise
y = 0.5 * X.ravel() + rng.randn(n_samples, 1).ravel()
clf = self.factory(loss='squared_loss', alpha=0.1, max_iter=20,
fit_intercept=False)
clf.fit(X, y)
score = clf.score(X, y)
assert_greater(score, 0.5)
def test_sgd_epsilon_insensitive(self):
xmin, xmax = -5, 5
n_samples = 100
rng = np.random.RandomState(0)
X = np.linspace(xmin, xmax, n_samples).reshape(n_samples, 1)
# simple linear function without noise
y = 0.5 * X.ravel()
clf = self.factory(loss='epsilon_insensitive', epsilon=0.01,
alpha=0.1, max_iter=20,
fit_intercept=False)
clf.fit(X, y)
score = clf.score(X, y)
assert_true(score > 0.99)
# simple linear function with noise
y = 0.5 * X.ravel() + rng.randn(n_samples, 1).ravel()
clf = self.factory(loss='epsilon_insensitive', epsilon=0.01,
alpha=0.1, max_iter=20,
fit_intercept=False)
clf.fit(X, y)
score = clf.score(X, y)
assert_true(score > 0.5)
def test_sgd_huber_fit(self):
xmin, xmax = -5, 5
n_samples = 100
rng = np.random.RandomState(0)
X = np.linspace(xmin, xmax, n_samples).reshape(n_samples, 1)
# simple linear function without noise
y = 0.5 * X.ravel()
clf = self.factory(loss="huber", epsilon=0.1, alpha=0.1, max_iter=20,
fit_intercept=False)
clf.fit(X, y)
score = clf.score(X, y)
assert_greater(score, 0.99)
# simple linear function with noise
y = 0.5 * X.ravel() + rng.randn(n_samples, 1).ravel()
clf = self.factory(loss="huber", epsilon=0.1, alpha=0.1, max_iter=20,
fit_intercept=False)
clf.fit(X, y)
score = clf.score(X, y)
assert_greater(score, 0.5)
def test_elasticnet_convergence(self):
# Check that the SGD output is consistent with coordinate descent
n_samples, n_features = 1000, 5
rng = np.random.RandomState(0)
X = rng.randn(n_samples, n_features)
# ground_truth linear model that generate y from X and to which the
# models should converge if the regularizer would be set to 0.0
ground_truth_coef = rng.randn(n_features)
y = np.dot(X, ground_truth_coef)
# XXX: alpha = 0.1 seems to cause convergence problems
for alpha in [0.01, 0.001]:
for l1_ratio in [0.5, 0.8, 1.0]:
cd = linear_model.ElasticNet(alpha=alpha, l1_ratio=l1_ratio,
fit_intercept=False)
cd.fit(X, y)
sgd = self.factory(penalty='elasticnet', max_iter=50,
alpha=alpha, l1_ratio=l1_ratio,
fit_intercept=False)
sgd.fit(X, y)
err_msg = ("cd and sgd did not converge to comparable "
"results for alpha=%f and l1_ratio=%f"
% (alpha, l1_ratio))
assert_almost_equal(cd.coef_, sgd.coef_, decimal=2,
err_msg=err_msg)
@ignore_warnings
def test_partial_fit(self):
third = X.shape[0] // 3
clf = self.factory(alpha=0.01)
clf.partial_fit(X[:third], Y[:third])
assert_equal(clf.coef_.shape, (X.shape[1], ))
assert_equal(clf.intercept_.shape, (1,))
assert_equal(clf.predict([[0, 0]]).shape, (1, ))
id1 = id(clf.coef_.data)
clf.partial_fit(X[third:], Y[third:])
id2 = id(clf.coef_.data)
# check that coef_ haven't been re-allocated
assert_true(id1, id2)
def _test_partial_fit_equal_fit(self, lr):
clf = self.factory(alpha=0.01, max_iter=2, eta0=0.01,
learning_rate=lr, shuffle=False)
clf.fit(X, Y)
y_pred = clf.predict(T)
t = clf.t_
clf = self.factory(alpha=0.01, eta0=0.01,
learning_rate=lr, shuffle=False)
for i in range(2):
clf.partial_fit(X, Y)
y_pred2 = clf.predict(T)
assert_equal(clf.t_, t)
assert_array_almost_equal(y_pred, y_pred2, decimal=2)
def test_partial_fit_equal_fit_constant(self):
self._test_partial_fit_equal_fit("constant")
def test_partial_fit_equal_fit_optimal(self):
self._test_partial_fit_equal_fit("optimal")
def test_partial_fit_equal_fit_invscaling(self):
self._test_partial_fit_equal_fit("invscaling")
def test_loss_function_epsilon(self):
clf = self.factory(epsilon=0.9)
clf.set_params(epsilon=0.1)
assert clf.loss_functions['huber'][1] == 0.1
class SparseSGDRegressorTestCase(DenseSGDRegressorTestCase):
# Run exactly the same tests using the sparse representation variant
factory_class = SparseSGDRegressor
def test_l1_ratio():
# Test if l1 ratio extremes match L1 and L2 penalty settings.
X, y = datasets.make_classification(n_samples=1000,
n_features=100, n_informative=20,
random_state=1234)
# test if elasticnet with l1_ratio near 1 gives same result as pure l1
est_en = SGDClassifier(alpha=0.001, penalty='elasticnet', tol=None,
max_iter=6, l1_ratio=0.9999999999,
random_state=42).fit(X, y)
est_l1 = SGDClassifier(alpha=0.001, penalty='l1', max_iter=6,
random_state=42, tol=None).fit(X, y)
assert_array_almost_equal(est_en.coef_, est_l1.coef_)
# test if elasticnet with l1_ratio near 0 gives same result as pure l2
est_en = SGDClassifier(alpha=0.001, penalty='elasticnet', tol=None,
max_iter=6, l1_ratio=0.0000000001,
random_state=42).fit(X, y)
est_l2 = SGDClassifier(alpha=0.001, penalty='l2', max_iter=6,
random_state=42, tol=None).fit(X, y)
assert_array_almost_equal(est_en.coef_, est_l2.coef_)
def test_underflow_or_overlow():
with np.errstate(all='raise'):
# Generate some weird data with hugely unscaled features
rng = np.random.RandomState(0)
n_samples = 100
n_features = 10
X = rng.normal(size=(n_samples, n_features))
X[:, :2] *= 1e300
assert_true(np.isfinite(X).all())
# Use MinMaxScaler to scale the data without introducing a numerical
# instability (computing the standard deviation naively is not possible
# on this data)
X_scaled = MinMaxScaler().fit_transform(X)
assert_true(np.isfinite(X_scaled).all())
# Define a ground truth on the scaled data
ground_truth = rng.normal(size=n_features)
y = (np.dot(X_scaled, ground_truth) > 0.).astype(np.int32)
assert_array_equal(np.unique(y), [0, 1])
model = SGDClassifier(alpha=0.1, loss='squared_hinge', max_iter=500)
# smoke test: model is stable on scaled data
model.fit(X_scaled, y)
assert_true(np.isfinite(model.coef_).all())
# model is numerically unstable on unscaled data
msg_regxp = (r"Floating-point under-/overflow occurred at epoch #.*"
" Scaling input data with StandardScaler or MinMaxScaler"
" might help.")
assert_raises_regexp(ValueError, msg_regxp, model.fit, X, y)
def test_numerical_stability_large_gradient():
# Non regression test case for numerical stability on scaled problems
# where the gradient can still explode with some losses
model = SGDClassifier(loss='squared_hinge', max_iter=10, shuffle=True,
penalty='elasticnet', l1_ratio=0.3, alpha=0.01,
eta0=0.001, random_state=0, tol=None)
with np.errstate(all='raise'):
model.fit(iris.data, iris.target)
assert_true(np.isfinite(model.coef_).all())
def test_large_regularization():
# Non regression tests for numerical stability issues caused by large
# regularization parameters
for penalty in ['l2', 'l1', 'elasticnet']:
model = SGDClassifier(alpha=1e5, learning_rate='constant', eta0=0.1,
penalty=penalty, shuffle=False,
tol=None, max_iter=6)
with np.errstate(all='raise'):
model.fit(iris.data, iris.target)
assert_array_almost_equal(model.coef_, np.zeros_like(model.coef_))
def test_tol_parameter():
# Test that the tol parameter behaves as expected
X = StandardScaler().fit_transform(iris.data)
y = iris.target == 1
# With tol is None, the number of iteration should be equal to max_iter
max_iter = 42
model_0 = SGDClassifier(tol=None, random_state=0, max_iter=max_iter)
model_0.fit(X, y)
assert_equal(max_iter, model_0.n_iter_)
# If tol is not None, the number of iteration should be less than max_iter
max_iter = 2000
model_1 = SGDClassifier(tol=0, random_state=0, max_iter=max_iter)
model_1.fit(X, y)
assert_greater(max_iter, model_1.n_iter_)
assert_greater(model_1.n_iter_, 5)
# A larger tol should yield a smaller number of iteration
model_2 = SGDClassifier(tol=0.1, random_state=0, max_iter=max_iter)
model_2.fit(X, y)
assert_greater(model_1.n_iter_, model_2.n_iter_)
assert_greater(model_2.n_iter_, 3)
# Strict tolerance and small max_iter should trigger a warning
model_3 = SGDClassifier(max_iter=3, tol=1e-3, random_state=0)
model_3 = assert_warns(ConvergenceWarning, model_3.fit, X, y)
assert_equal(model_3.n_iter_, 3)
def test_future_and_deprecation_warnings():
# Test that warnings are raised. Will be removed in 0.21
def init(max_iter=None, tol=None, n_iter=None):
sgd = SGDClassifier(max_iter=max_iter, tol=tol, n_iter=n_iter)
sgd._validate_params()
# When all default values are used
msg_future = "max_iter and tol parameters have been added in "
assert_warns_message(FutureWarning, msg_future, init)
# When n_iter is specified
msg_deprecation = "n_iter parameter is deprecated"
assert_warns_message(DeprecationWarning, msg_deprecation, init, 6, 0, 5)
# When n_iter=None, and at least one of tol and max_iter is specified
assert_no_warnings(init, 100, None, None)
assert_no_warnings(init, None, 1e-3, None)
assert_no_warnings(init, 100, 1e-3, None)
@ignore_warnings(category=(DeprecationWarning, FutureWarning))
def test_tol_and_max_iter_default_values():
# Test that the default values are correctly changed
est = SGDClassifier()
est._validate_params()
assert_equal(est._tol, None)
assert_equal(est._max_iter, 5)
est = SGDClassifier(n_iter=42)
est._validate_params()
assert_equal(est._tol, None)
assert_equal(est._max_iter, 42)
est = SGDClassifier(tol=1e-2)
est._validate_params()
assert_equal(est._tol, 1e-2)
assert_equal(est._max_iter, 1000)
est = SGDClassifier(max_iter=42)
est._validate_params()
assert_equal(est._tol, None)
assert_equal(est._max_iter, 42)
est = SGDClassifier(max_iter=42, tol=1e-2)
est._validate_params()
assert_equal(est._tol, 1e-2)
assert_equal(est._max_iter, 42)
def _test_gradient_common(loss_function, cases):
# Test gradient of different loss functions
# cases is a list of (p, y, expected)
for p, y, expected in cases:
assert_almost_equal(loss_function.dloss(p, y), expected)
def test_gradient_hinge():
# Test Hinge (hinge / perceptron)
# hinge
loss = sgd_fast.Hinge(1.0)
cases = [
# (p, y, expected)
(1.1, 1.0, 0.0), (-2.0, -1.0, 0.0),
(1.0, 1.0, -1.0), (-1.0, -1.0, 1.0), (0.5, 1.0, -1.0),
(2.0, -1.0, 1.0), (-0.5, -1.0, 1.0), (0.0, 1.0, -1.0)
]
_test_gradient_common(loss, cases)
# perceptron
loss = sgd_fast.Hinge(0.0)
cases = [
# (p, y, expected)
(1.0, 1.0, 0.0), (-0.1, -1.0, 0.0),
(0.0, 1.0, -1.0), (0.0, -1.0, 1.0), (0.5, -1.0, 1.0),
(2.0, -1.0, 1.0), (-0.5, 1.0, -1.0), (-1.0, 1.0, -1.0),
]
_test_gradient_common(loss, cases)
def test_gradient_squared_hinge():
# Test SquaredHinge
loss = sgd_fast.SquaredHinge(1.0)
cases = [
# (p, y, expected)
(1.0, 1.0, 0.0), (-2.0, -1.0, 0.0), (1.0, -1.0, 4.0),
(-1.0, 1.0, -4.0), (0.5, 1.0, -1.0), (0.5, -1.0, 3.0)
]
_test_gradient_common(loss, cases)
def test_gradient_log():
# Test Log (logistic loss)
loss = sgd_fast.Log()
cases = [
# (p, y, expected)
(1.0, 1.0, -1.0 / (np.exp(1.0) + 1.0)),
(1.0, -1.0, 1.0 / (np.exp(-1.0) + 1.0)),
(-1.0, -1.0, 1.0 / (np.exp(1.0) + 1.0)),
(-1.0, 1.0, -1.0 / (np.exp(-1.0) + 1.0)),
(0.0, 1.0, -0.5), (0.0, -1.0, 0.5),
(17.9, -1.0, 1.0), (-17.9, 1.0, -1.0),
]
_test_gradient_common(loss, cases)
assert_almost_equal(loss.dloss(18.1, 1.0), np.exp(-18.1) * -1.0, 16)
assert_almost_equal(loss.dloss(-18.1, -1.0), np.exp(-18.1) * 1.0, 16)
def test_gradient_squared_loss():
# Test SquaredLoss
loss = sgd_fast.SquaredLoss()
cases = [
# (p, y, expected)
(0.0, 0.0, 0.0), (1.0, 1.0, 0.0), (1.0, 0.0, 1.0),
(0.5, -1.0, 1.5), (-2.5, 2.0, -4.5)
]
_test_gradient_common(loss, cases)
def test_gradient_huber():
# Test Huber
loss = sgd_fast.Huber(0.1)
cases = [
# (p, y, expected)
(0.0, 0.0, 0.0), (0.1, 0.0, 0.1), (0.0, 0.1, -0.1),
(3.95, 4.0, -0.05), (5.0, 2.0, 0.1), (-1.0, 5.0, -0.1)
]
_test_gradient_common(loss, cases)
def test_gradient_modified_huber():
# Test ModifiedHuber
loss = sgd_fast.ModifiedHuber()
cases = [
# (p, y, expected)
(1.0, 1.0, 0.0), (-1.0, -1.0, 0.0), (2.0, 1.0, 0.0),
(0.0, 1.0, -2.0), (-1.0, 1.0, -4.0), (0.5, -1.0, 3.0),
(0.5, -1.0, 3.0), (-2.0, 1.0, -4.0), (-3.0, 1.0, -4.0)
]
_test_gradient_common(loss, cases)
def test_gradient_epsilon_insensitive():
# Test EpsilonInsensitive
loss = sgd_fast.EpsilonInsensitive(0.1)
cases = [
(0.0, 0.0, 0.0), (0.1, 0.0, 0.0), (-2.05, -2.0, 0.0),
(3.05, 3.0, 0.0), (2.2, 2.0, 1.0), (2.0, -1.0, 1.0),
(2.0, 2.2, -1.0), (-2.0, 1.0, -1.0)
]
_test_gradient_common(loss, cases)
def test_gradient_squared_epsilon_insensitive():
# Test SquaredEpsilonInsensitive
loss = sgd_fast.SquaredEpsilonInsensitive(0.1)
cases = [
(0.0, 0.0, 0.0), (0.1, 0.0, 0.0), (-2.05, -2.0, 0.0),
(3.05, 3.0, 0.0), (2.2, 2.0, 0.2), (2.0, -1.0, 5.8),
(2.0, 2.2, -0.2), (-2.0, 1.0, -5.8)
]
_test_gradient_common(loss, cases)
| 50,983 | 36.241782 | 83 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_logistic.py | import numpy as np
import scipy.sparse as sp
from scipy import linalg, optimize, sparse
from sklearn.datasets import load_iris, make_classification
from sklearn.metrics import log_loss
from sklearn.model_selection import StratifiedKFold
from sklearn.preprocessing import LabelEncoder
from sklearn.utils import compute_class_weight
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_raise_message
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.testing import assert_warns_message
from sklearn.utils.testing import raises
from sklearn.exceptions import ConvergenceWarning
from sklearn.linear_model.logistic import (
LogisticRegression,
logistic_regression_path, LogisticRegressionCV,
_logistic_loss_and_grad, _logistic_grad_hess,
_multinomial_grad_hess, _logistic_loss,
)
X = [[-1, 0], [0, 1], [1, 1]]
X_sp = sp.csr_matrix(X)
Y1 = [0, 1, 1]
Y2 = [2, 1, 0]
iris = load_iris()
def check_predictions(clf, X, y):
"""Check that the model is able to fit the classification data"""
n_samples = len(y)
classes = np.unique(y)
n_classes = classes.shape[0]
predicted = clf.fit(X, y).predict(X)
assert_array_equal(clf.classes_, classes)
assert_equal(predicted.shape, (n_samples,))
assert_array_equal(predicted, y)
probabilities = clf.predict_proba(X)
assert_equal(probabilities.shape, (n_samples, n_classes))
assert_array_almost_equal(probabilities.sum(axis=1), np.ones(n_samples))
assert_array_equal(probabilities.argmax(axis=1), y)
def test_predict_2_classes():
# Simple sanity check on a 2 classes dataset
# Make sure it predicts the correct result on simple datasets.
check_predictions(LogisticRegression(random_state=0), X, Y1)
check_predictions(LogisticRegression(random_state=0), X_sp, Y1)
check_predictions(LogisticRegression(C=100, random_state=0), X, Y1)
check_predictions(LogisticRegression(C=100, random_state=0), X_sp, Y1)
check_predictions(LogisticRegression(fit_intercept=False,
random_state=0), X, Y1)
check_predictions(LogisticRegression(fit_intercept=False,
random_state=0), X_sp, Y1)
def test_error():
# Test for appropriate exception on errors
msg = "Penalty term must be positive"
assert_raise_message(ValueError, msg,
LogisticRegression(C=-1).fit, X, Y1)
assert_raise_message(ValueError, msg,
LogisticRegression(C="test").fit, X, Y1)
for LR in [LogisticRegression, LogisticRegressionCV]:
msg = "Tolerance for stopping criteria must be positive"
assert_raise_message(ValueError, msg, LR(tol=-1).fit, X, Y1)
assert_raise_message(ValueError, msg, LR(tol="test").fit, X, Y1)
msg = "Maximum number of iteration must be positive"
assert_raise_message(ValueError, msg, LR(max_iter=-1).fit, X, Y1)
assert_raise_message(ValueError, msg, LR(max_iter="test").fit, X, Y1)
def test_lr_liblinear_warning():
n_samples, n_features = iris.data.shape
target = iris.target_names[iris.target]
lr = LogisticRegression(solver='liblinear', n_jobs=2)
assert_warns_message(UserWarning,
"'n_jobs' > 1 does not have any effect when"
" 'solver' is set to 'liblinear'. Got 'n_jobs'"
" = 2.",
lr.fit, iris.data, target)
def test_predict_3_classes():
check_predictions(LogisticRegression(C=10), X, Y2)
check_predictions(LogisticRegression(C=10), X_sp, Y2)
def test_predict_iris():
# Test logistic regression with the iris dataset
n_samples, n_features = iris.data.shape
target = iris.target_names[iris.target]
# Test that both multinomial and OvR solvers handle
# multiclass data correctly and give good accuracy
# score (>0.95) for the training data.
for clf in [LogisticRegression(C=len(iris.data)),
LogisticRegression(C=len(iris.data), solver='lbfgs',
multi_class='multinomial'),
LogisticRegression(C=len(iris.data), solver='newton-cg',
multi_class='multinomial'),
LogisticRegression(C=len(iris.data), solver='sag', tol=1e-2,
multi_class='ovr', random_state=42),
LogisticRegression(C=len(iris.data), solver='saga', tol=1e-2,
multi_class='ovr', random_state=42)
]:
clf.fit(iris.data, target)
assert_array_equal(np.unique(target), clf.classes_)
pred = clf.predict(iris.data)
assert_greater(np.mean(pred == target), .95)
probabilities = clf.predict_proba(iris.data)
assert_array_almost_equal(probabilities.sum(axis=1),
np.ones(n_samples))
pred = iris.target_names[probabilities.argmax(axis=1)]
assert_greater(np.mean(pred == target), .95)
def test_multinomial_validation():
for solver in ['lbfgs', 'newton-cg', 'sag', 'saga']:
lr = LogisticRegression(C=-1, solver=solver, multi_class='multinomial')
assert_raises(ValueError, lr.fit, [[0, 1], [1, 0]], [0, 1])
def test_check_solver_option():
X, y = iris.data, iris.target
for LR in [LogisticRegression, LogisticRegressionCV]:
msg = ('Logistic Regression supports only liblinear, newton-cg, '
'lbfgs, sag and saga solvers, got wrong_name')
lr = LR(solver="wrong_name")
assert_raise_message(ValueError, msg, lr.fit, X, y)
msg = "multi_class should be either multinomial or ovr, got wrong_name"
lr = LR(solver='newton-cg', multi_class="wrong_name")
assert_raise_message(ValueError, msg, lr.fit, X, y)
# only 'liblinear' solver
msg = "Solver liblinear does not support a multinomial backend."
lr = LR(solver='liblinear', multi_class='multinomial')
assert_raise_message(ValueError, msg, lr.fit, X, y)
# all solvers except 'liblinear'
for solver in ['newton-cg', 'lbfgs', 'sag']:
msg = ("Solver %s supports only l2 penalties, got l1 penalty." %
solver)
lr = LR(solver=solver, penalty='l1')
assert_raise_message(ValueError, msg, lr.fit, X, y)
for solver in ['newton-cg', 'lbfgs', 'sag', 'saga']:
msg = ("Solver %s supports only dual=False, got dual=True" %
solver)
lr = LR(solver=solver, dual=True)
assert_raise_message(ValueError, msg, lr.fit, X, y)
def test_multinomial_binary():
# Test multinomial LR on a binary problem.
target = (iris.target > 0).astype(np.intp)
target = np.array(["setosa", "not-setosa"])[target]
for solver in ['lbfgs', 'newton-cg', 'sag', 'saga']:
clf = LogisticRegression(solver=solver, multi_class='multinomial',
random_state=42, max_iter=2000)
clf.fit(iris.data, target)
assert_equal(clf.coef_.shape, (1, iris.data.shape[1]))
assert_equal(clf.intercept_.shape, (1,))
assert_array_equal(clf.predict(iris.data), target)
mlr = LogisticRegression(solver=solver, multi_class='multinomial',
random_state=42, fit_intercept=False)
mlr.fit(iris.data, target)
pred = clf.classes_[np.argmax(clf.predict_log_proba(iris.data),
axis=1)]
assert_greater(np.mean(pred == target), .9)
def test_sparsify():
# Test sparsify and densify members.
n_samples, n_features = iris.data.shape
target = iris.target_names[iris.target]
clf = LogisticRegression(random_state=0).fit(iris.data, target)
pred_d_d = clf.decision_function(iris.data)
clf.sparsify()
assert_true(sp.issparse(clf.coef_))
pred_s_d = clf.decision_function(iris.data)
sp_data = sp.coo_matrix(iris.data)
pred_s_s = clf.decision_function(sp_data)
clf.densify()
pred_d_s = clf.decision_function(sp_data)
assert_array_almost_equal(pred_d_d, pred_s_d)
assert_array_almost_equal(pred_d_d, pred_s_s)
assert_array_almost_equal(pred_d_d, pred_d_s)
def test_inconsistent_input():
# Test that an exception is raised on inconsistent input
rng = np.random.RandomState(0)
X_ = rng.random_sample((5, 10))
y_ = np.ones(X_.shape[0])
y_[0] = 0
clf = LogisticRegression(random_state=0)
# Wrong dimensions for training data
y_wrong = y_[:-1]
assert_raises(ValueError, clf.fit, X, y_wrong)
# Wrong dimensions for test data
assert_raises(ValueError, clf.fit(X_, y_).predict,
rng.random_sample((3, 12)))
def test_write_parameters():
# Test that we can write to coef_ and intercept_
clf = LogisticRegression(random_state=0)
clf.fit(X, Y1)
clf.coef_[:] = 0
clf.intercept_[:] = 0
assert_array_almost_equal(clf.decision_function(X), 0)
@raises(ValueError)
def test_nan():
# Test proper NaN handling.
# Regression test for Issue #252: fit used to go into an infinite loop.
Xnan = np.array(X, dtype=np.float64)
Xnan[0, 1] = np.nan
LogisticRegression(random_state=0).fit(Xnan, Y1)
def test_consistency_path():
# Test that the path algorithm is consistent
rng = np.random.RandomState(0)
X = np.concatenate((rng.randn(100, 2) + [1, 1], rng.randn(100, 2)))
y = [1] * 100 + [-1] * 100
Cs = np.logspace(0, 4, 10)
f = ignore_warnings
# can't test with fit_intercept=True since LIBLINEAR
# penalizes the intercept
for solver in ['sag', 'saga']:
coefs, Cs, _ = f(logistic_regression_path)(
X, y, Cs=Cs, fit_intercept=False, tol=1e-5, solver=solver,
max_iter=1000,
random_state=0)
for i, C in enumerate(Cs):
lr = LogisticRegression(C=C, fit_intercept=False, tol=1e-5,
solver=solver,
random_state=0)
lr.fit(X, y)
lr_coef = lr.coef_.ravel()
assert_array_almost_equal(lr_coef, coefs[i], decimal=4,
err_msg="with solver = %s" % solver)
# test for fit_intercept=True
for solver in ('lbfgs', 'newton-cg', 'liblinear', 'sag', 'saga'):
Cs = [1e3]
coefs, Cs, _ = f(logistic_regression_path)(
X, y, Cs=Cs, fit_intercept=True, tol=1e-6, solver=solver,
intercept_scaling=10000., random_state=0)
lr = LogisticRegression(C=Cs[0], fit_intercept=True, tol=1e-4,
intercept_scaling=10000., random_state=0)
lr.fit(X, y)
lr_coef = np.concatenate([lr.coef_.ravel(), lr.intercept_])
assert_array_almost_equal(lr_coef, coefs[0], decimal=4,
err_msg="with solver = %s" % solver)
def test_liblinear_dual_random_state():
# random_state is relevant for liblinear solver only if dual=True
X, y = make_classification(n_samples=20, random_state=0)
lr1 = LogisticRegression(random_state=0, dual=True, max_iter=1, tol=1e-15)
lr1.fit(X, y)
lr2 = LogisticRegression(random_state=0, dual=True, max_iter=1, tol=1e-15)
lr2.fit(X, y)
lr3 = LogisticRegression(random_state=8, dual=True, max_iter=1, tol=1e-15)
lr3.fit(X, y)
# same result for same random state
assert_array_almost_equal(lr1.coef_, lr2.coef_)
# different results for different random states
msg = "Arrays are not almost equal to 6 decimals"
assert_raise_message(AssertionError, msg,
assert_array_almost_equal, lr1.coef_, lr3.coef_)
def test_logistic_loss_and_grad():
X_ref, y = make_classification(n_samples=20, random_state=0)
n_features = X_ref.shape[1]
X_sp = X_ref.copy()
X_sp[X_sp < .1] = 0
X_sp = sp.csr_matrix(X_sp)
for X in (X_ref, X_sp):
w = np.zeros(n_features)
# First check that our derivation of the grad is correct
loss, grad = _logistic_loss_and_grad(w, X, y, alpha=1.)
approx_grad = optimize.approx_fprime(
w, lambda w: _logistic_loss_and_grad(w, X, y, alpha=1.)[0], 1e-3
)
assert_array_almost_equal(grad, approx_grad, decimal=2)
# Second check that our intercept implementation is good
w = np.zeros(n_features + 1)
loss_interp, grad_interp = _logistic_loss_and_grad(
w, X, y, alpha=1.
)
assert_array_almost_equal(loss, loss_interp)
approx_grad = optimize.approx_fprime(
w, lambda w: _logistic_loss_and_grad(w, X, y, alpha=1.)[0], 1e-3
)
assert_array_almost_equal(grad_interp, approx_grad, decimal=2)
def test_logistic_grad_hess():
rng = np.random.RandomState(0)
n_samples, n_features = 50, 5
X_ref = rng.randn(n_samples, n_features)
y = np.sign(X_ref.dot(5 * rng.randn(n_features)))
X_ref -= X_ref.mean()
X_ref /= X_ref.std()
X_sp = X_ref.copy()
X_sp[X_sp < .1] = 0
X_sp = sp.csr_matrix(X_sp)
for X in (X_ref, X_sp):
w = .1 * np.ones(n_features)
# First check that _logistic_grad_hess is consistent
# with _logistic_loss_and_grad
loss, grad = _logistic_loss_and_grad(w, X, y, alpha=1.)
grad_2, hess = _logistic_grad_hess(w, X, y, alpha=1.)
assert_array_almost_equal(grad, grad_2)
# Now check our hessian along the second direction of the grad
vector = np.zeros_like(grad)
vector[1] = 1
hess_col = hess(vector)
# Computation of the Hessian is particularly fragile to numerical
# errors when doing simple finite differences. Here we compute the
# grad along a path in the direction of the vector and then use a
# least-square regression to estimate the slope
e = 1e-3
d_x = np.linspace(-e, e, 30)
d_grad = np.array([
_logistic_loss_and_grad(w + t * vector, X, y, alpha=1.)[1]
for t in d_x
])
d_grad -= d_grad.mean(axis=0)
approx_hess_col = linalg.lstsq(d_x[:, np.newaxis], d_grad)[0].ravel()
assert_array_almost_equal(approx_hess_col, hess_col, decimal=3)
# Second check that our intercept implementation is good
w = np.zeros(n_features + 1)
loss_interp, grad_interp = _logistic_loss_and_grad(w, X, y, alpha=1.)
loss_interp_2 = _logistic_loss(w, X, y, alpha=1.)
grad_interp_2, hess = _logistic_grad_hess(w, X, y, alpha=1.)
assert_array_almost_equal(loss_interp, loss_interp_2)
assert_array_almost_equal(grad_interp, grad_interp_2)
def test_logistic_cv():
# test for LogisticRegressionCV object
n_samples, n_features = 50, 5
rng = np.random.RandomState(0)
X_ref = rng.randn(n_samples, n_features)
y = np.sign(X_ref.dot(5 * rng.randn(n_features)))
X_ref -= X_ref.mean()
X_ref /= X_ref.std()
lr_cv = LogisticRegressionCV(Cs=[1.], fit_intercept=False,
solver='liblinear')
lr_cv.fit(X_ref, y)
lr = LogisticRegression(C=1., fit_intercept=False)
lr.fit(X_ref, y)
assert_array_almost_equal(lr.coef_, lr_cv.coef_)
assert_array_equal(lr_cv.coef_.shape, (1, n_features))
assert_array_equal(lr_cv.classes_, [-1, 1])
assert_equal(len(lr_cv.classes_), 2)
coefs_paths = np.asarray(list(lr_cv.coefs_paths_.values()))
assert_array_equal(coefs_paths.shape, (1, 3, 1, n_features))
assert_array_equal(lr_cv.Cs_.shape, (1,))
scores = np.asarray(list(lr_cv.scores_.values()))
assert_array_equal(scores.shape, (1, 3, 1))
def test_multinomial_logistic_regression_string_inputs():
# Test with string labels for LogisticRegression(CV)
n_samples, n_features, n_classes = 50, 5, 3
X_ref, y = make_classification(n_samples=n_samples, n_features=n_features,
n_classes=n_classes, n_informative=3,
random_state=0)
y_str = LabelEncoder().fit(['bar', 'baz', 'foo']).inverse_transform(y)
# For numerical labels, let y values be taken from set (-1, 0, 1)
y = np.array(y) - 1
# Test for string labels
lr = LogisticRegression(solver='lbfgs', multi_class='multinomial')
lr_cv = LogisticRegressionCV(solver='lbfgs', multi_class='multinomial')
lr_str = LogisticRegression(solver='lbfgs', multi_class='multinomial')
lr_cv_str = LogisticRegressionCV(solver='lbfgs', multi_class='multinomial')
lr.fit(X_ref, y)
lr_cv.fit(X_ref, y)
lr_str.fit(X_ref, y_str)
lr_cv_str.fit(X_ref, y_str)
assert_array_almost_equal(lr.coef_, lr_str.coef_)
assert_equal(sorted(lr_str.classes_), ['bar', 'baz', 'foo'])
assert_array_almost_equal(lr_cv.coef_, lr_cv_str.coef_)
assert_equal(sorted(lr_str.classes_), ['bar', 'baz', 'foo'])
assert_equal(sorted(lr_cv_str.classes_), ['bar', 'baz', 'foo'])
# The predictions should be in original labels
assert_equal(sorted(np.unique(lr_str.predict(X_ref))),
['bar', 'baz', 'foo'])
assert_equal(sorted(np.unique(lr_cv_str.predict(X_ref))),
['bar', 'baz', 'foo'])
# Make sure class weights can be given with string labels
lr_cv_str = LogisticRegression(
solver='lbfgs', class_weight={'bar': 1, 'baz': 2, 'foo': 0},
multi_class='multinomial').fit(X_ref, y_str)
assert_equal(sorted(np.unique(lr_cv_str.predict(X_ref))), ['bar', 'baz'])
def test_logistic_cv_sparse():
X, y = make_classification(n_samples=50, n_features=5,
random_state=0)
X[X < 1.0] = 0.0
csr = sp.csr_matrix(X)
clf = LogisticRegressionCV(fit_intercept=True)
clf.fit(X, y)
clfs = LogisticRegressionCV(fit_intercept=True)
clfs.fit(csr, y)
assert_array_almost_equal(clfs.coef_, clf.coef_)
assert_array_almost_equal(clfs.intercept_, clf.intercept_)
assert_equal(clfs.C_, clf.C_)
def test_intercept_logistic_helper():
n_samples, n_features = 10, 5
X, y = make_classification(n_samples=n_samples, n_features=n_features,
random_state=0)
# Fit intercept case.
alpha = 1.
w = np.ones(n_features + 1)
grad_interp, hess_interp = _logistic_grad_hess(w, X, y, alpha)
loss_interp = _logistic_loss(w, X, y, alpha)
# Do not fit intercept. This can be considered equivalent to adding
# a feature vector of ones, i.e column of one vectors.
X_ = np.hstack((X, np.ones(10)[:, np.newaxis]))
grad, hess = _logistic_grad_hess(w, X_, y, alpha)
loss = _logistic_loss(w, X_, y, alpha)
# In the fit_intercept=False case, the feature vector of ones is
# penalized. This should be taken care of.
assert_almost_equal(loss_interp + 0.5 * (w[-1] ** 2), loss)
# Check gradient.
assert_array_almost_equal(grad_interp[:n_features], grad[:n_features])
assert_almost_equal(grad_interp[-1] + alpha * w[-1], grad[-1])
rng = np.random.RandomState(0)
grad = rng.rand(n_features + 1)
hess_interp = hess_interp(grad)
hess = hess(grad)
assert_array_almost_equal(hess_interp[:n_features], hess[:n_features])
assert_almost_equal(hess_interp[-1] + alpha * grad[-1], hess[-1])
def test_ovr_multinomial_iris():
# Test that OvR and multinomial are correct using the iris dataset.
train, target = iris.data, iris.target
n_samples, n_features = train.shape
# The cv indices from stratified kfold (where stratification is done based
# on the fine-grained iris classes, i.e, before the classes 0 and 1 are
# conflated) is used for both clf and clf1
n_cv = 2
cv = StratifiedKFold(n_cv)
precomputed_folds = list(cv.split(train, target))
# Train clf on the original dataset where classes 0 and 1 are separated
clf = LogisticRegressionCV(cv=precomputed_folds)
clf.fit(train, target)
# Conflate classes 0 and 1 and train clf1 on this modified dataset
clf1 = LogisticRegressionCV(cv=precomputed_folds)
target_copy = target.copy()
target_copy[target_copy == 0] = 1
clf1.fit(train, target_copy)
# Ensure that what OvR learns for class2 is same regardless of whether
# classes 0 and 1 are separated or not
assert_array_almost_equal(clf.scores_[2], clf1.scores_[2])
assert_array_almost_equal(clf.intercept_[2:], clf1.intercept_)
assert_array_almost_equal(clf.coef_[2][np.newaxis, :], clf1.coef_)
# Test the shape of various attributes.
assert_equal(clf.coef_.shape, (3, n_features))
assert_array_equal(clf.classes_, [0, 1, 2])
coefs_paths = np.asarray(list(clf.coefs_paths_.values()))
assert_array_almost_equal(coefs_paths.shape, (3, n_cv, 10, n_features + 1))
assert_equal(clf.Cs_.shape, (10,))
scores = np.asarray(list(clf.scores_.values()))
assert_equal(scores.shape, (3, n_cv, 10))
# Test that for the iris data multinomial gives a better accuracy than OvR
for solver in ['lbfgs', 'newton-cg', 'sag', 'saga']:
max_iter = 2000 if solver in ['sag', 'saga'] else 15
clf_multi = LogisticRegressionCV(
solver=solver, multi_class='multinomial', max_iter=max_iter,
random_state=42, tol=1e-5 if solver in ['sag', 'saga'] else 1e-2,
cv=2)
clf_multi.fit(train, target)
multi_score = clf_multi.score(train, target)
ovr_score = clf.score(train, target)
assert_greater(multi_score, ovr_score)
# Test attributes of LogisticRegressionCV
assert_equal(clf.coef_.shape, clf_multi.coef_.shape)
assert_array_equal(clf_multi.classes_, [0, 1, 2])
coefs_paths = np.asarray(list(clf_multi.coefs_paths_.values()))
assert_array_almost_equal(coefs_paths.shape, (3, n_cv, 10,
n_features + 1))
assert_equal(clf_multi.Cs_.shape, (10,))
scores = np.asarray(list(clf_multi.scores_.values()))
assert_equal(scores.shape, (3, n_cv, 10))
def test_logistic_regression_solvers():
X, y = make_classification(n_features=10, n_informative=5, random_state=0)
ncg = LogisticRegression(solver='newton-cg', fit_intercept=False)
lbf = LogisticRegression(solver='lbfgs', fit_intercept=False)
lib = LogisticRegression(fit_intercept=False)
sag = LogisticRegression(solver='sag', fit_intercept=False,
random_state=42)
saga = LogisticRegression(solver='saga', fit_intercept=False,
random_state=42)
ncg.fit(X, y)
lbf.fit(X, y)
sag.fit(X, y)
saga.fit(X, y)
lib.fit(X, y)
assert_array_almost_equal(ncg.coef_, lib.coef_, decimal=3)
assert_array_almost_equal(lib.coef_, lbf.coef_, decimal=3)
assert_array_almost_equal(ncg.coef_, lbf.coef_, decimal=3)
assert_array_almost_equal(sag.coef_, lib.coef_, decimal=3)
assert_array_almost_equal(sag.coef_, ncg.coef_, decimal=3)
assert_array_almost_equal(sag.coef_, lbf.coef_, decimal=3)
assert_array_almost_equal(saga.coef_, sag.coef_, decimal=3)
assert_array_almost_equal(saga.coef_, lbf.coef_, decimal=3)
assert_array_almost_equal(saga.coef_, ncg.coef_, decimal=3)
assert_array_almost_equal(saga.coef_, lib.coef_, decimal=3)
def test_logistic_regression_solvers_multiclass():
X, y = make_classification(n_samples=20, n_features=20, n_informative=10,
n_classes=3, random_state=0)
tol = 1e-7
ncg = LogisticRegression(solver='newton-cg', fit_intercept=False, tol=tol)
lbf = LogisticRegression(solver='lbfgs', fit_intercept=False, tol=tol)
lib = LogisticRegression(fit_intercept=False, tol=tol)
sag = LogisticRegression(solver='sag', fit_intercept=False, tol=tol,
max_iter=1000, random_state=42)
saga = LogisticRegression(solver='saga', fit_intercept=False, tol=tol,
max_iter=10000, random_state=42)
ncg.fit(X, y)
lbf.fit(X, y)
sag.fit(X, y)
saga.fit(X, y)
lib.fit(X, y)
assert_array_almost_equal(ncg.coef_, lib.coef_, decimal=4)
assert_array_almost_equal(lib.coef_, lbf.coef_, decimal=4)
assert_array_almost_equal(ncg.coef_, lbf.coef_, decimal=4)
assert_array_almost_equal(sag.coef_, lib.coef_, decimal=4)
assert_array_almost_equal(sag.coef_, ncg.coef_, decimal=4)
assert_array_almost_equal(sag.coef_, lbf.coef_, decimal=4)
assert_array_almost_equal(saga.coef_, sag.coef_, decimal=4)
assert_array_almost_equal(saga.coef_, lbf.coef_, decimal=4)
assert_array_almost_equal(saga.coef_, ncg.coef_, decimal=4)
assert_array_almost_equal(saga.coef_, lib.coef_, decimal=4)
def test_logistic_regressioncv_class_weights():
for weight in [{0: 0.1, 1: 0.2}, {0: 0.1, 1: 0.2, 2: 0.5}]:
n_classes = len(weight)
for class_weight in (weight, 'balanced'):
X, y = make_classification(n_samples=30, n_features=3,
n_repeated=0,
n_informative=3, n_redundant=0,
n_classes=n_classes, random_state=0)
clf_lbf = LogisticRegressionCV(solver='lbfgs', Cs=1,
fit_intercept=False,
class_weight=class_weight)
clf_ncg = LogisticRegressionCV(solver='newton-cg', Cs=1,
fit_intercept=False,
class_weight=class_weight)
clf_lib = LogisticRegressionCV(solver='liblinear', Cs=1,
fit_intercept=False,
class_weight=class_weight)
clf_sag = LogisticRegressionCV(solver='sag', Cs=1,
fit_intercept=False,
class_weight=class_weight,
tol=1e-5, max_iter=10000,
random_state=0)
clf_saga = LogisticRegressionCV(solver='saga', Cs=1,
fit_intercept=False,
class_weight=class_weight,
tol=1e-5, max_iter=10000,
random_state=0)
clf_lbf.fit(X, y)
clf_ncg.fit(X, y)
clf_lib.fit(X, y)
clf_sag.fit(X, y)
clf_saga.fit(X, y)
assert_array_almost_equal(clf_lib.coef_, clf_lbf.coef_, decimal=4)
assert_array_almost_equal(clf_ncg.coef_, clf_lbf.coef_, decimal=4)
assert_array_almost_equal(clf_sag.coef_, clf_lbf.coef_, decimal=4)
assert_array_almost_equal(clf_saga.coef_, clf_lbf.coef_, decimal=4)
def test_logistic_regression_sample_weights():
X, y = make_classification(n_samples=20, n_features=5, n_informative=3,
n_classes=2, random_state=0)
sample_weight = y + 1
for LR in [LogisticRegression, LogisticRegressionCV]:
# Test that passing sample_weight as ones is the same as
# not passing them at all (default None)
for solver in ['lbfgs', 'liblinear']:
clf_sw_none = LR(solver=solver, fit_intercept=False,
random_state=42)
clf_sw_none.fit(X, y)
clf_sw_ones = LR(solver=solver, fit_intercept=False,
random_state=42)
clf_sw_ones.fit(X, y, sample_weight=np.ones(y.shape[0]))
assert_array_almost_equal(
clf_sw_none.coef_, clf_sw_ones.coef_, decimal=4)
# Test that sample weights work the same with the lbfgs,
# newton-cg, and 'sag' solvers
clf_sw_lbfgs = LR(solver='lbfgs', fit_intercept=False, random_state=42)
clf_sw_lbfgs.fit(X, y, sample_weight=sample_weight)
clf_sw_n = LR(solver='newton-cg', fit_intercept=False, random_state=42)
clf_sw_n.fit(X, y, sample_weight=sample_weight)
clf_sw_sag = LR(solver='sag', fit_intercept=False, tol=1e-10,
random_state=42)
# ignore convergence warning due to small dataset
with ignore_warnings():
clf_sw_sag.fit(X, y, sample_weight=sample_weight)
clf_sw_liblinear = LR(solver='liblinear', fit_intercept=False,
random_state=42)
clf_sw_liblinear.fit(X, y, sample_weight=sample_weight)
assert_array_almost_equal(
clf_sw_lbfgs.coef_, clf_sw_n.coef_, decimal=4)
assert_array_almost_equal(
clf_sw_lbfgs.coef_, clf_sw_sag.coef_, decimal=4)
assert_array_almost_equal(
clf_sw_lbfgs.coef_, clf_sw_liblinear.coef_, decimal=4)
# Test that passing class_weight as [1,2] is the same as
# passing class weight = [1,1] but adjusting sample weights
# to be 2 for all instances of class 2
for solver in ['lbfgs', 'liblinear']:
clf_cw_12 = LR(solver=solver, fit_intercept=False,
class_weight={0: 1, 1: 2}, random_state=42)
clf_cw_12.fit(X, y)
clf_sw_12 = LR(solver=solver, fit_intercept=False, random_state=42)
clf_sw_12.fit(X, y, sample_weight=sample_weight)
assert_array_almost_equal(
clf_cw_12.coef_, clf_sw_12.coef_, decimal=4)
# Test the above for l1 penalty and l2 penalty with dual=True.
# since the patched liblinear code is different.
clf_cw = LogisticRegression(
solver="liblinear", fit_intercept=False, class_weight={0: 1, 1: 2},
penalty="l1", tol=1e-5, random_state=42)
clf_cw.fit(X, y)
clf_sw = LogisticRegression(
solver="liblinear", fit_intercept=False, penalty="l1", tol=1e-5,
random_state=42)
clf_sw.fit(X, y, sample_weight)
assert_array_almost_equal(clf_cw.coef_, clf_sw.coef_, decimal=4)
clf_cw = LogisticRegression(
solver="liblinear", fit_intercept=False, class_weight={0: 1, 1: 2},
penalty="l2", dual=True, random_state=42)
clf_cw.fit(X, y)
clf_sw = LogisticRegression(
solver="liblinear", fit_intercept=False, penalty="l2", dual=True,
random_state=42)
clf_sw.fit(X, y, sample_weight)
assert_array_almost_equal(clf_cw.coef_, clf_sw.coef_, decimal=4)
def _compute_class_weight_dictionary(y):
# helper for returning a dictionary instead of an array
classes = np.unique(y)
class_weight = compute_class_weight("balanced", classes, y)
class_weight_dict = dict(zip(classes, class_weight))
return class_weight_dict
def test_logistic_regression_class_weights():
# Multinomial case: remove 90% of class 0
X = iris.data[45:, :]
y = iris.target[45:]
solvers = ("lbfgs", "newton-cg")
class_weight_dict = _compute_class_weight_dictionary(y)
for solver in solvers:
clf1 = LogisticRegression(solver=solver, multi_class="multinomial",
class_weight="balanced")
clf2 = LogisticRegression(solver=solver, multi_class="multinomial",
class_weight=class_weight_dict)
clf1.fit(X, y)
clf2.fit(X, y)
assert_array_almost_equal(clf1.coef_, clf2.coef_, decimal=4)
# Binary case: remove 90% of class 0 and 100% of class 2
X = iris.data[45:100, :]
y = iris.target[45:100]
solvers = ("lbfgs", "newton-cg", "liblinear")
class_weight_dict = _compute_class_weight_dictionary(y)
for solver in solvers:
clf1 = LogisticRegression(solver=solver, multi_class="ovr",
class_weight="balanced")
clf2 = LogisticRegression(solver=solver, multi_class="ovr",
class_weight=class_weight_dict)
clf1.fit(X, y)
clf2.fit(X, y)
assert_array_almost_equal(clf1.coef_, clf2.coef_, decimal=6)
def test_logistic_regression_convergence_warnings():
# Test that warnings are raised if model does not converge
X, y = make_classification(n_samples=20, n_features=20, random_state=0)
clf_lib = LogisticRegression(solver='liblinear', max_iter=2, verbose=1)
assert_warns(ConvergenceWarning, clf_lib.fit, X, y)
assert_equal(clf_lib.n_iter_, 2)
def test_logistic_regression_multinomial():
# Tests for the multinomial option in logistic regression
# Some basic attributes of Logistic Regression
n_samples, n_features, n_classes = 50, 20, 3
X, y = make_classification(n_samples=n_samples,
n_features=n_features,
n_informative=10,
n_classes=n_classes, random_state=0)
# 'lbfgs' is used as a referenced
solver = 'lbfgs'
ref_i = LogisticRegression(solver=solver, multi_class='multinomial')
ref_w = LogisticRegression(solver=solver, multi_class='multinomial',
fit_intercept=False)
ref_i.fit(X, y)
ref_w.fit(X, y)
assert_array_equal(ref_i.coef_.shape, (n_classes, n_features))
assert_array_equal(ref_w.coef_.shape, (n_classes, n_features))
for solver in ['sag', 'saga', 'newton-cg']:
clf_i = LogisticRegression(solver=solver, multi_class='multinomial',
random_state=42, max_iter=2000, tol=1e-7,
)
clf_w = LogisticRegression(solver=solver, multi_class='multinomial',
random_state=42, max_iter=2000, tol=1e-7,
fit_intercept=False)
clf_i.fit(X, y)
clf_w.fit(X, y)
assert_array_equal(clf_i.coef_.shape, (n_classes, n_features))
assert_array_equal(clf_w.coef_.shape, (n_classes, n_features))
# Compare solutions between lbfgs and the other solvers
assert_almost_equal(ref_i.coef_, clf_i.coef_, decimal=3)
assert_almost_equal(ref_w.coef_, clf_w.coef_, decimal=3)
assert_almost_equal(ref_i.intercept_, clf_i.intercept_, decimal=3)
# Test that the path give almost the same results. However since in this
# case we take the average of the coefs after fitting across all the
# folds, it need not be exactly the same.
for solver in ['lbfgs', 'newton-cg', 'sag', 'saga']:
clf_path = LogisticRegressionCV(solver=solver, max_iter=2000, tol=1e-6,
multi_class='multinomial', Cs=[1.])
clf_path.fit(X, y)
assert_array_almost_equal(clf_path.coef_, ref_i.coef_, decimal=3)
assert_almost_equal(clf_path.intercept_, ref_i.intercept_, decimal=3)
def test_multinomial_grad_hess():
rng = np.random.RandomState(0)
n_samples, n_features, n_classes = 100, 5, 3
X = rng.randn(n_samples, n_features)
w = rng.rand(n_classes, n_features)
Y = np.zeros((n_samples, n_classes))
ind = np.argmax(np.dot(X, w.T), axis=1)
Y[range(0, n_samples), ind] = 1
w = w.ravel()
sample_weights = np.ones(X.shape[0])
grad, hessp = _multinomial_grad_hess(w, X, Y, alpha=1.,
sample_weight=sample_weights)
# extract first column of hessian matrix
vec = np.zeros(n_features * n_classes)
vec[0] = 1
hess_col = hessp(vec)
# Estimate hessian using least squares as done in
# test_logistic_grad_hess
e = 1e-3
d_x = np.linspace(-e, e, 30)
d_grad = np.array([
_multinomial_grad_hess(w + t * vec, X, Y, alpha=1.,
sample_weight=sample_weights)[0]
for t in d_x
])
d_grad -= d_grad.mean(axis=0)
approx_hess_col = linalg.lstsq(d_x[:, np.newaxis], d_grad)[0].ravel()
assert_array_almost_equal(hess_col, approx_hess_col)
def test_liblinear_decision_function_zero():
# Test negative prediction when decision_function values are zero.
# Liblinear predicts the positive class when decision_function values
# are zero. This is a test to verify that we do not do the same.
# See Issue: https://github.com/scikit-learn/scikit-learn/issues/3600
# and the PR https://github.com/scikit-learn/scikit-learn/pull/3623
X, y = make_classification(n_samples=5, n_features=5, random_state=0)
clf = LogisticRegression(fit_intercept=False)
clf.fit(X, y)
# Dummy data such that the decision function becomes zero.
X = np.zeros((5, 5))
assert_array_equal(clf.predict(X), np.zeros(5))
def test_liblinear_logregcv_sparse():
# Test LogRegCV with solver='liblinear' works for sparse matrices
X, y = make_classification(n_samples=10, n_features=5, random_state=0)
clf = LogisticRegressionCV(solver='liblinear')
clf.fit(sparse.csr_matrix(X), y)
def test_saga_sparse():
# Test LogRegCV with solver='liblinear' works for sparse matrices
X, y = make_classification(n_samples=10, n_features=5, random_state=0)
clf = LogisticRegressionCV(solver='saga')
clf.fit(sparse.csr_matrix(X), y)
def test_logreg_intercept_scaling():
# Test that the right error message is thrown when intercept_scaling <= 0
for i in [-1, 0]:
clf = LogisticRegression(intercept_scaling=i)
msg = ('Intercept scaling is %r but needs to be greater than 0.'
' To disable fitting an intercept,'
' set fit_intercept=False.' % clf.intercept_scaling)
assert_raise_message(ValueError, msg, clf.fit, X, Y1)
def test_logreg_intercept_scaling_zero():
# Test that intercept_scaling is ignored when fit_intercept is False
clf = LogisticRegression(fit_intercept=False)
clf.fit(X, Y1)
assert_equal(clf.intercept_, 0.)
def test_logreg_l1():
# Because liblinear penalizes the intercept and saga does not, we do not
# fit the intercept to make it possible to compare the coefficients of
# the two models at convergence.
rng = np.random.RandomState(42)
n_samples = 50
X, y = make_classification(n_samples=n_samples, n_features=20,
random_state=0)
X_noise = rng.normal(size=(n_samples, 3))
X_constant = np.ones(shape=(n_samples, 2))
X = np.concatenate((X, X_noise, X_constant), axis=1)
lr_liblinear = LogisticRegression(penalty="l1", C=1.0, solver='liblinear',
fit_intercept=False,
tol=1e-10)
lr_liblinear.fit(X, y)
lr_saga = LogisticRegression(penalty="l1", C=1.0, solver='saga',
fit_intercept=False,
max_iter=1000, tol=1e-10)
lr_saga.fit(X, y)
assert_array_almost_equal(lr_saga.coef_, lr_liblinear.coef_)
# Noise and constant features should be regularized to zero by the l1
# penalty
assert_array_almost_equal(lr_liblinear.coef_[0, -5:], np.zeros(5))
assert_array_almost_equal(lr_saga.coef_[0, -5:], np.zeros(5))
def test_logreg_l1_sparse_data():
# Because liblinear penalizes the intercept and saga does not, we do not
# fit the intercept to make it possible to compare the coefficients of
# the two models at convergence.
rng = np.random.RandomState(42)
n_samples = 50
X, y = make_classification(n_samples=n_samples, n_features=20,
random_state=0)
X_noise = rng.normal(scale=0.1, size=(n_samples, 3))
X_constant = np.zeros(shape=(n_samples, 2))
X = np.concatenate((X, X_noise, X_constant), axis=1)
X[X < 1] = 0
X = sparse.csr_matrix(X)
lr_liblinear = LogisticRegression(penalty="l1", C=1.0, solver='liblinear',
fit_intercept=False,
tol=1e-10)
lr_liblinear.fit(X, y)
lr_saga = LogisticRegression(penalty="l1", C=1.0, solver='saga',
fit_intercept=False,
max_iter=1000, tol=1e-10)
lr_saga.fit(X, y)
assert_array_almost_equal(lr_saga.coef_, lr_liblinear.coef_)
# Noise and constant features should be regularized to zero by the l1
# penalty
assert_array_almost_equal(lr_liblinear.coef_[0, -5:], np.zeros(5))
assert_array_almost_equal(lr_saga.coef_[0, -5:], np.zeros(5))
# Check that solving on the sparse and dense data yield the same results
lr_saga_dense = LogisticRegression(penalty="l1", C=1.0, solver='saga',
fit_intercept=False,
max_iter=1000, tol=1e-10)
lr_saga_dense.fit(X.toarray(), y)
assert_array_almost_equal(lr_saga.coef_, lr_saga_dense.coef_)
def test_logreg_cv_penalty():
# Test that the correct penalty is passed to the final fit.
X, y = make_classification(n_samples=50, n_features=20, random_state=0)
lr_cv = LogisticRegressionCV(penalty="l1", Cs=[1.0], solver='liblinear')
lr_cv.fit(X, y)
lr = LogisticRegression(penalty="l1", C=1.0, solver='liblinear')
lr.fit(X, y)
assert_equal(np.count_nonzero(lr_cv.coef_), np.count_nonzero(lr.coef_))
def test_logreg_predict_proba_multinomial():
X, y = make_classification(n_samples=10, n_features=20, random_state=0,
n_classes=3, n_informative=10)
# Predicted probabilities using the true-entropy loss should give a
# smaller loss than those using the ovr method.
clf_multi = LogisticRegression(multi_class="multinomial", solver="lbfgs")
clf_multi.fit(X, y)
clf_multi_loss = log_loss(y, clf_multi.predict_proba(X))
clf_ovr = LogisticRegression(multi_class="ovr", solver="lbfgs")
clf_ovr.fit(X, y)
clf_ovr_loss = log_loss(y, clf_ovr.predict_proba(X))
assert_greater(clf_ovr_loss, clf_multi_loss)
# Predicted probabilities using the soft-max function should give a
# smaller loss than those using the logistic function.
clf_multi_loss = log_loss(y, clf_multi.predict_proba(X))
clf_wrong_loss = log_loss(y, clf_multi._predict_proba_lr(X))
assert_greater(clf_wrong_loss, clf_multi_loss)
@ignore_warnings
def test_max_iter():
# Test that the maximum number of iteration is reached
X, y_bin = iris.data, iris.target.copy()
y_bin[y_bin == 2] = 0
solvers = ['newton-cg', 'liblinear', 'sag', 'saga', 'lbfgs']
for max_iter in range(1, 5):
for solver in solvers:
for multi_class in ['ovr', 'multinomial']:
if solver == 'liblinear' and multi_class == 'multinomial':
continue
lr = LogisticRegression(max_iter=max_iter, tol=1e-15,
multi_class=multi_class,
random_state=0, solver=solver)
lr.fit(X, y_bin)
assert_equal(lr.n_iter_[0], max_iter)
def test_n_iter():
# Test that self.n_iter_ has the correct format.
X, y = iris.data, iris.target
y_bin = y.copy()
y_bin[y_bin == 2] = 0
n_Cs = 4
n_cv_fold = 2
for solver in ['newton-cg', 'liblinear', 'sag', 'saga', 'lbfgs']:
# OvR case
n_classes = 1 if solver == 'liblinear' else np.unique(y).shape[0]
clf = LogisticRegression(tol=1e-2, multi_class='ovr',
solver=solver, C=1.,
random_state=42, max_iter=100)
clf.fit(X, y)
assert_equal(clf.n_iter_.shape, (n_classes,))
n_classes = np.unique(y).shape[0]
clf = LogisticRegressionCV(tol=1e-2, multi_class='ovr',
solver=solver, Cs=n_Cs, cv=n_cv_fold,
random_state=42, max_iter=100)
clf.fit(X, y)
assert_equal(clf.n_iter_.shape, (n_classes, n_cv_fold, n_Cs))
clf.fit(X, y_bin)
assert_equal(clf.n_iter_.shape, (1, n_cv_fold, n_Cs))
# multinomial case
n_classes = 1
if solver in ('liblinear', 'sag', 'saga'):
break
clf = LogisticRegression(tol=1e-2, multi_class='multinomial',
solver=solver, C=1.,
random_state=42, max_iter=100)
clf.fit(X, y)
assert_equal(clf.n_iter_.shape, (n_classes,))
clf = LogisticRegressionCV(tol=1e-2, multi_class='multinomial',
solver=solver, Cs=n_Cs, cv=n_cv_fold,
random_state=42, max_iter=100)
clf.fit(X, y)
assert_equal(clf.n_iter_.shape, (n_classes, n_cv_fold, n_Cs))
clf.fit(X, y_bin)
assert_equal(clf.n_iter_.shape, (1, n_cv_fold, n_Cs))
def test_warm_start():
# A 1-iteration second fit on same data should give almost same result
# with warm starting, and quite different result without warm starting.
# Warm starting does not work with liblinear solver.
X, y = iris.data, iris.target
solvers = ['newton-cg', 'sag', 'saga', 'lbfgs']
for warm_start in [True, False]:
for fit_intercept in [True, False]:
for solver in solvers:
for multi_class in ['ovr', 'multinomial']:
clf = LogisticRegression(tol=1e-4, multi_class=multi_class,
warm_start=warm_start,
solver=solver,
random_state=42, max_iter=100,
fit_intercept=fit_intercept)
with ignore_warnings(category=ConvergenceWarning):
clf.fit(X, y)
coef_1 = clf.coef_
clf.max_iter = 1
clf.fit(X, y)
cum_diff = np.sum(np.abs(coef_1 - clf.coef_))
msg = ("Warm starting issue with %s solver in %s mode "
"with fit_intercept=%s and warm_start=%s"
% (solver, multi_class, str(fit_intercept),
str(warm_start)))
if warm_start:
assert_greater(2.0, cum_diff, msg)
else:
assert_greater(cum_diff, 2.0, msg)
def test_saga_vs_liblinear():
iris = load_iris()
X, y = iris.data, iris.target
X = np.concatenate([X] * 10)
y = np.concatenate([y] * 10)
X_bin = X[y <= 1]
y_bin = y[y <= 1] * 2 - 1
X_sparse, y_sparse = make_classification(n_samples=50, n_features=20,
random_state=0)
X_sparse = sparse.csr_matrix(X_sparse)
for (X, y) in ((X_bin, y_bin), (X_sparse, y_sparse)):
for penalty in ['l1', 'l2']:
n_samples = X.shape[0]
# alpha=1e-3 is time consuming
for alpha in np.logspace(-1, 1, 3):
saga = LogisticRegression(
C=1. / (n_samples * alpha),
solver='saga',
multi_class='ovr',
max_iter=200,
fit_intercept=False,
penalty=penalty, random_state=0, tol=1e-24)
liblinear = LogisticRegression(
C=1. / (n_samples * alpha),
solver='liblinear',
multi_class='ovr',
max_iter=200,
fit_intercept=False,
penalty=penalty, random_state=0, tol=1e-24)
saga.fit(X, y)
liblinear.fit(X, y)
# Convergence for alpha=1e-3 is very slow
assert_array_almost_equal(saga.coef_, liblinear.coef_, 3)
def test_dtype_match():
# Test that np.float32 input data is not cast to np.float64 when possible
X_32 = np.array(X).astype(np.float32)
y_32 = np.array(Y1).astype(np.float32)
X_64 = np.array(X).astype(np.float64)
y_64 = np.array(Y1).astype(np.float64)
X_sparse_32 = sp.csr_matrix(X, dtype=np.float32)
for solver in ['newton-cg']:
for multi_class in ['ovr', 'multinomial']:
# Check type consistency
lr_32 = LogisticRegression(solver=solver, multi_class=multi_class)
lr_32.fit(X_32, y_32)
assert_equal(lr_32.coef_.dtype, X_32.dtype)
# check consistency with sparsity
lr_32_sparse = LogisticRegression(solver=solver,
multi_class=multi_class)
lr_32_sparse.fit(X_sparse_32, y_32)
assert_equal(lr_32_sparse.coef_.dtype, X_sparse_32.dtype)
# Check accuracy consistency
lr_64 = LogisticRegression(solver=solver, multi_class=multi_class)
lr_64.fit(X_64, y_64)
assert_equal(lr_64.coef_.dtype, X_64.dtype)
assert_almost_equal(lr_32.coef_, lr_64.coef_.astype(np.float32))
| 49,337 | 40.989787 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_ransac.py | from scipy import sparse
import numpy as np
from scipy import sparse
from numpy.testing import assert_equal, assert_raises
from numpy.testing import assert_array_almost_equal
from numpy.testing import assert_array_equal
from sklearn.utils import check_random_state
from sklearn.utils.testing import assert_less
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_raises_regexp
from sklearn.linear_model import LinearRegression, RANSACRegressor, Lasso
from sklearn.linear_model.ransac import _dynamic_max_trials
# Generate coordinates of line
X = np.arange(-200, 200)
y = 0.2 * X + 20
data = np.column_stack([X, y])
# Add some faulty data
rng = np.random.RandomState(1000)
outliers = np.unique(rng.randint(len(X), size=200))
data[outliers, :] += 50 + rng.rand(len(outliers), 2) * 10
X = data[:, 0][:, np.newaxis]
y = data[:, 1]
def test_ransac_inliers_outliers():
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
# Estimate parameters of corrupted data
ransac_estimator.fit(X, y)
# Ground truth / reference inlier mask
ref_inlier_mask = np.ones_like(ransac_estimator.inlier_mask_
).astype(np.bool_)
ref_inlier_mask[outliers] = False
assert_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
def test_ransac_is_data_valid():
def is_data_valid(X, y):
assert_equal(X.shape[0], 2)
assert_equal(y.shape[0], 2)
return False
rng = np.random.RandomState(0)
X = rng.rand(10, 2)
y = rng.rand(10, 1)
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5,
is_data_valid=is_data_valid,
random_state=0)
assert_raises(ValueError, ransac_estimator.fit, X, y)
def test_ransac_is_model_valid():
def is_model_valid(estimator, X, y):
assert_equal(X.shape[0], 2)
assert_equal(y.shape[0], 2)
return False
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5,
is_model_valid=is_model_valid,
random_state=0)
assert_raises(ValueError, ransac_estimator.fit, X, y)
def test_ransac_max_trials():
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, max_trials=0,
random_state=0)
assert_raises(ValueError, ransac_estimator.fit, X, y)
# there is a 1e-9 chance it will take these many trials. No good reason
# 1e-2 isn't enough, can still happen
# 2 is the what ransac defines as min_samples = X.shape[1] + 1
max_trials = _dynamic_max_trials(
len(X) - len(outliers), X.shape[0], 2, 1 - 1e-9)
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2)
for i in range(50):
ransac_estimator.set_params(min_samples=2, random_state=i)
ransac_estimator.fit(X, y)
assert_less(ransac_estimator.n_trials_, max_trials + 1)
def test_ransac_stop_n_inliers():
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, stop_n_inliers=2,
random_state=0)
ransac_estimator.fit(X, y)
assert_equal(ransac_estimator.n_trials_, 1)
def test_ransac_stop_score():
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, stop_score=0,
random_state=0)
ransac_estimator.fit(X, y)
assert_equal(ransac_estimator.n_trials_, 1)
def test_ransac_score():
X = np.arange(100)[:, None]
y = np.zeros((100, ))
y[0] = 1
y[1] = 100
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=0.5, random_state=0)
ransac_estimator.fit(X, y)
assert_equal(ransac_estimator.score(X[2:], y[2:]), 1)
assert_less(ransac_estimator.score(X[:2], y[:2]), 1)
def test_ransac_predict():
X = np.arange(100)[:, None]
y = np.zeros((100, ))
y[0] = 1
y[1] = 100
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=0.5, random_state=0)
ransac_estimator.fit(X, y)
assert_equal(ransac_estimator.predict(X), np.zeros(100))
def test_ransac_resid_thresh_no_inliers():
# When residual_threshold=0.0 there are no inliers and a
# ValueError with a message should be raised
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=0.0, random_state=0,
max_trials=5)
msg = ("RANSAC could not find a valid consensus set")
assert_raises_regexp(ValueError, msg, ransac_estimator.fit, X, y)
assert_equal(ransac_estimator.n_skips_no_inliers_, 5)
assert_equal(ransac_estimator.n_skips_invalid_data_, 0)
assert_equal(ransac_estimator.n_skips_invalid_model_, 0)
def test_ransac_no_valid_data():
def is_data_valid(X, y):
return False
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator,
is_data_valid=is_data_valid,
max_trials=5)
msg = ("RANSAC could not find a valid consensus set")
assert_raises_regexp(ValueError, msg, ransac_estimator.fit, X, y)
assert_equal(ransac_estimator.n_skips_no_inliers_, 0)
assert_equal(ransac_estimator.n_skips_invalid_data_, 5)
assert_equal(ransac_estimator.n_skips_invalid_model_, 0)
def test_ransac_no_valid_model():
def is_model_valid(estimator, X, y):
return False
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator,
is_model_valid=is_model_valid,
max_trials=5)
msg = ("RANSAC could not find a valid consensus set")
assert_raises_regexp(ValueError, msg, ransac_estimator.fit, X, y)
assert_equal(ransac_estimator.n_skips_no_inliers_, 0)
assert_equal(ransac_estimator.n_skips_invalid_data_, 0)
assert_equal(ransac_estimator.n_skips_invalid_model_, 5)
def test_ransac_exceed_max_skips():
def is_data_valid(X, y):
return False
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator,
is_data_valid=is_data_valid,
max_trials=5,
max_skips=3)
msg = ("RANSAC skipped more iterations than `max_skips`")
assert_raises_regexp(ValueError, msg, ransac_estimator.fit, X, y)
assert_equal(ransac_estimator.n_skips_no_inliers_, 0)
assert_equal(ransac_estimator.n_skips_invalid_data_, 4)
assert_equal(ransac_estimator.n_skips_invalid_model_, 0)
def test_ransac_warn_exceed_max_skips():
global cause_skip
cause_skip = False
def is_data_valid(X, y):
global cause_skip
if not cause_skip:
cause_skip = True
return True
else:
return False
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator,
is_data_valid=is_data_valid,
max_skips=3,
max_trials=5)
assert_warns(UserWarning, ransac_estimator.fit, X, y)
assert_equal(ransac_estimator.n_skips_no_inliers_, 0)
assert_equal(ransac_estimator.n_skips_invalid_data_, 4)
assert_equal(ransac_estimator.n_skips_invalid_model_, 0)
def test_ransac_sparse_coo():
X_sparse = sparse.coo_matrix(X)
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
ransac_estimator.fit(X_sparse, y)
ref_inlier_mask = np.ones_like(ransac_estimator.inlier_mask_
).astype(np.bool_)
ref_inlier_mask[outliers] = False
assert_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
def test_ransac_sparse_csr():
X_sparse = sparse.csr_matrix(X)
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
ransac_estimator.fit(X_sparse, y)
ref_inlier_mask = np.ones_like(ransac_estimator.inlier_mask_
).astype(np.bool_)
ref_inlier_mask[outliers] = False
assert_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
def test_ransac_sparse_csc():
X_sparse = sparse.csc_matrix(X)
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
ransac_estimator.fit(X_sparse, y)
ref_inlier_mask = np.ones_like(ransac_estimator.inlier_mask_
).astype(np.bool_)
ref_inlier_mask[outliers] = False
assert_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
def test_ransac_none_estimator():
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
ransac_none_estimator = RANSACRegressor(None, 2, 5, random_state=0)
ransac_estimator.fit(X, y)
ransac_none_estimator.fit(X, y)
assert_array_almost_equal(ransac_estimator.predict(X),
ransac_none_estimator.predict(X))
def test_ransac_min_n_samples():
base_estimator = LinearRegression()
ransac_estimator1 = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
ransac_estimator2 = RANSACRegressor(base_estimator,
min_samples=2. / X.shape[0],
residual_threshold=5, random_state=0)
ransac_estimator3 = RANSACRegressor(base_estimator, min_samples=-1,
residual_threshold=5, random_state=0)
ransac_estimator4 = RANSACRegressor(base_estimator, min_samples=5.2,
residual_threshold=5, random_state=0)
ransac_estimator5 = RANSACRegressor(base_estimator, min_samples=2.0,
residual_threshold=5, random_state=0)
ransac_estimator6 = RANSACRegressor(base_estimator,
residual_threshold=5, random_state=0)
ransac_estimator7 = RANSACRegressor(base_estimator,
min_samples=X.shape[0] + 1,
residual_threshold=5, random_state=0)
ransac_estimator1.fit(X, y)
ransac_estimator2.fit(X, y)
ransac_estimator5.fit(X, y)
ransac_estimator6.fit(X, y)
assert_array_almost_equal(ransac_estimator1.predict(X),
ransac_estimator2.predict(X))
assert_array_almost_equal(ransac_estimator1.predict(X),
ransac_estimator5.predict(X))
assert_array_almost_equal(ransac_estimator1.predict(X),
ransac_estimator6.predict(X))
assert_raises(ValueError, ransac_estimator3.fit, X, y)
assert_raises(ValueError, ransac_estimator4.fit, X, y)
assert_raises(ValueError, ransac_estimator7.fit, X, y)
def test_ransac_multi_dimensional_targets():
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
# 3-D target values
yyy = np.column_stack([y, y, y])
# Estimate parameters of corrupted data
ransac_estimator.fit(X, yyy)
# Ground truth / reference inlier mask
ref_inlier_mask = np.ones_like(ransac_estimator.inlier_mask_
).astype(np.bool_)
ref_inlier_mask[outliers] = False
assert_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
# XXX: Remove in 0.20
def test_ransac_residual_metric():
residual_metric1 = lambda dy: np.sum(np.abs(dy), axis=1)
residual_metric2 = lambda dy: np.sum(dy ** 2, axis=1)
yyy = np.column_stack([y, y, y])
base_estimator = LinearRegression()
ransac_estimator0 = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
ransac_estimator1 = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0,
residual_metric=residual_metric1)
ransac_estimator2 = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0,
residual_metric=residual_metric2)
# multi-dimensional
ransac_estimator0.fit(X, yyy)
assert_warns(DeprecationWarning, ransac_estimator1.fit, X, yyy)
assert_warns(DeprecationWarning, ransac_estimator2.fit, X, yyy)
assert_array_almost_equal(ransac_estimator0.predict(X),
ransac_estimator1.predict(X))
assert_array_almost_equal(ransac_estimator0.predict(X),
ransac_estimator2.predict(X))
# one-dimensional
ransac_estimator0.fit(X, y)
assert_warns(DeprecationWarning, ransac_estimator2.fit, X, y)
assert_array_almost_equal(ransac_estimator0.predict(X),
ransac_estimator2.predict(X))
def test_ransac_residual_loss():
loss_multi1 = lambda y_true, y_pred: np.sum(np.abs(y_true - y_pred), axis=1)
loss_multi2 = lambda y_true, y_pred: np.sum((y_true - y_pred) ** 2, axis=1)
loss_mono = lambda y_true, y_pred : np.abs(y_true - y_pred)
yyy = np.column_stack([y, y, y])
base_estimator = LinearRegression()
ransac_estimator0 = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
ransac_estimator1 = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0,
loss=loss_multi1)
ransac_estimator2 = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0,
loss=loss_multi2)
# multi-dimensional
ransac_estimator0.fit(X, yyy)
ransac_estimator1.fit(X, yyy)
ransac_estimator2.fit(X, yyy)
assert_array_almost_equal(ransac_estimator0.predict(X),
ransac_estimator1.predict(X))
assert_array_almost_equal(ransac_estimator0.predict(X),
ransac_estimator2.predict(X))
# one-dimensional
ransac_estimator0.fit(X, y)
ransac_estimator2.loss = loss_mono
ransac_estimator2.fit(X, y)
assert_array_almost_equal(ransac_estimator0.predict(X),
ransac_estimator2.predict(X))
ransac_estimator3 = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0,
loss="squared_loss")
ransac_estimator3.fit(X, y)
assert_array_almost_equal(ransac_estimator0.predict(X),
ransac_estimator2.predict(X))
def test_ransac_default_residual_threshold():
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
random_state=0)
# Estimate parameters of corrupted data
ransac_estimator.fit(X, y)
# Ground truth / reference inlier mask
ref_inlier_mask = np.ones_like(ransac_estimator.inlier_mask_
).astype(np.bool_)
ref_inlier_mask[outliers] = False
assert_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
def test_ransac_dynamic_max_trials():
# Numbers hand-calculated and confirmed on page 119 (Table 4.3) in
# Hartley, R.~I. and Zisserman, A., 2004,
# Multiple View Geometry in Computer Vision, Second Edition,
# Cambridge University Press, ISBN: 0521540518
# e = 0%, min_samples = X
assert_equal(_dynamic_max_trials(100, 100, 2, 0.99), 1)
# e = 5%, min_samples = 2
assert_equal(_dynamic_max_trials(95, 100, 2, 0.99), 2)
# e = 10%, min_samples = 2
assert_equal(_dynamic_max_trials(90, 100, 2, 0.99), 3)
# e = 30%, min_samples = 2
assert_equal(_dynamic_max_trials(70, 100, 2, 0.99), 7)
# e = 50%, min_samples = 2
assert_equal(_dynamic_max_trials(50, 100, 2, 0.99), 17)
# e = 5%, min_samples = 8
assert_equal(_dynamic_max_trials(95, 100, 8, 0.99), 5)
# e = 10%, min_samples = 8
assert_equal(_dynamic_max_trials(90, 100, 8, 0.99), 9)
# e = 30%, min_samples = 8
assert_equal(_dynamic_max_trials(70, 100, 8, 0.99), 78)
# e = 50%, min_samples = 8
assert_equal(_dynamic_max_trials(50, 100, 8, 0.99), 1177)
# e = 0%, min_samples = 10
assert_equal(_dynamic_max_trials(1, 100, 10, 0), 0)
assert_equal(_dynamic_max_trials(1, 100, 10, 1), float('inf'))
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
stop_probability=-0.1)
assert_raises(ValueError, ransac_estimator.fit, X, y)
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
stop_probability=1.1)
assert_raises(ValueError, ransac_estimator.fit, X, y)
def test_ransac_fit_sample_weight():
ransac_estimator = RANSACRegressor(random_state=0)
n_samples = y.shape[0]
weights = np.ones(n_samples)
ransac_estimator.fit(X, y, weights)
# sanity check
assert_equal(ransac_estimator.inlier_mask_.shape[0], n_samples)
ref_inlier_mask = np.ones_like(ransac_estimator.inlier_mask_
).astype(np.bool_)
ref_inlier_mask[outliers] = False
# check that mask is correct
assert_array_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
# check that fit(X) = fit([X1, X2, X3],sample_weight = [n1, n2, n3]) where
# X = X1 repeated n1 times, X2 repeated n2 times and so forth
random_state = check_random_state(0)
X_ = random_state.randint(0, 200, [10, 1])
y_ = np.ndarray.flatten(0.2 * X_ + 2)
sample_weight = random_state.randint(0, 10, 10)
outlier_X = random_state.randint(0, 1000, [1, 1])
outlier_weight = random_state.randint(0, 10, 1)
outlier_y = random_state.randint(-1000, 0, 1)
X_flat = np.append(np.repeat(X_, sample_weight, axis=0),
np.repeat(outlier_X, outlier_weight, axis=0), axis=0)
y_flat = np.ndarray.flatten(np.append(np.repeat(y_, sample_weight, axis=0),
np.repeat(outlier_y, outlier_weight, axis=0),
axis=0))
ransac_estimator.fit(X_flat, y_flat)
ref_coef_ = ransac_estimator.estimator_.coef_
sample_weight = np.append(sample_weight, outlier_weight)
X_ = np.append(X_, outlier_X, axis=0)
y_ = np.append(y_, outlier_y)
ransac_estimator.fit(X_, y_, sample_weight)
assert_almost_equal(ransac_estimator.estimator_.coef_, ref_coef_)
# check that if base_estimator.fit doesn't support
# sample_weight, raises error
base_estimator = Lasso()
ransac_estimator = RANSACRegressor(base_estimator)
assert_raises(ValueError, ransac_estimator.fit, X, y, weights)
| 20,592 | 37.928166 | 80 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_randomized_l1.py | # Authors: Alexandre Gramfort <[email protected]>
# License: BSD 3 clause
from tempfile import mkdtemp
import shutil
import numpy as np
from scipy import sparse
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_raises_regex
from sklearn.utils.testing import assert_allclose
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.testing import assert_warns_message
from sklearn.linear_model.randomized_l1 import(lasso_stability_path,
RandomizedLasso,
RandomizedLogisticRegression)
from sklearn.datasets import load_diabetes, load_iris
from sklearn.feature_selection import f_regression, f_classif
from sklearn.preprocessing import StandardScaler
from sklearn.linear_model.base import _preprocess_data
diabetes = load_diabetes()
X = diabetes.data
y = diabetes.target
X = StandardScaler().fit_transform(X)
X = X[:, [2, 3, 6, 7, 8]]
# test that the feature score of the best features
F, _ = f_regression(X, y)
@ignore_warnings(category=DeprecationWarning)
def test_lasso_stability_path():
# Check lasso stability path
# Load diabetes data and add noisy features
scaling = 0.3
coef_grid, scores_path = lasso_stability_path(X, y, scaling=scaling,
random_state=42,
n_resampling=30)
assert_array_equal(np.argsort(F)[-3:],
np.argsort(np.sum(scores_path, axis=1))[-3:])
@ignore_warnings(category=DeprecationWarning)
def test_randomized_lasso_error_memory():
scaling = 0.3
selection_threshold = 0.5
tempdir = 5
clf = RandomizedLasso(verbose=False, alpha=[1, 0.8], random_state=42,
scaling=scaling,
selection_threshold=selection_threshold,
memory=tempdir)
assert_raises_regex(ValueError, "'memory' should either be a string or"
" a sklearn.externals.joblib.Memory instance",
clf.fit, X, y)
@ignore_warnings(category=DeprecationWarning)
def test_randomized_lasso():
# Check randomized lasso
scaling = 0.3
selection_threshold = 0.5
n_resampling = 20
# or with 1 alpha
clf = RandomizedLasso(verbose=False, alpha=1, random_state=42,
scaling=scaling, n_resampling=n_resampling,
selection_threshold=selection_threshold)
feature_scores = clf.fit(X, y).scores_
assert_array_equal(np.argsort(F)[-3:], np.argsort(feature_scores)[-3:])
# or with many alphas
clf = RandomizedLasso(verbose=False, alpha=[1, 0.8], random_state=42,
scaling=scaling, n_resampling=n_resampling,
selection_threshold=selection_threshold)
feature_scores = clf.fit(X, y).scores_
assert_equal(clf.all_scores_.shape, (X.shape[1], 2))
assert_array_equal(np.argsort(F)[-3:], np.argsort(feature_scores)[-3:])
# test caching
try:
tempdir = mkdtemp()
clf = RandomizedLasso(verbose=False, alpha=[1, 0.8], random_state=42,
scaling=scaling,
selection_threshold=selection_threshold,
memory=tempdir)
feature_scores = clf.fit(X, y).scores_
assert_equal(clf.all_scores_.shape, (X.shape[1], 2))
assert_array_equal(np.argsort(F)[-3:], np.argsort(feature_scores)[-3:])
finally:
shutil.rmtree(tempdir)
X_r = clf.transform(X)
X_full = clf.inverse_transform(X_r)
assert_equal(X_r.shape[1], np.sum(feature_scores > selection_threshold))
assert_equal(X_full.shape, X.shape)
clf = RandomizedLasso(verbose=False, alpha='aic', random_state=42,
scaling=scaling, n_resampling=100)
feature_scores = clf.fit(X, y).scores_
assert_allclose(feature_scores, [1., 1., 1., 0.225, 1.], rtol=0.2)
clf = RandomizedLasso(verbose=False, scaling=-0.1)
assert_raises(ValueError, clf.fit, X, y)
clf = RandomizedLasso(verbose=False, scaling=1.1)
assert_raises(ValueError, clf.fit, X, y)
def test_randomized_lasso_precompute():
# Check randomized lasso for different values of precompute
n_resampling = 20
alpha = 1
random_state = 42
G = np.dot(X.T, X)
clf = RandomizedLasso(alpha=alpha, random_state=random_state,
precompute=G, n_resampling=n_resampling)
feature_scores_1 = clf.fit(X, y).scores_
for precompute in [True, False, None, 'auto']:
clf = RandomizedLasso(alpha=alpha, random_state=random_state,
precompute=precompute, n_resampling=n_resampling)
feature_scores_2 = clf.fit(X, y).scores_
assert_array_equal(feature_scores_1, feature_scores_2)
@ignore_warnings(category=DeprecationWarning)
def test_randomized_logistic():
# Check randomized sparse logistic regression
iris = load_iris()
X = iris.data[:, [0, 2]]
y = iris.target
X = X[y != 2]
y = y[y != 2]
F, _ = f_classif(X, y)
scaling = 0.3
clf = RandomizedLogisticRegression(verbose=False, C=1., random_state=42,
scaling=scaling, n_resampling=50,
tol=1e-3)
X_orig = X.copy()
feature_scores = clf.fit(X, y).scores_
assert_array_equal(X, X_orig) # fit does not modify X
assert_array_equal(np.argsort(F), np.argsort(feature_scores))
clf = RandomizedLogisticRegression(verbose=False, C=[1., 0.5],
random_state=42, scaling=scaling,
n_resampling=50, tol=1e-3)
feature_scores = clf.fit(X, y).scores_
assert_array_equal(np.argsort(F), np.argsort(feature_scores))
clf = RandomizedLogisticRegression(verbose=False, C=[[1., 0.5]])
assert_raises(ValueError, clf.fit, X, y)
@ignore_warnings(category=DeprecationWarning)
def test_randomized_logistic_sparse():
# Check randomized sparse logistic regression on sparse data
iris = load_iris()
X = iris.data[:, [0, 2]]
y = iris.target
X = X[y != 2]
y = y[y != 2]
# center here because sparse matrices are usually not centered
# labels should not be centered
X, _, _, _, _ = _preprocess_data(X, y, True, True)
X_sp = sparse.csr_matrix(X)
F, _ = f_classif(X, y)
scaling = 0.3
clf = RandomizedLogisticRegression(verbose=False, C=1., random_state=42,
scaling=scaling, n_resampling=50,
tol=1e-3)
feature_scores = clf.fit(X, y).scores_
clf = RandomizedLogisticRegression(verbose=False, C=1., random_state=42,
scaling=scaling, n_resampling=50,
tol=1e-3)
feature_scores_sp = clf.fit(X_sp, y).scores_
assert_array_equal(feature_scores, feature_scores_sp)
def test_warning_raised():
scaling = 0.3
selection_threshold = 0.5
tempdir = 5
assert_warns_message(DeprecationWarning, "The function"
" lasso_stability_path is "
"deprecated in 0.19 and will be removed in 0.21.",
lasso_stability_path, X, y, scaling=scaling,
random_state=42, n_resampling=30)
assert_warns_message(DeprecationWarning, "Class RandomizedLasso is"
" deprecated; The class RandomizedLasso is "
"deprecated in 0.19 and will be removed in 0.21.",
RandomizedLasso, verbose=False, alpha=[1, 0.8],
random_state=42, scaling=scaling,
selection_threshold=selection_threshold,
memory=tempdir)
assert_warns_message(DeprecationWarning, "The class"
" RandomizedLogisticRegression is "
"deprecated in 0.19 and will be removed in 0.21.",
RandomizedLogisticRegression,
verbose=False, C=1., random_state=42,
scaling=scaling, n_resampling=50,
tol=1e-3)
| 8,448 | 37.756881 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_perceptron.py | import numpy as np
import scipy.sparse as sp
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_raises
from sklearn.utils import check_random_state
from sklearn.datasets import load_iris
from sklearn.linear_model import Perceptron
iris = load_iris()
random_state = check_random_state(12)
indices = np.arange(iris.data.shape[0])
random_state.shuffle(indices)
X = iris.data[indices]
y = iris.target[indices]
X_csr = sp.csr_matrix(X)
X_csr.sort_indices()
class MyPerceptron(object):
def __init__(self, n_iter=1):
self.n_iter = n_iter
def fit(self, X, y):
n_samples, n_features = X.shape
self.w = np.zeros(n_features, dtype=np.float64)
self.b = 0.0
for t in range(self.n_iter):
for i in range(n_samples):
if self.predict(X[i])[0] != y[i]:
self.w += y[i] * X[i]
self.b += y[i]
def project(self, X):
return np.dot(X, self.w) + self.b
def predict(self, X):
X = np.atleast_2d(X)
return np.sign(self.project(X))
def test_perceptron_accuracy():
for data in (X, X_csr):
clf = Perceptron(max_iter=100, tol=None, shuffle=False)
clf.fit(data, y)
score = clf.score(data, y)
assert_greater(score, 0.7)
def test_perceptron_correctness():
y_bin = y.copy()
y_bin[y != 1] = -1
clf1 = MyPerceptron(n_iter=2)
clf1.fit(X, y_bin)
clf2 = Perceptron(max_iter=2, shuffle=False, tol=None)
clf2.fit(X, y_bin)
assert_array_almost_equal(clf1.w, clf2.coef_.ravel())
def test_undefined_methods():
clf = Perceptron(max_iter=100)
for meth in ("predict_proba", "predict_log_proba"):
assert_raises(AttributeError, lambda x: getattr(clf, x), meth)
| 1,856 | 25.15493 | 70 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_passive_aggressive.py | from sklearn.utils.testing import assert_true
import numpy as np
import scipy.sparse as sp
from sklearn.utils.testing import assert_less
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_array_almost_equal, assert_array_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_raises
from sklearn.base import ClassifierMixin
from sklearn.utils import check_random_state
from sklearn.datasets import load_iris
from sklearn.linear_model import PassiveAggressiveClassifier
from sklearn.linear_model import PassiveAggressiveRegressor
iris = load_iris()
random_state = check_random_state(12)
indices = np.arange(iris.data.shape[0])
random_state.shuffle(indices)
X = iris.data[indices]
y = iris.target[indices]
X_csr = sp.csr_matrix(X)
class MyPassiveAggressive(ClassifierMixin):
def __init__(self, C=1.0, epsilon=0.01, loss="hinge",
fit_intercept=True, n_iter=1, random_state=None):
self.C = C
self.epsilon = epsilon
self.loss = loss
self.fit_intercept = fit_intercept
self.n_iter = n_iter
def fit(self, X, y):
n_samples, n_features = X.shape
self.w = np.zeros(n_features, dtype=np.float64)
self.b = 0.0
for t in range(self.n_iter):
for i in range(n_samples):
p = self.project(X[i])
if self.loss in ("hinge", "squared_hinge"):
loss = max(1 - y[i] * p, 0)
else:
loss = max(np.abs(p - y[i]) - self.epsilon, 0)
sqnorm = np.dot(X[i], X[i])
if self.loss in ("hinge", "epsilon_insensitive"):
step = min(self.C, loss / sqnorm)
elif self.loss in ("squared_hinge",
"squared_epsilon_insensitive"):
step = loss / (sqnorm + 1.0 / (2 * self.C))
if self.loss in ("hinge", "squared_hinge"):
step *= y[i]
else:
step *= np.sign(y[i] - p)
self.w += step * X[i]
if self.fit_intercept:
self.b += step
def project(self, X):
return np.dot(X, self.w) + self.b
def test_classifier_accuracy():
for data in (X, X_csr):
for fit_intercept in (True, False):
for average in (False, True):
clf = PassiveAggressiveClassifier(
C=1.0, max_iter=30, fit_intercept=fit_intercept,
random_state=0, average=average, tol=None)
clf.fit(data, y)
score = clf.score(data, y)
assert_greater(score, 0.79)
if average:
assert_true(hasattr(clf, 'average_coef_'))
assert_true(hasattr(clf, 'average_intercept_'))
assert_true(hasattr(clf, 'standard_intercept_'))
assert_true(hasattr(clf, 'standard_coef_'))
def test_classifier_partial_fit():
classes = np.unique(y)
for data in (X, X_csr):
for average in (False, True):
clf = PassiveAggressiveClassifier(
C=1.0, fit_intercept=True, random_state=0,
average=average, max_iter=5)
for t in range(30):
clf.partial_fit(data, y, classes)
score = clf.score(data, y)
assert_greater(score, 0.79)
if average:
assert_true(hasattr(clf, 'average_coef_'))
assert_true(hasattr(clf, 'average_intercept_'))
assert_true(hasattr(clf, 'standard_intercept_'))
assert_true(hasattr(clf, 'standard_coef_'))
def test_classifier_refit():
# Classifier can be retrained on different labels and features.
clf = PassiveAggressiveClassifier(max_iter=5).fit(X, y)
assert_array_equal(clf.classes_, np.unique(y))
clf.fit(X[:, :-1], iris.target_names[y])
assert_array_equal(clf.classes_, iris.target_names)
def test_classifier_correctness():
y_bin = y.copy()
y_bin[y != 1] = -1
for loss in ("hinge", "squared_hinge"):
clf1 = MyPassiveAggressive(
C=1.0, loss=loss, fit_intercept=True, n_iter=2)
clf1.fit(X, y_bin)
for data in (X, X_csr):
clf2 = PassiveAggressiveClassifier(
C=1.0, loss=loss, fit_intercept=True, max_iter=2,
shuffle=False, tol=None)
clf2.fit(data, y_bin)
assert_array_almost_equal(clf1.w, clf2.coef_.ravel(), decimal=2)
def test_classifier_undefined_methods():
clf = PassiveAggressiveClassifier(max_iter=100)
for meth in ("predict_proba", "predict_log_proba", "transform"):
assert_raises(AttributeError, lambda x: getattr(clf, x), meth)
def test_class_weights():
# Test class weights.
X2 = np.array([[-1.0, -1.0], [-1.0, 0], [-.8, -1.0],
[1.0, 1.0], [1.0, 0.0]])
y2 = [1, 1, 1, -1, -1]
clf = PassiveAggressiveClassifier(C=0.1, max_iter=100, class_weight=None,
random_state=100)
clf.fit(X2, y2)
assert_array_equal(clf.predict([[0.2, -1.0]]), np.array([1]))
# we give a small weights to class 1
clf = PassiveAggressiveClassifier(C=0.1, max_iter=100,
class_weight={1: 0.001},
random_state=100)
clf.fit(X2, y2)
# now the hyperplane should rotate clock-wise and
# the prediction on this point should shift
assert_array_equal(clf.predict([[0.2, -1.0]]), np.array([-1]))
def test_partial_fit_weight_class_balanced():
# partial_fit with class_weight='balanced' not supported
clf = PassiveAggressiveClassifier(class_weight="balanced", max_iter=100)
assert_raises(ValueError, clf.partial_fit, X, y, classes=np.unique(y))
def test_equal_class_weight():
X2 = [[1, 0], [1, 0], [0, 1], [0, 1]]
y2 = [0, 0, 1, 1]
clf = PassiveAggressiveClassifier(
C=0.1, max_iter=1000, tol=None, class_weight=None)
clf.fit(X2, y2)
# Already balanced, so "balanced" weights should have no effect
clf_balanced = PassiveAggressiveClassifier(
C=0.1, max_iter=1000, tol=None, class_weight="balanced")
clf_balanced.fit(X2, y2)
clf_weighted = PassiveAggressiveClassifier(
C=0.1, max_iter=1000, tol=None, class_weight={0: 0.5, 1: 0.5})
clf_weighted.fit(X2, y2)
# should be similar up to some epsilon due to learning rate schedule
assert_almost_equal(clf.coef_, clf_weighted.coef_, decimal=2)
assert_almost_equal(clf.coef_, clf_balanced.coef_, decimal=2)
def test_wrong_class_weight_label():
# ValueError due to wrong class_weight label.
X2 = np.array([[-1.0, -1.0], [-1.0, 0], [-.8, -1.0],
[1.0, 1.0], [1.0, 0.0]])
y2 = [1, 1, 1, -1, -1]
clf = PassiveAggressiveClassifier(class_weight={0: 0.5}, max_iter=100)
assert_raises(ValueError, clf.fit, X2, y2)
def test_wrong_class_weight_format():
# ValueError due to wrong class_weight argument type.
X2 = np.array([[-1.0, -1.0], [-1.0, 0], [-.8, -1.0],
[1.0, 1.0], [1.0, 0.0]])
y2 = [1, 1, 1, -1, -1]
clf = PassiveAggressiveClassifier(class_weight=[0.5], max_iter=100)
assert_raises(ValueError, clf.fit, X2, y2)
clf = PassiveAggressiveClassifier(class_weight="the larch", max_iter=100)
assert_raises(ValueError, clf.fit, X2, y2)
def test_regressor_mse():
y_bin = y.copy()
y_bin[y != 1] = -1
for data in (X, X_csr):
for fit_intercept in (True, False):
for average in (False, True):
reg = PassiveAggressiveRegressor(
C=1.0, fit_intercept=fit_intercept,
random_state=0, average=average, max_iter=5)
reg.fit(data, y_bin)
pred = reg.predict(data)
assert_less(np.mean((pred - y_bin) ** 2), 1.7)
if average:
assert_true(hasattr(reg, 'average_coef_'))
assert_true(hasattr(reg, 'average_intercept_'))
assert_true(hasattr(reg, 'standard_intercept_'))
assert_true(hasattr(reg, 'standard_coef_'))
def test_regressor_partial_fit():
y_bin = y.copy()
y_bin[y != 1] = -1
for data in (X, X_csr):
for average in (False, True):
reg = PassiveAggressiveRegressor(
C=1.0, fit_intercept=True, random_state=0,
average=average, max_iter=100)
for t in range(50):
reg.partial_fit(data, y_bin)
pred = reg.predict(data)
assert_less(np.mean((pred - y_bin) ** 2), 1.7)
if average:
assert_true(hasattr(reg, 'average_coef_'))
assert_true(hasattr(reg, 'average_intercept_'))
assert_true(hasattr(reg, 'standard_intercept_'))
assert_true(hasattr(reg, 'standard_coef_'))
def test_regressor_correctness():
y_bin = y.copy()
y_bin[y != 1] = -1
for loss in ("epsilon_insensitive", "squared_epsilon_insensitive"):
reg1 = MyPassiveAggressive(
C=1.0, loss=loss, fit_intercept=True, n_iter=2)
reg1.fit(X, y_bin)
for data in (X, X_csr):
reg2 = PassiveAggressiveRegressor(
C=1.0, tol=None, loss=loss, fit_intercept=True, max_iter=2,
shuffle=False)
reg2.fit(data, y_bin)
assert_array_almost_equal(reg1.w, reg2.coef_.ravel(), decimal=2)
def test_regressor_undefined_methods():
reg = PassiveAggressiveRegressor(max_iter=100)
for meth in ("transform",):
assert_raises(AttributeError, lambda x: getattr(reg, x), meth)
| 9,812 | 34.945055 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_huber.py | # Authors: Manoj Kumar [email protected]
# License: BSD 3 clause
import numpy as np
from scipy import optimize, sparse
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_false
from sklearn.datasets import make_regression
from sklearn.linear_model import (
HuberRegressor, LinearRegression, SGDRegressor, Ridge)
from sklearn.linear_model.huber import _huber_loss_and_gradient
def make_regression_with_outliers(n_samples=50, n_features=20):
rng = np.random.RandomState(0)
# Generate data with outliers by replacing 10% of the samples with noise.
X, y = make_regression(
n_samples=n_samples, n_features=n_features,
random_state=0, noise=0.05)
# Replace 10% of the sample with noise.
num_noise = int(0.1 * n_samples)
random_samples = rng.randint(0, n_samples, num_noise)
X[random_samples, :] = 2.0 * rng.normal(0, 1, (num_noise, X.shape[1]))
return X, y
def test_huber_equals_lr_for_high_epsilon():
# Test that Ridge matches LinearRegression for large epsilon
X, y = make_regression_with_outliers()
lr = LinearRegression(fit_intercept=True)
lr.fit(X, y)
huber = HuberRegressor(fit_intercept=True, epsilon=1e3, alpha=0.0)
huber.fit(X, y)
assert_almost_equal(huber.coef_, lr.coef_, 3)
assert_almost_equal(huber.intercept_, lr.intercept_, 2)
def test_huber_gradient():
# Test that the gradient calculated by _huber_loss_and_gradient is correct
rng = np.random.RandomState(1)
X, y = make_regression_with_outliers()
sample_weight = rng.randint(1, 3, (y.shape[0]))
loss_func = lambda x, *args: _huber_loss_and_gradient(x, *args)[0]
grad_func = lambda x, *args: _huber_loss_and_gradient(x, *args)[1]
# Check using optimize.check_grad that the gradients are equal.
for _ in range(5):
# Check for both fit_intercept and otherwise.
for n_features in [X.shape[1] + 1, X.shape[1] + 2]:
w = rng.randn(n_features)
w[-1] = np.abs(w[-1])
grad_same = optimize.check_grad(
loss_func, grad_func, w, X, y, 0.01, 0.1, sample_weight)
assert_almost_equal(grad_same, 1e-6, 4)
def test_huber_sample_weights():
# Test sample_weights implementation in HuberRegressor"""
X, y = make_regression_with_outliers()
huber = HuberRegressor(fit_intercept=True)
huber.fit(X, y)
huber_coef = huber.coef_
huber_intercept = huber.intercept_
# Rescale coefs before comparing with assert_array_almost_equal to make sure
# that the number of decimal places used is somewhat insensitive to the
# amplitude of the coefficients and therefore to the scale of the data
# and the regularization parameter
scale = max(np.mean(np.abs(huber.coef_)),
np.mean(np.abs(huber.intercept_)))
huber.fit(X, y, sample_weight=np.ones(y.shape[0]))
assert_array_almost_equal(huber.coef_ / scale, huber_coef / scale)
assert_array_almost_equal(huber.intercept_ / scale,
huber_intercept / scale)
X, y = make_regression_with_outliers(n_samples=5, n_features=20)
X_new = np.vstack((X, np.vstack((X[1], X[1], X[3]))))
y_new = np.concatenate((y, [y[1]], [y[1]], [y[3]]))
huber.fit(X_new, y_new)
huber_coef = huber.coef_
huber_intercept = huber.intercept_
sample_weight = np.ones(X.shape[0])
sample_weight[1] = 3
sample_weight[3] = 2
huber.fit(X, y, sample_weight=sample_weight)
assert_array_almost_equal(huber.coef_ / scale, huber_coef / scale)
assert_array_almost_equal(huber.intercept_ / scale,
huber_intercept / scale)
# Test sparse implementation with sample weights.
X_csr = sparse.csr_matrix(X)
huber_sparse = HuberRegressor(fit_intercept=True)
huber_sparse.fit(X_csr, y, sample_weight=sample_weight)
assert_array_almost_equal(huber_sparse.coef_ / scale,
huber_coef / scale)
def test_huber_sparse():
X, y = make_regression_with_outliers()
huber = HuberRegressor(fit_intercept=True, alpha=0.1)
huber.fit(X, y)
X_csr = sparse.csr_matrix(X)
huber_sparse = HuberRegressor(fit_intercept=True, alpha=0.1)
huber_sparse.fit(X_csr, y)
assert_array_almost_equal(huber_sparse.coef_, huber.coef_)
assert_array_equal(huber.outliers_, huber_sparse.outliers_)
def test_huber_scaling_invariant():
# Test that outliers filtering is scaling independent.
X, y = make_regression_with_outliers()
huber = HuberRegressor(fit_intercept=False, alpha=0.0, max_iter=100)
huber.fit(X, y)
n_outliers_mask_1 = huber.outliers_
assert_false(np.all(n_outliers_mask_1))
huber.fit(X, 2. * y)
n_outliers_mask_2 = huber.outliers_
assert_array_equal(n_outliers_mask_2, n_outliers_mask_1)
huber.fit(2. * X, 2. * y)
n_outliers_mask_3 = huber.outliers_
assert_array_equal(n_outliers_mask_3, n_outliers_mask_1)
def test_huber_and_sgd_same_results():
# Test they should converge to same coefficients for same parameters
X, y = make_regression_with_outliers(n_samples=10, n_features=2)
# Fit once to find out the scale parameter. Scale down X and y by scale
# so that the scale parameter is optimized to 1.0
huber = HuberRegressor(fit_intercept=False, alpha=0.0, max_iter=100,
epsilon=1.35)
huber.fit(X, y)
X_scale = X / huber.scale_
y_scale = y / huber.scale_
huber.fit(X_scale, y_scale)
assert_almost_equal(huber.scale_, 1.0, 3)
sgdreg = SGDRegressor(
alpha=0.0, loss="huber", shuffle=True, random_state=0, max_iter=10000,
fit_intercept=False, epsilon=1.35, tol=None)
sgdreg.fit(X_scale, y_scale)
assert_array_almost_equal(huber.coef_, sgdreg.coef_, 1)
def test_huber_warm_start():
X, y = make_regression_with_outliers()
huber_warm = HuberRegressor(
fit_intercept=True, alpha=1.0, max_iter=10000, warm_start=True, tol=1e-1)
huber_warm.fit(X, y)
huber_warm_coef = huber_warm.coef_.copy()
huber_warm.fit(X, y)
# SciPy performs the tol check after doing the coef updates, so
# these would be almost same but not equal.
assert_array_almost_equal(huber_warm.coef_, huber_warm_coef, 1)
# No n_iter_ in old SciPy (<=0.9)
if huber_warm.n_iter_ is not None:
assert_equal(0, huber_warm.n_iter_)
def test_huber_better_r2_score():
# Test that huber returns a better r2 score than non-outliers"""
X, y = make_regression_with_outliers()
huber = HuberRegressor(fit_intercept=True, alpha=0.01, max_iter=100)
huber.fit(X, y)
linear_loss = np.dot(X, huber.coef_) + huber.intercept_ - y
mask = np.abs(linear_loss) < huber.epsilon * huber.scale_
huber_score = huber.score(X[mask], y[mask])
huber_outlier_score = huber.score(X[~mask], y[~mask])
# The Ridge regressor should be influenced by the outliers and hence
# give a worse score on the non-outliers as compared to the huber regressor.
ridge = Ridge(fit_intercept=True, alpha=0.01)
ridge.fit(X, y)
ridge_score = ridge.score(X[mask], y[mask])
ridge_outlier_score = ridge.score(X[~mask], y[~mask])
assert_greater(huber_score, ridge_score)
# The huber model should also fit poorly on the outliers.
assert_greater(ridge_outlier_score, huber_outlier_score)
| 7,588 | 37.719388 | 81 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_least_angle.py | import warnings
import numpy as np
from scipy import linalg
from sklearn.model_selection import train_test_split
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import assert_false
from sklearn.utils.testing import assert_less
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import TempMemmap
from sklearn.exceptions import ConvergenceWarning
from sklearn import linear_model, datasets
from sklearn.linear_model.least_angle import _lars_path_residues
diabetes = datasets.load_diabetes()
X, y = diabetes.data, diabetes.target
# TODO: use another dataset that has multiple drops
def test_simple():
# Principle of Lars is to keep covariances tied and decreasing
# also test verbose output
from sklearn.externals.six.moves import cStringIO as StringIO
import sys
old_stdout = sys.stdout
try:
sys.stdout = StringIO()
alphas_, active, coef_path_ = linear_model.lars_path(
diabetes.data, diabetes.target, method="lar", verbose=10)
sys.stdout = old_stdout
for (i, coef_) in enumerate(coef_path_.T):
res = y - np.dot(X, coef_)
cov = np.dot(X.T, res)
C = np.max(abs(cov))
eps = 1e-3
ocur = len(cov[C - eps < abs(cov)])
if i < X.shape[1]:
assert_true(ocur == i + 1)
else:
# no more than max_pred variables can go into the active set
assert_true(ocur == X.shape[1])
finally:
sys.stdout = old_stdout
def test_simple_precomputed():
# The same, with precomputed Gram matrix
G = np.dot(diabetes.data.T, diabetes.data)
alphas_, active, coef_path_ = linear_model.lars_path(
diabetes.data, diabetes.target, Gram=G, method="lar")
for i, coef_ in enumerate(coef_path_.T):
res = y - np.dot(X, coef_)
cov = np.dot(X.T, res)
C = np.max(abs(cov))
eps = 1e-3
ocur = len(cov[C - eps < abs(cov)])
if i < X.shape[1]:
assert_true(ocur == i + 1)
else:
# no more than max_pred variables can go into the active set
assert_true(ocur == X.shape[1])
def test_all_precomputed():
# Test that lars_path with precomputed Gram and Xy gives the right answer
X, y = diabetes.data, diabetes.target
G = np.dot(X.T, X)
Xy = np.dot(X.T, y)
for method in 'lar', 'lasso':
output = linear_model.lars_path(X, y, method=method)
output_pre = linear_model.lars_path(X, y, Gram=G, Xy=Xy, method=method)
for expected, got in zip(output, output_pre):
assert_array_almost_equal(expected, got)
def test_lars_lstsq():
# Test that Lars gives least square solution at the end
# of the path
X1 = 3 * diabetes.data # use un-normalized dataset
clf = linear_model.LassoLars(alpha=0.)
clf.fit(X1, y)
coef_lstsq = np.linalg.lstsq(X1, y)[0]
assert_array_almost_equal(clf.coef_, coef_lstsq)
def test_lasso_gives_lstsq_solution():
# Test that Lars Lasso gives least square solution at the end
# of the path
alphas_, active, coef_path_ = linear_model.lars_path(X, y, method="lasso")
coef_lstsq = np.linalg.lstsq(X, y)[0]
assert_array_almost_equal(coef_lstsq, coef_path_[:, -1])
def test_collinearity():
# Check that lars_path is robust to collinearity in input
X = np.array([[3., 3., 1.],
[2., 2., 0.],
[1., 1., 0]])
y = np.array([1., 0., 0])
rng = np.random.RandomState(0)
f = ignore_warnings
_, _, coef_path_ = f(linear_model.lars_path)(X, y, alpha_min=0.01)
assert_true(not np.isnan(coef_path_).any())
residual = np.dot(X, coef_path_[:, -1]) - y
assert_less((residual ** 2).sum(), 1.) # just make sure it's bounded
n_samples = 10
X = rng.rand(n_samples, 5)
y = np.zeros(n_samples)
_, _, coef_path_ = linear_model.lars_path(X, y, Gram='auto', copy_X=False,
copy_Gram=False, alpha_min=0.,
method='lasso', verbose=0,
max_iter=500)
assert_array_almost_equal(coef_path_, np.zeros_like(coef_path_))
def test_no_path():
# Test that the ``return_path=False`` option returns the correct output
alphas_, active_, coef_path_ = linear_model.lars_path(
diabetes.data, diabetes.target, method="lar")
alpha_, active, coef = linear_model.lars_path(
diabetes.data, diabetes.target, method="lar", return_path=False)
assert_array_almost_equal(coef, coef_path_[:, -1])
assert_true(alpha_ == alphas_[-1])
def test_no_path_precomputed():
# Test that the ``return_path=False`` option with Gram remains correct
G = np.dot(diabetes.data.T, diabetes.data)
alphas_, active_, coef_path_ = linear_model.lars_path(
diabetes.data, diabetes.target, method="lar", Gram=G)
alpha_, active, coef = linear_model.lars_path(
diabetes.data, diabetes.target, method="lar", Gram=G,
return_path=False)
assert_array_almost_equal(coef, coef_path_[:, -1])
assert_true(alpha_ == alphas_[-1])
def test_no_path_all_precomputed():
# Test that the ``return_path=False`` option with Gram and Xy remains
# correct
X, y = 3 * diabetes.data, diabetes.target
G = np.dot(X.T, X)
Xy = np.dot(X.T, y)
alphas_, active_, coef_path_ = linear_model.lars_path(
X, y, method="lasso", Gram=G, Xy=Xy, alpha_min=0.9)
print("---")
alpha_, active, coef = linear_model.lars_path(
X, y, method="lasso", Gram=G, Xy=Xy, alpha_min=0.9, return_path=False)
assert_array_almost_equal(coef, coef_path_[:, -1])
assert_true(alpha_ == alphas_[-1])
def test_lars_precompute():
# Check for different values of precompute
X, y = diabetes.data, diabetes.target
G = np.dot(X.T, X)
for classifier in [linear_model.Lars, linear_model.LarsCV,
linear_model.LassoLarsIC]:
clf = classifier(precompute=G)
output_1 = ignore_warnings(clf.fit)(X, y).coef_
for precompute in [True, False, 'auto', None]:
clf = classifier(precompute=precompute)
output_2 = clf.fit(X, y).coef_
assert_array_almost_equal(output_1, output_2, decimal=8)
def test_singular_matrix():
# Test when input is a singular matrix
X1 = np.array([[1, 1.], [1., 1.]])
y1 = np.array([1, 1])
alphas, active, coef_path = linear_model.lars_path(X1, y1)
assert_array_almost_equal(coef_path.T, [[0, 0], [1, 0]])
def test_rank_deficient_design():
# consistency test that checks that LARS Lasso is handling rank
# deficient input data (with n_features < rank) in the same way
# as coordinate descent Lasso
y = [5, 0, 5]
for X in ([[5, 0],
[0, 5],
[10, 10]],
[[10, 10, 0],
[1e-32, 0, 0],
[0, 0, 1]],
):
# To be able to use the coefs to compute the objective function,
# we need to turn off normalization
lars = linear_model.LassoLars(.1, normalize=False)
coef_lars_ = lars.fit(X, y).coef_
obj_lars = (1. / (2. * 3.)
* linalg.norm(y - np.dot(X, coef_lars_)) ** 2
+ .1 * linalg.norm(coef_lars_, 1))
coord_descent = linear_model.Lasso(.1, tol=1e-6, normalize=False)
coef_cd_ = coord_descent.fit(X, y).coef_
obj_cd = ((1. / (2. * 3.)) * linalg.norm(y - np.dot(X, coef_cd_)) ** 2
+ .1 * linalg.norm(coef_cd_, 1))
assert_less(obj_lars, obj_cd * (1. + 1e-8))
def test_lasso_lars_vs_lasso_cd(verbose=False):
# Test that LassoLars and Lasso using coordinate descent give the
# same results.
X = 3 * diabetes.data
alphas, _, lasso_path = linear_model.lars_path(X, y, method='lasso')
lasso_cd = linear_model.Lasso(fit_intercept=False, tol=1e-8)
for c, a in zip(lasso_path.T, alphas):
if a == 0:
continue
lasso_cd.alpha = a
lasso_cd.fit(X, y)
error = linalg.norm(c - lasso_cd.coef_)
assert_less(error, 0.01)
# similar test, with the classifiers
for alpha in np.linspace(1e-2, 1 - 1e-2, 20):
clf1 = linear_model.LassoLars(alpha=alpha, normalize=False).fit(X, y)
clf2 = linear_model.Lasso(alpha=alpha, tol=1e-8,
normalize=False).fit(X, y)
err = linalg.norm(clf1.coef_ - clf2.coef_)
assert_less(err, 1e-3)
# same test, with normalized data
X = diabetes.data
alphas, _, lasso_path = linear_model.lars_path(X, y, method='lasso')
lasso_cd = linear_model.Lasso(fit_intercept=False, normalize=True,
tol=1e-8)
for c, a in zip(lasso_path.T, alphas):
if a == 0:
continue
lasso_cd.alpha = a
lasso_cd.fit(X, y)
error = linalg.norm(c - lasso_cd.coef_)
assert_less(error, 0.01)
def test_lasso_lars_vs_lasso_cd_early_stopping(verbose=False):
# Test that LassoLars and Lasso using coordinate descent give the
# same results when early stopping is used.
# (test : before, in the middle, and in the last part of the path)
alphas_min = [10, 0.9, 1e-4]
for alpha_min in alphas_min:
alphas, _, lasso_path = linear_model.lars_path(X, y, method='lasso',
alpha_min=alpha_min)
lasso_cd = linear_model.Lasso(fit_intercept=False, tol=1e-8)
lasso_cd.alpha = alphas[-1]
lasso_cd.fit(X, y)
error = linalg.norm(lasso_path[:, -1] - lasso_cd.coef_)
assert_less(error, 0.01)
# same test, with normalization
for alpha_min in alphas_min:
alphas, _, lasso_path = linear_model.lars_path(X, y, method='lasso',
alpha_min=alpha_min)
lasso_cd = linear_model.Lasso(fit_intercept=True, normalize=True,
tol=1e-8)
lasso_cd.alpha = alphas[-1]
lasso_cd.fit(X, y)
error = linalg.norm(lasso_path[:, -1] - lasso_cd.coef_)
assert_less(error, 0.01)
def test_lasso_lars_path_length():
# Test that the path length of the LassoLars is right
lasso = linear_model.LassoLars()
lasso.fit(X, y)
lasso2 = linear_model.LassoLars(alpha=lasso.alphas_[2])
lasso2.fit(X, y)
assert_array_almost_equal(lasso.alphas_[:3], lasso2.alphas_)
# Also check that the sequence of alphas is always decreasing
assert_true(np.all(np.diff(lasso.alphas_) < 0))
def test_lasso_lars_vs_lasso_cd_ill_conditioned():
# Test lasso lars on a very ill-conditioned design, and check that
# it does not blow up, and stays somewhat close to a solution given
# by the coordinate descent solver
# Also test that lasso_path (using lars_path output style) gives
# the same result as lars_path and previous lasso output style
# under these conditions.
rng = np.random.RandomState(42)
# Generate data
n, m = 70, 100
k = 5
X = rng.randn(n, m)
w = np.zeros((m, 1))
i = np.arange(0, m)
rng.shuffle(i)
supp = i[:k]
w[supp] = np.sign(rng.randn(k, 1)) * (rng.rand(k, 1) + 1)
y = np.dot(X, w)
sigma = 0.2
y += sigma * rng.rand(*y.shape)
y = y.squeeze()
lars_alphas, _, lars_coef = linear_model.lars_path(X, y, method='lasso')
_, lasso_coef2, _ = linear_model.lasso_path(X, y,
alphas=lars_alphas,
tol=1e-6,
fit_intercept=False)
assert_array_almost_equal(lars_coef, lasso_coef2, decimal=1)
def test_lasso_lars_vs_lasso_cd_ill_conditioned2():
# Create an ill-conditioned situation in which the LARS has to go
# far in the path to converge, and check that LARS and coordinate
# descent give the same answers
# Note it used to be the case that Lars had to use the drop for good
# strategy for this but this is no longer the case with the
# equality_tolerance checks
X = [[1e20, 1e20, 0],
[-1e-32, 0, 0],
[1, 1, 1]]
y = [10, 10, 1]
alpha = .0001
def objective_function(coef):
return (1. / (2. * len(X)) * linalg.norm(y - np.dot(X, coef)) ** 2
+ alpha * linalg.norm(coef, 1))
lars = linear_model.LassoLars(alpha=alpha, normalize=False)
assert_warns(ConvergenceWarning, lars.fit, X, y)
lars_coef_ = lars.coef_
lars_obj = objective_function(lars_coef_)
coord_descent = linear_model.Lasso(alpha=alpha, tol=1e-4, normalize=False)
cd_coef_ = coord_descent.fit(X, y).coef_
cd_obj = objective_function(cd_coef_)
assert_less(lars_obj, cd_obj * (1. + 1e-8))
def test_lars_add_features():
# assure that at least some features get added if necessary
# test for 6d2b4c
# Hilbert matrix
n = 5
H = 1. / (np.arange(1, n + 1) + np.arange(n)[:, np.newaxis])
clf = linear_model.Lars(fit_intercept=False).fit(
H, np.arange(n))
assert_true(np.all(np.isfinite(clf.coef_)))
def test_lars_n_nonzero_coefs(verbose=False):
lars = linear_model.Lars(n_nonzero_coefs=6, verbose=verbose)
lars.fit(X, y)
assert_equal(len(lars.coef_.nonzero()[0]), 6)
# The path should be of length 6 + 1 in a Lars going down to 6
# non-zero coefs
assert_equal(len(lars.alphas_), 7)
@ignore_warnings
def test_multitarget():
# Assure that estimators receiving multidimensional y do the right thing
X = diabetes.data
Y = np.vstack([diabetes.target, diabetes.target ** 2]).T
n_targets = Y.shape[1]
estimators = [
linear_model.LassoLars(),
linear_model.Lars(),
# regression test for gh-1615
linear_model.LassoLars(fit_intercept=False),
linear_model.Lars(fit_intercept=False),
]
for estimator in estimators:
estimator.fit(X, Y)
Y_pred = estimator.predict(X)
alphas, active, coef, path = (estimator.alphas_, estimator.active_,
estimator.coef_, estimator.coef_path_)
for k in range(n_targets):
estimator.fit(X, Y[:, k])
y_pred = estimator.predict(X)
assert_array_almost_equal(alphas[k], estimator.alphas_)
assert_array_almost_equal(active[k], estimator.active_)
assert_array_almost_equal(coef[k], estimator.coef_)
assert_array_almost_equal(path[k], estimator.coef_path_)
assert_array_almost_equal(Y_pred[:, k], y_pred)
def test_lars_cv():
# Test the LassoLarsCV object by checking that the optimal alpha
# increases as the number of samples increases.
# This property is not actually guaranteed in general and is just a
# property of the given dataset, with the given steps chosen.
old_alpha = 0
lars_cv = linear_model.LassoLarsCV()
for length in (400, 200, 100):
X = diabetes.data[:length]
y = diabetes.target[:length]
lars_cv.fit(X, y)
np.testing.assert_array_less(old_alpha, lars_cv.alpha_)
old_alpha = lars_cv.alpha_
assert_false(hasattr(lars_cv, 'n_nonzero_coefs'))
def test_lars_cv_max_iter():
with warnings.catch_warnings(record=True) as w:
X = diabetes.data
y = diabetes.target
rng = np.random.RandomState(42)
x = rng.randn(len(y))
X = np.c_[X, x, x] # add correlated features
lars_cv = linear_model.LassoLarsCV(max_iter=5)
lars_cv.fit(X, y)
assert_true(len(w) == 0)
def test_lasso_lars_ic():
# Test the LassoLarsIC object by checking that
# - some good features are selected.
# - alpha_bic > alpha_aic
# - n_nonzero_bic < n_nonzero_aic
lars_bic = linear_model.LassoLarsIC('bic')
lars_aic = linear_model.LassoLarsIC('aic')
rng = np.random.RandomState(42)
X = diabetes.data
y = diabetes.target
X = np.c_[X, rng.randn(X.shape[0], 5)] # add 5 bad features
lars_bic.fit(X, y)
lars_aic.fit(X, y)
nonzero_bic = np.where(lars_bic.coef_)[0]
nonzero_aic = np.where(lars_aic.coef_)[0]
assert_greater(lars_bic.alpha_, lars_aic.alpha_)
assert_less(len(nonzero_bic), len(nonzero_aic))
assert_less(np.max(nonzero_bic), diabetes.data.shape[1])
# test error on unknown IC
lars_broken = linear_model.LassoLarsIC('<unknown>')
assert_raises(ValueError, lars_broken.fit, X, y)
def test_lars_path_readonly_data():
# When using automated memory mapping on large input, the
# fold data is in read-only mode
# This is a non-regression test for:
# https://github.com/scikit-learn/scikit-learn/issues/4597
splitted_data = train_test_split(X, y, random_state=42)
with TempMemmap(splitted_data) as (X_train, X_test, y_train, y_test):
# The following should not fail despite copy=False
_lars_path_residues(X_train, y_train, X_test, y_test, copy=False)
def test_lars_path_positive_constraint():
# this is the main test for the positive parameter on the lars_path method
# the estimator classes just make use of this function
# we do the test on the diabetes dataset
# ensure that we get negative coefficients when positive=False
# and all positive when positive=True
# for method 'lar' (default) and lasso
for method in ['lar', 'lasso']:
alpha, active, coefs = \
linear_model.lars_path(diabetes['data'], diabetes['target'],
return_path=True, method=method,
positive=False)
assert_true(coefs.min() < 0)
alpha, active, coefs = \
linear_model.lars_path(diabetes['data'], diabetes['target'],
return_path=True, method=method,
positive=True)
assert_true(coefs.min() >= 0)
# now we gonna test the positive option for all estimator classes
default_parameter = {'fit_intercept': False}
estimator_parameter_map = {'Lars': {'n_nonzero_coefs': 5},
'LassoLars': {'alpha': 0.1},
'LarsCV': {},
'LassoLarsCV': {},
'LassoLarsIC': {}}
def test_estimatorclasses_positive_constraint():
# testing the transmissibility for the positive option of all estimator
# classes in this same function here
for estname in estimator_parameter_map:
params = default_parameter.copy()
params.update(estimator_parameter_map[estname])
estimator = getattr(linear_model, estname)(positive=False, **params)
estimator.fit(diabetes['data'], diabetes['target'])
assert_true(estimator.coef_.min() < 0)
estimator = getattr(linear_model, estname)(positive=True, **params)
estimator.fit(diabetes['data'], diabetes['target'])
assert_true(min(estimator.coef_) >= 0)
def test_lasso_lars_vs_lasso_cd_positive(verbose=False):
# Test that LassoLars and Lasso using coordinate descent give the
# same results when using the positive option
# This test is basically a copy of the above with additional positive
# option. However for the middle part, the comparison of coefficient values
# for a range of alphas, we had to make an adaptations. See below.
# not normalized data
X = 3 * diabetes.data
alphas, _, lasso_path = linear_model.lars_path(X, y, method='lasso',
positive=True)
lasso_cd = linear_model.Lasso(fit_intercept=False, tol=1e-8, positive=True)
for c, a in zip(lasso_path.T, alphas):
if a == 0:
continue
lasso_cd.alpha = a
lasso_cd.fit(X, y)
error = linalg.norm(c - lasso_cd.coef_)
assert_less(error, 0.01)
# The range of alphas chosen for coefficient comparison here is restricted
# as compared with the above test without the positive option. This is due
# to the circumstance that the Lars-Lasso algorithm does not converge to
# the least-squares-solution for small alphas, see 'Least Angle Regression'
# by Efron et al 2004. The coefficients are typically in congruence up to
# the smallest alpha reached by the Lars-Lasso algorithm and start to
# diverge thereafter. See
# https://gist.github.com/michigraber/7e7d7c75eca694c7a6ff
for alpha in np.linspace(6e-1, 1 - 1e-2, 20):
clf1 = linear_model.LassoLars(fit_intercept=False, alpha=alpha,
normalize=False, positive=True).fit(X, y)
clf2 = linear_model.Lasso(fit_intercept=False, alpha=alpha, tol=1e-8,
normalize=False, positive=True).fit(X, y)
err = linalg.norm(clf1.coef_ - clf2.coef_)
assert_less(err, 1e-3)
# normalized data
X = diabetes.data
alphas, _, lasso_path = linear_model.lars_path(X, y, method='lasso',
positive=True)
lasso_cd = linear_model.Lasso(fit_intercept=False, normalize=True,
tol=1e-8, positive=True)
for c, a in zip(lasso_path.T[:-1], alphas[:-1]): # don't include alpha=0
lasso_cd.alpha = a
lasso_cd.fit(X, y)
error = linalg.norm(c - lasso_cd.coef_)
assert_less(error, 0.01)
def test_lasso_lars_vs_R_implementation():
# Test that sklearn LassoLars implementation agrees with the LassoLars
# implementation available in R (lars library) under the following
# scenarios:
# 1) fit_intercept=False and normalize=False
# 2) fit_intercept=True and normalize=True
# Let's generate the data used in the bug report 7778
y = np.array([-6.45006793, -3.51251449, -8.52445396, 6.12277822,
-19.42109366])
x = np.array([[0.47299829, 0, 0, 0, 0],
[0.08239882, 0.85784863, 0, 0, 0],
[0.30114139, -0.07501577, 0.80895216, 0, 0],
[-0.01460346, -0.1015233, 0.0407278, 0.80338378, 0],
[-0.69363927, 0.06754067, 0.18064514, -0.0803561,
0.40427291]])
X = x.T
###########################################################################
# Scenario 1: Let's compare R vs sklearn when fit_intercept=False and
# normalize=False
###########################################################################
#
# The R result was obtained using the following code:
#
# library(lars)
# model_lasso_lars = lars(X, t(y), type="lasso", intercept=FALSE,
# trace=TRUE, normalize=FALSE)
# r = t(model_lasso_lars$beta)
#
r = np.array([[0, 0, 0, 0, 0, -79.810362809499026, -83.528788732782829,
-83.777653739190711, -83.784156932888934,
-84.033390591756657],
[0, 0, 0, 0, -0.476624256777266, 0, 0, 0, 0,
0.025219751009936],
[0, -3.577397088285891, -4.702795355871871,
-7.016748621359461, -7.614898471899412, -0.336938391359179,
0, 0, 0.001213370600853, 0.048162321585148],
[0, 0, 0, 2.231558436628169, 2.723267514525966,
2.811549786389614, 2.813766976061531, 2.817462468949557,
2.817368178703816, 2.816221090636795],
[0, 0, -1.218422599914637, -3.457726183014808,
-4.021304522060710, -45.827461592423745,
-47.776608869312305,
-47.911561610746404, -47.914845922736234,
-48.039562334265717]])
model_lasso_lars = linear_model.LassoLars(alpha=0, fit_intercept=False,
normalize=False)
model_lasso_lars.fit(X, y)
skl_betas = model_lasso_lars.coef_path_
assert_array_almost_equal(r, skl_betas, decimal=12)
###########################################################################
###########################################################################
# Scenario 2: Let's compare R vs sklearn when fit_intercept=True and
# normalize=True
#
# Note: When normalize is equal to True, R returns the coefficients in
# their original units, that is, they are rescaled back, whereas sklearn
# does not do that, therefore, we need to do this step before comparing
# their results.
###########################################################################
#
# The R result was obtained using the following code:
#
# library(lars)
# model_lasso_lars2 = lars(X, t(y), type="lasso", intercept=TRUE,
# trace=TRUE, normalize=TRUE)
# r2 = t(model_lasso_lars2$beta)
r2 = np.array([[0, 0, 0, 0, 0],
[0, 0, 0, 8.371887668009453, 19.463768371044026],
[0, 0, 0, 0, 9.901611055290553],
[0, 7.495923132833733, 9.245133544334507,
17.389369207545062, 26.971656815643499],
[0, 0, -1.569380717440311, -5.924804108067312,
-7.996385265061972]])
model_lasso_lars2 = linear_model.LassoLars(alpha=0, fit_intercept=True,
normalize=True)
model_lasso_lars2.fit(X, y)
skl_betas2 = model_lasso_lars2.coef_path_
# Let's rescale back the coefficients returned by sklearn before comparing
# against the R result (read the note above)
temp = X - np.mean(X, axis=0)
normx = np.sqrt(np.sum(temp ** 2, axis=0))
skl_betas2 /= normx[:, np.newaxis]
assert_array_almost_equal(r2, skl_betas2, decimal=12)
###########################################################################
| 26,139 | 38.131737 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_omp.py | # Author: Vlad Niculae
# License: BSD 3 clause
import numpy as np
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import ignore_warnings
from sklearn.linear_model import (orthogonal_mp, orthogonal_mp_gram,
OrthogonalMatchingPursuit,
OrthogonalMatchingPursuitCV,
LinearRegression)
from sklearn.utils import check_random_state
from sklearn.datasets import make_sparse_coded_signal
n_samples, n_features, n_nonzero_coefs, n_targets = 20, 30, 5, 3
y, X, gamma = make_sparse_coded_signal(n_targets, n_features, n_samples,
n_nonzero_coefs, random_state=0)
G, Xy = np.dot(X.T, X), np.dot(X.T, y)
# this makes X (n_samples, n_features)
# and y (n_samples, 3)
def test_correct_shapes():
assert_equal(orthogonal_mp(X, y[:, 0], n_nonzero_coefs=5).shape,
(n_features,))
assert_equal(orthogonal_mp(X, y, n_nonzero_coefs=5).shape,
(n_features, 3))
def test_correct_shapes_gram():
assert_equal(orthogonal_mp_gram(G, Xy[:, 0], n_nonzero_coefs=5).shape,
(n_features,))
assert_equal(orthogonal_mp_gram(G, Xy, n_nonzero_coefs=5).shape,
(n_features, 3))
def test_n_nonzero_coefs():
assert_true(np.count_nonzero(orthogonal_mp(X, y[:, 0],
n_nonzero_coefs=5)) <= 5)
assert_true(np.count_nonzero(orthogonal_mp(X, y[:, 0], n_nonzero_coefs=5,
precompute=True)) <= 5)
def test_tol():
tol = 0.5
gamma = orthogonal_mp(X, y[:, 0], tol=tol)
gamma_gram = orthogonal_mp(X, y[:, 0], tol=tol, precompute=True)
assert_true(np.sum((y[:, 0] - np.dot(X, gamma)) ** 2) <= tol)
assert_true(np.sum((y[:, 0] - np.dot(X, gamma_gram)) ** 2) <= tol)
def test_with_without_gram():
assert_array_almost_equal(
orthogonal_mp(X, y, n_nonzero_coefs=5),
orthogonal_mp(X, y, n_nonzero_coefs=5, precompute=True))
def test_with_without_gram_tol():
assert_array_almost_equal(
orthogonal_mp(X, y, tol=1.),
orthogonal_mp(X, y, tol=1., precompute=True))
def test_unreachable_accuracy():
assert_array_almost_equal(
orthogonal_mp(X, y, tol=0),
orthogonal_mp(X, y, n_nonzero_coefs=n_features))
assert_array_almost_equal(
assert_warns(RuntimeWarning, orthogonal_mp, X, y, tol=0,
precompute=True),
orthogonal_mp(X, y, precompute=True,
n_nonzero_coefs=n_features))
def test_bad_input():
assert_raises(ValueError, orthogonal_mp, X, y, tol=-1)
assert_raises(ValueError, orthogonal_mp, X, y, n_nonzero_coefs=-1)
assert_raises(ValueError, orthogonal_mp, X, y,
n_nonzero_coefs=n_features + 1)
assert_raises(ValueError, orthogonal_mp_gram, G, Xy, tol=-1)
assert_raises(ValueError, orthogonal_mp_gram, G, Xy, n_nonzero_coefs=-1)
assert_raises(ValueError, orthogonal_mp_gram, G, Xy,
n_nonzero_coefs=n_features + 1)
def test_perfect_signal_recovery():
idx, = gamma[:, 0].nonzero()
gamma_rec = orthogonal_mp(X, y[:, 0], 5)
gamma_gram = orthogonal_mp_gram(G, Xy[:, 0], 5)
assert_array_equal(idx, np.flatnonzero(gamma_rec))
assert_array_equal(idx, np.flatnonzero(gamma_gram))
assert_array_almost_equal(gamma[:, 0], gamma_rec, decimal=2)
assert_array_almost_equal(gamma[:, 0], gamma_gram, decimal=2)
def test_estimator():
omp = OrthogonalMatchingPursuit(n_nonzero_coefs=n_nonzero_coefs)
omp.fit(X, y[:, 0])
assert_equal(omp.coef_.shape, (n_features,))
assert_equal(omp.intercept_.shape, ())
assert_true(np.count_nonzero(omp.coef_) <= n_nonzero_coefs)
omp.fit(X, y)
assert_equal(omp.coef_.shape, (n_targets, n_features))
assert_equal(omp.intercept_.shape, (n_targets,))
assert_true(np.count_nonzero(omp.coef_) <= n_targets * n_nonzero_coefs)
omp.set_params(fit_intercept=False, normalize=False)
omp.fit(X, y[:, 0])
assert_equal(omp.coef_.shape, (n_features,))
assert_equal(omp.intercept_, 0)
assert_true(np.count_nonzero(omp.coef_) <= n_nonzero_coefs)
omp.fit(X, y)
assert_equal(omp.coef_.shape, (n_targets, n_features))
assert_equal(omp.intercept_, 0)
assert_true(np.count_nonzero(omp.coef_) <= n_targets * n_nonzero_coefs)
def test_identical_regressors():
newX = X.copy()
newX[:, 1] = newX[:, 0]
gamma = np.zeros(n_features)
gamma[0] = gamma[1] = 1.
newy = np.dot(newX, gamma)
assert_warns(RuntimeWarning, orthogonal_mp, newX, newy, 2)
def test_swapped_regressors():
gamma = np.zeros(n_features)
# X[:, 21] should be selected first, then X[:, 0] selected second,
# which will take X[:, 21]'s place in case the algorithm does
# column swapping for optimization (which is the case at the moment)
gamma[21] = 1.0
gamma[0] = 0.5
new_y = np.dot(X, gamma)
new_Xy = np.dot(X.T, new_y)
gamma_hat = orthogonal_mp(X, new_y, 2)
gamma_hat_gram = orthogonal_mp_gram(G, new_Xy, 2)
assert_array_equal(np.flatnonzero(gamma_hat), [0, 21])
assert_array_equal(np.flatnonzero(gamma_hat_gram), [0, 21])
def test_no_atoms():
y_empty = np.zeros_like(y)
Xy_empty = np.dot(X.T, y_empty)
gamma_empty = ignore_warnings(orthogonal_mp)(X, y_empty, 1)
gamma_empty_gram = ignore_warnings(orthogonal_mp)(G, Xy_empty, 1)
assert_equal(np.all(gamma_empty == 0), True)
assert_equal(np.all(gamma_empty_gram == 0), True)
def test_omp_path():
path = orthogonal_mp(X, y, n_nonzero_coefs=5, return_path=True)
last = orthogonal_mp(X, y, n_nonzero_coefs=5, return_path=False)
assert_equal(path.shape, (n_features, n_targets, 5))
assert_array_almost_equal(path[:, :, -1], last)
path = orthogonal_mp_gram(G, Xy, n_nonzero_coefs=5, return_path=True)
last = orthogonal_mp_gram(G, Xy, n_nonzero_coefs=5, return_path=False)
assert_equal(path.shape, (n_features, n_targets, 5))
assert_array_almost_equal(path[:, :, -1], last)
def test_omp_return_path_prop_with_gram():
path = orthogonal_mp(X, y, n_nonzero_coefs=5, return_path=True,
precompute=True)
last = orthogonal_mp(X, y, n_nonzero_coefs=5, return_path=False,
precompute=True)
assert_equal(path.shape, (n_features, n_targets, 5))
assert_array_almost_equal(path[:, :, -1], last)
def test_omp_cv():
y_ = y[:, 0]
gamma_ = gamma[:, 0]
ompcv = OrthogonalMatchingPursuitCV(normalize=True, fit_intercept=False,
max_iter=10, cv=5)
ompcv.fit(X, y_)
assert_equal(ompcv.n_nonzero_coefs_, n_nonzero_coefs)
assert_array_almost_equal(ompcv.coef_, gamma_)
omp = OrthogonalMatchingPursuit(normalize=True, fit_intercept=False,
n_nonzero_coefs=ompcv.n_nonzero_coefs_)
omp.fit(X, y_)
assert_array_almost_equal(ompcv.coef_, omp.coef_)
def test_omp_reaches_least_squares():
# Use small simple data; it's a sanity check but OMP can stop early
rng = check_random_state(0)
n_samples, n_features = (10, 8)
n_targets = 3
X = rng.randn(n_samples, n_features)
Y = rng.randn(n_samples, n_targets)
omp = OrthogonalMatchingPursuit(n_nonzero_coefs=n_features)
lstsq = LinearRegression()
omp.fit(X, Y)
lstsq.fit(X, Y)
assert_array_almost_equal(omp.coef_, lstsq.coef_)
| 7,752 | 36.274038 | 77 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_bayes.py | # Author: Alexandre Gramfort <[email protected]>
# Fabian Pedregosa <[email protected]>
#
# License: BSD 3 clause
import numpy as np
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import SkipTest
from sklearn.linear_model.bayes import BayesianRidge, ARDRegression
from sklearn.linear_model import Ridge
from sklearn import datasets
def test_bayesian_on_diabetes():
# Test BayesianRidge on diabetes
raise SkipTest("XFailed Test")
diabetes = datasets.load_diabetes()
X, y = diabetes.data, diabetes.target
clf = BayesianRidge(compute_score=True)
# Test with more samples than features
clf.fit(X, y)
# Test that scores are increasing at each iteration
assert_array_equal(np.diff(clf.scores_) > 0, True)
# Test with more features than samples
X = X[:5, :]
y = y[:5]
clf.fit(X, y)
# Test that scores are increasing at each iteration
assert_array_equal(np.diff(clf.scores_) > 0, True)
def test_bayesian_ridge_parameter():
# Test correctness of lambda_ and alpha_ parameters (GitHub issue #8224)
X = np.array([[1, 1], [3, 4], [5, 7], [4, 1], [2, 6], [3, 10], [3, 2]])
y = np.array([1, 2, 3, 2, 0, 4, 5]).T
# A Ridge regression model using an alpha value equal to the ratio of
# lambda_ and alpha_ from the Bayesian Ridge model must be identical
br_model = BayesianRidge(compute_score=True).fit(X, y)
rr_model = Ridge(alpha=br_model.lambda_ / br_model.alpha_).fit(X, y)
assert_array_almost_equal(rr_model.coef_, br_model.coef_)
assert_almost_equal(rr_model.intercept_, br_model.intercept_)
def test_toy_bayesian_ridge_object():
# Test BayesianRidge on toy
X = np.array([[1], [2], [6], [8], [10]])
Y = np.array([1, 2, 6, 8, 10])
clf = BayesianRidge(compute_score=True)
clf.fit(X, Y)
# Check that the model could approximately learn the identity function
test = [[1], [3], [4]]
assert_array_almost_equal(clf.predict(test), [1, 3, 4], 2)
def test_toy_ard_object():
# Test BayesianRegression ARD classifier
X = np.array([[1], [2], [3]])
Y = np.array([1, 2, 3])
clf = ARDRegression(compute_score=True)
clf.fit(X, Y)
# Check that the model could approximately learn the identity function
test = [[1], [3], [4]]
assert_array_almost_equal(clf.predict(test), [1, 3, 4], 2)
def test_return_std():
# Test return_std option for both Bayesian regressors
def f(X):
return np.dot(X, w) + b
def f_noise(X, noise_mult):
return f(X) + np.random.randn(X.shape[0]) * noise_mult
d = 5
n_train = 50
n_test = 10
w = np.array([1.0, 0.0, 1.0, -1.0, 0.0])
b = 1.0
X = np.random.random((n_train, d))
X_test = np.random.random((n_test, d))
for decimal, noise_mult in enumerate([1, 0.1, 0.01]):
y = f_noise(X, noise_mult)
m1 = BayesianRidge()
m1.fit(X, y)
y_mean1, y_std1 = m1.predict(X_test, return_std=True)
assert_array_almost_equal(y_std1, noise_mult, decimal=decimal)
m2 = ARDRegression()
m2.fit(X, y)
y_mean2, y_std2 = m2.predict(X_test, return_std=True)
assert_array_almost_equal(y_std2, noise_mult, decimal=decimal)
| 3,376 | 31.161905 | 76 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_coordinate_descent.py | # Authors: Olivier Grisel <[email protected]>
# Alexandre Gramfort <[email protected]>
# License: BSD 3 clause
import numpy as np
from scipy import interpolate, sparse
from copy import deepcopy
from sklearn.datasets import load_boston
from sklearn.exceptions import ConvergenceWarning
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_raises_regex
from sklearn.utils.testing import assert_raise_message
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import assert_warns_message
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import TempMemmap
from sklearn.linear_model.coordinate_descent import Lasso, \
LassoCV, ElasticNet, ElasticNetCV, MultiTaskLasso, MultiTaskElasticNet, \
MultiTaskElasticNetCV, MultiTaskLassoCV, lasso_path, enet_path
from sklearn.linear_model import LassoLarsCV, lars_path
from sklearn.utils import check_array
def test_lasso_zero():
# Check that the lasso can handle zero data without crashing
X = [[0], [0], [0]]
y = [0, 0, 0]
clf = Lasso(alpha=0.1).fit(X, y)
pred = clf.predict([[1], [2], [3]])
assert_array_almost_equal(clf.coef_, [0])
assert_array_almost_equal(pred, [0, 0, 0])
assert_almost_equal(clf.dual_gap_, 0)
def test_lasso_toy():
# Test Lasso on a toy example for various values of alpha.
# When validating this against glmnet notice that glmnet divides it
# against nobs.
X = [[-1], [0], [1]]
Y = [-1, 0, 1] # just a straight line
T = [[2], [3], [4]] # test sample
clf = Lasso(alpha=1e-8)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [1])
assert_array_almost_equal(pred, [2, 3, 4])
assert_almost_equal(clf.dual_gap_, 0)
clf = Lasso(alpha=0.1)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [.85])
assert_array_almost_equal(pred, [1.7, 2.55, 3.4])
assert_almost_equal(clf.dual_gap_, 0)
clf = Lasso(alpha=0.5)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [.25])
assert_array_almost_equal(pred, [0.5, 0.75, 1.])
assert_almost_equal(clf.dual_gap_, 0)
clf = Lasso(alpha=1)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [.0])
assert_array_almost_equal(pred, [0, 0, 0])
assert_almost_equal(clf.dual_gap_, 0)
def test_enet_toy():
# Test ElasticNet for various parameters of alpha and l1_ratio.
# Actually, the parameters alpha = 0 should not be allowed. However,
# we test it as a border case.
# ElasticNet is tested with and without precomputed Gram matrix
X = np.array([[-1.], [0.], [1.]])
Y = [-1, 0, 1] # just a straight line
T = [[2.], [3.], [4.]] # test sample
# this should be the same as lasso
clf = ElasticNet(alpha=1e-8, l1_ratio=1.0)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [1])
assert_array_almost_equal(pred, [2, 3, 4])
assert_almost_equal(clf.dual_gap_, 0)
clf = ElasticNet(alpha=0.5, l1_ratio=0.3, max_iter=100,
precompute=False)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [0.50819], decimal=3)
assert_array_almost_equal(pred, [1.0163, 1.5245, 2.0327], decimal=3)
assert_almost_equal(clf.dual_gap_, 0)
clf.set_params(max_iter=100, precompute=True)
clf.fit(X, Y) # with Gram
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [0.50819], decimal=3)
assert_array_almost_equal(pred, [1.0163, 1.5245, 2.0327], decimal=3)
assert_almost_equal(clf.dual_gap_, 0)
clf.set_params(max_iter=100, precompute=np.dot(X.T, X))
clf.fit(X, Y) # with Gram
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [0.50819], decimal=3)
assert_array_almost_equal(pred, [1.0163, 1.5245, 2.0327], decimal=3)
assert_almost_equal(clf.dual_gap_, 0)
clf = ElasticNet(alpha=0.5, l1_ratio=0.5)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [0.45454], 3)
assert_array_almost_equal(pred, [0.9090, 1.3636, 1.8181], 3)
assert_almost_equal(clf.dual_gap_, 0)
def build_dataset(n_samples=50, n_features=200, n_informative_features=10,
n_targets=1):
"""
build an ill-posed linear regression problem with many noisy features and
comparatively few samples
"""
random_state = np.random.RandomState(0)
if n_targets > 1:
w = random_state.randn(n_features, n_targets)
else:
w = random_state.randn(n_features)
w[n_informative_features:] = 0.0
X = random_state.randn(n_samples, n_features)
y = np.dot(X, w)
X_test = random_state.randn(n_samples, n_features)
y_test = np.dot(X_test, w)
return X, y, X_test, y_test
def test_lasso_cv():
X, y, X_test, y_test = build_dataset()
max_iter = 150
clf = LassoCV(n_alphas=10, eps=1e-3, max_iter=max_iter).fit(X, y)
assert_almost_equal(clf.alpha_, 0.056, 2)
clf = LassoCV(n_alphas=10, eps=1e-3, max_iter=max_iter, precompute=True)
clf.fit(X, y)
assert_almost_equal(clf.alpha_, 0.056, 2)
# Check that the lars and the coordinate descent implementation
# select a similar alpha
lars = LassoLarsCV(normalize=False, max_iter=30).fit(X, y)
# for this we check that they don't fall in the grid of
# clf.alphas further than 1
assert_true(np.abs(
np.searchsorted(clf.alphas_[::-1], lars.alpha_) -
np.searchsorted(clf.alphas_[::-1], clf.alpha_)) <= 1)
# check that they also give a similar MSE
mse_lars = interpolate.interp1d(lars.cv_alphas_, lars.mse_path_.T)
np.testing.assert_approx_equal(mse_lars(clf.alphas_[5]).mean(),
clf.mse_path_[5].mean(), significant=2)
# test set
assert_greater(clf.score(X_test, y_test), 0.99)
def test_lasso_cv_with_some_model_selection():
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.model_selection import StratifiedKFold
from sklearn import datasets
from sklearn.linear_model import LassoCV
diabetes = datasets.load_diabetes()
X = diabetes.data
y = diabetes.target
pipe = make_pipeline(
StandardScaler(),
LassoCV(cv=StratifiedKFold(n_splits=5))
)
pipe.fit(X, y)
def test_lasso_cv_positive_constraint():
X, y, X_test, y_test = build_dataset()
max_iter = 500
# Ensure the unconstrained fit has a negative coefficient
clf_unconstrained = LassoCV(n_alphas=3, eps=1e-1, max_iter=max_iter, cv=2,
n_jobs=1)
clf_unconstrained.fit(X, y)
assert_true(min(clf_unconstrained.coef_) < 0)
# On same data, constrained fit has non-negative coefficients
clf_constrained = LassoCV(n_alphas=3, eps=1e-1, max_iter=max_iter,
positive=True, cv=2, n_jobs=1)
clf_constrained.fit(X, y)
assert_true(min(clf_constrained.coef_) >= 0)
def test_lasso_path_return_models_vs_new_return_gives_same_coefficients():
# Test that lasso_path with lars_path style output gives the
# same result
# Some toy data
X = np.array([[1, 2, 3.1], [2.3, 5.4, 4.3]]).T
y = np.array([1, 2, 3.1])
alphas = [5., 1., .5]
# Use lars_path and lasso_path(new output) with 1D linear interpolation
# to compute the same path
alphas_lars, _, coef_path_lars = lars_path(X, y, method='lasso')
coef_path_cont_lars = interpolate.interp1d(alphas_lars[::-1],
coef_path_lars[:, ::-1])
alphas_lasso2, coef_path_lasso2, _ = lasso_path(X, y, alphas=alphas,
return_models=False)
coef_path_cont_lasso = interpolate.interp1d(alphas_lasso2[::-1],
coef_path_lasso2[:, ::-1])
assert_array_almost_equal(
coef_path_cont_lasso(alphas), coef_path_cont_lars(alphas),
decimal=1)
def test_enet_path():
# We use a large number of samples and of informative features so that
# the l1_ratio selected is more toward ridge than lasso
X, y, X_test, y_test = build_dataset(n_samples=200, n_features=100,
n_informative_features=100)
max_iter = 150
# Here we have a small number of iterations, and thus the
# ElasticNet might not converge. This is to speed up tests
clf = ElasticNetCV(alphas=[0.01, 0.05, 0.1], eps=2e-3,
l1_ratio=[0.5, 0.7], cv=3,
max_iter=max_iter)
ignore_warnings(clf.fit)(X, y)
# Well-conditioned settings, we should have selected our
# smallest penalty
assert_almost_equal(clf.alpha_, min(clf.alphas_))
# Non-sparse ground truth: we should have selected an elastic-net
# that is closer to ridge than to lasso
assert_equal(clf.l1_ratio_, min(clf.l1_ratio))
clf = ElasticNetCV(alphas=[0.01, 0.05, 0.1], eps=2e-3,
l1_ratio=[0.5, 0.7], cv=3,
max_iter=max_iter, precompute=True)
ignore_warnings(clf.fit)(X, y)
# Well-conditioned settings, we should have selected our
# smallest penalty
assert_almost_equal(clf.alpha_, min(clf.alphas_))
# Non-sparse ground truth: we should have selected an elastic-net
# that is closer to ridge than to lasso
assert_equal(clf.l1_ratio_, min(clf.l1_ratio))
# We are in well-conditioned settings with low noise: we should
# have a good test-set performance
assert_greater(clf.score(X_test, y_test), 0.99)
# Multi-output/target case
X, y, X_test, y_test = build_dataset(n_features=10, n_targets=3)
clf = MultiTaskElasticNetCV(n_alphas=5, eps=2e-3, l1_ratio=[0.5, 0.7],
cv=3, max_iter=max_iter)
ignore_warnings(clf.fit)(X, y)
# We are in well-conditioned settings with low noise: we should
# have a good test-set performance
assert_greater(clf.score(X_test, y_test), 0.99)
assert_equal(clf.coef_.shape, (3, 10))
# Mono-output should have same cross-validated alpha_ and l1_ratio_
# in both cases.
X, y, _, _ = build_dataset(n_features=10)
clf1 = ElasticNetCV(n_alphas=5, eps=2e-3, l1_ratio=[0.5, 0.7])
clf1.fit(X, y)
clf2 = MultiTaskElasticNetCV(n_alphas=5, eps=2e-3, l1_ratio=[0.5, 0.7])
clf2.fit(X, y[:, np.newaxis])
assert_almost_equal(clf1.l1_ratio_, clf2.l1_ratio_)
assert_almost_equal(clf1.alpha_, clf2.alpha_)
def test_path_parameters():
X, y, _, _ = build_dataset()
max_iter = 100
clf = ElasticNetCV(n_alphas=50, eps=1e-3, max_iter=max_iter,
l1_ratio=0.5, tol=1e-3)
clf.fit(X, y) # new params
assert_almost_equal(0.5, clf.l1_ratio)
assert_equal(50, clf.n_alphas)
assert_equal(50, len(clf.alphas_))
def test_warm_start():
X, y, _, _ = build_dataset()
clf = ElasticNet(alpha=0.1, max_iter=5, warm_start=True)
ignore_warnings(clf.fit)(X, y)
ignore_warnings(clf.fit)(X, y) # do a second round with 5 iterations
clf2 = ElasticNet(alpha=0.1, max_iter=10)
ignore_warnings(clf2.fit)(X, y)
assert_array_almost_equal(clf2.coef_, clf.coef_)
def test_lasso_alpha_warning():
X = [[-1], [0], [1]]
Y = [-1, 0, 1] # just a straight line
clf = Lasso(alpha=0)
assert_warns(UserWarning, clf.fit, X, Y)
def test_lasso_positive_constraint():
X = [[-1], [0], [1]]
y = [1, 0, -1] # just a straight line with negative slope
lasso = Lasso(alpha=0.1, max_iter=1000, positive=True)
lasso.fit(X, y)
assert_true(min(lasso.coef_) >= 0)
lasso = Lasso(alpha=0.1, max_iter=1000, precompute=True, positive=True)
lasso.fit(X, y)
assert_true(min(lasso.coef_) >= 0)
def test_enet_positive_constraint():
X = [[-1], [0], [1]]
y = [1, 0, -1] # just a straight line with negative slope
enet = ElasticNet(alpha=0.1, max_iter=1000, positive=True)
enet.fit(X, y)
assert_true(min(enet.coef_) >= 0)
def test_enet_cv_positive_constraint():
X, y, X_test, y_test = build_dataset()
max_iter = 500
# Ensure the unconstrained fit has a negative coefficient
enetcv_unconstrained = ElasticNetCV(n_alphas=3, eps=1e-1,
max_iter=max_iter,
cv=2, n_jobs=1)
enetcv_unconstrained.fit(X, y)
assert_true(min(enetcv_unconstrained.coef_) < 0)
# On same data, constrained fit has non-negative coefficients
enetcv_constrained = ElasticNetCV(n_alphas=3, eps=1e-1, max_iter=max_iter,
cv=2, positive=True, n_jobs=1)
enetcv_constrained.fit(X, y)
assert_true(min(enetcv_constrained.coef_) >= 0)
def test_uniform_targets():
enet = ElasticNetCV(fit_intercept=True, n_alphas=3)
m_enet = MultiTaskElasticNetCV(fit_intercept=True, n_alphas=3)
lasso = LassoCV(fit_intercept=True, n_alphas=3)
m_lasso = MultiTaskLassoCV(fit_intercept=True, n_alphas=3)
models_single_task = (enet, lasso)
models_multi_task = (m_enet, m_lasso)
rng = np.random.RandomState(0)
X_train = rng.random_sample(size=(10, 3))
X_test = rng.random_sample(size=(10, 3))
y1 = np.empty(10)
y2 = np.empty((10, 2))
for model in models_single_task:
for y_values in (0, 5):
y1.fill(y_values)
assert_array_equal(model.fit(X_train, y1).predict(X_test), y1)
assert_array_equal(model.alphas_, [np.finfo(float).resolution]*3)
for model in models_multi_task:
for y_values in (0, 5):
y2[:, 0].fill(y_values)
y2[:, 1].fill(2 * y_values)
assert_array_equal(model.fit(X_train, y2).predict(X_test), y2)
assert_array_equal(model.alphas_, [np.finfo(float).resolution]*3)
def test_multi_task_lasso_and_enet():
X, y, X_test, y_test = build_dataset()
Y = np.c_[y, y]
# Y_test = np.c_[y_test, y_test]
clf = MultiTaskLasso(alpha=1, tol=1e-8).fit(X, Y)
assert_true(0 < clf.dual_gap_ < 1e-5)
assert_array_almost_equal(clf.coef_[0], clf.coef_[1])
clf = MultiTaskElasticNet(alpha=1, tol=1e-8).fit(X, Y)
assert_true(0 < clf.dual_gap_ < 1e-5)
assert_array_almost_equal(clf.coef_[0], clf.coef_[1])
clf = MultiTaskElasticNet(alpha=1.0, tol=1e-8, max_iter=1)
assert_warns_message(ConvergenceWarning, 'did not converge', clf.fit, X, Y)
def test_lasso_readonly_data():
X = np.array([[-1], [0], [1]])
Y = np.array([-1, 0, 1]) # just a straight line
T = np.array([[2], [3], [4]]) # test sample
with TempMemmap((X, Y)) as (X, Y):
clf = Lasso(alpha=0.5)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [.25])
assert_array_almost_equal(pred, [0.5, 0.75, 1.])
assert_almost_equal(clf.dual_gap_, 0)
def test_multi_task_lasso_readonly_data():
X, y, X_test, y_test = build_dataset()
Y = np.c_[y, y]
with TempMemmap((X, Y)) as (X, Y):
Y = np.c_[y, y]
clf = MultiTaskLasso(alpha=1, tol=1e-8).fit(X, Y)
assert_true(0 < clf.dual_gap_ < 1e-5)
assert_array_almost_equal(clf.coef_[0], clf.coef_[1])
def test_enet_multitarget():
n_targets = 3
X, y, _, _ = build_dataset(n_samples=10, n_features=8,
n_informative_features=10, n_targets=n_targets)
estimator = ElasticNet(alpha=0.01, fit_intercept=True)
estimator.fit(X, y)
coef, intercept, dual_gap = (estimator.coef_, estimator.intercept_,
estimator.dual_gap_)
for k in range(n_targets):
estimator.fit(X, y[:, k])
assert_array_almost_equal(coef[k, :], estimator.coef_)
assert_array_almost_equal(intercept[k], estimator.intercept_)
assert_array_almost_equal(dual_gap[k], estimator.dual_gap_)
def test_multioutput_enetcv_error():
rng = np.random.RandomState(0)
X = rng.randn(10, 2)
y = rng.randn(10, 2)
clf = ElasticNetCV()
assert_raises(ValueError, clf.fit, X, y)
def test_multitask_enet_and_lasso_cv():
X, y, _, _ = build_dataset(n_features=50, n_targets=3)
clf = MultiTaskElasticNetCV().fit(X, y)
assert_almost_equal(clf.alpha_, 0.00556, 3)
clf = MultiTaskLassoCV().fit(X, y)
assert_almost_equal(clf.alpha_, 0.00278, 3)
X, y, _, _ = build_dataset(n_targets=3)
clf = MultiTaskElasticNetCV(n_alphas=10, eps=1e-3, max_iter=100,
l1_ratio=[0.3, 0.5], tol=1e-3)
clf.fit(X, y)
assert_equal(0.5, clf.l1_ratio_)
assert_equal((3, X.shape[1]), clf.coef_.shape)
assert_equal((3, ), clf.intercept_.shape)
assert_equal((2, 10, 3), clf.mse_path_.shape)
assert_equal((2, 10), clf.alphas_.shape)
X, y, _, _ = build_dataset(n_targets=3)
clf = MultiTaskLassoCV(n_alphas=10, eps=1e-3, max_iter=100, tol=1e-3)
clf.fit(X, y)
assert_equal((3, X.shape[1]), clf.coef_.shape)
assert_equal((3, ), clf.intercept_.shape)
assert_equal((10, 3), clf.mse_path_.shape)
assert_equal(10, len(clf.alphas_))
def test_1d_multioutput_enet_and_multitask_enet_cv():
X, y, _, _ = build_dataset(n_features=10)
y = y[:, np.newaxis]
clf = ElasticNetCV(n_alphas=5, eps=2e-3, l1_ratio=[0.5, 0.7])
clf.fit(X, y[:, 0])
clf1 = MultiTaskElasticNetCV(n_alphas=5, eps=2e-3, l1_ratio=[0.5, 0.7])
clf1.fit(X, y)
assert_almost_equal(clf.l1_ratio_, clf1.l1_ratio_)
assert_almost_equal(clf.alpha_, clf1.alpha_)
assert_almost_equal(clf.coef_, clf1.coef_[0])
assert_almost_equal(clf.intercept_, clf1.intercept_[0])
def test_1d_multioutput_lasso_and_multitask_lasso_cv():
X, y, _, _ = build_dataset(n_features=10)
y = y[:, np.newaxis]
clf = LassoCV(n_alphas=5, eps=2e-3)
clf.fit(X, y[:, 0])
clf1 = MultiTaskLassoCV(n_alphas=5, eps=2e-3)
clf1.fit(X, y)
assert_almost_equal(clf.alpha_, clf1.alpha_)
assert_almost_equal(clf.coef_, clf1.coef_[0])
assert_almost_equal(clf.intercept_, clf1.intercept_[0])
def test_sparse_input_dtype_enet_and_lassocv():
X, y, _, _ = build_dataset(n_features=10)
clf = ElasticNetCV(n_alphas=5)
clf.fit(sparse.csr_matrix(X), y)
clf1 = ElasticNetCV(n_alphas=5)
clf1.fit(sparse.csr_matrix(X, dtype=np.float32), y)
assert_almost_equal(clf.alpha_, clf1.alpha_, decimal=6)
assert_almost_equal(clf.coef_, clf1.coef_, decimal=6)
clf = LassoCV(n_alphas=5)
clf.fit(sparse.csr_matrix(X), y)
clf1 = LassoCV(n_alphas=5)
clf1.fit(sparse.csr_matrix(X, dtype=np.float32), y)
assert_almost_equal(clf.alpha_, clf1.alpha_, decimal=6)
assert_almost_equal(clf.coef_, clf1.coef_, decimal=6)
def test_precompute_invalid_argument():
X, y, _, _ = build_dataset()
for clf in [ElasticNetCV(precompute="invalid"),
LassoCV(precompute="invalid")]:
assert_raises_regex(ValueError, ".*should be.*True.*False.*auto.*"
"array-like.*Got 'invalid'", clf.fit, X, y)
# Precompute = 'auto' is not supported for ElasticNet
assert_raises_regex(ValueError, ".*should be.*True.*False.*array-like.*"
"Got 'auto'", ElasticNet(precompute='auto').fit, X, y)
def test_warm_start_convergence():
X, y, _, _ = build_dataset()
model = ElasticNet(alpha=1e-3, tol=1e-3).fit(X, y)
n_iter_reference = model.n_iter_
# This dataset is not trivial enough for the model to converge in one pass.
assert_greater(n_iter_reference, 2)
# Check that n_iter_ is invariant to multiple calls to fit
# when warm_start=False, all else being equal.
model.fit(X, y)
n_iter_cold_start = model.n_iter_
assert_equal(n_iter_cold_start, n_iter_reference)
# Fit the same model again, using a warm start: the optimizer just performs
# a single pass before checking that it has already converged
model.set_params(warm_start=True)
model.fit(X, y)
n_iter_warm_start = model.n_iter_
assert_equal(n_iter_warm_start, 1)
def test_warm_start_convergence_with_regularizer_decrement():
boston = load_boston()
X, y = boston.data, boston.target
# Train a model to converge on a lightly regularized problem
final_alpha = 1e-5
low_reg_model = ElasticNet(alpha=final_alpha).fit(X, y)
# Fitting a new model on a more regularized version of the same problem.
# Fitting with high regularization is easier it should converge faster
# in general.
high_reg_model = ElasticNet(alpha=final_alpha * 10).fit(X, y)
assert_greater(low_reg_model.n_iter_, high_reg_model.n_iter_)
# Fit the solution to the original, less regularized version of the
# problem but from the solution of the highly regularized variant of
# the problem as a better starting point. This should also converge
# faster than the original model that starts from zero.
warm_low_reg_model = deepcopy(high_reg_model)
warm_low_reg_model.set_params(warm_start=True, alpha=final_alpha)
warm_low_reg_model.fit(X, y)
assert_greater(low_reg_model.n_iter_, warm_low_reg_model.n_iter_)
def test_random_descent():
# Test that both random and cyclic selection give the same results.
# Ensure that the test models fully converge and check a wide
# range of conditions.
# This uses the coordinate descent algo using the gram trick.
X, y, _, _ = build_dataset(n_samples=50, n_features=20)
clf_cyclic = ElasticNet(selection='cyclic', tol=1e-8)
clf_cyclic.fit(X, y)
clf_random = ElasticNet(selection='random', tol=1e-8, random_state=42)
clf_random.fit(X, y)
assert_array_almost_equal(clf_cyclic.coef_, clf_random.coef_)
assert_almost_equal(clf_cyclic.intercept_, clf_random.intercept_)
# This uses the descent algo without the gram trick
clf_cyclic = ElasticNet(selection='cyclic', tol=1e-8)
clf_cyclic.fit(X.T, y[:20])
clf_random = ElasticNet(selection='random', tol=1e-8, random_state=42)
clf_random.fit(X.T, y[:20])
assert_array_almost_equal(clf_cyclic.coef_, clf_random.coef_)
assert_almost_equal(clf_cyclic.intercept_, clf_random.intercept_)
# Sparse Case
clf_cyclic = ElasticNet(selection='cyclic', tol=1e-8)
clf_cyclic.fit(sparse.csr_matrix(X), y)
clf_random = ElasticNet(selection='random', tol=1e-8, random_state=42)
clf_random.fit(sparse.csr_matrix(X), y)
assert_array_almost_equal(clf_cyclic.coef_, clf_random.coef_)
assert_almost_equal(clf_cyclic.intercept_, clf_random.intercept_)
# Multioutput case.
new_y = np.hstack((y[:, np.newaxis], y[:, np.newaxis]))
clf_cyclic = MultiTaskElasticNet(selection='cyclic', tol=1e-8)
clf_cyclic.fit(X, new_y)
clf_random = MultiTaskElasticNet(selection='random', tol=1e-8,
random_state=42)
clf_random.fit(X, new_y)
assert_array_almost_equal(clf_cyclic.coef_, clf_random.coef_)
assert_almost_equal(clf_cyclic.intercept_, clf_random.intercept_)
# Raise error when selection is not in cyclic or random.
clf_random = ElasticNet(selection='invalid')
assert_raises(ValueError, clf_random.fit, X, y)
def test_enet_path_positive():
# Test positive parameter
X, Y, _, _ = build_dataset(n_samples=50, n_features=50, n_targets=2)
# For mono output
# Test that the coefs returned by positive=True in enet_path are positive
for path in [enet_path, lasso_path]:
pos_path_coef = path(X, Y[:, 0], positive=True)[1]
assert_true(np.all(pos_path_coef >= 0))
# For multi output, positive parameter is not allowed
# Test that an error is raised
for path in [enet_path, lasso_path]:
assert_raises(ValueError, path, X, Y, positive=True)
def test_sparse_dense_descent_paths():
# Test that dense and sparse input give the same input for descent paths.
X, y, _, _ = build_dataset(n_samples=50, n_features=20)
csr = sparse.csr_matrix(X)
for path in [enet_path, lasso_path]:
_, coefs, _ = path(X, y, fit_intercept=False)
_, sparse_coefs, _ = path(csr, y, fit_intercept=False)
assert_array_almost_equal(coefs, sparse_coefs)
def test_check_input_false():
X, y, _, _ = build_dataset(n_samples=20, n_features=10)
X = check_array(X, order='F', dtype='float64')
y = check_array(X, order='F', dtype='float64')
clf = ElasticNet(selection='cyclic', tol=1e-8)
# Check that no error is raised if data is provided in the right format
clf.fit(X, y, check_input=False)
# With check_input=False, an exhaustive check is not made on y but its
# dtype is still cast in _preprocess_data to X's dtype. So the test should
# pass anyway
X = check_array(X, order='F', dtype='float32')
clf.fit(X, y, check_input=False)
# With no input checking, providing X in C order should result in false
# computation
X = check_array(X, order='C', dtype='float64')
assert_raises(ValueError, clf.fit, X, y, check_input=False)
def test_overrided_gram_matrix():
X, y, _, _ = build_dataset(n_samples=20, n_features=10)
Gram = X.T.dot(X)
clf = ElasticNet(selection='cyclic', tol=1e-8, precompute=Gram,
fit_intercept=True)
assert_warns_message(UserWarning,
"Gram matrix was provided but X was centered"
" to fit intercept, "
"or X was normalized : recomputing Gram matrix.",
clf.fit, X, y)
def test_lasso_non_float_y():
X = [[0, 0], [1, 1], [-1, -1]]
y = [0, 1, 2]
y_float = [0.0, 1.0, 2.0]
for model in [ElasticNet, Lasso]:
clf = model(fit_intercept=False)
clf.fit(X, y)
clf_float = model(fit_intercept=False)
clf_float.fit(X, y_float)
assert_array_equal(clf.coef_, clf_float.coef_)
def test_enet_float_precision():
# Generate dataset
X, y, X_test, y_test = build_dataset(n_samples=20, n_features=10)
# Here we have a small number of iterations, and thus the
# ElasticNet might not converge. This is to speed up tests
for normalize in [True, False]:
for fit_intercept in [True, False]:
coef = {}
intercept = {}
for dtype in [np.float64, np.float32]:
clf = ElasticNet(alpha=0.5, max_iter=100, precompute=False,
fit_intercept=fit_intercept,
normalize=normalize)
X = dtype(X)
y = dtype(y)
ignore_warnings(clf.fit)(X, y)
coef[('simple', dtype)] = clf.coef_
intercept[('simple', dtype)] = clf.intercept_
assert_equal(clf.coef_.dtype, dtype)
# test precompute Gram array
Gram = X.T.dot(X)
clf_precompute = ElasticNet(alpha=0.5, max_iter=100,
precompute=Gram,
fit_intercept=fit_intercept,
normalize=normalize)
ignore_warnings(clf_precompute.fit)(X, y)
assert_array_almost_equal(clf.coef_, clf_precompute.coef_)
assert_array_almost_equal(clf.intercept_,
clf_precompute.intercept_)
# test multi task enet
multi_y = np.hstack((y[:, np.newaxis], y[:, np.newaxis]))
clf_multioutput = MultiTaskElasticNet(
alpha=0.5, max_iter=100, fit_intercept=fit_intercept,
normalize=normalize)
clf_multioutput.fit(X, multi_y)
coef[('multi', dtype)] = clf_multioutput.coef_
intercept[('multi', dtype)] = clf_multioutput.intercept_
assert_equal(clf.coef_.dtype, dtype)
for v in ['simple', 'multi']:
assert_array_almost_equal(coef[(v, np.float32)],
coef[(v, np.float64)],
decimal=4)
assert_array_almost_equal(intercept[(v, np.float32)],
intercept[(v, np.float64)],
decimal=4)
def test_enet_l1_ratio():
# Test that an error message is raised if an estimator that
# uses _alpha_grid is called with l1_ratio=0
msg = ("Automatic alpha grid generation is not supported for l1_ratio=0. "
"Please supply a grid by providing your estimator with the "
"appropriate `alphas=` argument.")
X = np.array([[1, 2, 4, 5, 8], [3, 5, 7, 7, 8]]).T
y = np.array([12, 10, 11, 21, 5])
assert_raise_message(ValueError, msg, ElasticNetCV(
l1_ratio=0, random_state=42).fit, X, y)
assert_raise_message(ValueError, msg, MultiTaskElasticNetCV(
l1_ratio=0, random_state=42).fit, X, y[:, None])
# Test that l1_ratio=0 is allowed if we supply a grid manually
alphas = [0.1, 10]
estkwds = {'alphas': alphas, 'random_state': 42}
est_desired = ElasticNetCV(l1_ratio=0.00001, **estkwds)
est = ElasticNetCV(l1_ratio=0, **estkwds)
with ignore_warnings():
est_desired.fit(X, y)
est.fit(X, y)
assert_array_almost_equal(est.coef_, est_desired.coef_, decimal=5)
est_desired = MultiTaskElasticNetCV(l1_ratio=0.00001, **estkwds)
est = MultiTaskElasticNetCV(l1_ratio=0, **estkwds)
with ignore_warnings():
est.fit(X, y[:, None])
est_desired.fit(X, y[:, None])
assert_array_almost_equal(est.coef_, est_desired.coef_, decimal=5)
| 30,080 | 37.516005 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_sparse_coordinate_descent.py | import numpy as np
import scipy.sparse as sp
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_less
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import ignore_warnings
from sklearn.linear_model.coordinate_descent import (Lasso, ElasticNet,
LassoCV, ElasticNetCV)
def test_sparse_coef():
# Check that the sparse_coef property works
clf = ElasticNet()
clf.coef_ = [1, 2, 3]
assert_true(sp.isspmatrix(clf.sparse_coef_))
assert_equal(clf.sparse_coef_.toarray().tolist()[0], clf.coef_)
def test_normalize_option():
# Check that the normalize option in enet works
X = sp.csc_matrix([[-1], [0], [1]])
y = [-1, 0, 1]
clf_dense = ElasticNet(fit_intercept=True, normalize=True)
clf_sparse = ElasticNet(fit_intercept=True, normalize=True)
clf_dense.fit(X, y)
X = sp.csc_matrix(X)
clf_sparse.fit(X, y)
assert_almost_equal(clf_dense.dual_gap_, 0)
assert_array_almost_equal(clf_dense.coef_, clf_sparse.coef_)
def test_lasso_zero():
# Check that the sparse lasso can handle zero data without crashing
X = sp.csc_matrix((3, 1))
y = [0, 0, 0]
T = np.array([[1], [2], [3]])
clf = Lasso().fit(X, y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [0])
assert_array_almost_equal(pred, [0, 0, 0])
assert_almost_equal(clf.dual_gap_, 0)
def test_enet_toy_list_input():
# Test ElasticNet for various values of alpha and l1_ratio with list X
X = np.array([[-1], [0], [1]])
X = sp.csc_matrix(X)
Y = [-1, 0, 1] # just a straight line
T = np.array([[2], [3], [4]]) # test sample
# this should be the same as unregularized least squares
clf = ElasticNet(alpha=0, l1_ratio=1.0)
# catch warning about alpha=0.
# this is discouraged but should work.
ignore_warnings(clf.fit)(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [1])
assert_array_almost_equal(pred, [2, 3, 4])
assert_almost_equal(clf.dual_gap_, 0)
clf = ElasticNet(alpha=0.5, l1_ratio=0.3, max_iter=1000)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [0.50819], decimal=3)
assert_array_almost_equal(pred, [1.0163, 1.5245, 2.0327], decimal=3)
assert_almost_equal(clf.dual_gap_, 0)
clf = ElasticNet(alpha=0.5, l1_ratio=0.5)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [0.45454], 3)
assert_array_almost_equal(pred, [0.9090, 1.3636, 1.8181], 3)
assert_almost_equal(clf.dual_gap_, 0)
def test_enet_toy_explicit_sparse_input():
# Test ElasticNet for various values of alpha and l1_ratio with sparse X
f = ignore_warnings
# training samples
X = sp.lil_matrix((3, 1))
X[0, 0] = -1
# X[1, 0] = 0
X[2, 0] = 1
Y = [-1, 0, 1] # just a straight line (the identity function)
# test samples
T = sp.lil_matrix((3, 1))
T[0, 0] = 2
T[1, 0] = 3
T[2, 0] = 4
# this should be the same as lasso
clf = ElasticNet(alpha=0, l1_ratio=1.0)
f(clf.fit)(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [1])
assert_array_almost_equal(pred, [2, 3, 4])
assert_almost_equal(clf.dual_gap_, 0)
clf = ElasticNet(alpha=0.5, l1_ratio=0.3, max_iter=1000)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [0.50819], decimal=3)
assert_array_almost_equal(pred, [1.0163, 1.5245, 2.0327], decimal=3)
assert_almost_equal(clf.dual_gap_, 0)
clf = ElasticNet(alpha=0.5, l1_ratio=0.5)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [0.45454], 3)
assert_array_almost_equal(pred, [0.9090, 1.3636, 1.8181], 3)
assert_almost_equal(clf.dual_gap_, 0)
def make_sparse_data(n_samples=100, n_features=100, n_informative=10, seed=42,
positive=False, n_targets=1):
random_state = np.random.RandomState(seed)
# build an ill-posed linear regression problem with many noisy features and
# comparatively few samples
# generate a ground truth model
w = random_state.randn(n_features, n_targets)
w[n_informative:] = 0.0 # only the top features are impacting the model
if positive:
w = np.abs(w)
X = random_state.randn(n_samples, n_features)
rnd = random_state.uniform(size=(n_samples, n_features))
X[rnd > 0.5] = 0.0 # 50% of zeros in input signal
# generate training ground truth labels
y = np.dot(X, w)
X = sp.csc_matrix(X)
if n_targets == 1:
y = np.ravel(y)
return X, y
def _test_sparse_enet_not_as_toy_dataset(alpha, fit_intercept, positive):
n_samples, n_features, max_iter = 100, 100, 1000
n_informative = 10
X, y = make_sparse_data(n_samples, n_features, n_informative,
positive=positive)
X_train, X_test = X[n_samples // 2:], X[:n_samples // 2]
y_train, y_test = y[n_samples // 2:], y[:n_samples // 2]
s_clf = ElasticNet(alpha=alpha, l1_ratio=0.8, fit_intercept=fit_intercept,
max_iter=max_iter, tol=1e-7, positive=positive,
warm_start=True)
s_clf.fit(X_train, y_train)
assert_almost_equal(s_clf.dual_gap_, 0, 4)
assert_greater(s_clf.score(X_test, y_test), 0.85)
# check the convergence is the same as the dense version
d_clf = ElasticNet(alpha=alpha, l1_ratio=0.8, fit_intercept=fit_intercept,
max_iter=max_iter, tol=1e-7, positive=positive,
warm_start=True)
d_clf.fit(X_train.toarray(), y_train)
assert_almost_equal(d_clf.dual_gap_, 0, 4)
assert_greater(d_clf.score(X_test, y_test), 0.85)
assert_almost_equal(s_clf.coef_, d_clf.coef_, 5)
assert_almost_equal(s_clf.intercept_, d_clf.intercept_, 5)
# check that the coefs are sparse
assert_less(np.sum(s_clf.coef_ != 0.0), 2 * n_informative)
def test_sparse_enet_not_as_toy_dataset():
_test_sparse_enet_not_as_toy_dataset(alpha=0.1, fit_intercept=False,
positive=False)
_test_sparse_enet_not_as_toy_dataset(alpha=0.1, fit_intercept=True,
positive=False)
_test_sparse_enet_not_as_toy_dataset(alpha=1e-3, fit_intercept=False,
positive=True)
_test_sparse_enet_not_as_toy_dataset(alpha=1e-3, fit_intercept=True,
positive=True)
def test_sparse_lasso_not_as_toy_dataset():
n_samples = 100
max_iter = 1000
n_informative = 10
X, y = make_sparse_data(n_samples=n_samples, n_informative=n_informative)
X_train, X_test = X[n_samples // 2:], X[:n_samples // 2]
y_train, y_test = y[n_samples // 2:], y[:n_samples // 2]
s_clf = Lasso(alpha=0.1, fit_intercept=False, max_iter=max_iter, tol=1e-7)
s_clf.fit(X_train, y_train)
assert_almost_equal(s_clf.dual_gap_, 0, 4)
assert_greater(s_clf.score(X_test, y_test), 0.85)
# check the convergence is the same as the dense version
d_clf = Lasso(alpha=0.1, fit_intercept=False, max_iter=max_iter, tol=1e-7)
d_clf.fit(X_train.toarray(), y_train)
assert_almost_equal(d_clf.dual_gap_, 0, 4)
assert_greater(d_clf.score(X_test, y_test), 0.85)
# check that the coefs are sparse
assert_equal(np.sum(s_clf.coef_ != 0.0), n_informative)
def test_enet_multitarget():
n_targets = 3
X, y = make_sparse_data(n_targets=n_targets)
estimator = ElasticNet(alpha=0.01, fit_intercept=True, precompute=None)
# XXX: There is a bug when precompute is not None!
estimator.fit(X, y)
coef, intercept, dual_gap = (estimator.coef_,
estimator.intercept_,
estimator.dual_gap_)
for k in range(n_targets):
estimator.fit(X, y[:, k])
assert_array_almost_equal(coef[k, :], estimator.coef_)
assert_array_almost_equal(intercept[k], estimator.intercept_)
assert_array_almost_equal(dual_gap[k], estimator.dual_gap_)
def test_path_parameters():
X, y = make_sparse_data()
max_iter = 50
n_alphas = 10
clf = ElasticNetCV(n_alphas=n_alphas, eps=1e-3, max_iter=max_iter,
l1_ratio=0.5, fit_intercept=False)
ignore_warnings(clf.fit)(X, y) # new params
assert_almost_equal(0.5, clf.l1_ratio)
assert_equal(n_alphas, clf.n_alphas)
assert_equal(n_alphas, len(clf.alphas_))
sparse_mse_path = clf.mse_path_
ignore_warnings(clf.fit)(X.toarray(), y) # compare with dense data
assert_almost_equal(clf.mse_path_, sparse_mse_path)
def test_same_output_sparse_dense_lasso_and_enet_cv():
X, y = make_sparse_data(n_samples=40, n_features=10)
for normalize in [True, False]:
clfs = ElasticNetCV(max_iter=100, cv=5, normalize=normalize)
ignore_warnings(clfs.fit)(X, y)
clfd = ElasticNetCV(max_iter=100, cv=5, normalize=normalize)
ignore_warnings(clfd.fit)(X.toarray(), y)
assert_almost_equal(clfs.alpha_, clfd.alpha_, 7)
assert_almost_equal(clfs.intercept_, clfd.intercept_, 7)
assert_array_almost_equal(clfs.mse_path_, clfd.mse_path_)
assert_array_almost_equal(clfs.alphas_, clfd.alphas_)
clfs = LassoCV(max_iter=100, cv=4, normalize=normalize)
ignore_warnings(clfs.fit)(X, y)
clfd = LassoCV(max_iter=100, cv=4, normalize=normalize)
ignore_warnings(clfd.fit)(X.toarray(), y)
assert_almost_equal(clfs.alpha_, clfd.alpha_, 7)
assert_almost_equal(clfs.intercept_, clfd.intercept_, 7)
assert_array_almost_equal(clfs.mse_path_, clfd.mse_path_)
assert_array_almost_equal(clfs.alphas_, clfd.alphas_)
def test_same_multiple_output_sparse_dense():
for normalize in [True, False]:
l = ElasticNet(normalize=normalize)
X = [[0, 1, 2, 3, 4],
[0, 2, 5, 8, 11],
[9, 10, 11, 12, 13],
[10, 11, 12, 13, 14]]
y = [[1, 2, 3, 4, 5],
[1, 3, 6, 9, 12],
[10, 11, 12, 13, 14],
[11, 12, 13, 14, 15]]
ignore_warnings(l.fit)(X, y)
sample = np.array([1, 2, 3, 4, 5]).reshape(1, -1)
predict_dense = l.predict(sample)
l_sp = ElasticNet(normalize=normalize)
X_sp = sp.coo_matrix(X)
ignore_warnings(l_sp.fit)(X_sp, y)
sample_sparse = sp.coo_matrix(sample)
predict_sparse = l_sp.predict(sample_sparse)
assert_array_almost_equal(predict_sparse, predict_dense)
| 10,801 | 35.741497 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/__init__.py | 0 | 0 | 0 | py |
|
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_base.py | # Author: Alexandre Gramfort <[email protected]>
# Fabian Pedregosa <[email protected]>
#
# License: BSD 3 clause
import numpy as np
from scipy import sparse
from scipy import linalg
from itertools import product
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import ignore_warnings
from sklearn.linear_model.base import LinearRegression
from sklearn.linear_model.base import _preprocess_data
from sklearn.linear_model.base import sparse_center_data, center_data
from sklearn.linear_model.base import _rescale_data
from sklearn.utils import check_random_state
from sklearn.utils.testing import assert_greater
from sklearn.datasets.samples_generator import make_sparse_uncorrelated
from sklearn.datasets.samples_generator import make_regression
rng = np.random.RandomState(0)
def test_linear_regression():
# Test LinearRegression on a simple dataset.
# a simple dataset
X = [[1], [2]]
Y = [1, 2]
reg = LinearRegression()
reg.fit(X, Y)
assert_array_almost_equal(reg.coef_, [1])
assert_array_almost_equal(reg.intercept_, [0])
assert_array_almost_equal(reg.predict(X), [1, 2])
# test it also for degenerate input
X = [[1]]
Y = [0]
reg = LinearRegression()
reg.fit(X, Y)
assert_array_almost_equal(reg.coef_, [0])
assert_array_almost_equal(reg.intercept_, [0])
assert_array_almost_equal(reg.predict(X), [0])
def test_linear_regression_sample_weights():
# TODO: loop over sparse data as well
rng = np.random.RandomState(0)
# It would not work with under-determined systems
for n_samples, n_features in ((6, 5), ):
y = rng.randn(n_samples)
X = rng.randn(n_samples, n_features)
sample_weight = 1.0 + rng.rand(n_samples)
for intercept in (True, False):
# LinearRegression with explicit sample_weight
reg = LinearRegression(fit_intercept=intercept)
reg.fit(X, y, sample_weight=sample_weight)
coefs1 = reg.coef_
inter1 = reg.intercept_
assert_equal(reg.coef_.shape, (X.shape[1], )) # sanity checks
assert_greater(reg.score(X, y), 0.5)
# Closed form of the weighted least square
# theta = (X^T W X)^(-1) * X^T W y
W = np.diag(sample_weight)
if intercept is False:
X_aug = X
else:
dummy_column = np.ones(shape=(n_samples, 1))
X_aug = np.concatenate((dummy_column, X), axis=1)
coefs2 = linalg.solve(X_aug.T.dot(W).dot(X_aug),
X_aug.T.dot(W).dot(y))
if intercept is False:
assert_array_almost_equal(coefs1, coefs2)
else:
assert_array_almost_equal(coefs1, coefs2[1:])
assert_almost_equal(inter1, coefs2[0])
def test_raises_value_error_if_sample_weights_greater_than_1d():
# Sample weights must be either scalar or 1D
n_sampless = [2, 3]
n_featuress = [3, 2]
for n_samples, n_features in zip(n_sampless, n_featuress):
X = rng.randn(n_samples, n_features)
y = rng.randn(n_samples)
sample_weights_OK = rng.randn(n_samples) ** 2 + 1
sample_weights_OK_1 = 1.
sample_weights_OK_2 = 2.
reg = LinearRegression()
# make sure the "OK" sample weights actually work
reg.fit(X, y, sample_weights_OK)
reg.fit(X, y, sample_weights_OK_1)
reg.fit(X, y, sample_weights_OK_2)
def test_fit_intercept():
# Test assertions on betas shape.
X2 = np.array([[0.38349978, 0.61650022],
[0.58853682, 0.41146318]])
X3 = np.array([[0.27677969, 0.70693172, 0.01628859],
[0.08385139, 0.20692515, 0.70922346]])
y = np.array([1, 1])
lr2_without_intercept = LinearRegression(fit_intercept=False).fit(X2, y)
lr2_with_intercept = LinearRegression(fit_intercept=True).fit(X2, y)
lr3_without_intercept = LinearRegression(fit_intercept=False).fit(X3, y)
lr3_with_intercept = LinearRegression(fit_intercept=True).fit(X3, y)
assert_equal(lr2_with_intercept.coef_.shape,
lr2_without_intercept.coef_.shape)
assert_equal(lr3_with_intercept.coef_.shape,
lr3_without_intercept.coef_.shape)
assert_equal(lr2_without_intercept.coef_.ndim,
lr3_without_intercept.coef_.ndim)
def test_linear_regression_sparse(random_state=0):
# Test that linear regression also works with sparse data
random_state = check_random_state(random_state)
for i in range(10):
n = 100
X = sparse.eye(n, n)
beta = random_state.rand(n)
y = X * beta[:, np.newaxis]
ols = LinearRegression()
ols.fit(X, y.ravel())
assert_array_almost_equal(beta, ols.coef_ + ols.intercept_)
assert_array_almost_equal(ols.predict(X) - y.ravel(), 0)
def test_linear_regression_multiple_outcome(random_state=0):
# Test multiple-outcome linear regressions
X, y = make_regression(random_state=random_state)
Y = np.vstack((y, y)).T
n_features = X.shape[1]
reg = LinearRegression(fit_intercept=True)
reg.fit((X), Y)
assert_equal(reg.coef_.shape, (2, n_features))
Y_pred = reg.predict(X)
reg.fit(X, y)
y_pred = reg.predict(X)
assert_array_almost_equal(np.vstack((y_pred, y_pred)).T, Y_pred, decimal=3)
def test_linear_regression_sparse_multiple_outcome(random_state=0):
# Test multiple-outcome linear regressions with sparse data
random_state = check_random_state(random_state)
X, y = make_sparse_uncorrelated(random_state=random_state)
X = sparse.coo_matrix(X)
Y = np.vstack((y, y)).T
n_features = X.shape[1]
ols = LinearRegression()
ols.fit(X, Y)
assert_equal(ols.coef_.shape, (2, n_features))
Y_pred = ols.predict(X)
ols.fit(X, y.ravel())
y_pred = ols.predict(X)
assert_array_almost_equal(np.vstack((y_pred, y_pred)).T, Y_pred, decimal=3)
def test_preprocess_data():
n_samples = 200
n_features = 2
X = rng.rand(n_samples, n_features)
y = rng.rand(n_samples)
expected_X_mean = np.mean(X, axis=0)
expected_X_norm = np.std(X, axis=0) * np.sqrt(X.shape[0])
expected_y_mean = np.mean(y, axis=0)
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=False, normalize=False)
assert_array_almost_equal(X_mean, np.zeros(n_features))
assert_array_almost_equal(y_mean, 0)
assert_array_almost_equal(X_norm, np.ones(n_features))
assert_array_almost_equal(Xt, X)
assert_array_almost_equal(yt, y)
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=True, normalize=False)
assert_array_almost_equal(X_mean, expected_X_mean)
assert_array_almost_equal(y_mean, expected_y_mean)
assert_array_almost_equal(X_norm, np.ones(n_features))
assert_array_almost_equal(Xt, X - expected_X_mean)
assert_array_almost_equal(yt, y - expected_y_mean)
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=True, normalize=True)
assert_array_almost_equal(X_mean, expected_X_mean)
assert_array_almost_equal(y_mean, expected_y_mean)
assert_array_almost_equal(X_norm, expected_X_norm)
assert_array_almost_equal(Xt, (X - expected_X_mean) / expected_X_norm)
assert_array_almost_equal(yt, y - expected_y_mean)
def test_preprocess_data_multioutput():
n_samples = 200
n_features = 3
n_outputs = 2
X = rng.rand(n_samples, n_features)
y = rng.rand(n_samples, n_outputs)
expected_y_mean = np.mean(y, axis=0)
args = [X, sparse.csc_matrix(X)]
for X in args:
_, yt, _, y_mean, _ = _preprocess_data(X, y, fit_intercept=False,
normalize=False)
assert_array_almost_equal(y_mean, np.zeros(n_outputs))
assert_array_almost_equal(yt, y)
_, yt, _, y_mean, _ = _preprocess_data(X, y, fit_intercept=True,
normalize=False)
assert_array_almost_equal(y_mean, expected_y_mean)
assert_array_almost_equal(yt, y - y_mean)
_, yt, _, y_mean, _ = _preprocess_data(X, y, fit_intercept=True,
normalize=True)
assert_array_almost_equal(y_mean, expected_y_mean)
assert_array_almost_equal(yt, y - y_mean)
def test_preprocess_data_weighted():
n_samples = 200
n_features = 2
X = rng.rand(n_samples, n_features)
y = rng.rand(n_samples)
sample_weight = rng.rand(n_samples)
expected_X_mean = np.average(X, axis=0, weights=sample_weight)
expected_y_mean = np.average(y, axis=0, weights=sample_weight)
# XXX: if normalize=True, should we expect a weighted standard deviation?
# Currently not weighted, but calculated with respect to weighted mean
expected_X_norm = (np.sqrt(X.shape[0]) *
np.mean((X - expected_X_mean) ** 2, axis=0) ** .5)
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=True, normalize=False,
sample_weight=sample_weight)
assert_array_almost_equal(X_mean, expected_X_mean)
assert_array_almost_equal(y_mean, expected_y_mean)
assert_array_almost_equal(X_norm, np.ones(n_features))
assert_array_almost_equal(Xt, X - expected_X_mean)
assert_array_almost_equal(yt, y - expected_y_mean)
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=True, normalize=True,
sample_weight=sample_weight)
assert_array_almost_equal(X_mean, expected_X_mean)
assert_array_almost_equal(y_mean, expected_y_mean)
assert_array_almost_equal(X_norm, expected_X_norm)
assert_array_almost_equal(Xt, (X - expected_X_mean) / expected_X_norm)
assert_array_almost_equal(yt, y - expected_y_mean)
def test_sparse_preprocess_data_with_return_mean():
n_samples = 200
n_features = 2
# random_state not supported yet in sparse.rand
X = sparse.rand(n_samples, n_features, density=.5) # , random_state=rng
X = X.tolil()
y = rng.rand(n_samples)
XA = X.toarray()
expected_X_norm = np.std(XA, axis=0) * np.sqrt(X.shape[0])
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=False, normalize=False,
return_mean=True)
assert_array_almost_equal(X_mean, np.zeros(n_features))
assert_array_almost_equal(y_mean, 0)
assert_array_almost_equal(X_norm, np.ones(n_features))
assert_array_almost_equal(Xt.A, XA)
assert_array_almost_equal(yt, y)
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=True, normalize=False,
return_mean=True)
assert_array_almost_equal(X_mean, np.mean(XA, axis=0))
assert_array_almost_equal(y_mean, np.mean(y, axis=0))
assert_array_almost_equal(X_norm, np.ones(n_features))
assert_array_almost_equal(Xt.A, XA)
assert_array_almost_equal(yt, y - np.mean(y, axis=0))
Xt, yt, X_mean, y_mean, X_norm = \
_preprocess_data(X, y, fit_intercept=True, normalize=True,
return_mean=True)
assert_array_almost_equal(X_mean, np.mean(XA, axis=0))
assert_array_almost_equal(y_mean, np.mean(y, axis=0))
assert_array_almost_equal(X_norm, expected_X_norm)
assert_array_almost_equal(Xt.A, XA / expected_X_norm)
assert_array_almost_equal(yt, y - np.mean(y, axis=0))
def test_csr_preprocess_data():
# Test output format of _preprocess_data, when input is csr
X, y = make_regression()
X[X < 2.5] = 0.0
csr = sparse.csr_matrix(X)
csr_, y, _, _, _ = _preprocess_data(csr, y, True)
assert_equal(csr_.getformat(), 'csr')
def test_dtype_preprocess_data():
n_samples = 200
n_features = 2
X = rng.rand(n_samples, n_features)
y = rng.rand(n_samples)
X_32 = np.asarray(X, dtype=np.float32)
y_32 = np.asarray(y, dtype=np.float32)
X_64 = np.asarray(X, dtype=np.float64)
y_64 = np.asarray(y, dtype=np.float64)
for fit_intercept in [True, False]:
for normalize in [True, False]:
Xt_32, yt_32, X_mean_32, y_mean_32, X_norm_32 = _preprocess_data(
X_32, y_32, fit_intercept=fit_intercept, normalize=normalize,
return_mean=True)
Xt_64, yt_64, X_mean_64, y_mean_64, X_norm_64 = _preprocess_data(
X_64, y_64, fit_intercept=fit_intercept, normalize=normalize,
return_mean=True)
Xt_3264, yt_3264, X_mean_3264, y_mean_3264, X_norm_3264 = (
_preprocess_data(X_32, y_64, fit_intercept=fit_intercept,
normalize=normalize, return_mean=True))
Xt_6432, yt_6432, X_mean_6432, y_mean_6432, X_norm_6432 = (
_preprocess_data(X_64, y_32, fit_intercept=fit_intercept,
normalize=normalize, return_mean=True))
assert_equal(Xt_32.dtype, np.float32)
assert_equal(yt_32.dtype, np.float32)
assert_equal(X_mean_32.dtype, np.float32)
assert_equal(y_mean_32.dtype, np.float32)
assert_equal(X_norm_32.dtype, np.float32)
assert_equal(Xt_64.dtype, np.float64)
assert_equal(yt_64.dtype, np.float64)
assert_equal(X_mean_64.dtype, np.float64)
assert_equal(y_mean_64.dtype, np.float64)
assert_equal(X_norm_64.dtype, np.float64)
assert_equal(Xt_3264.dtype, np.float32)
assert_equal(yt_3264.dtype, np.float32)
assert_equal(X_mean_3264.dtype, np.float32)
assert_equal(y_mean_3264.dtype, np.float32)
assert_equal(X_norm_3264.dtype, np.float32)
assert_equal(Xt_6432.dtype, np.float64)
assert_equal(yt_6432.dtype, np.float64)
assert_equal(X_mean_6432.dtype, np.float64)
assert_equal(y_mean_6432.dtype, np.float64)
assert_equal(X_norm_6432.dtype, np.float64)
assert_equal(X_32.dtype, np.float32)
assert_equal(y_32.dtype, np.float32)
assert_equal(X_64.dtype, np.float64)
assert_equal(y_64.dtype, np.float64)
assert_array_almost_equal(Xt_32, Xt_64)
assert_array_almost_equal(yt_32, yt_64)
assert_array_almost_equal(X_mean_32, X_mean_64)
assert_array_almost_equal(y_mean_32, y_mean_64)
assert_array_almost_equal(X_norm_32, X_norm_64)
def test_rescale_data():
n_samples = 200
n_features = 2
sample_weight = 1.0 + rng.rand(n_samples)
X = rng.rand(n_samples, n_features)
y = rng.rand(n_samples)
rescaled_X, rescaled_y = _rescale_data(X, y, sample_weight)
rescaled_X2 = X * np.sqrt(sample_weight)[:, np.newaxis]
rescaled_y2 = y * np.sqrt(sample_weight)
assert_array_almost_equal(rescaled_X, rescaled_X2)
assert_array_almost_equal(rescaled_y, rescaled_y2)
@ignore_warnings # all deprecation warnings
def test_deprecation_center_data():
n_samples = 200
n_features = 2
w = 1.0 + rng.rand(n_samples)
X = rng.rand(n_samples, n_features)
y = rng.rand(n_samples)
param_grid = product([True, False], [True, False], [True, False],
[None, w])
for (fit_intercept, normalize, copy, sample_weight) in param_grid:
XX = X.copy() # such that we can try copy=False as well
X1, y1, X1_mean, X1_var, y1_mean = \
center_data(XX, y, fit_intercept=fit_intercept,
normalize=normalize, copy=copy,
sample_weight=sample_weight)
XX = X.copy()
X2, y2, X2_mean, X2_var, y2_mean = \
_preprocess_data(XX, y, fit_intercept=fit_intercept,
normalize=normalize, copy=copy,
sample_weight=sample_weight)
assert_array_almost_equal(X1, X2)
assert_array_almost_equal(y1, y2)
assert_array_almost_equal(X1_mean, X2_mean)
assert_array_almost_equal(X1_var, X2_var)
assert_array_almost_equal(y1_mean, y2_mean)
# Sparse cases
X = sparse.csr_matrix(X)
for (fit_intercept, normalize, copy, sample_weight) in param_grid:
X1, y1, X1_mean, X1_var, y1_mean = \
center_data(X, y, fit_intercept=fit_intercept, normalize=normalize,
copy=copy, sample_weight=sample_weight)
X2, y2, X2_mean, X2_var, y2_mean = \
_preprocess_data(X, y, fit_intercept=fit_intercept,
normalize=normalize, copy=copy,
sample_weight=sample_weight, return_mean=False)
assert_array_almost_equal(X1.toarray(), X2.toarray())
assert_array_almost_equal(y1, y2)
assert_array_almost_equal(X1_mean, X2_mean)
assert_array_almost_equal(X1_var, X2_var)
assert_array_almost_equal(y1_mean, y2_mean)
for (fit_intercept, normalize) in product([True, False], [True, False]):
X1, y1, X1_mean, X1_var, y1_mean = \
sparse_center_data(X, y, fit_intercept=fit_intercept,
normalize=normalize)
X2, y2, X2_mean, X2_var, y2_mean = \
_preprocess_data(X, y, fit_intercept=fit_intercept,
normalize=normalize, return_mean=True)
assert_array_almost_equal(X1.toarray(), X2.toarray())
assert_array_almost_equal(y1, y2)
assert_array_almost_equal(X1_mean, X2_mean)
assert_array_almost_equal(X1_var, X2_var)
assert_array_almost_equal(y1_mean, y2_mean)
| 17,862 | 36.527311 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/linear_model/tests/test_ridge.py | import numpy as np
import scipy.sparse as sp
from scipy import linalg
from itertools import product
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_raise_message
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.testing import assert_warns
from sklearn import datasets
from sklearn.metrics import mean_squared_error
from sklearn.metrics import make_scorer
from sklearn.metrics import get_scorer
from sklearn.linear_model.base import LinearRegression
from sklearn.linear_model.ridge import ridge_regression
from sklearn.linear_model.ridge import Ridge
from sklearn.linear_model.ridge import _RidgeGCV
from sklearn.linear_model.ridge import RidgeCV
from sklearn.linear_model.ridge import RidgeClassifier
from sklearn.linear_model.ridge import RidgeClassifierCV
from sklearn.linear_model.ridge import _solve_cholesky
from sklearn.linear_model.ridge import _solve_cholesky_kernel
from sklearn.datasets import make_regression
from sklearn.model_selection import GridSearchCV
from sklearn.model_selection import KFold
from sklearn.utils import check_random_state
from sklearn.datasets import make_multilabel_classification
diabetes = datasets.load_diabetes()
X_diabetes, y_diabetes = diabetes.data, diabetes.target
ind = np.arange(X_diabetes.shape[0])
rng = np.random.RandomState(0)
rng.shuffle(ind)
ind = ind[:200]
X_diabetes, y_diabetes = X_diabetes[ind], y_diabetes[ind]
iris = datasets.load_iris()
X_iris = sp.csr_matrix(iris.data)
y_iris = iris.target
DENSE_FILTER = lambda X: X
SPARSE_FILTER = lambda X: sp.csr_matrix(X)
def test_ridge():
# Ridge regression convergence test using score
# TODO: for this test to be robust, we should use a dataset instead
# of np.random.
rng = np.random.RandomState(0)
alpha = 1.0
for solver in ("svd", "sparse_cg", "cholesky", "lsqr", "sag"):
# With more samples than features
n_samples, n_features = 6, 5
y = rng.randn(n_samples)
X = rng.randn(n_samples, n_features)
ridge = Ridge(alpha=alpha, solver=solver)
ridge.fit(X, y)
assert_equal(ridge.coef_.shape, (X.shape[1], ))
assert_greater(ridge.score(X, y), 0.47)
if solver in ("cholesky", "sag"):
# Currently the only solvers to support sample_weight.
ridge.fit(X, y, sample_weight=np.ones(n_samples))
assert_greater(ridge.score(X, y), 0.47)
# With more features than samples
n_samples, n_features = 5, 10
y = rng.randn(n_samples)
X = rng.randn(n_samples, n_features)
ridge = Ridge(alpha=alpha, solver=solver)
ridge.fit(X, y)
assert_greater(ridge.score(X, y), .9)
if solver in ("cholesky", "sag"):
# Currently the only solvers to support sample_weight.
ridge.fit(X, y, sample_weight=np.ones(n_samples))
assert_greater(ridge.score(X, y), 0.9)
def test_primal_dual_relationship():
y = y_diabetes.reshape(-1, 1)
coef = _solve_cholesky(X_diabetes, y, alpha=[1e-2])
K = np.dot(X_diabetes, X_diabetes.T)
dual_coef = _solve_cholesky_kernel(K, y, alpha=[1e-2])
coef2 = np.dot(X_diabetes.T, dual_coef).T
assert_array_almost_equal(coef, coef2)
def test_ridge_singular():
# test on a singular matrix
rng = np.random.RandomState(0)
n_samples, n_features = 6, 6
y = rng.randn(n_samples // 2)
y = np.concatenate((y, y))
X = rng.randn(n_samples // 2, n_features)
X = np.concatenate((X, X), axis=0)
ridge = Ridge(alpha=0)
ridge.fit(X, y)
assert_greater(ridge.score(X, y), 0.9)
def test_ridge_regression_sample_weights():
rng = np.random.RandomState(0)
for solver in ("cholesky", ):
for n_samples, n_features in ((6, 5), (5, 10)):
for alpha in (1.0, 1e-2):
y = rng.randn(n_samples)
X = rng.randn(n_samples, n_features)
sample_weight = 1.0 + rng.rand(n_samples)
coefs = ridge_regression(X, y,
alpha=alpha,
sample_weight=sample_weight,
solver=solver)
# Sample weight can be implemented via a simple rescaling
# for the square loss.
coefs2 = ridge_regression(
X * np.sqrt(sample_weight)[:, np.newaxis],
y * np.sqrt(sample_weight),
alpha=alpha, solver=solver)
assert_array_almost_equal(coefs, coefs2)
def test_ridge_sample_weights():
# TODO: loop over sparse data as well
rng = np.random.RandomState(0)
param_grid = product((1.0, 1e-2), (True, False),
('svd', 'cholesky', 'lsqr', 'sparse_cg'))
for n_samples, n_features in ((6, 5), (5, 10)):
y = rng.randn(n_samples)
X = rng.randn(n_samples, n_features)
sample_weight = 1.0 + rng.rand(n_samples)
for (alpha, intercept, solver) in param_grid:
# Ridge with explicit sample_weight
est = Ridge(alpha=alpha, fit_intercept=intercept, solver=solver)
est.fit(X, y, sample_weight=sample_weight)
coefs = est.coef_
inter = est.intercept_
# Closed form of the weighted regularized least square
# theta = (X^T W X + alpha I)^(-1) * X^T W y
W = np.diag(sample_weight)
if intercept is False:
X_aug = X
I = np.eye(n_features)
else:
dummy_column = np.ones(shape=(n_samples, 1))
X_aug = np.concatenate((dummy_column, X), axis=1)
I = np.eye(n_features + 1)
I[0, 0] = 0
cf_coefs = linalg.solve(X_aug.T.dot(W).dot(X_aug) + alpha * I,
X_aug.T.dot(W).dot(y))
if intercept is False:
assert_array_almost_equal(coefs, cf_coefs)
else:
assert_array_almost_equal(coefs, cf_coefs[1:])
assert_almost_equal(inter, cf_coefs[0])
def test_ridge_shapes():
# Test shape of coef_ and intercept_
rng = np.random.RandomState(0)
n_samples, n_features = 5, 10
X = rng.randn(n_samples, n_features)
y = rng.randn(n_samples)
Y1 = y[:, np.newaxis]
Y = np.c_[y, 1 + y]
ridge = Ridge()
ridge.fit(X, y)
assert_equal(ridge.coef_.shape, (n_features,))
assert_equal(ridge.intercept_.shape, ())
ridge.fit(X, Y1)
assert_equal(ridge.coef_.shape, (1, n_features))
assert_equal(ridge.intercept_.shape, (1, ))
ridge.fit(X, Y)
assert_equal(ridge.coef_.shape, (2, n_features))
assert_equal(ridge.intercept_.shape, (2, ))
def test_ridge_intercept():
# Test intercept with multiple targets GH issue #708
rng = np.random.RandomState(0)
n_samples, n_features = 5, 10
X = rng.randn(n_samples, n_features)
y = rng.randn(n_samples)
Y = np.c_[y, 1. + y]
ridge = Ridge()
ridge.fit(X, y)
intercept = ridge.intercept_
ridge.fit(X, Y)
assert_almost_equal(ridge.intercept_[0], intercept)
assert_almost_equal(ridge.intercept_[1], intercept + 1.)
def test_toy_ridge_object():
# Test BayesianRegression ridge classifier
# TODO: test also n_samples > n_features
X = np.array([[1], [2]])
Y = np.array([1, 2])
reg = Ridge(alpha=0.0)
reg.fit(X, Y)
X_test = [[1], [2], [3], [4]]
assert_almost_equal(reg.predict(X_test), [1., 2, 3, 4])
assert_equal(len(reg.coef_.shape), 1)
assert_equal(type(reg.intercept_), np.float64)
Y = np.vstack((Y, Y)).T
reg.fit(X, Y)
X_test = [[1], [2], [3], [4]]
assert_equal(len(reg.coef_.shape), 2)
assert_equal(type(reg.intercept_), np.ndarray)
def test_ridge_vs_lstsq():
# On alpha=0., Ridge and OLS yield the same solution.
rng = np.random.RandomState(0)
# we need more samples than features
n_samples, n_features = 5, 4
y = rng.randn(n_samples)
X = rng.randn(n_samples, n_features)
ridge = Ridge(alpha=0., fit_intercept=False)
ols = LinearRegression(fit_intercept=False)
ridge.fit(X, y)
ols.fit(X, y)
assert_almost_equal(ridge.coef_, ols.coef_)
ridge.fit(X, y)
ols.fit(X, y)
assert_almost_equal(ridge.coef_, ols.coef_)
def test_ridge_individual_penalties():
# Tests the ridge object using individual penalties
rng = np.random.RandomState(42)
n_samples, n_features, n_targets = 20, 10, 5
X = rng.randn(n_samples, n_features)
y = rng.randn(n_samples, n_targets)
penalties = np.arange(n_targets)
coef_cholesky = np.array([
Ridge(alpha=alpha, solver="cholesky").fit(X, target).coef_
for alpha, target in zip(penalties, y.T)])
coefs_indiv_pen = [
Ridge(alpha=penalties, solver=solver, tol=1e-8).fit(X, y).coef_
for solver in ['svd', 'sparse_cg', 'lsqr', 'cholesky', 'sag', 'saga']]
for coef_indiv_pen in coefs_indiv_pen:
assert_array_almost_equal(coef_cholesky, coef_indiv_pen)
# Test error is raised when number of targets and penalties do not match.
ridge = Ridge(alpha=penalties[:-1])
assert_raises(ValueError, ridge.fit, X, y)
def _test_ridge_loo(filter_):
# test that can work with both dense or sparse matrices
n_samples = X_diabetes.shape[0]
ret = []
fit_intercept = filter_ == DENSE_FILTER
if fit_intercept:
X_diabetes_ = X_diabetes - X_diabetes.mean(0)
else:
X_diabetes_ = X_diabetes
ridge_gcv = _RidgeGCV(fit_intercept=fit_intercept)
ridge = Ridge(alpha=1.0, fit_intercept=fit_intercept)
# because fit_intercept is applied
# generalized cross-validation (efficient leave-one-out)
decomp = ridge_gcv._pre_compute(X_diabetes_, y_diabetes, fit_intercept)
errors, c = ridge_gcv._errors(1.0, y_diabetes, *decomp)
values, c = ridge_gcv._values(1.0, y_diabetes, *decomp)
# brute-force leave-one-out: remove one example at a time
errors2 = []
values2 = []
for i in range(n_samples):
sel = np.arange(n_samples) != i
X_new = X_diabetes_[sel]
y_new = y_diabetes[sel]
ridge.fit(X_new, y_new)
value = ridge.predict([X_diabetes_[i]])[0]
error = (y_diabetes[i] - value) ** 2
errors2.append(error)
values2.append(value)
# check that efficient and brute-force LOO give same results
assert_almost_equal(errors, errors2)
assert_almost_equal(values, values2)
# generalized cross-validation (efficient leave-one-out,
# SVD variation)
decomp = ridge_gcv._pre_compute_svd(X_diabetes_, y_diabetes, fit_intercept)
errors3, c = ridge_gcv._errors_svd(ridge.alpha, y_diabetes, *decomp)
values3, c = ridge_gcv._values_svd(ridge.alpha, y_diabetes, *decomp)
# check that efficient and SVD efficient LOO give same results
assert_almost_equal(errors, errors3)
assert_almost_equal(values, values3)
# check best alpha
ridge_gcv.fit(filter_(X_diabetes), y_diabetes)
alpha_ = ridge_gcv.alpha_
ret.append(alpha_)
# check that we get same best alpha with custom loss_func
f = ignore_warnings
scoring = make_scorer(mean_squared_error, greater_is_better=False)
ridge_gcv2 = RidgeCV(fit_intercept=False, scoring=scoring)
f(ridge_gcv2.fit)(filter_(X_diabetes), y_diabetes)
assert_equal(ridge_gcv2.alpha_, alpha_)
# check that we get same best alpha with custom score_func
func = lambda x, y: -mean_squared_error(x, y)
scoring = make_scorer(func)
ridge_gcv3 = RidgeCV(fit_intercept=False, scoring=scoring)
f(ridge_gcv3.fit)(filter_(X_diabetes), y_diabetes)
assert_equal(ridge_gcv3.alpha_, alpha_)
# check that we get same best alpha with a scorer
scorer = get_scorer('neg_mean_squared_error')
ridge_gcv4 = RidgeCV(fit_intercept=False, scoring=scorer)
ridge_gcv4.fit(filter_(X_diabetes), y_diabetes)
assert_equal(ridge_gcv4.alpha_, alpha_)
# check that we get same best alpha with sample weights
ridge_gcv.fit(filter_(X_diabetes), y_diabetes,
sample_weight=np.ones(n_samples))
assert_equal(ridge_gcv.alpha_, alpha_)
# simulate several responses
Y = np.vstack((y_diabetes, y_diabetes)).T
ridge_gcv.fit(filter_(X_diabetes), Y)
Y_pred = ridge_gcv.predict(filter_(X_diabetes))
ridge_gcv.fit(filter_(X_diabetes), y_diabetes)
y_pred = ridge_gcv.predict(filter_(X_diabetes))
assert_array_almost_equal(np.vstack((y_pred, y_pred)).T,
Y_pred, decimal=5)
return ret
def _test_ridge_cv_normalize(filter_):
ridge_cv = RidgeCV(normalize=True, cv=3)
ridge_cv.fit(filter_(10. * X_diabetes), y_diabetes)
gs = GridSearchCV(Ridge(normalize=True), cv=3,
param_grid={'alpha': ridge_cv.alphas})
gs.fit(filter_(10. * X_diabetes), y_diabetes)
assert_equal(gs.best_estimator_.alpha, ridge_cv.alpha_)
def _test_ridge_cv(filter_):
ridge_cv = RidgeCV()
ridge_cv.fit(filter_(X_diabetes), y_diabetes)
ridge_cv.predict(filter_(X_diabetes))
assert_equal(len(ridge_cv.coef_.shape), 1)
assert_equal(type(ridge_cv.intercept_), np.float64)
cv = KFold(5)
ridge_cv.set_params(cv=cv)
ridge_cv.fit(filter_(X_diabetes), y_diabetes)
ridge_cv.predict(filter_(X_diabetes))
assert_equal(len(ridge_cv.coef_.shape), 1)
assert_equal(type(ridge_cv.intercept_), np.float64)
def _test_ridge_diabetes(filter_):
ridge = Ridge(fit_intercept=False)
ridge.fit(filter_(X_diabetes), y_diabetes)
return np.round(ridge.score(filter_(X_diabetes), y_diabetes), 5)
def _test_multi_ridge_diabetes(filter_):
# simulate several responses
Y = np.vstack((y_diabetes, y_diabetes)).T
n_features = X_diabetes.shape[1]
ridge = Ridge(fit_intercept=False)
ridge.fit(filter_(X_diabetes), Y)
assert_equal(ridge.coef_.shape, (2, n_features))
Y_pred = ridge.predict(filter_(X_diabetes))
ridge.fit(filter_(X_diabetes), y_diabetes)
y_pred = ridge.predict(filter_(X_diabetes))
assert_array_almost_equal(np.vstack((y_pred, y_pred)).T,
Y_pred, decimal=3)
def _test_ridge_classifiers(filter_):
n_classes = np.unique(y_iris).shape[0]
n_features = X_iris.shape[1]
for reg in (RidgeClassifier(), RidgeClassifierCV()):
reg.fit(filter_(X_iris), y_iris)
assert_equal(reg.coef_.shape, (n_classes, n_features))
y_pred = reg.predict(filter_(X_iris))
assert_greater(np.mean(y_iris == y_pred), .79)
cv = KFold(5)
reg = RidgeClassifierCV(cv=cv)
reg.fit(filter_(X_iris), y_iris)
y_pred = reg.predict(filter_(X_iris))
assert_true(np.mean(y_iris == y_pred) >= 0.8)
def _test_tolerance(filter_):
ridge = Ridge(tol=1e-5, fit_intercept=False)
ridge.fit(filter_(X_diabetes), y_diabetes)
score = ridge.score(filter_(X_diabetes), y_diabetes)
ridge2 = Ridge(tol=1e-3, fit_intercept=False)
ridge2.fit(filter_(X_diabetes), y_diabetes)
score2 = ridge2.score(filter_(X_diabetes), y_diabetes)
assert_true(score >= score2)
def check_dense_sparse(test_func):
# test dense matrix
ret_dense = test_func(DENSE_FILTER)
# test sparse matrix
ret_sparse = test_func(SPARSE_FILTER)
# test that the outputs are the same
if ret_dense is not None and ret_sparse is not None:
assert_array_almost_equal(ret_dense, ret_sparse, decimal=3)
def test_dense_sparse():
for test_func in (_test_ridge_loo,
_test_ridge_cv,
_test_ridge_cv_normalize,
_test_ridge_diabetes,
_test_multi_ridge_diabetes,
_test_ridge_classifiers,
_test_tolerance):
yield check_dense_sparse, test_func
def test_ridge_cv_sparse_svd():
X = sp.csr_matrix(X_diabetes)
ridge = RidgeCV(gcv_mode="svd")
assert_raises(TypeError, ridge.fit, X)
def test_ridge_sparse_svd():
X = sp.csc_matrix(rng.rand(100, 10))
y = rng.rand(100)
ridge = Ridge(solver='svd', fit_intercept=False)
assert_raises(TypeError, ridge.fit, X, y)
def test_class_weights():
# Test class weights.
X = np.array([[-1.0, -1.0], [-1.0, 0], [-.8, -1.0],
[1.0, 1.0], [1.0, 0.0]])
y = [1, 1, 1, -1, -1]
reg = RidgeClassifier(class_weight=None)
reg.fit(X, y)
assert_array_equal(reg.predict([[0.2, -1.0]]), np.array([1]))
# we give a small weights to class 1
reg = RidgeClassifier(class_weight={1: 0.001})
reg.fit(X, y)
# now the hyperplane should rotate clock-wise and
# the prediction on this point should shift
assert_array_equal(reg.predict([[0.2, -1.0]]), np.array([-1]))
# check if class_weight = 'balanced' can handle negative labels.
reg = RidgeClassifier(class_weight='balanced')
reg.fit(X, y)
assert_array_equal(reg.predict([[0.2, -1.0]]), np.array([1]))
# class_weight = 'balanced', and class_weight = None should return
# same values when y has equal number of all labels
X = np.array([[-1.0, -1.0], [-1.0, 0], [-.8, -1.0], [1.0, 1.0]])
y = [1, 1, -1, -1]
reg = RidgeClassifier(class_weight=None)
reg.fit(X, y)
rega = RidgeClassifier(class_weight='balanced')
rega.fit(X, y)
assert_equal(len(rega.classes_), 2)
assert_array_almost_equal(reg.coef_, rega.coef_)
assert_array_almost_equal(reg.intercept_, rega.intercept_)
def test_class_weight_vs_sample_weight():
"""Check class_weights resemble sample_weights behavior."""
for reg in (RidgeClassifier, RidgeClassifierCV):
# Iris is balanced, so no effect expected for using 'balanced' weights
reg1 = reg()
reg1.fit(iris.data, iris.target)
reg2 = reg(class_weight='balanced')
reg2.fit(iris.data, iris.target)
assert_almost_equal(reg1.coef_, reg2.coef_)
# Inflate importance of class 1, check against user-defined weights
sample_weight = np.ones(iris.target.shape)
sample_weight[iris.target == 1] *= 100
class_weight = {0: 1., 1: 100., 2: 1.}
reg1 = reg()
reg1.fit(iris.data, iris.target, sample_weight)
reg2 = reg(class_weight=class_weight)
reg2.fit(iris.data, iris.target)
assert_almost_equal(reg1.coef_, reg2.coef_)
# Check that sample_weight and class_weight are multiplicative
reg1 = reg()
reg1.fit(iris.data, iris.target, sample_weight ** 2)
reg2 = reg(class_weight=class_weight)
reg2.fit(iris.data, iris.target, sample_weight)
assert_almost_equal(reg1.coef_, reg2.coef_)
def test_class_weights_cv():
# Test class weights for cross validated ridge classifier.
X = np.array([[-1.0, -1.0], [-1.0, 0], [-.8, -1.0],
[1.0, 1.0], [1.0, 0.0]])
y = [1, 1, 1, -1, -1]
reg = RidgeClassifierCV(class_weight=None, alphas=[.01, .1, 1])
reg.fit(X, y)
# we give a small weights to class 1
reg = RidgeClassifierCV(class_weight={1: 0.001}, alphas=[.01, .1, 1, 10])
reg.fit(X, y)
assert_array_equal(reg.predict([[-.2, 2]]), np.array([-1]))
def test_ridgecv_store_cv_values():
# Test _RidgeCV's store_cv_values attribute.
rng = rng = np.random.RandomState(42)
n_samples = 8
n_features = 5
x = rng.randn(n_samples, n_features)
alphas = [1e-1, 1e0, 1e1]
n_alphas = len(alphas)
r = RidgeCV(alphas=alphas, store_cv_values=True)
# with len(y.shape) == 1
y = rng.randn(n_samples)
r.fit(x, y)
assert_equal(r.cv_values_.shape, (n_samples, n_alphas))
# with len(y.shape) == 2
n_responses = 3
y = rng.randn(n_samples, n_responses)
r.fit(x, y)
assert_equal(r.cv_values_.shape, (n_samples, n_responses, n_alphas))
def test_ridgecv_sample_weight():
rng = np.random.RandomState(0)
alphas = (0.1, 1.0, 10.0)
# There are different algorithms for n_samples > n_features
# and the opposite, so test them both.
for n_samples, n_features in ((6, 5), (5, 10)):
y = rng.randn(n_samples)
X = rng.randn(n_samples, n_features)
sample_weight = 1.0 + rng.rand(n_samples)
cv = KFold(5)
ridgecv = RidgeCV(alphas=alphas, cv=cv)
ridgecv.fit(X, y, sample_weight=sample_weight)
# Check using GridSearchCV directly
parameters = {'alpha': alphas}
gs = GridSearchCV(Ridge(), parameters, cv=cv)
gs.fit(X, y, sample_weight=sample_weight)
assert_equal(ridgecv.alpha_, gs.best_estimator_.alpha)
assert_array_almost_equal(ridgecv.coef_, gs.best_estimator_.coef_)
def test_raises_value_error_if_sample_weights_greater_than_1d():
# Sample weights must be either scalar or 1D
n_sampless = [2, 3]
n_featuress = [3, 2]
rng = np.random.RandomState(42)
for n_samples, n_features in zip(n_sampless, n_featuress):
X = rng.randn(n_samples, n_features)
y = rng.randn(n_samples)
sample_weights_OK = rng.randn(n_samples) ** 2 + 1
sample_weights_OK_1 = 1.
sample_weights_OK_2 = 2.
sample_weights_not_OK = sample_weights_OK[:, np.newaxis]
sample_weights_not_OK_2 = sample_weights_OK[np.newaxis, :]
ridge = Ridge(alpha=1)
# make sure the "OK" sample weights actually work
ridge.fit(X, y, sample_weights_OK)
ridge.fit(X, y, sample_weights_OK_1)
ridge.fit(X, y, sample_weights_OK_2)
def fit_ridge_not_ok():
ridge.fit(X, y, sample_weights_not_OK)
def fit_ridge_not_ok_2():
ridge.fit(X, y, sample_weights_not_OK_2)
assert_raise_message(ValueError,
"Sample weights must be 1D array or scalar",
fit_ridge_not_ok)
assert_raise_message(ValueError,
"Sample weights must be 1D array or scalar",
fit_ridge_not_ok_2)
def test_sparse_design_with_sample_weights():
# Sample weights must work with sparse matrices
n_sampless = [2, 3]
n_featuress = [3, 2]
rng = np.random.RandomState(42)
sparse_matrix_converters = [sp.coo_matrix,
sp.csr_matrix,
sp.csc_matrix,
sp.lil_matrix,
sp.dok_matrix
]
sparse_ridge = Ridge(alpha=1., fit_intercept=False)
dense_ridge = Ridge(alpha=1., fit_intercept=False)
for n_samples, n_features in zip(n_sampless, n_featuress):
X = rng.randn(n_samples, n_features)
y = rng.randn(n_samples)
sample_weights = rng.randn(n_samples) ** 2 + 1
for sparse_converter in sparse_matrix_converters:
X_sparse = sparse_converter(X)
sparse_ridge.fit(X_sparse, y, sample_weight=sample_weights)
dense_ridge.fit(X, y, sample_weight=sample_weights)
assert_array_almost_equal(sparse_ridge.coef_, dense_ridge.coef_,
decimal=6)
def test_raises_value_error_if_solver_not_supported():
# Tests whether a ValueError is raised if a non-identified solver
# is passed to ridge_regression
wrong_solver = "This is not a solver (MagritteSolveCV QuantumBitcoin)"
exception = ValueError
message = "Solver %s not understood" % wrong_solver
def func():
X = np.eye(3)
y = np.ones(3)
ridge_regression(X, y, alpha=1., solver=wrong_solver)
assert_raise_message(exception, message, func)
def test_sparse_cg_max_iter():
reg = Ridge(solver="sparse_cg", max_iter=1)
reg.fit(X_diabetes, y_diabetes)
assert_equal(reg.coef_.shape[0], X_diabetes.shape[1])
@ignore_warnings
def test_n_iter():
# Test that self.n_iter_ is correct.
n_targets = 2
X, y = X_diabetes, y_diabetes
y_n = np.tile(y, (n_targets, 1)).T
for max_iter in range(1, 4):
for solver in ('sag', 'saga', 'lsqr'):
reg = Ridge(solver=solver, max_iter=max_iter, tol=1e-12)
reg.fit(X, y_n)
assert_array_equal(reg.n_iter_, np.tile(max_iter, n_targets))
for solver in ('sparse_cg', 'svd', 'cholesky'):
reg = Ridge(solver=solver, max_iter=1, tol=1e-1)
reg.fit(X, y_n)
assert_equal(reg.n_iter_, None)
def test_ridge_fit_intercept_sparse():
X, y = make_regression(n_samples=1000, n_features=2, n_informative=2,
bias=10., random_state=42)
X_csr = sp.csr_matrix(X)
for solver in ['saga', 'sag']:
dense = Ridge(alpha=1., tol=1.e-15, solver=solver, fit_intercept=True)
sparse = Ridge(alpha=1., tol=1.e-15, solver=solver, fit_intercept=True)
dense.fit(X, y)
sparse.fit(X_csr, y)
assert_almost_equal(dense.intercept_, sparse.intercept_)
assert_array_almost_equal(dense.coef_, sparse.coef_)
# test the solver switch and the corresponding warning
sparse = Ridge(alpha=1., tol=1.e-15, solver='lsqr', fit_intercept=True)
assert_warns(UserWarning, sparse.fit, X_csr, y)
assert_almost_equal(dense.intercept_, sparse.intercept_)
assert_array_almost_equal(dense.coef_, sparse.coef_)
def test_errors_and_values_helper():
ridgecv = _RidgeGCV()
rng = check_random_state(42)
alpha = 1.
n = 5
y = rng.randn(n)
v = rng.randn(n)
Q = rng.randn(len(v), len(v))
QT_y = Q.T.dot(y)
G_diag, c = ridgecv._errors_and_values_helper(alpha, y, v, Q, QT_y)
# test that helper function behaves as expected
out, c_ = ridgecv._errors(alpha, y, v, Q, QT_y)
np.testing.assert_array_equal(out, (c / G_diag) ** 2)
np.testing.assert_array_equal(c, c)
out, c_ = ridgecv._values(alpha, y, v, Q, QT_y)
np.testing.assert_array_equal(out, y - (c / G_diag))
np.testing.assert_array_equal(c_, c)
def test_errors_and_values_svd_helper():
ridgecv = _RidgeGCV()
rng = check_random_state(42)
alpha = 1.
for n, p in zip((5, 10), (12, 6)):
y = rng.randn(n)
v = rng.randn(p)
U = rng.randn(n, p)
UT_y = U.T.dot(y)
G_diag, c = ridgecv._errors_and_values_svd_helper(alpha, y, v, U, UT_y)
# test that helper function behaves as expected
out, c_ = ridgecv._errors_svd(alpha, y, v, U, UT_y)
np.testing.assert_array_equal(out, (c / G_diag) ** 2)
np.testing.assert_array_equal(c, c)
out, c_ = ridgecv._values_svd(alpha, y, v, U, UT_y)
np.testing.assert_array_equal(out, y - (c / G_diag))
np.testing.assert_array_equal(c_, c)
def test_ridge_classifier_no_support_multilabel():
X, y = make_multilabel_classification(n_samples=10, random_state=0)
assert_raises(ValueError, RidgeClassifier().fit, X, y)
def test_dtype_match():
rng = np.random.RandomState(0)
alpha = 1.0
n_samples, n_features = 6, 5
X_64 = rng.randn(n_samples, n_features)
y_64 = rng.randn(n_samples)
X_32 = X_64.astype(np.float32)
y_32 = y_64.astype(np.float32)
solvers = ["svd", "sparse_cg", "cholesky", "lsqr"]
for solver in solvers:
# Check type consistency 32bits
ridge_32 = Ridge(alpha=alpha, solver=solver)
ridge_32.fit(X_32, y_32)
coef_32 = ridge_32.coef_
# Check type consistency 64 bits
ridge_64 = Ridge(alpha=alpha, solver=solver)
ridge_64.fit(X_64, y_64)
coef_64 = ridge_64.coef_
# Do the actual checks at once for easier debug
assert coef_32.dtype == X_32.dtype
assert coef_64.dtype == X_64.dtype
assert ridge_32.predict(X_32).dtype == X_32.dtype
assert ridge_64.predict(X_64).dtype == X_64.dtype
assert_almost_equal(ridge_32.coef_, ridge_64.coef_, decimal=5)
def test_dtype_match_cholesky():
# Test different alphas in cholesky solver to ensure full coverage.
# This test is separated from test_dtype_match for clarity.
rng = np.random.RandomState(0)
alpha = (1.0, 0.5)
n_samples, n_features, n_target = 6, 7, 2
X_64 = rng.randn(n_samples, n_features)
y_64 = rng.randn(n_samples, n_target)
X_32 = X_64.astype(np.float32)
y_32 = y_64.astype(np.float32)
# Check type consistency 32bits
ridge_32 = Ridge(alpha=alpha, solver='cholesky')
ridge_32.fit(X_32, y_32)
coef_32 = ridge_32.coef_
# Check type consistency 64 bits
ridge_64 = Ridge(alpha=alpha, solver='cholesky')
ridge_64.fit(X_64, y_64)
coef_64 = ridge_64.coef_
# Do all the checks at once, like this is easier to debug
assert coef_32.dtype == X_32.dtype
assert coef_64.dtype == X_64.dtype
assert ridge_32.predict(X_32).dtype == X_32.dtype
assert ridge_64.predict(X_64).dtype == X_64.dtype
assert_almost_equal(ridge_32.coef_, ridge_64.coef_, decimal=5)
| 29,229 | 32.87022 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/base.py | """Base and mixin classes for nearest neighbors"""
# Authors: Jake Vanderplas <[email protected]>
# Fabian Pedregosa <[email protected]>
# Alexandre Gramfort <[email protected]>
# Sparseness support by Lars Buitinck
# Multi-output support by Arnaud Joly <[email protected]>
#
# License: BSD 3 clause (C) INRIA, University of Amsterdam
import warnings
from abc import ABCMeta, abstractmethod
import numpy as np
from scipy.sparse import csr_matrix, issparse
from .ball_tree import BallTree
from .kd_tree import KDTree
from ..base import BaseEstimator
from ..metrics import pairwise_distances
from ..metrics.pairwise import PAIRWISE_DISTANCE_FUNCTIONS
from ..utils import check_X_y, check_array, _get_n_jobs, gen_even_slices
from ..utils.multiclass import check_classification_targets
from ..externals import six
from ..externals.joblib import Parallel, delayed
from ..exceptions import NotFittedError
from ..exceptions import DataConversionWarning
VALID_METRICS = dict(ball_tree=BallTree.valid_metrics,
kd_tree=KDTree.valid_metrics,
# The following list comes from the
# sklearn.metrics.pairwise doc string
brute=(list(PAIRWISE_DISTANCE_FUNCTIONS.keys()) +
['braycurtis', 'canberra', 'chebyshev',
'correlation', 'cosine', 'dice', 'hamming',
'jaccard', 'kulsinski', 'mahalanobis',
'matching', 'minkowski', 'rogerstanimoto',
'russellrao', 'seuclidean', 'sokalmichener',
'sokalsneath', 'sqeuclidean',
'yule', 'wminkowski']))
VALID_METRICS_SPARSE = dict(ball_tree=[],
kd_tree=[],
brute=PAIRWISE_DISTANCE_FUNCTIONS.keys())
def _check_weights(weights):
"""Check to make sure weights are valid"""
if weights in (None, 'uniform', 'distance'):
return weights
elif callable(weights):
return weights
else:
raise ValueError("weights not recognized: should be 'uniform', "
"'distance', or a callable function")
def _get_weights(dist, weights):
"""Get the weights from an array of distances and a parameter ``weights``
Parameters
===========
dist : ndarray
The input distances
weights : {'uniform', 'distance' or a callable}
The kind of weighting used
Returns
========
weights_arr : array of the same shape as ``dist``
if ``weights == 'uniform'``, then returns None
"""
if weights in (None, 'uniform'):
return None
elif weights == 'distance':
# if user attempts to classify a point that was zero distance from one
# or more training points, those training points are weighted as 1.0
# and the other points as 0.0
if dist.dtype is np.dtype(object):
for point_dist_i, point_dist in enumerate(dist):
# check if point_dist is iterable
# (ex: RadiusNeighborClassifier.predict may set an element of
# dist to 1e-6 to represent an 'outlier')
if hasattr(point_dist, '__contains__') and 0. in point_dist:
dist[point_dist_i] = point_dist == 0.
else:
dist[point_dist_i] = 1. / point_dist
else:
with np.errstate(divide='ignore'):
dist = 1. / dist
inf_mask = np.isinf(dist)
inf_row = np.any(inf_mask, axis=1)
dist[inf_row] = inf_mask[inf_row]
return dist
elif callable(weights):
return weights(dist)
else:
raise ValueError("weights not recognized: should be 'uniform', "
"'distance', or a callable function")
class NeighborsBase(six.with_metaclass(ABCMeta, BaseEstimator)):
"""Base class for nearest neighbors estimators."""
@abstractmethod
def __init__(self):
pass
def _init_params(self, n_neighbors=None, radius=None,
algorithm='auto', leaf_size=30, metric='minkowski',
p=2, metric_params=None, n_jobs=1):
self.n_neighbors = n_neighbors
self.radius = radius
self.algorithm = algorithm
self.leaf_size = leaf_size
self.metric = metric
self.metric_params = metric_params
self.p = p
self.n_jobs = n_jobs
if algorithm not in ['auto', 'brute',
'kd_tree', 'ball_tree']:
raise ValueError("unrecognized algorithm: '%s'" % algorithm)
if algorithm == 'auto':
if metric == 'precomputed':
alg_check = 'brute'
elif callable(metric) or metric in VALID_METRICS['ball_tree']:
alg_check = 'ball_tree'
else:
alg_check = 'brute'
else:
alg_check = algorithm
if callable(metric):
if algorithm == 'kd_tree':
# callable metric is only valid for brute force and ball_tree
raise ValueError(
"kd_tree algorithm does not support callable metric '%s'"
% metric)
elif metric not in VALID_METRICS[alg_check]:
raise ValueError("Metric '%s' not valid for algorithm '%s'"
% (metric, algorithm))
if self.metric_params is not None and 'p' in self.metric_params:
warnings.warn("Parameter p is found in metric_params. "
"The corresponding parameter from __init__ "
"is ignored.", SyntaxWarning, stacklevel=3)
effective_p = metric_params['p']
else:
effective_p = self.p
if self.metric in ['wminkowski', 'minkowski'] and effective_p < 1:
raise ValueError("p must be greater than one for minkowski metric")
self._fit_X = None
self._tree = None
self._fit_method = None
def _fit(self, X):
if self.metric_params is None:
self.effective_metric_params_ = {}
else:
self.effective_metric_params_ = self.metric_params.copy()
effective_p = self.effective_metric_params_.get('p', self.p)
if self.metric in ['wminkowski', 'minkowski']:
self.effective_metric_params_['p'] = effective_p
self.effective_metric_ = self.metric
# For minkowski distance, use more efficient methods where available
if self.metric == 'minkowski':
p = self.effective_metric_params_.pop('p', 2)
if p < 1:
raise ValueError("p must be greater than one "
"for minkowski metric")
elif p == 1:
self.effective_metric_ = 'manhattan'
elif p == 2:
self.effective_metric_ = 'euclidean'
elif p == np.inf:
self.effective_metric_ = 'chebyshev'
else:
self.effective_metric_params_['p'] = p
if isinstance(X, NeighborsBase):
self._fit_X = X._fit_X
self._tree = X._tree
self._fit_method = X._fit_method
return self
elif isinstance(X, BallTree):
self._fit_X = X.data
self._tree = X
self._fit_method = 'ball_tree'
return self
elif isinstance(X, KDTree):
self._fit_X = X.data
self._tree = X
self._fit_method = 'kd_tree'
return self
X = check_array(X, accept_sparse='csr')
n_samples = X.shape[0]
if n_samples == 0:
raise ValueError("n_samples must be greater than 0")
if issparse(X):
if self.algorithm not in ('auto', 'brute'):
warnings.warn("cannot use tree with sparse input: "
"using brute force")
if self.effective_metric_ not in VALID_METRICS_SPARSE['brute']:
raise ValueError("metric '%s' not valid for sparse input"
% self.effective_metric_)
self._fit_X = X.copy()
self._tree = None
self._fit_method = 'brute'
return self
self._fit_method = self.algorithm
self._fit_X = X
if self._fit_method == 'auto':
# A tree approach is better for small number of neighbors,
# and KDTree is generally faster when available
if ((self.n_neighbors is None or
self.n_neighbors < self._fit_X.shape[0] // 2) and
self.metric != 'precomputed'):
if self.effective_metric_ in VALID_METRICS['kd_tree']:
self._fit_method = 'kd_tree'
elif (callable(self.effective_metric_) or
self.effective_metric_ in VALID_METRICS['ball_tree']):
self._fit_method = 'ball_tree'
else:
self._fit_method = 'brute'
else:
self._fit_method = 'brute'
if self._fit_method == 'ball_tree':
self._tree = BallTree(X, self.leaf_size,
metric=self.effective_metric_,
**self.effective_metric_params_)
elif self._fit_method == 'kd_tree':
self._tree = KDTree(X, self.leaf_size,
metric=self.effective_metric_,
**self.effective_metric_params_)
elif self._fit_method == 'brute':
self._tree = None
else:
raise ValueError("algorithm = '%s' not recognized"
% self.algorithm)
if self.n_neighbors is not None:
if self.n_neighbors <= 0:
raise ValueError(
"Expected n_neighbors > 0. Got %d" %
self.n_neighbors
)
return self
@property
def _pairwise(self):
# For cross-validation routines to split data correctly
return self.metric == 'precomputed'
class KNeighborsMixin(object):
"""Mixin for k-neighbors searches"""
def kneighbors(self, X=None, n_neighbors=None, return_distance=True):
"""Finds the K-neighbors of a point.
Returns indices of and distances to the neighbors of each point.
Parameters
----------
X : array-like, shape (n_query, n_features), \
or (n_query, n_indexed) if metric == 'precomputed'
The query point or points.
If not provided, neighbors of each indexed point are returned.
In this case, the query point is not considered its own neighbor.
n_neighbors : int
Number of neighbors to get (default is the value
passed to the constructor).
return_distance : boolean, optional. Defaults to True.
If False, distances will not be returned
Returns
-------
dist : array
Array representing the lengths to points, only present if
return_distance=True
ind : array
Indices of the nearest points in the population matrix.
Examples
--------
In the following example, we construct a NeighborsClassifier
class from an array representing our data set and ask who's
the closest point to [1,1,1]
>>> samples = [[0., 0., 0.], [0., .5, 0.], [1., 1., .5]]
>>> from sklearn.neighbors import NearestNeighbors
>>> neigh = NearestNeighbors(n_neighbors=1)
>>> neigh.fit(samples) # doctest: +ELLIPSIS
NearestNeighbors(algorithm='auto', leaf_size=30, ...)
>>> print(neigh.kneighbors([[1., 1., 1.]])) # doctest: +ELLIPSIS
(array([[ 0.5]]), array([[2]]...))
As you can see, it returns [[0.5]], and [[2]], which means that the
element is at distance 0.5 and is the third element of samples
(indexes start at 0). You can also query for multiple points:
>>> X = [[0., 1., 0.], [1., 0., 1.]]
>>> neigh.kneighbors(X, return_distance=False) # doctest: +ELLIPSIS
array([[1],
[2]]...)
"""
if self._fit_method is None:
raise NotFittedError("Must fit neighbors before querying.")
if n_neighbors is None:
n_neighbors = self.n_neighbors
if X is not None:
query_is_train = False
X = check_array(X, accept_sparse='csr')
else:
query_is_train = True
X = self._fit_X
# Include an extra neighbor to account for the sample itself being
# returned, which is removed later
n_neighbors += 1
train_size = self._fit_X.shape[0]
if n_neighbors > train_size:
raise ValueError(
"Expected n_neighbors <= n_samples, "
" but n_samples = %d, n_neighbors = %d" %
(train_size, n_neighbors)
)
n_samples, _ = X.shape
sample_range = np.arange(n_samples)[:, None]
n_jobs = _get_n_jobs(self.n_jobs)
if self._fit_method == 'brute':
# for efficiency, use squared euclidean distances
if self.effective_metric_ == 'euclidean':
dist = pairwise_distances(X, self._fit_X, 'euclidean',
n_jobs=n_jobs, squared=True)
else:
dist = pairwise_distances(
X, self._fit_X, self.effective_metric_, n_jobs=n_jobs,
**self.effective_metric_params_)
neigh_ind = np.argpartition(dist, n_neighbors - 1, axis=1)
neigh_ind = neigh_ind[:, :n_neighbors]
# argpartition doesn't guarantee sorted order, so we sort again
neigh_ind = neigh_ind[
sample_range, np.argsort(dist[sample_range, neigh_ind])]
if return_distance:
if self.effective_metric_ == 'euclidean':
result = np.sqrt(dist[sample_range, neigh_ind]), neigh_ind
else:
result = dist[sample_range, neigh_ind], neigh_ind
else:
result = neigh_ind
elif self._fit_method in ['ball_tree', 'kd_tree']:
if issparse(X):
raise ValueError(
"%s does not work with sparse matrices. Densify the data, "
"or set algorithm='brute'" % self._fit_method)
result = Parallel(n_jobs, backend='threading')(
delayed(self._tree.query, check_pickle=False)(
X[s], n_neighbors, return_distance)
for s in gen_even_slices(X.shape[0], n_jobs)
)
if return_distance:
dist, neigh_ind = tuple(zip(*result))
result = np.vstack(dist), np.vstack(neigh_ind)
else:
result = np.vstack(result)
else:
raise ValueError("internal: _fit_method not recognized")
if not query_is_train:
return result
else:
# If the query data is the same as the indexed data, we would like
# to ignore the first nearest neighbor of every sample, i.e
# the sample itself.
if return_distance:
dist, neigh_ind = result
else:
neigh_ind = result
sample_mask = neigh_ind != sample_range
# Corner case: When the number of duplicates are more
# than the number of neighbors, the first NN will not
# be the sample, but a duplicate.
# In that case mask the first duplicate.
dup_gr_nbrs = np.all(sample_mask, axis=1)
sample_mask[:, 0][dup_gr_nbrs] = False
neigh_ind = np.reshape(
neigh_ind[sample_mask], (n_samples, n_neighbors - 1))
if return_distance:
dist = np.reshape(
dist[sample_mask], (n_samples, n_neighbors - 1))
return dist, neigh_ind
return neigh_ind
def kneighbors_graph(self, X=None, n_neighbors=None,
mode='connectivity'):
"""Computes the (weighted) graph of k-Neighbors for points in X
Parameters
----------
X : array-like, shape (n_query, n_features), \
or (n_query, n_indexed) if metric == 'precomputed'
The query point or points.
If not provided, neighbors of each indexed point are returned.
In this case, the query point is not considered its own neighbor.
n_neighbors : int
Number of neighbors for each sample.
(default is value passed to the constructor).
mode : {'connectivity', 'distance'}, optional
Type of returned matrix: 'connectivity' will return the
connectivity matrix with ones and zeros, in 'distance' the
edges are Euclidean distance between points.
Returns
-------
A : sparse matrix in CSR format, shape = [n_samples, n_samples_fit]
n_samples_fit is the number of samples in the fitted data
A[i, j] is assigned the weight of edge that connects i to j.
Examples
--------
>>> X = [[0], [3], [1]]
>>> from sklearn.neighbors import NearestNeighbors
>>> neigh = NearestNeighbors(n_neighbors=2)
>>> neigh.fit(X) # doctest: +ELLIPSIS
NearestNeighbors(algorithm='auto', leaf_size=30, ...)
>>> A = neigh.kneighbors_graph(X)
>>> A.toarray()
array([[ 1., 0., 1.],
[ 0., 1., 1.],
[ 1., 0., 1.]])
See also
--------
NearestNeighbors.radius_neighbors_graph
"""
if n_neighbors is None:
n_neighbors = self.n_neighbors
# kneighbors does the None handling.
if X is not None:
X = check_array(X, accept_sparse='csr')
n_samples1 = X.shape[0]
else:
n_samples1 = self._fit_X.shape[0]
n_samples2 = self._fit_X.shape[0]
n_nonzero = n_samples1 * n_neighbors
A_indptr = np.arange(0, n_nonzero + 1, n_neighbors)
# construct CSR matrix representation of the k-NN graph
if mode == 'connectivity':
A_data = np.ones(n_samples1 * n_neighbors)
A_ind = self.kneighbors(X, n_neighbors, return_distance=False)
elif mode == 'distance':
A_data, A_ind = self.kneighbors(
X, n_neighbors, return_distance=True)
A_data = np.ravel(A_data)
else:
raise ValueError(
'Unsupported mode, must be one of "connectivity" '
'or "distance" but got "%s" instead' % mode)
kneighbors_graph = csr_matrix((A_data, A_ind.ravel(), A_indptr),
shape=(n_samples1, n_samples2))
return kneighbors_graph
class RadiusNeighborsMixin(object):
"""Mixin for radius-based neighbors searches"""
def radius_neighbors(self, X=None, radius=None, return_distance=True):
"""Finds the neighbors within a given radius of a point or points.
Return the indices and distances of each point from the dataset
lying in a ball with size ``radius`` around the points of the query
array. Points lying on the boundary are included in the results.
The result points are *not* necessarily sorted by distance to their
query point.
Parameters
----------
X : array-like, (n_samples, n_features), optional
The query point or points.
If not provided, neighbors of each indexed point are returned.
In this case, the query point is not considered its own neighbor.
radius : float
Limiting distance of neighbors to return.
(default is the value passed to the constructor).
return_distance : boolean, optional. Defaults to True.
If False, distances will not be returned
Returns
-------
dist : array, shape (n_samples,) of arrays
Array representing the distances to each point, only present if
return_distance=True. The distance values are computed according
to the ``metric`` constructor parameter.
ind : array, shape (n_samples,) of arrays
An array of arrays of indices of the approximate nearest points
from the population matrix that lie within a ball of size
``radius`` around the query points.
Examples
--------
In the following example, we construct a NeighborsClassifier
class from an array representing our data set and ask who's
the closest point to [1, 1, 1]:
>>> import numpy as np
>>> samples = [[0., 0., 0.], [0., .5, 0.], [1., 1., .5]]
>>> from sklearn.neighbors import NearestNeighbors
>>> neigh = NearestNeighbors(radius=1.6)
>>> neigh.fit(samples) # doctest: +ELLIPSIS
NearestNeighbors(algorithm='auto', leaf_size=30, ...)
>>> rng = neigh.radius_neighbors([[1., 1., 1.]])
>>> print(np.asarray(rng[0][0])) # doctest: +ELLIPSIS
[ 1.5 0.5]
>>> print(np.asarray(rng[1][0])) # doctest: +ELLIPSIS
[1 2]
The first array returned contains the distances to all points which
are closer than 1.6, while the second array returned contains their
indices. In general, multiple points can be queried at the same time.
Notes
-----
Because the number of neighbors of each point is not necessarily
equal, the results for multiple query points cannot be fit in a
standard data array.
For efficiency, `radius_neighbors` returns arrays of objects, where
each object is a 1D array of indices or distances.
"""
if self._fit_method is None:
raise NotFittedError("Must fit neighbors before querying.")
if X is not None:
query_is_train = False
X = check_array(X, accept_sparse='csr')
else:
query_is_train = True
X = self._fit_X
if radius is None:
radius = self.radius
n_samples = X.shape[0]
if self._fit_method == 'brute':
# for efficiency, use squared euclidean distances
if self.effective_metric_ == 'euclidean':
dist = pairwise_distances(X, self._fit_X, 'euclidean',
n_jobs=self.n_jobs, squared=True)
radius *= radius
else:
dist = pairwise_distances(X, self._fit_X,
self.effective_metric_,
n_jobs=self.n_jobs,
**self.effective_metric_params_)
neigh_ind_list = [np.where(d <= radius)[0] for d in dist]
# See https://github.com/numpy/numpy/issues/5456
# if you want to understand why this is initialized this way.
neigh_ind = np.empty(n_samples, dtype='object')
neigh_ind[:] = neigh_ind_list
if return_distance:
dist_array = np.empty(n_samples, dtype='object')
if self.effective_metric_ == 'euclidean':
dist_list = [np.sqrt(d[neigh_ind[i]])
for i, d in enumerate(dist)]
else:
dist_list = [d[neigh_ind[i]]
for i, d in enumerate(dist)]
dist_array[:] = dist_list
results = dist_array, neigh_ind
else:
results = neigh_ind
elif self._fit_method in ['ball_tree', 'kd_tree']:
if issparse(X):
raise ValueError(
"%s does not work with sparse matrices. Densify the data, "
"or set algorithm='brute'" % self._fit_method)
results = self._tree.query_radius(X, radius,
return_distance=return_distance)
if return_distance:
results = results[::-1]
else:
raise ValueError("internal: _fit_method not recognized")
if not query_is_train:
return results
else:
# If the query data is the same as the indexed data, we would like
# to ignore the first nearest neighbor of every sample, i.e
# the sample itself.
if return_distance:
dist, neigh_ind = results
else:
neigh_ind = results
for ind, ind_neighbor in enumerate(neigh_ind):
mask = ind_neighbor != ind
neigh_ind[ind] = ind_neighbor[mask]
if return_distance:
dist[ind] = dist[ind][mask]
if return_distance:
return dist, neigh_ind
return neigh_ind
def radius_neighbors_graph(self, X=None, radius=None, mode='connectivity'):
"""Computes the (weighted) graph of Neighbors for points in X
Neighborhoods are restricted the points at a distance lower than
radius.
Parameters
----------
X : array-like, shape = [n_samples, n_features], optional
The query point or points.
If not provided, neighbors of each indexed point are returned.
In this case, the query point is not considered its own neighbor.
radius : float
Radius of neighborhoods.
(default is the value passed to the constructor).
mode : {'connectivity', 'distance'}, optional
Type of returned matrix: 'connectivity' will return the
connectivity matrix with ones and zeros, in 'distance' the
edges are Euclidean distance between points.
Returns
-------
A : sparse matrix in CSR format, shape = [n_samples, n_samples]
A[i, j] is assigned the weight of edge that connects i to j.
Examples
--------
>>> X = [[0], [3], [1]]
>>> from sklearn.neighbors import NearestNeighbors
>>> neigh = NearestNeighbors(radius=1.5)
>>> neigh.fit(X) # doctest: +ELLIPSIS
NearestNeighbors(algorithm='auto', leaf_size=30, ...)
>>> A = neigh.radius_neighbors_graph(X)
>>> A.toarray()
array([[ 1., 0., 1.],
[ 0., 1., 0.],
[ 1., 0., 1.]])
See also
--------
kneighbors_graph
"""
if X is not None:
X = check_array(X, accept_sparse=['csr', 'csc', 'coo'])
n_samples2 = self._fit_X.shape[0]
if radius is None:
radius = self.radius
# construct CSR matrix representation of the NN graph
if mode == 'connectivity':
A_ind = self.radius_neighbors(X, radius,
return_distance=False)
A_data = None
elif mode == 'distance':
dist, A_ind = self.radius_neighbors(X, radius,
return_distance=True)
A_data = np.concatenate(list(dist))
else:
raise ValueError(
'Unsupported mode, must be one of "connectivity", '
'or "distance" but got %s instead' % mode)
n_samples1 = A_ind.shape[0]
n_neighbors = np.array([len(a) for a in A_ind])
A_ind = np.concatenate(list(A_ind))
if A_data is None:
A_data = np.ones(len(A_ind))
A_indptr = np.concatenate((np.zeros(1, dtype=int),
np.cumsum(n_neighbors)))
return csr_matrix((A_data, A_ind, A_indptr),
shape=(n_samples1, n_samples2))
class SupervisedFloatMixin(object):
def fit(self, X, y):
"""Fit the model using X as training data and y as target values
Parameters
----------
X : {array-like, sparse matrix, BallTree, KDTree}
Training data. If array or matrix, shape [n_samples, n_features],
or [n_samples, n_samples] if metric='precomputed'.
y : {array-like, sparse matrix}
Target values, array of float values, shape = [n_samples]
or [n_samples, n_outputs]
"""
if not isinstance(X, (KDTree, BallTree)):
X, y = check_X_y(X, y, "csr", multi_output=True)
self._y = y
return self._fit(X)
class SupervisedIntegerMixin(object):
def fit(self, X, y):
"""Fit the model using X as training data and y as target values
Parameters
----------
X : {array-like, sparse matrix, BallTree, KDTree}
Training data. If array or matrix, shape [n_samples, n_features],
or [n_samples, n_samples] if metric='precomputed'.
y : {array-like, sparse matrix}
Target values of shape = [n_samples] or [n_samples, n_outputs]
"""
if not isinstance(X, (KDTree, BallTree)):
X, y = check_X_y(X, y, "csr", multi_output=True)
if y.ndim == 1 or y.ndim == 2 and y.shape[1] == 1:
if y.ndim != 1:
warnings.warn("A column-vector y was passed when a 1d array "
"was expected. Please change the shape of y to "
"(n_samples, ), for example using ravel().",
DataConversionWarning, stacklevel=2)
self.outputs_2d_ = False
y = y.reshape((-1, 1))
else:
self.outputs_2d_ = True
check_classification_targets(y)
self.classes_ = []
self._y = np.empty(y.shape, dtype=np.int)
for k in range(self._y.shape[1]):
classes, self._y[:, k] = np.unique(y[:, k], return_inverse=True)
self.classes_.append(classes)
if not self.outputs_2d_:
self.classes_ = self.classes_[0]
self._y = self._y.ravel()
return self._fit(X)
class UnsupervisedMixin(object):
def fit(self, X, y=None):
"""Fit the model using X as training data
Parameters
----------
X : {array-like, sparse matrix, BallTree, KDTree}
Training data. If array or matrix, shape [n_samples, n_features],
or [n_samples, n_samples] if metric='precomputed'.
"""
return self._fit(X)
| 30,908 | 37.44403 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/classification.py | """Nearest Neighbor Classification"""
# Authors: Jake Vanderplas <[email protected]>
# Fabian Pedregosa <[email protected]>
# Alexandre Gramfort <[email protected]>
# Sparseness support by Lars Buitinck
# Multi-output support by Arnaud Joly <[email protected]>
#
# License: BSD 3 clause (C) INRIA, University of Amsterdam
import numpy as np
from scipy import stats
from ..utils.extmath import weighted_mode
from .base import \
_check_weights, _get_weights, \
NeighborsBase, KNeighborsMixin,\
RadiusNeighborsMixin, SupervisedIntegerMixin
from ..base import ClassifierMixin
from ..utils import check_array
class KNeighborsClassifier(NeighborsBase, KNeighborsMixin,
SupervisedIntegerMixin, ClassifierMixin):
"""Classifier implementing the k-nearest neighbors vote.
Read more in the :ref:`User Guide <classification>`.
Parameters
----------
n_neighbors : int, optional (default = 5)
Number of neighbors to use by default for :meth:`kneighbors` queries.
weights : str or callable, optional (default = 'uniform')
weight function used in prediction. Possible values:
- 'uniform' : uniform weights. All points in each neighborhood
are weighted equally.
- 'distance' : weight points by the inverse of their distance.
in this case, closer neighbors of a query point will have a
greater influence than neighbors which are further away.
- [callable] : a user-defined function which accepts an
array of distances, and returns an array of the same shape
containing the weights.
algorithm : {'auto', 'ball_tree', 'kd_tree', 'brute'}, optional
Algorithm used to compute the nearest neighbors:
- 'ball_tree' will use :class:`BallTree`
- 'kd_tree' will use :class:`KDTree`
- 'brute' will use a brute-force search.
- 'auto' will attempt to decide the most appropriate algorithm
based on the values passed to :meth:`fit` method.
Note: fitting on sparse input will override the setting of
this parameter, using brute force.
leaf_size : int, optional (default = 30)
Leaf size passed to BallTree or KDTree. This can affect the
speed of the construction and query, as well as the memory
required to store the tree. The optimal value depends on the
nature of the problem.
p : integer, optional (default = 2)
Power parameter for the Minkowski metric. When p = 1, this is
equivalent to using manhattan_distance (l1), and euclidean_distance
(l2) for p = 2. For arbitrary p, minkowski_distance (l_p) is used.
metric : string or callable, default 'minkowski'
the distance metric to use for the tree. The default metric is
minkowski, and with p=2 is equivalent to the standard Euclidean
metric. See the documentation of the DistanceMetric class for a
list of available metrics.
metric_params : dict, optional (default = None)
Additional keyword arguments for the metric function.
n_jobs : int, optional (default = 1)
The number of parallel jobs to run for neighbors search.
If ``-1``, then the number of jobs is set to the number of CPU cores.
Doesn't affect :meth:`fit` method.
Examples
--------
>>> X = [[0], [1], [2], [3]]
>>> y = [0, 0, 1, 1]
>>> from sklearn.neighbors import KNeighborsClassifier
>>> neigh = KNeighborsClassifier(n_neighbors=3)
>>> neigh.fit(X, y) # doctest: +ELLIPSIS
KNeighborsClassifier(...)
>>> print(neigh.predict([[1.1]]))
[0]
>>> print(neigh.predict_proba([[0.9]]))
[[ 0.66666667 0.33333333]]
See also
--------
RadiusNeighborsClassifier
KNeighborsRegressor
RadiusNeighborsRegressor
NearestNeighbors
Notes
-----
See :ref:`Nearest Neighbors <neighbors>` in the online documentation
for a discussion of the choice of ``algorithm`` and ``leaf_size``.
.. warning::
Regarding the Nearest Neighbors algorithms, if it is found that two
neighbors, neighbor `k+1` and `k`, have identical distances
but different labels, the results will depend on the ordering of the
training data.
https://en.wikipedia.org/wiki/K-nearest_neighbor_algorithm
"""
def __init__(self, n_neighbors=5,
weights='uniform', algorithm='auto', leaf_size=30,
p=2, metric='minkowski', metric_params=None, n_jobs=1,
**kwargs):
self._init_params(n_neighbors=n_neighbors,
algorithm=algorithm,
leaf_size=leaf_size, metric=metric, p=p,
metric_params=metric_params, n_jobs=n_jobs, **kwargs)
self.weights = _check_weights(weights)
def predict(self, X):
"""Predict the class labels for the provided data
Parameters
----------
X : array-like, shape (n_query, n_features), \
or (n_query, n_indexed) if metric == 'precomputed'
Test samples.
Returns
-------
y : array of shape [n_samples] or [n_samples, n_outputs]
Class labels for each data sample.
"""
X = check_array(X, accept_sparse='csr')
neigh_dist, neigh_ind = self.kneighbors(X)
classes_ = self.classes_
_y = self._y
if not self.outputs_2d_:
_y = self._y.reshape((-1, 1))
classes_ = [self.classes_]
n_outputs = len(classes_)
n_samples = X.shape[0]
weights = _get_weights(neigh_dist, self.weights)
y_pred = np.empty((n_samples, n_outputs), dtype=classes_[0].dtype)
for k, classes_k in enumerate(classes_):
if weights is None:
mode, _ = stats.mode(_y[neigh_ind, k], axis=1)
else:
mode, _ = weighted_mode(_y[neigh_ind, k], weights, axis=1)
mode = np.asarray(mode.ravel(), dtype=np.intp)
y_pred[:, k] = classes_k.take(mode)
if not self.outputs_2d_:
y_pred = y_pred.ravel()
return y_pred
def predict_proba(self, X):
"""Return probability estimates for the test data X.
Parameters
----------
X : array-like, shape (n_query, n_features), \
or (n_query, n_indexed) if metric == 'precomputed'
Test samples.
Returns
-------
p : array of shape = [n_samples, n_classes], or a list of n_outputs
of such arrays if n_outputs > 1.
The class probabilities of the input samples. Classes are ordered
by lexicographic order.
"""
X = check_array(X, accept_sparse='csr')
neigh_dist, neigh_ind = self.kneighbors(X)
classes_ = self.classes_
_y = self._y
if not self.outputs_2d_:
_y = self._y.reshape((-1, 1))
classes_ = [self.classes_]
n_samples = X.shape[0]
weights = _get_weights(neigh_dist, self.weights)
if weights is None:
weights = np.ones_like(neigh_ind)
all_rows = np.arange(X.shape[0])
probabilities = []
for k, classes_k in enumerate(classes_):
pred_labels = _y[:, k][neigh_ind]
proba_k = np.zeros((n_samples, classes_k.size))
# a simple ':' index doesn't work right
for i, idx in enumerate(pred_labels.T): # loop is O(n_neighbors)
proba_k[all_rows, idx] += weights[:, i]
# normalize 'votes' into real [0,1] probabilities
normalizer = proba_k.sum(axis=1)[:, np.newaxis]
normalizer[normalizer == 0.0] = 1.0
proba_k /= normalizer
probabilities.append(proba_k)
if not self.outputs_2d_:
probabilities = probabilities[0]
return probabilities
class RadiusNeighborsClassifier(NeighborsBase, RadiusNeighborsMixin,
SupervisedIntegerMixin, ClassifierMixin):
"""Classifier implementing a vote among neighbors within a given radius
Read more in the :ref:`User Guide <classification>`.
Parameters
----------
radius : float, optional (default = 1.0)
Range of parameter space to use by default for :meth:`radius_neighbors`
queries.
weights : str or callable
weight function used in prediction. Possible values:
- 'uniform' : uniform weights. All points in each neighborhood
are weighted equally.
- 'distance' : weight points by the inverse of their distance.
in this case, closer neighbors of a query point will have a
greater influence than neighbors which are further away.
- [callable] : a user-defined function which accepts an
array of distances, and returns an array of the same shape
containing the weights.
Uniform weights are used by default.
algorithm : {'auto', 'ball_tree', 'kd_tree', 'brute'}, optional
Algorithm used to compute the nearest neighbors:
- 'ball_tree' will use :class:`BallTree`
- 'kd_tree' will use :class:`KDTree`
- 'brute' will use a brute-force search.
- 'auto' will attempt to decide the most appropriate algorithm
based on the values passed to :meth:`fit` method.
Note: fitting on sparse input will override the setting of
this parameter, using brute force.
leaf_size : int, optional (default = 30)
Leaf size passed to BallTree or KDTree. This can affect the
speed of the construction and query, as well as the memory
required to store the tree. The optimal value depends on the
nature of the problem.
p : integer, optional (default = 2)
Power parameter for the Minkowski metric. When p = 1, this is
equivalent to using manhattan_distance (l1), and euclidean_distance
(l2) for p = 2. For arbitrary p, minkowski_distance (l_p) is used.
metric : string or callable, default 'minkowski'
the distance metric to use for the tree. The default metric is
minkowski, and with p=2 is equivalent to the standard Euclidean
metric. See the documentation of the DistanceMetric class for a
list of available metrics.
outlier_label : int, optional (default = None)
Label, which is given for outlier samples (samples with no
neighbors on given radius).
If set to None, ValueError is raised, when outlier is detected.
metric_params : dict, optional (default = None)
Additional keyword arguments for the metric function.
Examples
--------
>>> X = [[0], [1], [2], [3]]
>>> y = [0, 0, 1, 1]
>>> from sklearn.neighbors import RadiusNeighborsClassifier
>>> neigh = RadiusNeighborsClassifier(radius=1.0)
>>> neigh.fit(X, y) # doctest: +ELLIPSIS
RadiusNeighborsClassifier(...)
>>> print(neigh.predict([[1.5]]))
[0]
See also
--------
KNeighborsClassifier
RadiusNeighborsRegressor
KNeighborsRegressor
NearestNeighbors
Notes
-----
See :ref:`Nearest Neighbors <neighbors>` in the online documentation
for a discussion of the choice of ``algorithm`` and ``leaf_size``.
https://en.wikipedia.org/wiki/K-nearest_neighbor_algorithm
"""
def __init__(self, radius=1.0, weights='uniform',
algorithm='auto', leaf_size=30, p=2, metric='minkowski',
outlier_label=None, metric_params=None, **kwargs):
self._init_params(radius=radius,
algorithm=algorithm,
leaf_size=leaf_size,
metric=metric, p=p, metric_params=metric_params,
**kwargs)
self.weights = _check_weights(weights)
self.outlier_label = outlier_label
def predict(self, X):
"""Predict the class labels for the provided data
Parameters
----------
X : array-like, shape (n_query, n_features), \
or (n_query, n_indexed) if metric == 'precomputed'
Test samples.
Returns
-------
y : array of shape [n_samples] or [n_samples, n_outputs]
Class labels for each data sample.
"""
X = check_array(X, accept_sparse='csr')
n_samples = X.shape[0]
neigh_dist, neigh_ind = self.radius_neighbors(X)
inliers = [i for i, nind in enumerate(neigh_ind) if len(nind) != 0]
outliers = [i for i, nind in enumerate(neigh_ind) if len(nind) == 0]
classes_ = self.classes_
_y = self._y
if not self.outputs_2d_:
_y = self._y.reshape((-1, 1))
classes_ = [self.classes_]
n_outputs = len(classes_)
if self.outlier_label is not None:
neigh_dist[outliers] = 1e-6
elif outliers:
raise ValueError('No neighbors found for test samples %r, '
'you can try using larger radius, '
'give a label for outliers, '
'or consider removing them from your dataset.'
% outliers)
weights = _get_weights(neigh_dist, self.weights)
y_pred = np.empty((n_samples, n_outputs), dtype=classes_[0].dtype)
for k, classes_k in enumerate(classes_):
pred_labels = np.zeros(len(neigh_ind), dtype=object)
pred_labels[:] = [_y[ind, k] for ind in neigh_ind]
if weights is None:
mode = np.array([stats.mode(pl)[0]
for pl in pred_labels[inliers]], dtype=np.int)
else:
mode = np.array([weighted_mode(pl, w)[0]
for (pl, w)
in zip(pred_labels[inliers], weights[inliers])],
dtype=np.int)
mode = mode.ravel()
y_pred[inliers, k] = classes_k.take(mode)
if outliers:
y_pred[outliers, :] = self.outlier_label
if not self.outputs_2d_:
y_pred = y_pred.ravel()
return y_pred
| 14,338 | 35.672634 | 81 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/setup.py | import os
def configuration(parent_package='', top_path=None):
import numpy
from numpy.distutils.misc_util import Configuration
config = Configuration('neighbors', parent_package, top_path)
libraries = []
if os.name == 'posix':
libraries.append('m')
config.add_extension('ball_tree',
sources=['ball_tree.pyx'],
include_dirs=[numpy.get_include()],
libraries=libraries)
config.add_extension('kd_tree',
sources=['kd_tree.pyx'],
include_dirs=[numpy.get_include()],
libraries=libraries)
config.add_extension('dist_metrics',
sources=['dist_metrics.pyx'],
include_dirs=[numpy.get_include(),
os.path.join(numpy.get_include(),
'numpy')],
libraries=libraries)
config.add_extension('typedefs',
sources=['typedefs.pyx'],
include_dirs=[numpy.get_include()],
libraries=libraries)
config.add_extension("quad_tree",
sources=["quad_tree.pyx"],
include_dirs=[numpy.get_include()],
libraries=libraries)
config.add_subpackage('tests')
return config
| 1,460 | 33.785714 | 72 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/kde.py | """
Kernel Density Estimation
-------------------------
"""
# Author: Jake Vanderplas <[email protected]>
import numpy as np
from scipy.special import gammainc
from ..base import BaseEstimator
from ..utils import check_array, check_random_state
from ..utils.extmath import row_norms
from .ball_tree import BallTree, DTYPE
from .kd_tree import KDTree
VALID_KERNELS = ['gaussian', 'tophat', 'epanechnikov', 'exponential', 'linear',
'cosine']
TREE_DICT = {'ball_tree': BallTree, 'kd_tree': KDTree}
# TODO: implement a brute force version for testing purposes
# TODO: bandwidth estimation
# TODO: create a density estimation base class?
class KernelDensity(BaseEstimator):
"""Kernel Density Estimation
Read more in the :ref:`User Guide <kernel_density>`.
Parameters
----------
bandwidth : float
The bandwidth of the kernel.
algorithm : string
The tree algorithm to use. Valid options are
['kd_tree'|'ball_tree'|'auto']. Default is 'auto'.
kernel : string
The kernel to use. Valid kernels are
['gaussian'|'tophat'|'epanechnikov'|'exponential'|'linear'|'cosine']
Default is 'gaussian'.
metric : string
The distance metric to use. Note that not all metrics are
valid with all algorithms. Refer to the documentation of
:class:`BallTree` and :class:`KDTree` for a description of
available algorithms. Note that the normalization of the density
output is correct only for the Euclidean distance metric. Default
is 'euclidean'.
atol : float
The desired absolute tolerance of the result. A larger tolerance will
generally lead to faster execution. Default is 0.
rtol : float
The desired relative tolerance of the result. A larger tolerance will
generally lead to faster execution. Default is 1E-8.
breadth_first : boolean
If true (default), use a breadth-first approach to the problem.
Otherwise use a depth-first approach.
leaf_size : int
Specify the leaf size of the underlying tree. See :class:`BallTree`
or :class:`KDTree` for details. Default is 40.
metric_params : dict
Additional parameters to be passed to the tree for use with the
metric. For more information, see the documentation of
:class:`BallTree` or :class:`KDTree`.
"""
def __init__(self, bandwidth=1.0, algorithm='auto',
kernel='gaussian', metric="euclidean", atol=0, rtol=0,
breadth_first=True, leaf_size=40, metric_params=None):
self.algorithm = algorithm
self.bandwidth = bandwidth
self.kernel = kernel
self.metric = metric
self.atol = atol
self.rtol = rtol
self.breadth_first = breadth_first
self.leaf_size = leaf_size
self.metric_params = metric_params
# run the choose algorithm code so that exceptions will happen here
# we're using clone() in the GenerativeBayes classifier,
# so we can't do this kind of logic in __init__
self._choose_algorithm(self.algorithm, self.metric)
if bandwidth <= 0:
raise ValueError("bandwidth must be positive")
if kernel not in VALID_KERNELS:
raise ValueError("invalid kernel: '{0}'".format(kernel))
def _choose_algorithm(self, algorithm, metric):
# given the algorithm string + metric string, choose the optimal
# algorithm to compute the result.
if algorithm == 'auto':
# use KD Tree if possible
if metric in KDTree.valid_metrics:
return 'kd_tree'
elif metric in BallTree.valid_metrics:
return 'ball_tree'
else:
raise ValueError("invalid metric: '{0}'".format(metric))
elif algorithm in TREE_DICT:
if metric not in TREE_DICT[algorithm].valid_metrics:
raise ValueError("invalid metric for {0}: "
"'{1}'".format(TREE_DICT[algorithm],
metric))
return algorithm
else:
raise ValueError("invalid algorithm: '{0}'".format(algorithm))
def fit(self, X, y=None):
"""Fit the Kernel Density model on the data.
Parameters
----------
X : array_like, shape (n_samples, n_features)
List of n_features-dimensional data points. Each row
corresponds to a single data point.
"""
algorithm = self._choose_algorithm(self.algorithm, self.metric)
X = check_array(X, order='C', dtype=DTYPE)
kwargs = self.metric_params
if kwargs is None:
kwargs = {}
self.tree_ = TREE_DICT[algorithm](X, metric=self.metric,
leaf_size=self.leaf_size,
**kwargs)
return self
def score_samples(self, X):
"""Evaluate the density model on the data.
Parameters
----------
X : array_like, shape (n_samples, n_features)
An array of points to query. Last dimension should match dimension
of training data (n_features).
Returns
-------
density : ndarray, shape (n_samples,)
The array of log(density) evaluations.
"""
# The returned density is normalized to the number of points.
# For it to be a probability, we must scale it. For this reason
# we'll also scale atol.
X = check_array(X, order='C', dtype=DTYPE)
N = self.tree_.data.shape[0]
atol_N = self.atol * N
log_density = self.tree_.kernel_density(
X, h=self.bandwidth, kernel=self.kernel, atol=atol_N,
rtol=self.rtol, breadth_first=self.breadth_first, return_log=True)
log_density -= np.log(N)
return log_density
def score(self, X, y=None):
"""Compute the total log probability under the model.
Parameters
----------
X : array_like, shape (n_samples, n_features)
List of n_features-dimensional data points. Each row
corresponds to a single data point.
Returns
-------
logprob : float
Total log-likelihood of the data in X.
"""
return np.sum(self.score_samples(X))
def sample(self, n_samples=1, random_state=None):
"""Generate random samples from the model.
Currently, this is implemented only for gaussian and tophat kernels.
Parameters
----------
n_samples : int, optional
Number of samples to generate. Defaults to 1.
random_state : int, RandomState instance or None. default to None
If int, random_state is the seed used by the random number
generator; If RandomState instance, random_state is the random
number generator; If None, the random number generator is the
RandomState instance used by `np.random`.
Returns
-------
X : array_like, shape (n_samples, n_features)
List of samples.
"""
# TODO: implement sampling for other valid kernel shapes
if self.kernel not in ['gaussian', 'tophat']:
raise NotImplementedError()
data = np.asarray(self.tree_.data)
rng = check_random_state(random_state)
i = rng.randint(data.shape[0], size=n_samples)
if self.kernel == 'gaussian':
return np.atleast_2d(rng.normal(data[i], self.bandwidth))
elif self.kernel == 'tophat':
# we first draw points from a d-dimensional normal distribution,
# then use an incomplete gamma function to map them to a uniform
# d-dimensional tophat distribution.
dim = data.shape[1]
X = rng.normal(size=(n_samples, dim))
s_sq = row_norms(X, squared=True)
correction = (gammainc(0.5 * dim, 0.5 * s_sq) ** (1. / dim)
* self.bandwidth / np.sqrt(s_sq))
return data[i] + X * correction[:, np.newaxis]
| 8,218 | 36.359091 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/graph.py | """Nearest Neighbors graph functions"""
# Author: Jake Vanderplas <[email protected]>
#
# License: BSD 3 clause (C) INRIA, University of Amsterdam
from .base import KNeighborsMixin, RadiusNeighborsMixin
from .unsupervised import NearestNeighbors
def _check_params(X, metric, p, metric_params):
"""Check the validity of the input parameters"""
params = zip(['metric', 'p', 'metric_params'],
[metric, p, metric_params])
est_params = X.get_params()
for param_name, func_param in params:
if func_param != est_params[param_name]:
raise ValueError(
"Got %s for %s, while the estimator has %s for "
"the same parameter." % (
func_param, param_name, est_params[param_name]))
def _query_include_self(X, include_self):
"""Return the query based on include_self param"""
if include_self:
query = X._fit_X
else:
query = None
return query
def kneighbors_graph(X, n_neighbors, mode='connectivity', metric='minkowski',
p=2, metric_params=None, include_self=False, n_jobs=1):
"""Computes the (weighted) graph of k-Neighbors for points in X
Read more in the :ref:`User Guide <unsupervised_neighbors>`.
Parameters
----------
X : array-like or BallTree, shape = [n_samples, n_features]
Sample data, in the form of a numpy array or a precomputed
:class:`BallTree`.
n_neighbors : int
Number of neighbors for each sample.
mode : {'connectivity', 'distance'}, optional
Type of returned matrix: 'connectivity' will return the connectivity
matrix with ones and zeros, and 'distance' will return the distances
between neighbors according to the given metric.
metric : string, default 'minkowski'
The distance metric used to calculate the k-Neighbors for each sample
point. The DistanceMetric class gives a list of available metrics.
The default distance is 'euclidean' ('minkowski' metric with the p
param equal to 2.)
p : int, default 2
Power parameter for the Minkowski metric. When p = 1, this is
equivalent to using manhattan_distance (l1), and euclidean_distance
(l2) for p = 2. For arbitrary p, minkowski_distance (l_p) is used.
metric_params : dict, optional
additional keyword arguments for the metric function.
include_self : bool, default=False.
Whether or not to mark each sample as the first nearest neighbor to
itself. If `None`, then True is used for mode='connectivity' and False
for mode='distance' as this will preserve backwards compatibilty.
n_jobs : int, optional (default = 1)
The number of parallel jobs to run for neighbors search.
If ``-1``, then the number of jobs is set to the number of CPU cores.
Returns
-------
A : sparse matrix in CSR format, shape = [n_samples, n_samples]
A[i, j] is assigned the weight of edge that connects i to j.
Examples
--------
>>> X = [[0], [3], [1]]
>>> from sklearn.neighbors import kneighbors_graph
>>> A = kneighbors_graph(X, 2, mode='connectivity', include_self=True)
>>> A.toarray()
array([[ 1., 0., 1.],
[ 0., 1., 1.],
[ 1., 0., 1.]])
See also
--------
radius_neighbors_graph
"""
if not isinstance(X, KNeighborsMixin):
X = NearestNeighbors(n_neighbors, metric=metric, p=p,
metric_params=metric_params, n_jobs=n_jobs).fit(X)
else:
_check_params(X, metric, p, metric_params)
query = _query_include_self(X, include_self)
return X.kneighbors_graph(X=query, n_neighbors=n_neighbors, mode=mode)
def radius_neighbors_graph(X, radius, mode='connectivity', metric='minkowski',
p=2, metric_params=None, include_self=False, n_jobs=1):
"""Computes the (weighted) graph of Neighbors for points in X
Neighborhoods are restricted the points at a distance lower than
radius.
Read more in the :ref:`User Guide <unsupervised_neighbors>`.
Parameters
----------
X : array-like or BallTree, shape = [n_samples, n_features]
Sample data, in the form of a numpy array or a precomputed
:class:`BallTree`.
radius : float
Radius of neighborhoods.
mode : {'connectivity', 'distance'}, optional
Type of returned matrix: 'connectivity' will return the connectivity
matrix with ones and zeros, and 'distance' will return the distances
between neighbors according to the given metric.
metric : string, default 'minkowski'
The distance metric used to calculate the neighbors within a
given radius for each sample point. The DistanceMetric class
gives a list of available metrics. The default distance is
'euclidean' ('minkowski' metric with the param equal to 2.)
p : int, default 2
Power parameter for the Minkowski metric. When p = 1, this is
equivalent to using manhattan_distance (l1), and euclidean_distance
(l2) for p = 2. For arbitrary p, minkowski_distance (l_p) is used.
metric_params : dict, optional
additional keyword arguments for the metric function.
include_self : bool, default=False
Whether or not to mark each sample as the first nearest neighbor to
itself. If `None`, then True is used for mode='connectivity' and False
for mode='distance' as this will preserve backwards compatibilty.
n_jobs : int, optional (default = 1)
The number of parallel jobs to run for neighbors search.
If ``-1``, then the number of jobs is set to the number of CPU cores.
Returns
-------
A : sparse matrix in CSR format, shape = [n_samples, n_samples]
A[i, j] is assigned the weight of edge that connects i to j.
Examples
--------
>>> X = [[0], [3], [1]]
>>> from sklearn.neighbors import radius_neighbors_graph
>>> A = radius_neighbors_graph(X, 1.5, mode='connectivity', include_self=True)
>>> A.toarray()
array([[ 1., 0., 1.],
[ 0., 1., 0.],
[ 1., 0., 1.]])
See also
--------
kneighbors_graph
"""
if not isinstance(X, RadiusNeighborsMixin):
X = NearestNeighbors(radius=radius, metric=metric, p=p,
metric_params=metric_params, n_jobs=n_jobs).fit(X)
else:
_check_params(X, metric, p, metric_params)
query = _query_include_self(X, include_self)
return X.radius_neighbors_graph(query, radius, mode)
| 6,650 | 36.156425 | 82 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/approximate.py | """Approximate nearest neighbor search"""
# Author: Maheshakya Wijewardena <[email protected]>
# Joel Nothman <[email protected]>
import numpy as np
import warnings
from scipy import sparse
from .base import KNeighborsMixin, RadiusNeighborsMixin
from ..base import BaseEstimator
from ..utils.validation import check_array
from ..utils import check_random_state
from ..metrics.pairwise import pairwise_distances
from ..random_projection import GaussianRandomProjection
__all__ = ["LSHForest"]
HASH_DTYPE = '>u4'
MAX_HASH_SIZE = np.dtype(HASH_DTYPE).itemsize * 8
def _find_matching_indices(tree, bin_X, left_mask, right_mask):
"""Finds indices in sorted array of integers.
Most significant h bits in the binary representations of the
integers are matched with the items' most significant h bits.
"""
left_index = np.searchsorted(tree, bin_X & left_mask)
right_index = np.searchsorted(tree, bin_X | right_mask,
side='right')
return left_index, right_index
def _find_longest_prefix_match(tree, bin_X, hash_size,
left_masks, right_masks):
"""Find the longest prefix match in tree for each query in bin_X
Most significant bits are considered as the prefix.
"""
hi = np.empty_like(bin_X, dtype=np.intp)
hi.fill(hash_size)
lo = np.zeros_like(bin_X, dtype=np.intp)
res = np.empty_like(bin_X, dtype=np.intp)
left_idx, right_idx = _find_matching_indices(tree, bin_X,
left_masks[hi],
right_masks[hi])
found = right_idx > left_idx
res[found] = lo[found] = hash_size
r = np.arange(bin_X.shape[0])
kept = r[lo < hi] # indices remaining in bin_X mask
while kept.shape[0]:
mid = (lo.take(kept) + hi.take(kept)) // 2
left_idx, right_idx = _find_matching_indices(tree,
bin_X.take(kept),
left_masks[mid],
right_masks[mid])
found = right_idx > left_idx
mid_found = mid[found]
lo[kept[found]] = mid_found + 1
res[kept[found]] = mid_found
hi[kept[~found]] = mid[~found]
kept = r[lo < hi]
return res
class ProjectionToHashMixin(object):
"""Turn a transformed real-valued array into a hash"""
@staticmethod
def _to_hash(projected):
if projected.shape[1] % 8 != 0:
raise ValueError('Require reduced dimensionality to be a multiple '
'of 8 for hashing')
# XXX: perhaps non-copying operation better
out = np.packbits((projected > 0).astype(int)).view(dtype=HASH_DTYPE)
return out.reshape(projected.shape[0], -1)
def fit_transform(self, X, y=None):
self.fit(X)
return self.transform(X)
def transform(self, X):
return self._to_hash(super(ProjectionToHashMixin, self).transform(X))
class GaussianRandomProjectionHash(ProjectionToHashMixin,
GaussianRandomProjection):
"""Use GaussianRandomProjection to produce a cosine LSH fingerprint"""
def __init__(self,
n_components=32,
random_state=None):
super(GaussianRandomProjectionHash, self).__init__(
n_components=n_components,
random_state=random_state)
def _array_of_arrays(list_of_arrays):
"""Creates an array of array from list of arrays."""
out = np.empty(len(list_of_arrays), dtype=object)
out[:] = list_of_arrays
return out
class LSHForest(BaseEstimator, KNeighborsMixin, RadiusNeighborsMixin):
"""Performs approximate nearest neighbor search using LSH forest.
LSH Forest: Locality Sensitive Hashing forest [1] is an alternative
method for vanilla approximate nearest neighbor search methods.
LSH forest data structure has been implemented using sorted
arrays and binary search and 32 bit fixed-length hashes.
Random projection is used as the hash family which approximates
cosine distance.
The cosine distance is defined as ``1 - cosine_similarity``: the lowest
value is 0 (identical point) but it is bounded above by 2 for the farthest
points. Its value does not depend on the norm of the vector points but
only on their relative angles.
Parameters
----------
n_estimators : int (default = 10)
Number of trees in the LSH Forest.
radius : float, optinal (default = 1.0)
Radius from the data point to its neighbors. This is the parameter
space to use by default for the :meth:`radius_neighbors` queries.
n_candidates : int (default = 50)
Minimum number of candidates evaluated per estimator, assuming enough
items meet the `min_hash_match` constraint.
n_neighbors : int (default = 5)
Number of neighbors to be returned from query function when
it is not provided to the :meth:`kneighbors` method.
min_hash_match : int (default = 4)
lowest hash length to be searched when candidate selection is
performed for nearest neighbors.
radius_cutoff_ratio : float, optional (default = 0.9)
A value ranges from 0 to 1. Radius neighbors will be searched until
the ratio between total neighbors within the radius and the total
candidates becomes less than this value unless it is terminated by
hash length reaching `min_hash_match`.
random_state : int, RandomState instance or None, optional (default=None)
If int, random_state is the seed used by the random number generator;
If RandomState instance, random_state is the random number generator;
If None, the random number generator is the RandomState instance used
by `np.random`.
Attributes
----------
hash_functions_ : list of GaussianRandomProjectionHash objects
Hash function g(p,x) for a tree is an array of 32 randomly generated
float arrays with the same dimension as the data set. This array is
stored in GaussianRandomProjectionHash object and can be obtained
from ``components_`` attribute.
trees_ : array, shape (n_estimators, n_samples)
Each tree (corresponding to a hash function) contains an array of
sorted hashed values. The array representation may change in future
versions.
original_indices_ : array, shape (n_estimators, n_samples)
Original indices of sorted hashed values in the fitted index.
References
----------
.. [1] M. Bawa, T. Condie and P. Ganesan, "LSH Forest: Self-Tuning
Indexes for Similarity Search", WWW '05 Proceedings of the
14th international conference on World Wide Web, 651-660,
2005.
Examples
--------
>>> from sklearn.neighbors import LSHForest
>>> X_train = [[5, 5, 2], [21, 5, 5], [1, 1, 1], [8, 9, 1], [6, 10, 2]]
>>> X_test = [[9, 1, 6], [3, 1, 10], [7, 10, 3]]
>>> lshf = LSHForest(random_state=42)
>>> lshf.fit(X_train) # doctest: +NORMALIZE_WHITESPACE
LSHForest(min_hash_match=4, n_candidates=50, n_estimators=10,
n_neighbors=5, radius=1.0, radius_cutoff_ratio=0.9,
random_state=42)
>>> distances, indices = lshf.kneighbors(X_test, n_neighbors=2)
>>> distances # doctest: +ELLIPSIS
array([[ 0.069..., 0.149...],
[ 0.229..., 0.481...],
[ 0.004..., 0.014...]])
>>> indices
array([[1, 2],
[2, 0],
[4, 0]])
"""
def __init__(self, n_estimators=10, radius=1.0, n_candidates=50,
n_neighbors=5, min_hash_match=4, radius_cutoff_ratio=.9,
random_state=None):
self.n_estimators = n_estimators
self.radius = radius
self.random_state = random_state
self.n_candidates = n_candidates
self.n_neighbors = n_neighbors
self.min_hash_match = min_hash_match
self.radius_cutoff_ratio = radius_cutoff_ratio
warnings.warn("LSHForest has poor performance and has been deprecated "
"in 0.19. It will be removed in version 0.21.",
DeprecationWarning)
def _compute_distances(self, query, candidates):
"""Computes the cosine distance.
Distance is from the query to points in the candidates array.
Returns argsort of distances in the candidates
array and sorted distances.
"""
if candidates.shape == (0,):
# needed since _fit_X[np.array([])] doesn't work if _fit_X sparse
return np.empty(0, dtype=np.int), np.empty(0, dtype=float)
if sparse.issparse(self._fit_X):
candidate_X = self._fit_X[candidates]
else:
candidate_X = self._fit_X.take(candidates, axis=0, mode='clip')
distances = pairwise_distances(query, candidate_X,
metric='cosine')[0]
distance_positions = np.argsort(distances)
distances = distances.take(distance_positions, mode='clip', axis=0)
return distance_positions, distances
def _generate_masks(self):
"""Creates left and right masks for all hash lengths."""
tri_size = MAX_HASH_SIZE + 1
# Called once on fitting, output is independent of hashes
left_mask = np.tril(np.ones((tri_size, tri_size), dtype=int))[:, 1:]
right_mask = left_mask[::-1, ::-1]
self._left_mask = np.packbits(left_mask).view(dtype=HASH_DTYPE)
self._right_mask = np.packbits(right_mask).view(dtype=HASH_DTYPE)
def _get_candidates(self, query, max_depth, bin_queries, n_neighbors):
"""Performs the Synchronous ascending phase.
Returns an array of candidates, their distance ranks and
distances.
"""
index_size = self._fit_X.shape[0]
# Number of candidates considered including duplicates
# XXX: not sure whether this is being calculated correctly wrt
# duplicates from different iterations through a single tree
n_candidates = 0
candidate_set = set()
min_candidates = self.n_candidates * self.n_estimators
while (max_depth > self.min_hash_match and
(n_candidates < min_candidates or
len(candidate_set) < n_neighbors)):
left_mask = self._left_mask[max_depth]
right_mask = self._right_mask[max_depth]
for i in range(self.n_estimators):
start, stop = _find_matching_indices(self.trees_[i],
bin_queries[i],
left_mask, right_mask)
n_candidates += stop - start
candidate_set.update(
self.original_indices_[i][start:stop].tolist())
max_depth -= 1
candidates = np.fromiter(candidate_set, count=len(candidate_set),
dtype=np.intp)
# For insufficient candidates, candidates are filled.
# Candidates are filled from unselected indices uniformly.
if candidates.shape[0] < n_neighbors:
warnings.warn(
"Number of candidates is not sufficient to retrieve"
" %i neighbors with"
" min_hash_match = %i. Candidates are filled up"
" uniformly from unselected"
" indices." % (n_neighbors, self.min_hash_match))
remaining = np.setdiff1d(np.arange(0, index_size), candidates)
to_fill = n_neighbors - candidates.shape[0]
candidates = np.concatenate((candidates, remaining[:to_fill]))
ranks, distances = self._compute_distances(query,
candidates.astype(int))
return (candidates[ranks[:n_neighbors]],
distances[:n_neighbors])
def _get_radius_neighbors(self, query, max_depth, bin_queries, radius):
"""Finds radius neighbors from the candidates obtained.
Their distances from query are smaller than radius.
Returns radius neighbors and distances.
"""
ratio_within_radius = 1
threshold = 1 - self.radius_cutoff_ratio
total_candidates = np.array([], dtype=int)
total_neighbors = np.array([], dtype=int)
total_distances = np.array([], dtype=float)
while (max_depth > self.min_hash_match and
ratio_within_radius > threshold):
left_mask = self._left_mask[max_depth]
right_mask = self._right_mask[max_depth]
candidates = []
for i in range(self.n_estimators):
start, stop = _find_matching_indices(self.trees_[i],
bin_queries[i],
left_mask, right_mask)
candidates.extend(
self.original_indices_[i][start:stop].tolist())
candidates = np.setdiff1d(candidates, total_candidates)
total_candidates = np.append(total_candidates, candidates)
ranks, distances = self._compute_distances(query, candidates)
m = np.searchsorted(distances, radius, side='right')
positions = np.searchsorted(total_distances, distances[:m])
total_neighbors = np.insert(total_neighbors, positions,
candidates[ranks[:m]])
total_distances = np.insert(total_distances, positions,
distances[:m])
ratio_within_radius = (total_neighbors.shape[0] /
float(total_candidates.shape[0]))
max_depth = max_depth - 1
return total_neighbors, total_distances
def fit(self, X, y=None):
"""Fit the LSH forest on the data.
This creates binary hashes of input data points by getting the
dot product of input points and hash_function then
transforming the projection into a binary string array based
on the sign (positive/negative) of the projection.
A sorted array of binary hashes is created.
Parameters
----------
X : array_like or sparse (CSR) matrix, shape (n_samples, n_features)
List of n_features-dimensional data points. Each row
corresponds to a single data point.
Returns
-------
self : object
Returns self.
"""
self._fit_X = check_array(X, accept_sparse='csr')
# Creates a g(p,x) for each tree
self.hash_functions_ = []
self.trees_ = []
self.original_indices_ = []
rng = check_random_state(self.random_state)
int_max = np.iinfo(np.int32).max
for i in range(self.n_estimators):
# This is g(p,x) for a particular tree.
# Builds a single tree. Hashing is done on an array of data points.
# `GaussianRandomProjection` is used for hashing.
# `n_components=hash size and n_features=n_dim.
hasher = GaussianRandomProjectionHash(MAX_HASH_SIZE,
rng.randint(0, int_max))
hashes = hasher.fit_transform(self._fit_X)[:, 0]
original_index = np.argsort(hashes)
bin_hashes = hashes[original_index]
self.original_indices_.append(original_index)
self.trees_.append(bin_hashes)
self.hash_functions_.append(hasher)
self._generate_masks()
return self
def _query(self, X):
"""Performs descending phase to find maximum depth."""
# Calculate hashes of shape (n_samples, n_estimators, [hash_size])
bin_queries = np.asarray([hasher.transform(X)[:, 0]
for hasher in self.hash_functions_])
bin_queries = np.rollaxis(bin_queries, 1)
# descend phase
depths = [_find_longest_prefix_match(tree, tree_queries, MAX_HASH_SIZE,
self._left_mask, self._right_mask)
for tree, tree_queries in zip(self.trees_,
np.rollaxis(bin_queries, 1))]
return bin_queries, np.max(depths, axis=0)
def kneighbors(self, X, n_neighbors=None, return_distance=True):
"""Returns n_neighbors of approximate nearest neighbors.
Parameters
----------
X : array_like or sparse (CSR) matrix, shape (n_samples, n_features)
List of n_features-dimensional data points. Each row
corresponds to a single query.
n_neighbors : int, optional (default = None)
Number of neighbors required. If not provided, this will
return the number specified at the initialization.
return_distance : boolean, optional (default = True)
Returns the distances of neighbors if set to True.
Returns
-------
dist : array, shape (n_samples, n_neighbors)
Array representing the cosine distances to each point,
only present if return_distance=True.
ind : array, shape (n_samples, n_neighbors)
Indices of the approximate nearest points in the population
matrix.
"""
if not hasattr(self, 'hash_functions_'):
raise ValueError("estimator should be fitted.")
if n_neighbors is None:
n_neighbors = self.n_neighbors
X = check_array(X, accept_sparse='csr')
neighbors, distances = [], []
bin_queries, max_depth = self._query(X)
for i in range(X.shape[0]):
neighs, dists = self._get_candidates(X[[i]], max_depth[i],
bin_queries[i],
n_neighbors)
neighbors.append(neighs)
distances.append(dists)
if return_distance:
return np.array(distances), np.array(neighbors)
else:
return np.array(neighbors)
def radius_neighbors(self, X, radius=None, return_distance=True):
"""Finds the neighbors within a given radius of a point or points.
Return the indices and distances of some points from the dataset
lying in a ball with size ``radius`` around the points of the query
array. Points lying on the boundary are included in the results.
The result points are *not* necessarily sorted by distance to their
query point.
LSH Forest being an approximate method, some true neighbors from the
indexed dataset might be missing from the results.
Parameters
----------
X : array_like or sparse (CSR) matrix, shape (n_samples, n_features)
List of n_features-dimensional data points. Each row
corresponds to a single query.
radius : float
Limiting distance of neighbors to return.
(default is the value passed to the constructor).
return_distance : boolean, optional (default = False)
Returns the distances of neighbors if set to True.
Returns
-------
dist : array, shape (n_samples,) of arrays
Each element is an array representing the cosine distances
to some points found within ``radius`` of the respective query.
Only present if ``return_distance=True``.
ind : array, shape (n_samples,) of arrays
Each element is an array of indices for neighbors within ``radius``
of the respective query.
"""
if not hasattr(self, 'hash_functions_'):
raise ValueError("estimator should be fitted.")
if radius is None:
radius = self.radius
X = check_array(X, accept_sparse='csr')
neighbors, distances = [], []
bin_queries, max_depth = self._query(X)
for i in range(X.shape[0]):
neighs, dists = self._get_radius_neighbors(X[[i]], max_depth[i],
bin_queries[i], radius)
neighbors.append(neighs)
distances.append(dists)
if return_distance:
return _array_of_arrays(distances), _array_of_arrays(neighbors)
else:
return _array_of_arrays(neighbors)
def partial_fit(self, X, y=None):
"""
Inserts new data into the already fitted LSH Forest.
Cost is proportional to new total size, so additions
should be batched.
Parameters
----------
X : array_like or sparse (CSR) matrix, shape (n_samples, n_features)
New data point to be inserted into the LSH Forest.
"""
X = check_array(X, accept_sparse='csr')
if not hasattr(self, 'hash_functions_'):
return self.fit(X)
if X.shape[1] != self._fit_X.shape[1]:
raise ValueError("Number of features in X and"
" fitted array does not match.")
n_samples = X.shape[0]
n_indexed = self._fit_X.shape[0]
for i in range(self.n_estimators):
bin_X = self.hash_functions_[i].transform(X)[:, 0]
# gets the position to be added in the tree.
positions = self.trees_[i].searchsorted(bin_X)
# adds the hashed value into the tree.
self.trees_[i] = np.insert(self.trees_[i],
positions, bin_X)
# add the entry into the original_indices_.
self.original_indices_[i] = np.insert(self.original_indices_[i],
positions,
np.arange(n_indexed,
n_indexed +
n_samples))
# adds the entry into the input_array.
if sparse.issparse(X) or sparse.issparse(self._fit_X):
self._fit_X = sparse.vstack((self._fit_X, X))
else:
self._fit_X = np.row_stack((self._fit_X, X))
return self
| 22,482 | 39.65642 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/regression.py | """Nearest Neighbor Regression"""
# Authors: Jake Vanderplas <[email protected]>
# Fabian Pedregosa <[email protected]>
# Alexandre Gramfort <[email protected]>
# Sparseness support by Lars Buitinck
# Multi-output support by Arnaud Joly <[email protected]>
#
# License: BSD 3 clause (C) INRIA, University of Amsterdam
import numpy as np
from .base import _get_weights, _check_weights, NeighborsBase, KNeighborsMixin
from .base import RadiusNeighborsMixin, SupervisedFloatMixin
from ..base import RegressorMixin
from ..utils import check_array
class KNeighborsRegressor(NeighborsBase, KNeighborsMixin,
SupervisedFloatMixin,
RegressorMixin):
"""Regression based on k-nearest neighbors.
The target is predicted by local interpolation of the targets
associated of the nearest neighbors in the training set.
Read more in the :ref:`User Guide <regression>`.
Parameters
----------
n_neighbors : int, optional (default = 5)
Number of neighbors to use by default for :meth:`kneighbors` queries.
weights : str or callable
weight function used in prediction. Possible values:
- 'uniform' : uniform weights. All points in each neighborhood
are weighted equally.
- 'distance' : weight points by the inverse of their distance.
in this case, closer neighbors of a query point will have a
greater influence than neighbors which are further away.
- [callable] : a user-defined function which accepts an
array of distances, and returns an array of the same shape
containing the weights.
Uniform weights are used by default.
algorithm : {'auto', 'ball_tree', 'kd_tree', 'brute'}, optional
Algorithm used to compute the nearest neighbors:
- 'ball_tree' will use :class:`BallTree`
- 'kd_tree' will use :class:`KDTree`
- 'brute' will use a brute-force search.
- 'auto' will attempt to decide the most appropriate algorithm
based on the values passed to :meth:`fit` method.
Note: fitting on sparse input will override the setting of
this parameter, using brute force.
leaf_size : int, optional (default = 30)
Leaf size passed to BallTree or KDTree. This can affect the
speed of the construction and query, as well as the memory
required to store the tree. The optimal value depends on the
nature of the problem.
p : integer, optional (default = 2)
Power parameter for the Minkowski metric. When p = 1, this is
equivalent to using manhattan_distance (l1), and euclidean_distance
(l2) for p = 2. For arbitrary p, minkowski_distance (l_p) is used.
metric : string or callable, default 'minkowski'
the distance metric to use for the tree. The default metric is
minkowski, and with p=2 is equivalent to the standard Euclidean
metric. See the documentation of the DistanceMetric class for a
list of available metrics.
metric_params : dict, optional (default = None)
Additional keyword arguments for the metric function.
n_jobs : int, optional (default = 1)
The number of parallel jobs to run for neighbors search.
If ``-1``, then the number of jobs is set to the number of CPU cores.
Doesn't affect :meth:`fit` method.
Examples
--------
>>> X = [[0], [1], [2], [3]]
>>> y = [0, 0, 1, 1]
>>> from sklearn.neighbors import KNeighborsRegressor
>>> neigh = KNeighborsRegressor(n_neighbors=2)
>>> neigh.fit(X, y) # doctest: +ELLIPSIS
KNeighborsRegressor(...)
>>> print(neigh.predict([[1.5]]))
[ 0.5]
See also
--------
NearestNeighbors
RadiusNeighborsRegressor
KNeighborsClassifier
RadiusNeighborsClassifier
Notes
-----
See :ref:`Nearest Neighbors <neighbors>` in the online documentation
for a discussion of the choice of ``algorithm`` and ``leaf_size``.
.. warning::
Regarding the Nearest Neighbors algorithms, if it is found that two
neighbors, neighbor `k+1` and `k`, have identical distances but
different labels, the results will depend on the ordering of the
training data.
https://en.wikipedia.org/wiki/K-nearest_neighbor_algorithm
"""
def __init__(self, n_neighbors=5, weights='uniform',
algorithm='auto', leaf_size=30,
p=2, metric='minkowski', metric_params=None, n_jobs=1,
**kwargs):
self._init_params(n_neighbors=n_neighbors,
algorithm=algorithm,
leaf_size=leaf_size, metric=metric, p=p,
metric_params=metric_params, n_jobs=n_jobs, **kwargs)
self.weights = _check_weights(weights)
def predict(self, X):
"""Predict the target for the provided data
Parameters
----------
X : array-like, shape (n_query, n_features), \
or (n_query, n_indexed) if metric == 'precomputed'
Test samples.
Returns
-------
y : array of int, shape = [n_samples] or [n_samples, n_outputs]
Target values
"""
X = check_array(X, accept_sparse='csr')
neigh_dist, neigh_ind = self.kneighbors(X)
weights = _get_weights(neigh_dist, self.weights)
_y = self._y
if _y.ndim == 1:
_y = _y.reshape((-1, 1))
if weights is None:
y_pred = np.mean(_y[neigh_ind], axis=1)
else:
y_pred = np.empty((X.shape[0], _y.shape[1]), dtype=np.float64)
denom = np.sum(weights, axis=1)
for j in range(_y.shape[1]):
num = np.sum(_y[neigh_ind, j] * weights, axis=1)
y_pred[:, j] = num / denom
if self._y.ndim == 1:
y_pred = y_pred.ravel()
return y_pred
class RadiusNeighborsRegressor(NeighborsBase, RadiusNeighborsMixin,
SupervisedFloatMixin,
RegressorMixin):
"""Regression based on neighbors within a fixed radius.
The target is predicted by local interpolation of the targets
associated of the nearest neighbors in the training set.
Read more in the :ref:`User Guide <regression>`.
Parameters
----------
radius : float, optional (default = 1.0)
Range of parameter space to use by default for :meth:`radius_neighbors`
queries.
weights : str or callable
weight function used in prediction. Possible values:
- 'uniform' : uniform weights. All points in each neighborhood
are weighted equally.
- 'distance' : weight points by the inverse of their distance.
in this case, closer neighbors of a query point will have a
greater influence than neighbors which are further away.
- [callable] : a user-defined function which accepts an
array of distances, and returns an array of the same shape
containing the weights.
Uniform weights are used by default.
algorithm : {'auto', 'ball_tree', 'kd_tree', 'brute'}, optional
Algorithm used to compute the nearest neighbors:
- 'ball_tree' will use :class:`BallTree`
- 'kd_tree' will use :class:`KDTree`
- 'brute' will use a brute-force search.
- 'auto' will attempt to decide the most appropriate algorithm
based on the values passed to :meth:`fit` method.
Note: fitting on sparse input will override the setting of
this parameter, using brute force.
leaf_size : int, optional (default = 30)
Leaf size passed to BallTree or KDTree. This can affect the
speed of the construction and query, as well as the memory
required to store the tree. The optimal value depends on the
nature of the problem.
p : integer, optional (default = 2)
Power parameter for the Minkowski metric. When p = 1, this is
equivalent to using manhattan_distance (l1), and euclidean_distance
(l2) for p = 2. For arbitrary p, minkowski_distance (l_p) is used.
metric : string or callable, default 'minkowski'
the distance metric to use for the tree. The default metric is
minkowski, and with p=2 is equivalent to the standard Euclidean
metric. See the documentation of the DistanceMetric class for a
list of available metrics.
metric_params : dict, optional (default = None)
Additional keyword arguments for the metric function.
Examples
--------
>>> X = [[0], [1], [2], [3]]
>>> y = [0, 0, 1, 1]
>>> from sklearn.neighbors import RadiusNeighborsRegressor
>>> neigh = RadiusNeighborsRegressor(radius=1.0)
>>> neigh.fit(X, y) # doctest: +ELLIPSIS
RadiusNeighborsRegressor(...)
>>> print(neigh.predict([[1.5]]))
[ 0.5]
See also
--------
NearestNeighbors
KNeighborsRegressor
KNeighborsClassifier
RadiusNeighborsClassifier
Notes
-----
See :ref:`Nearest Neighbors <neighbors>` in the online documentation
for a discussion of the choice of ``algorithm`` and ``leaf_size``.
https://en.wikipedia.org/wiki/K-nearest_neighbor_algorithm
"""
def __init__(self, radius=1.0, weights='uniform',
algorithm='auto', leaf_size=30,
p=2, metric='minkowski', metric_params=None, **kwargs):
self._init_params(radius=radius,
algorithm=algorithm,
leaf_size=leaf_size,
p=p, metric=metric, metric_params=metric_params,
**kwargs)
self.weights = _check_weights(weights)
def predict(self, X):
"""Predict the target for the provided data
Parameters
----------
X : array-like, shape (n_query, n_features), \
or (n_query, n_indexed) if metric == 'precomputed'
Test samples.
Returns
-------
y : array of int, shape = [n_samples] or [n_samples, n_outputs]
Target values
"""
X = check_array(X, accept_sparse='csr')
neigh_dist, neigh_ind = self.radius_neighbors(X)
weights = _get_weights(neigh_dist, self.weights)
_y = self._y
if _y.ndim == 1:
_y = _y.reshape((-1, 1))
if weights is None:
y_pred = np.array([np.mean(_y[ind, :], axis=0)
for ind in neigh_ind])
else:
y_pred = np.array([(np.average(_y[ind, :], axis=0,
weights=weights[i]))
for (i, ind) in enumerate(neigh_ind)])
if self._y.ndim == 1:
y_pred = y_pred.ravel()
return y_pred
| 10,967 | 35.317881 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/nearest_centroid.py | # -*- coding: utf-8 -*-
"""
Nearest Centroid Classification
"""
# Author: Robert Layton <[email protected]>
# Olivier Grisel <[email protected]>
#
# License: BSD 3 clause
import warnings
import numpy as np
from scipy import sparse as sp
from ..base import BaseEstimator, ClassifierMixin
from ..metrics.pairwise import pairwise_distances
from ..preprocessing import LabelEncoder
from ..utils.validation import check_array, check_X_y, check_is_fitted
from ..utils.sparsefuncs import csc_median_axis_0
from ..utils.multiclass import check_classification_targets
class NearestCentroid(BaseEstimator, ClassifierMixin):
"""Nearest centroid classifier.
Each class is represented by its centroid, with test samples classified to
the class with the nearest centroid.
Read more in the :ref:`User Guide <nearest_centroid_classifier>`.
Parameters
----------
metric : string, or callable
The metric to use when calculating distance between instances in a
feature array. If metric is a string or callable, it must be one of
the options allowed by metrics.pairwise.pairwise_distances for its
metric parameter.
The centroids for the samples corresponding to each class is the point
from which the sum of the distances (according to the metric) of all
samples that belong to that particular class are minimized.
If the "manhattan" metric is provided, this centroid is the median and
for all other metrics, the centroid is now set to be the mean.
shrink_threshold : float, optional (default = None)
Threshold for shrinking centroids to remove features.
Attributes
----------
centroids_ : array-like, shape = [n_classes, n_features]
Centroid of each class
Examples
--------
>>> from sklearn.neighbors.nearest_centroid import NearestCentroid
>>> import numpy as np
>>> X = np.array([[-1, -1], [-2, -1], [-3, -2], [1, 1], [2, 1], [3, 2]])
>>> y = np.array([1, 1, 1, 2, 2, 2])
>>> clf = NearestCentroid()
>>> clf.fit(X, y)
NearestCentroid(metric='euclidean', shrink_threshold=None)
>>> print(clf.predict([[-0.8, -1]]))
[1]
See also
--------
sklearn.neighbors.KNeighborsClassifier: nearest neighbors classifier
Notes
-----
When used for text classification with tf-idf vectors, this classifier is
also known as the Rocchio classifier.
References
----------
Tibshirani, R., Hastie, T., Narasimhan, B., & Chu, G. (2002). Diagnosis of
multiple cancer types by shrunken centroids of gene expression. Proceedings
of the National Academy of Sciences of the United States of America,
99(10), 6567-6572. The National Academy of Sciences.
"""
def __init__(self, metric='euclidean', shrink_threshold=None):
self.metric = metric
self.shrink_threshold = shrink_threshold
def fit(self, X, y):
"""
Fit the NearestCentroid model according to the given training data.
Parameters
----------
X : {array-like, sparse matrix}, shape = [n_samples, n_features]
Training vector, where n_samples in the number of samples and
n_features is the number of features.
Note that centroid shrinking cannot be used with sparse matrices.
y : array, shape = [n_samples]
Target values (integers)
"""
if self.metric == 'precomputed':
raise ValueError("Precomputed is not supported.")
# If X is sparse and the metric is "manhattan", store it in a csc
# format is easier to calculate the median.
if self.metric == 'manhattan':
X, y = check_X_y(X, y, ['csc'])
else:
X, y = check_X_y(X, y, ['csr', 'csc'])
is_X_sparse = sp.issparse(X)
if is_X_sparse and self.shrink_threshold:
raise ValueError("threshold shrinking not supported"
" for sparse input")
check_classification_targets(y)
n_samples, n_features = X.shape
le = LabelEncoder()
y_ind = le.fit_transform(y)
self.classes_ = classes = le.classes_
n_classes = classes.size
if n_classes < 2:
raise ValueError('y has less than 2 classes')
# Mask mapping each class to its members.
self.centroids_ = np.empty((n_classes, n_features), dtype=np.float64)
# Number of clusters in each class.
nk = np.zeros(n_classes)
for cur_class in range(n_classes):
center_mask = y_ind == cur_class
nk[cur_class] = np.sum(center_mask)
if is_X_sparse:
center_mask = np.where(center_mask)[0]
# XXX: Update other averaging methods according to the metrics.
if self.metric == "manhattan":
# NumPy does not calculate median of sparse matrices.
if not is_X_sparse:
self.centroids_[cur_class] = np.median(X[center_mask], axis=0)
else:
self.centroids_[cur_class] = csc_median_axis_0(X[center_mask])
else:
if self.metric != 'euclidean':
warnings.warn("Averaging for metrics other than "
"euclidean and manhattan not supported. "
"The average is set to be the mean."
)
self.centroids_[cur_class] = X[center_mask].mean(axis=0)
if self.shrink_threshold:
dataset_centroid_ = np.mean(X, axis=0)
# m parameter for determining deviation
m = np.sqrt((1. / nk) - (1. / n_samples))
# Calculate deviation using the standard deviation of centroids.
variance = (X - self.centroids_[y_ind]) ** 2
variance = variance.sum(axis=0)
s = np.sqrt(variance / (n_samples - n_classes))
s += np.median(s) # To deter outliers from affecting the results.
mm = m.reshape(len(m), 1) # Reshape to allow broadcasting.
ms = mm * s
deviation = ((self.centroids_ - dataset_centroid_) / ms)
# Soft thresholding: if the deviation crosses 0 during shrinking,
# it becomes zero.
signs = np.sign(deviation)
deviation = (np.abs(deviation) - self.shrink_threshold)
deviation[deviation < 0] = 0
deviation *= signs
# Now adjust the centroids using the deviation
msd = ms * deviation
self.centroids_ = dataset_centroid_[np.newaxis, :] + msd
return self
def predict(self, X):
"""Perform classification on an array of test vectors X.
The predicted class C for each sample in X is returned.
Parameters
----------
X : array-like, shape = [n_samples, n_features]
Returns
-------
C : array, shape = [n_samples]
Notes
-----
If the metric constructor parameter is "precomputed", X is assumed to
be the distance matrix between the data to be predicted and
``self.centroids_``.
"""
check_is_fitted(self, 'centroids_')
X = check_array(X, accept_sparse='csr')
return self.classes_[pairwise_distances(
X, self.centroids_, metric=self.metric).argmin(axis=1)]
| 7,451 | 37.412371 | 82 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/unsupervised.py | """Unsupervised nearest neighbors learner"""
from .base import NeighborsBase
from .base import KNeighborsMixin
from .base import RadiusNeighborsMixin
from .base import UnsupervisedMixin
class NearestNeighbors(NeighborsBase, KNeighborsMixin,
RadiusNeighborsMixin, UnsupervisedMixin):
"""Unsupervised learner for implementing neighbor searches.
Read more in the :ref:`User Guide <unsupervised_neighbors>`.
Parameters
----------
n_neighbors : int, optional (default = 5)
Number of neighbors to use by default for :meth:`kneighbors` queries.
radius : float, optional (default = 1.0)
Range of parameter space to use by default for :meth:`radius_neighbors`
queries.
algorithm : {'auto', 'ball_tree', 'kd_tree', 'brute'}, optional
Algorithm used to compute the nearest neighbors:
- 'ball_tree' will use :class:`BallTree`
- 'kd_tree' will use :class:`KDTree`
- 'brute' will use a brute-force search.
- 'auto' will attempt to decide the most appropriate algorithm
based on the values passed to :meth:`fit` method.
Note: fitting on sparse input will override the setting of
this parameter, using brute force.
leaf_size : int, optional (default = 30)
Leaf size passed to BallTree or KDTree. This can affect the
speed of the construction and query, as well as the memory
required to store the tree. The optimal value depends on the
nature of the problem.
metric : string or callable, default 'minkowski'
metric to use for distance computation. Any metric from scikit-learn
or scipy.spatial.distance can be used.
If metric is a callable function, it is called on each
pair of instances (rows) and the resulting value recorded. The callable
should take two arrays as input and return one value indicating the
distance between them. This works for Scipy's metrics, but is less
efficient than passing the metric name as a string.
Distance matrices are not supported.
Valid values for metric are:
- from scikit-learn: ['cityblock', 'cosine', 'euclidean', 'l1', 'l2',
'manhattan']
- from scipy.spatial.distance: ['braycurtis', 'canberra', 'chebyshev',
'correlation', 'dice', 'hamming', 'jaccard', 'kulsinski',
'mahalanobis', 'matching', 'minkowski', 'rogerstanimoto',
'russellrao', 'seuclidean', 'sokalmichener', 'sokalsneath',
'sqeuclidean', 'yule']
See the documentation for scipy.spatial.distance for details on these
metrics.
p : integer, optional (default = 2)
Parameter for the Minkowski metric from
sklearn.metrics.pairwise.pairwise_distances. When p = 1, this is
equivalent to using manhattan_distance (l1), and euclidean_distance
(l2) for p = 2. For arbitrary p, minkowski_distance (l_p) is used.
metric_params : dict, optional (default = None)
Additional keyword arguments for the metric function.
n_jobs : int, optional (default = 1)
The number of parallel jobs to run for neighbors search.
If ``-1``, then the number of jobs is set to the number of CPU cores.
Affects only :meth:`kneighbors` and :meth:`kneighbors_graph` methods.
Examples
--------
>>> import numpy as np
>>> from sklearn.neighbors import NearestNeighbors
>>> samples = [[0, 0, 2], [1, 0, 0], [0, 0, 1]]
>>> neigh = NearestNeighbors(2, 0.4)
>>> neigh.fit(samples) #doctest: +ELLIPSIS
NearestNeighbors(...)
>>> neigh.kneighbors([[0, 0, 1.3]], 2, return_distance=False)
... #doctest: +ELLIPSIS
array([[2, 0]]...)
>>> nbrs = neigh.radius_neighbors([[0, 0, 1.3]], 0.4, return_distance=False)
>>> np.asarray(nbrs[0][0])
array(2)
See also
--------
KNeighborsClassifier
RadiusNeighborsClassifier
KNeighborsRegressor
RadiusNeighborsRegressor
BallTree
Notes
-----
See :ref:`Nearest Neighbors <neighbors>` in the online documentation
for a discussion of the choice of ``algorithm`` and ``leaf_size``.
https://en.wikipedia.org/wiki/K-nearest_neighbor_algorithm
"""
def __init__(self, n_neighbors=5, radius=1.0,
algorithm='auto', leaf_size=30, metric='minkowski',
p=2, metric_params=None, n_jobs=1, **kwargs):
self._init_params(n_neighbors=n_neighbors,
radius=radius,
algorithm=algorithm,
leaf_size=leaf_size, metric=metric, p=p,
metric_params=metric_params, n_jobs=n_jobs, **kwargs)
| 4,756 | 37.362903 | 82 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/__init__.py | """
The :mod:`sklearn.neighbors` module implements the k-nearest neighbors
algorithm.
"""
from .ball_tree import BallTree
from .kd_tree import KDTree
from .dist_metrics import DistanceMetric
from .graph import kneighbors_graph, radius_neighbors_graph
from .unsupervised import NearestNeighbors
from .classification import KNeighborsClassifier, RadiusNeighborsClassifier
from .regression import KNeighborsRegressor, RadiusNeighborsRegressor
from .nearest_centroid import NearestCentroid
from .kde import KernelDensity
from .approximate import LSHForest
from .lof import LocalOutlierFactor
__all__ = ['BallTree',
'DistanceMetric',
'KDTree',
'KNeighborsClassifier',
'KNeighborsRegressor',
'NearestCentroid',
'NearestNeighbors',
'RadiusNeighborsClassifier',
'RadiusNeighborsRegressor',
'kneighbors_graph',
'radius_neighbors_graph',
'KernelDensity',
'LSHForest',
'LocalOutlierFactor']
| 1,025 | 31.0625 | 75 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/lof.py | # Authors: Nicolas Goix <[email protected]>
# Alexandre Gramfort <[email protected]>
# License: BSD 3 clause
import numpy as np
from warnings import warn
from scipy.stats import scoreatpercentile
from .base import NeighborsBase
from .base import KNeighborsMixin
from .base import UnsupervisedMixin
from ..utils.validation import check_is_fitted
from ..utils import check_array
__all__ = ["LocalOutlierFactor"]
class LocalOutlierFactor(NeighborsBase, KNeighborsMixin, UnsupervisedMixin):
"""Unsupervised Outlier Detection using Local Outlier Factor (LOF)
The anomaly score of each sample is called Local Outlier Factor.
It measures the local deviation of density of a given sample with
respect to its neighbors.
It is local in that the anomaly score depends on how isolated the object
is with respect to the surrounding neighborhood.
More precisely, locality is given by k-nearest neighbors, whose distance
is used to estimate the local density.
By comparing the local density of a sample to the local densities of
its neighbors, one can identify samples that have a substantially lower
density than their neighbors. These are considered outliers.
Parameters
----------
n_neighbors : int, optional (default=20)
Number of neighbors to use by default for :meth:`kneighbors` queries.
If n_neighbors is larger than the number of samples provided,
all samples will be used.
algorithm : {'auto', 'ball_tree', 'kd_tree', 'brute'}, optional
Algorithm used to compute the nearest neighbors:
- 'ball_tree' will use :class:`BallTree`
- 'kd_tree' will use :class:`KDTree`
- 'brute' will use a brute-force search.
- 'auto' will attempt to decide the most appropriate algorithm
based on the values passed to :meth:`fit` method.
Note: fitting on sparse input will override the setting of
this parameter, using brute force.
leaf_size : int, optional (default=30)
Leaf size passed to :class:`BallTree` or :class:`KDTree`. This can
affect the speed of the construction and query, as well as the memory
required to store the tree. The optimal value depends on the
nature of the problem.
metric : string or callable, default 'minkowski'
metric used for the distance computation. Any metric from scikit-learn
or scipy.spatial.distance can be used.
If 'precomputed', the training input X is expected to be a distance
matrix.
If metric is a callable function, it is called on each
pair of instances (rows) and the resulting value recorded. The callable
should take two arrays as input and return one value indicating the
distance between them. This works for Scipy's metrics, but is less
efficient than passing the metric name as a string.
Valid values for metric are:
- from scikit-learn: ['cityblock', 'cosine', 'euclidean', 'l1', 'l2',
'manhattan']
- from scipy.spatial.distance: ['braycurtis', 'canberra', 'chebyshev',
'correlation', 'dice', 'hamming', 'jaccard', 'kulsinski',
'mahalanobis', 'matching', 'minkowski', 'rogerstanimoto',
'russellrao', 'seuclidean', 'sokalmichener', 'sokalsneath',
'sqeuclidean', 'yule']
See the documentation for scipy.spatial.distance for details on these
metrics:
http://docs.scipy.org/doc/scipy/reference/spatial.distance.html
p : integer, optional (default=2)
Parameter for the Minkowski metric from
:func:`sklearn.metrics.pairwise.pairwise_distances`. When p = 1, this
is equivalent to using manhattan_distance (l1), and euclidean_distance
(l2) for p = 2. For arbitrary p, minkowski_distance (l_p) is used.
metric_params : dict, optional (default=None)
Additional keyword arguments for the metric function.
contamination : float in (0., 0.5), optional (default=0.1)
The amount of contamination of the data set, i.e. the proportion
of outliers in the data set. When fitting this is used to define the
threshold on the decision function.
n_jobs : int, optional (default=1)
The number of parallel jobs to run for neighbors search.
If ``-1``, then the number of jobs is set to the number of CPU cores.
Affects only :meth:`kneighbors` and :meth:`kneighbors_graph` methods.
Attributes
----------
negative_outlier_factor_ : numpy array, shape (n_samples,)
The opposite LOF of the training samples. The lower, the more abnormal.
Inliers tend to have a LOF score close to 1, while outliers tend
to have a larger LOF score.
The local outlier factor (LOF) of a sample captures its
supposed 'degree of abnormality'.
It is the average of the ratio of the local reachability density of
a sample and those of its k-nearest neighbors.
n_neighbors_ : integer
The actual number of neighbors used for :meth:`kneighbors` queries.
References
----------
.. [1] Breunig, M. M., Kriegel, H. P., Ng, R. T., & Sander, J. (2000, May).
LOF: identifying density-based local outliers. In ACM sigmod record.
"""
def __init__(self, n_neighbors=20, algorithm='auto', leaf_size=30,
metric='minkowski', p=2, metric_params=None,
contamination=0.1, n_jobs=1):
self._init_params(n_neighbors=n_neighbors,
algorithm=algorithm,
leaf_size=leaf_size, metric=metric, p=p,
metric_params=metric_params, n_jobs=n_jobs)
self.contamination = contamination
def fit_predict(self, X, y=None):
""""Fits the model to the training set X and returns the labels
(1 inlier, -1 outlier) on the training set according to the LOF score
and the contamination parameter.
Parameters
----------
X : array-like, shape (n_samples, n_features), default=None
The query sample or samples to compute the Local Outlier Factor
w.r.t. to the training samples.
Returns
-------
is_inlier : array, shape (n_samples,)
Returns -1 for anomalies/outliers and 1 for inliers.
"""
return self.fit(X)._predict()
def fit(self, X, y=None):
"""Fit the model using X as training data.
Parameters
----------
X : {array-like, sparse matrix, BallTree, KDTree}
Training data. If array or matrix, shape [n_samples, n_features],
or [n_samples, n_samples] if metric='precomputed'.
Returns
-------
self : object
Returns self.
"""
if not (0. < self.contamination <= .5):
raise ValueError("contamination must be in (0, 0.5]")
super(LocalOutlierFactor, self).fit(X)
n_samples = self._fit_X.shape[0]
if self.n_neighbors > n_samples:
warn("n_neighbors (%s) is greater than the "
"total number of samples (%s). n_neighbors "
"will be set to (n_samples - 1) for estimation."
% (self.n_neighbors, n_samples))
self.n_neighbors_ = max(1, min(self.n_neighbors, n_samples - 1))
self._distances_fit_X_, _neighbors_indices_fit_X_ = (
self.kneighbors(None, n_neighbors=self.n_neighbors_))
self._lrd = self._local_reachability_density(
self._distances_fit_X_, _neighbors_indices_fit_X_)
# Compute lof score over training samples to define threshold_:
lrd_ratios_array = (self._lrd[_neighbors_indices_fit_X_] /
self._lrd[:, np.newaxis])
self.negative_outlier_factor_ = -np.mean(lrd_ratios_array, axis=1)
self.threshold_ = -scoreatpercentile(
-self.negative_outlier_factor_, 100. * (1. - self.contamination))
return self
def _predict(self, X=None):
"""Predict the labels (1 inlier, -1 outlier) of X according to LOF.
If X is None, returns the same as fit_predict(X_train).
This method allows to generalize prediction to new observations (not
in the training set). As LOF originally does not deal with new data,
this method is kept private.
Parameters
----------
X : array-like, shape (n_samples, n_features), default=None
The query sample or samples to compute the Local Outlier Factor
w.r.t. to the training samples. If None, makes prediction on the
training data without considering them as their own neighbors.
Returns
-------
is_inlier : array, shape (n_samples,)
Returns -1 for anomalies/outliers and +1 for inliers.
"""
check_is_fitted(self, ["threshold_", "negative_outlier_factor_",
"n_neighbors_", "_distances_fit_X_"])
if X is not None:
X = check_array(X, accept_sparse='csr')
is_inlier = np.ones(X.shape[0], dtype=int)
is_inlier[self._decision_function(X) <= self.threshold_] = -1
else:
is_inlier = np.ones(self._fit_X.shape[0], dtype=int)
is_inlier[self.negative_outlier_factor_ <= self.threshold_] = -1
return is_inlier
def _decision_function(self, X):
"""Opposite of the Local Outlier Factor of X (as bigger is better,
i.e. large values correspond to inliers).
The argument X is supposed to contain *new data*: if X contains a
point from training, it consider the later in its own neighborhood.
Also, the samples in X are not considered in the neighborhood of any
point.
The decision function on training data is available by considering the
opposite of the negative_outlier_factor_ attribute.
Parameters
----------
X : array-like, shape (n_samples, n_features)
The query sample or samples to compute the Local Outlier Factor
w.r.t. the training samples.
Returns
-------
opposite_lof_scores : array, shape (n_samples,)
The opposite of the Local Outlier Factor of each input samples.
The lower, the more abnormal.
"""
check_is_fitted(self, ["threshold_", "negative_outlier_factor_",
"_distances_fit_X_"])
X = check_array(X, accept_sparse='csr')
distances_X, neighbors_indices_X = (
self.kneighbors(X, n_neighbors=self.n_neighbors_))
X_lrd = self._local_reachability_density(distances_X,
neighbors_indices_X)
lrd_ratios_array = (self._lrd[neighbors_indices_X] /
X_lrd[:, np.newaxis])
# as bigger is better:
return -np.mean(lrd_ratios_array, axis=1)
def _local_reachability_density(self, distances_X, neighbors_indices):
"""The local reachability density (LRD)
The LRD of a sample is the inverse of the average reachability
distance of its k-nearest neighbors.
Parameters
----------
distances_X : array, shape (n_query, self.n_neighbors)
Distances to the neighbors (in the training samples `self._fit_X`)
of each query point to compute the LRD.
neighbors_indices : array, shape (n_query, self.n_neighbors)
Neighbors indices (of each query point) among training samples
self._fit_X.
Returns
-------
local_reachability_density : array, shape (n_samples,)
The local reachability density of each sample.
"""
dist_k = self._distances_fit_X_[neighbors_indices,
self.n_neighbors_ - 1]
reach_dist_array = np.maximum(distances_X, dist_k)
# 1e-10 to avoid `nan' when nb of duplicates > n_neighbors_:
return 1. / (np.mean(reach_dist_array, axis=1) + 1e-10)
| 12,184 | 39.752508 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/tests/test_approximate.py | """
Testing for the approximate neighbor search using
Locality Sensitive Hashing Forest module
(sklearn.neighbors.LSHForest).
"""
# Author: Maheshakya Wijewardena, Joel Nothman
import numpy as np
import scipy.sparse as sp
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_array_less
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import assert_not_equal
from sklearn.utils.testing import assert_warns_message
from sklearn.utils.testing import ignore_warnings
from sklearn.metrics.pairwise import pairwise_distances
from sklearn.neighbors import LSHForest
from sklearn.neighbors import NearestNeighbors
def test_lsh_forest_deprecation():
assert_warns_message(DeprecationWarning,
"LSHForest has poor performance and has been "
"deprecated in 0.19. It will be removed "
"in version 0.21.", LSHForest)
def test_neighbors_accuracy_with_n_candidates():
# Checks whether accuracy increases as `n_candidates` increases.
n_candidates_values = np.array([.1, 50, 500])
n_samples = 100
n_features = 10
n_iter = 10
n_points = 5
rng = np.random.RandomState(42)
accuracies = np.zeros(n_candidates_values.shape[0], dtype=float)
X = rng.rand(n_samples, n_features)
for i, n_candidates in enumerate(n_candidates_values):
lshf = ignore_warnings(LSHForest, category=DeprecationWarning)(
n_candidates=n_candidates)
ignore_warnings(lshf.fit)(X)
for j in range(n_iter):
query = X[rng.randint(0, n_samples)].reshape(1, -1)
neighbors = lshf.kneighbors(query, n_neighbors=n_points,
return_distance=False)
distances = pairwise_distances(query, X, metric='cosine')
ranks = np.argsort(distances)[0, :n_points]
intersection = np.intersect1d(ranks, neighbors).shape[0]
ratio = intersection / float(n_points)
accuracies[i] = accuracies[i] + ratio
accuracies[i] = accuracies[i] / float(n_iter)
# Sorted accuracies should be equal to original accuracies
print('accuracies:', accuracies)
assert_true(np.all(np.diff(accuracies) >= 0),
msg="Accuracies are not non-decreasing.")
# Highest accuracy should be strictly greater than the lowest
assert_true(np.ptp(accuracies) > 0,
msg="Highest accuracy is not strictly greater than lowest.")
def test_neighbors_accuracy_with_n_estimators():
# Checks whether accuracy increases as `n_estimators` increases.
n_estimators = np.array([1, 10, 100])
n_samples = 100
n_features = 10
n_iter = 10
n_points = 5
rng = np.random.RandomState(42)
accuracies = np.zeros(n_estimators.shape[0], dtype=float)
X = rng.rand(n_samples, n_features)
for i, t in enumerate(n_estimators):
lshf = ignore_warnings(LSHForest, category=DeprecationWarning)(
n_candidates=500, n_estimators=t)
ignore_warnings(lshf.fit)(X)
for j in range(n_iter):
query = X[rng.randint(0, n_samples)].reshape(1, -1)
neighbors = lshf.kneighbors(query, n_neighbors=n_points,
return_distance=False)
distances = pairwise_distances(query, X, metric='cosine')
ranks = np.argsort(distances)[0, :n_points]
intersection = np.intersect1d(ranks, neighbors).shape[0]
ratio = intersection / float(n_points)
accuracies[i] = accuracies[i] + ratio
accuracies[i] = accuracies[i] / float(n_iter)
# Sorted accuracies should be equal to original accuracies
assert_true(np.all(np.diff(accuracies) >= 0),
msg="Accuracies are not non-decreasing.")
# Highest accuracy should be strictly greater than the lowest
assert_true(np.ptp(accuracies) > 0,
msg="Highest accuracy is not strictly greater than lowest.")
@ignore_warnings
def test_kneighbors():
# Checks whether desired number of neighbors are returned.
# It is guaranteed to return the requested number of neighbors
# if `min_hash_match` is set to 0. Returned distances should be
# in ascending order.
n_samples = 12
n_features = 2
n_iter = 10
rng = np.random.RandomState(42)
X = rng.rand(n_samples, n_features)
lshf = ignore_warnings(LSHForest, category=DeprecationWarning)(
min_hash_match=0)
# Test unfitted estimator
assert_raises(ValueError, lshf.kneighbors, X[0])
ignore_warnings(lshf.fit)(X)
for i in range(n_iter):
n_neighbors = rng.randint(0, n_samples)
query = X[rng.randint(0, n_samples)].reshape(1, -1)
neighbors = lshf.kneighbors(query, n_neighbors=n_neighbors,
return_distance=False)
# Desired number of neighbors should be returned.
assert_equal(neighbors.shape[1], n_neighbors)
# Multiple points
n_queries = 5
queries = X[rng.randint(0, n_samples, n_queries)]
distances, neighbors = lshf.kneighbors(queries,
n_neighbors=1,
return_distance=True)
assert_equal(neighbors.shape[0], n_queries)
assert_equal(distances.shape[0], n_queries)
# Test only neighbors
neighbors = lshf.kneighbors(queries, n_neighbors=1,
return_distance=False)
assert_equal(neighbors.shape[0], n_queries)
# Test random point(not in the data set)
query = rng.randn(n_features).reshape(1, -1)
lshf.kneighbors(query, n_neighbors=1,
return_distance=False)
# Test n_neighbors at initialization
neighbors = lshf.kneighbors(query, return_distance=False)
assert_equal(neighbors.shape[1], 5)
# Test `neighbors` has an integer dtype
assert_true(neighbors.dtype.kind == 'i',
msg="neighbors are not in integer dtype.")
def test_radius_neighbors():
# Checks whether Returned distances are less than `radius`
# At least one point should be returned when the `radius` is set
# to mean distance from the considering point to other points in
# the database.
# Moreover, this test compares the radius neighbors of LSHForest
# with the `sklearn.neighbors.NearestNeighbors`.
n_samples = 12
n_features = 2
n_iter = 10
rng = np.random.RandomState(42)
X = rng.rand(n_samples, n_features)
lshf = ignore_warnings(LSHForest, category=DeprecationWarning)()
# Test unfitted estimator
assert_raises(ValueError, lshf.radius_neighbors, X[0])
ignore_warnings(lshf.fit)(X)
for i in range(n_iter):
# Select a random point in the dataset as the query
query = X[rng.randint(0, n_samples)].reshape(1, -1)
# At least one neighbor should be returned when the radius is the
# mean distance from the query to the points of the dataset.
mean_dist = np.mean(pairwise_distances(query, X, metric='cosine'))
neighbors = lshf.radius_neighbors(query, radius=mean_dist,
return_distance=False)
assert_equal(neighbors.shape, (1,))
assert_equal(neighbors.dtype, object)
assert_greater(neighbors[0].shape[0], 0)
# All distances to points in the results of the radius query should
# be less than mean_dist
distances, neighbors = lshf.radius_neighbors(query,
radius=mean_dist,
return_distance=True)
assert_array_less(distances[0], mean_dist)
# Multiple points
n_queries = 5
queries = X[rng.randint(0, n_samples, n_queries)]
distances, neighbors = lshf.radius_neighbors(queries,
return_distance=True)
# dists and inds should not be 1D arrays or arrays of variable lengths
# hence the use of the object dtype.
assert_equal(distances.shape, (n_queries,))
assert_equal(distances.dtype, object)
assert_equal(neighbors.shape, (n_queries,))
assert_equal(neighbors.dtype, object)
# Compare with exact neighbor search
query = X[rng.randint(0, n_samples)].reshape(1, -1)
mean_dist = np.mean(pairwise_distances(query, X, metric='cosine'))
nbrs = NearestNeighbors(algorithm='brute', metric='cosine').fit(X)
distances_exact, _ = nbrs.radius_neighbors(query, radius=mean_dist)
distances_approx, _ = lshf.radius_neighbors(query, radius=mean_dist)
# Radius-based queries do not sort the result points and the order
# depends on the method, the random_state and the dataset order. Therefore
# we need to sort the results ourselves before performing any comparison.
sorted_dists_exact = np.sort(distances_exact[0])
sorted_dists_approx = np.sort(distances_approx[0])
# Distances to exact neighbors are less than or equal to approximate
# counterparts as the approximate radius query might have missed some
# closer neighbors.
assert_true(np.all(np.less_equal(sorted_dists_exact,
sorted_dists_approx)))
@ignore_warnings
def test_radius_neighbors_boundary_handling():
X = [[0.999, 0.001], [0.5, 0.5], [0, 1.], [-1., 0.001]]
n_points = len(X)
# Build an exact nearest neighbors model as reference model to ensure
# consistency between exact and approximate methods
nnbrs = NearestNeighbors(algorithm='brute', metric='cosine').fit(X)
# Build a LSHForest model with hyperparameter values that always guarantee
# exact results on this toy dataset.
lsfh = ignore_warnings(LSHForest, category=DeprecationWarning)(
min_hash_match=0, n_candidates=n_points, random_state=42).fit(X)
# define a query aligned with the first axis
query = [[1., 0.]]
# Compute the exact cosine distances of the query to the four points of
# the dataset
dists = pairwise_distances(query, X, metric='cosine').ravel()
# The first point is almost aligned with the query (very small angle),
# the cosine distance should therefore be almost null:
assert_almost_equal(dists[0], 0, decimal=5)
# The second point form an angle of 45 degrees to the query vector
assert_almost_equal(dists[1], 1 - np.cos(np.pi / 4))
# The third point is orthogonal from the query vector hence at a distance
# exactly one:
assert_almost_equal(dists[2], 1)
# The last point is almost colinear but with opposite sign to the query
# therefore it has a cosine 'distance' very close to the maximum possible
# value of 2.
assert_almost_equal(dists[3], 2, decimal=5)
# If we query with a radius of one, all the samples except the last sample
# should be included in the results. This means that the third sample
# is lying on the boundary of the radius query:
exact_dists, exact_idx = nnbrs.radius_neighbors(query, radius=1)
approx_dists, approx_idx = lsfh.radius_neighbors(query, radius=1)
assert_array_equal(np.sort(exact_idx[0]), [0, 1, 2])
assert_array_equal(np.sort(approx_idx[0]), [0, 1, 2])
assert_array_almost_equal(np.sort(exact_dists[0]), dists[:-1])
assert_array_almost_equal(np.sort(approx_dists[0]), dists[:-1])
# If we perform the same query with a slightly lower radius, the third
# point of the dataset that lay on the boundary of the previous query
# is now rejected:
eps = np.finfo(np.float64).eps
exact_dists, exact_idx = nnbrs.radius_neighbors(query, radius=1 - eps)
approx_dists, approx_idx = lsfh.radius_neighbors(query, radius=1 - eps)
assert_array_equal(np.sort(exact_idx[0]), [0, 1])
assert_array_equal(np.sort(approx_idx[0]), [0, 1])
assert_array_almost_equal(np.sort(exact_dists[0]), dists[:-2])
assert_array_almost_equal(np.sort(approx_dists[0]), dists[:-2])
def test_distances():
# Checks whether returned neighbors are from closest to farthest.
n_samples = 12
n_features = 2
n_iter = 10
rng = np.random.RandomState(42)
X = rng.rand(n_samples, n_features)
lshf = ignore_warnings(LSHForest, category=DeprecationWarning)()
ignore_warnings(lshf.fit)(X)
for i in range(n_iter):
n_neighbors = rng.randint(0, n_samples)
query = X[rng.randint(0, n_samples)].reshape(1, -1)
distances, neighbors = lshf.kneighbors(query,
n_neighbors=n_neighbors,
return_distance=True)
# Returned neighbors should be from closest to farthest, that is
# increasing distance values.
assert_true(np.all(np.diff(distances[0]) >= 0))
# Note: the radius_neighbors method does not guarantee the order of
# the results.
def test_fit():
# Checks whether `fit` method sets all attribute values correctly.
n_samples = 12
n_features = 2
n_estimators = 5
rng = np.random.RandomState(42)
X = rng.rand(n_samples, n_features)
lshf = ignore_warnings(LSHForest, category=DeprecationWarning)(
n_estimators=n_estimators)
ignore_warnings(lshf.fit)(X)
# _input_array = X
assert_array_equal(X, lshf._fit_X)
# A hash function g(p) for each tree
assert_equal(n_estimators, len(lshf.hash_functions_))
# Hash length = 32
assert_equal(32, lshf.hash_functions_[0].components_.shape[0])
# Number of trees_ in the forest
assert_equal(n_estimators, len(lshf.trees_))
# Each tree has entries for every data point
assert_equal(n_samples, len(lshf.trees_[0]))
# Original indices after sorting the hashes
assert_equal(n_estimators, len(lshf.original_indices_))
# Each set of original indices in a tree has entries for every data point
assert_equal(n_samples, len(lshf.original_indices_[0]))
def test_partial_fit():
# Checks whether inserting array is consistent with fitted data.
# `partial_fit` method should set all attribute values correctly.
n_samples = 12
n_samples_partial_fit = 3
n_features = 2
rng = np.random.RandomState(42)
X = rng.rand(n_samples, n_features)
X_partial_fit = rng.rand(n_samples_partial_fit, n_features)
lshf = ignore_warnings(LSHForest, category=DeprecationWarning)()
# Test unfitted estimator
ignore_warnings(lshf.partial_fit)(X)
assert_array_equal(X, lshf._fit_X)
ignore_warnings(lshf.fit)(X)
# Insert wrong dimension
assert_raises(ValueError, lshf.partial_fit,
np.random.randn(n_samples_partial_fit, n_features - 1))
ignore_warnings(lshf.partial_fit)(X_partial_fit)
# size of _input_array = samples + 1 after insertion
assert_equal(lshf._fit_X.shape[0],
n_samples + n_samples_partial_fit)
# size of original_indices_[1] = samples + 1
assert_equal(len(lshf.original_indices_[0]),
n_samples + n_samples_partial_fit)
# size of trees_[1] = samples + 1
assert_equal(len(lshf.trees_[1]),
n_samples + n_samples_partial_fit)
def test_hash_functions():
# Checks randomness of hash functions.
# Variance and mean of each hash function (projection vector)
# should be different from flattened array of hash functions.
# If hash functions are not randomly built (seeded with
# same value), variances and means of all functions are equal.
n_samples = 12
n_features = 2
n_estimators = 5
rng = np.random.RandomState(42)
X = rng.rand(n_samples, n_features)
lshf = ignore_warnings(LSHForest, category=DeprecationWarning)(
n_estimators=n_estimators,
random_state=rng.randint(0, np.iinfo(np.int32).max))
ignore_warnings(lshf.fit)(X)
hash_functions = []
for i in range(n_estimators):
hash_functions.append(lshf.hash_functions_[i].components_)
for i in range(n_estimators):
assert_not_equal(np.var(hash_functions),
np.var(lshf.hash_functions_[i].components_))
for i in range(n_estimators):
assert_not_equal(np.mean(hash_functions),
np.mean(lshf.hash_functions_[i].components_))
def test_candidates():
# Checks whether candidates are sufficient.
# This should handle the cases when number of candidates is 0.
# User should be warned when number of candidates is less than
# requested number of neighbors.
X_train = np.array([[5, 5, 2], [21, 5, 5], [1, 1, 1], [8, 9, 1],
[6, 10, 2]], dtype=np.float32)
X_test = np.array([7, 10, 3], dtype=np.float32).reshape(1, -1)
# For zero candidates
lshf = ignore_warnings(LSHForest, category=DeprecationWarning)(
min_hash_match=32)
ignore_warnings(lshf.fit)(X_train)
message = ("Number of candidates is not sufficient to retrieve"
" %i neighbors with"
" min_hash_match = %i. Candidates are filled up"
" uniformly from unselected"
" indices." % (3, 32))
assert_warns_message(UserWarning, message, lshf.kneighbors,
X_test, n_neighbors=3)
distances, neighbors = lshf.kneighbors(X_test, n_neighbors=3)
assert_equal(distances.shape[1], 3)
# For candidates less than n_neighbors
lshf = ignore_warnings(LSHForest, category=DeprecationWarning)(
min_hash_match=31)
ignore_warnings(lshf.fit)(X_train)
message = ("Number of candidates is not sufficient to retrieve"
" %i neighbors with"
" min_hash_match = %i. Candidates are filled up"
" uniformly from unselected"
" indices." % (5, 31))
assert_warns_message(UserWarning, message, lshf.kneighbors,
X_test, n_neighbors=5)
distances, neighbors = lshf.kneighbors(X_test, n_neighbors=5)
assert_equal(distances.shape[1], 5)
def test_graphs():
# Smoke tests for graph methods.
n_samples_sizes = [5, 10, 20]
n_features = 3
rng = np.random.RandomState(42)
for n_samples in n_samples_sizes:
X = rng.rand(n_samples, n_features)
lshf = ignore_warnings(LSHForest, category=DeprecationWarning)(
min_hash_match=0)
ignore_warnings(lshf.fit)(X)
kneighbors_graph = lshf.kneighbors_graph(X)
radius_neighbors_graph = lshf.radius_neighbors_graph(X)
assert_equal(kneighbors_graph.shape[0], n_samples)
assert_equal(kneighbors_graph.shape[1], n_samples)
assert_equal(radius_neighbors_graph.shape[0], n_samples)
assert_equal(radius_neighbors_graph.shape[1], n_samples)
def test_sparse_input():
# note: Fixed random state in sp.rand is not supported in older scipy.
# The test should succeed regardless.
X1 = sp.rand(50, 100)
X2 = sp.rand(10, 100)
forest_sparse = ignore_warnings(LSHForest, category=DeprecationWarning)(
radius=1, random_state=0).fit(X1)
forest_dense = ignore_warnings(LSHForest, category=DeprecationWarning)(
radius=1, random_state=0).fit(X1.A)
d_sparse, i_sparse = forest_sparse.kneighbors(X2, return_distance=True)
d_dense, i_dense = forest_dense.kneighbors(X2.A, return_distance=True)
assert_almost_equal(d_sparse, d_dense)
assert_almost_equal(i_sparse, i_dense)
d_sparse, i_sparse = forest_sparse.radius_neighbors(X2,
return_distance=True)
d_dense, i_dense = forest_dense.radius_neighbors(X2.A,
return_distance=True)
assert_equal(d_sparse.shape, d_dense.shape)
for a, b in zip(d_sparse, d_dense):
assert_almost_equal(a, b)
for a, b in zip(i_sparse, i_dense):
assert_almost_equal(a, b)
| 20,126 | 39.415663 | 78 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/tests/test_kd_tree.py | import numpy as np
from numpy.testing import assert_array_almost_equal
from sklearn.neighbors.kd_tree import (KDTree, NeighborsHeap,
simultaneous_sort, kernel_norm,
nodeheap_sort, DTYPE, ITYPE)
from sklearn.neighbors.dist_metrics import DistanceMetric
from sklearn.utils import check_random_state
from sklearn.utils.testing import SkipTest, assert_allclose
rng = np.random.RandomState(42)
V = rng.random_sample((3, 3))
V = np.dot(V, V.T)
DIMENSION = 3
METRICS = {'euclidean': {},
'manhattan': {},
'chebyshev': {},
'minkowski': dict(p=3)}
def brute_force_neighbors(X, Y, k, metric, **kwargs):
D = DistanceMetric.get_metric(metric, **kwargs).pairwise(Y, X)
ind = np.argsort(D, axis=1)[:, :k]
dist = D[np.arange(Y.shape[0])[:, None], ind]
return dist, ind
def check_neighbors(dualtree, breadth_first, k, metric, X, Y, kwargs):
kdt = KDTree(X, leaf_size=1, metric=metric, **kwargs)
dist1, ind1 = kdt.query(Y, k, dualtree=dualtree,
breadth_first=breadth_first)
dist2, ind2 = brute_force_neighbors(X, Y, k, metric, **kwargs)
# don't check indices here: if there are any duplicate distances,
# the indices may not match. Distances should not have this problem.
assert_array_almost_equal(dist1, dist2)
def test_kd_tree_query():
rng = check_random_state(0)
X = rng.random_sample((40, DIMENSION))
Y = rng.random_sample((10, DIMENSION))
for (metric, kwargs) in METRICS.items():
for k in (1, 3, 5):
for dualtree in (True, False):
for breadth_first in (True, False):
yield (check_neighbors,
dualtree, breadth_first,
k, metric, X, Y, kwargs)
def test_kd_tree_query_radius(n_samples=100, n_features=10):
rng = check_random_state(0)
X = 2 * rng.random_sample(size=(n_samples, n_features)) - 1
query_pt = np.zeros(n_features, dtype=float)
eps = 1E-15 # roundoff error can cause test to fail
kdt = KDTree(X, leaf_size=5)
rad = np.sqrt(((X - query_pt) ** 2).sum(1))
for r in np.linspace(rad[0], rad[-1], 100):
ind = kdt.query_radius([query_pt], r + eps)[0]
i = np.where(rad <= r + eps)[0]
ind.sort()
i.sort()
assert_array_almost_equal(i, ind)
def test_kd_tree_query_radius_distance(n_samples=100, n_features=10):
rng = check_random_state(0)
X = 2 * rng.random_sample(size=(n_samples, n_features)) - 1
query_pt = np.zeros(n_features, dtype=float)
eps = 1E-15 # roundoff error can cause test to fail
kdt = KDTree(X, leaf_size=5)
rad = np.sqrt(((X - query_pt) ** 2).sum(1))
for r in np.linspace(rad[0], rad[-1], 100):
ind, dist = kdt.query_radius([query_pt], r + eps, return_distance=True)
ind = ind[0]
dist = dist[0]
d = np.sqrt(((query_pt - X[ind]) ** 2).sum(1))
assert_array_almost_equal(d, dist)
def compute_kernel_slow(Y, X, kernel, h):
d = np.sqrt(((Y[:, None, :] - X) ** 2).sum(-1))
norm = kernel_norm(h, X.shape[1], kernel)
if kernel == 'gaussian':
return norm * np.exp(-0.5 * (d * d) / (h * h)).sum(-1)
elif kernel == 'tophat':
return norm * (d < h).sum(-1)
elif kernel == 'epanechnikov':
return norm * ((1.0 - (d * d) / (h * h)) * (d < h)).sum(-1)
elif kernel == 'exponential':
return norm * (np.exp(-d / h)).sum(-1)
elif kernel == 'linear':
return norm * ((1 - d / h) * (d < h)).sum(-1)
elif kernel == 'cosine':
return norm * (np.cos(0.5 * np.pi * d / h) * (d < h)).sum(-1)
else:
raise ValueError('kernel not recognized')
def check_results(kernel, h, atol, rtol, breadth_first, Y, kdt, dens_true):
dens = kdt.kernel_density(Y, h, atol=atol, rtol=rtol,
kernel=kernel,
breadth_first=breadth_first)
assert_allclose(dens, dens_true, atol=atol,
rtol=max(rtol, 1e-7))
def test_kd_tree_kde(n_samples=100, n_features=3):
rng = check_random_state(0)
X = rng.random_sample((n_samples, n_features))
Y = rng.random_sample((n_samples, n_features))
kdt = KDTree(X, leaf_size=10)
for kernel in ['gaussian', 'tophat', 'epanechnikov',
'exponential', 'linear', 'cosine']:
for h in [0.01, 0.1, 1]:
dens_true = compute_kernel_slow(Y, X, kernel, h)
for rtol in [0, 1E-5]:
for atol in [1E-6, 1E-2]:
for breadth_first in (True, False):
yield (check_results, kernel, h, atol, rtol,
breadth_first, Y, kdt, dens_true)
def test_gaussian_kde(n_samples=1000):
# Compare gaussian KDE results to scipy.stats.gaussian_kde
from scipy.stats import gaussian_kde
rng = check_random_state(0)
x_in = rng.normal(0, 1, n_samples)
x_out = np.linspace(-5, 5, 30)
for h in [0.01, 0.1, 1]:
kdt = KDTree(x_in[:, None])
try:
gkde = gaussian_kde(x_in, bw_method=h / np.std(x_in))
except TypeError:
raise SkipTest("Old scipy, does not accept explicit bandwidth.")
dens_kdt = kdt.kernel_density(x_out[:, None], h) / n_samples
dens_gkde = gkde.evaluate(x_out)
assert_array_almost_equal(dens_kdt, dens_gkde, decimal=3)
def test_kd_tree_two_point(n_samples=100, n_features=3):
rng = check_random_state(0)
X = rng.random_sample((n_samples, n_features))
Y = rng.random_sample((n_samples, n_features))
r = np.linspace(0, 1, 10)
kdt = KDTree(X, leaf_size=10)
D = DistanceMetric.get_metric("euclidean").pairwise(Y, X)
counts_true = [(D <= ri).sum() for ri in r]
def check_two_point(r, dualtree):
counts = kdt.two_point_correlation(Y, r=r, dualtree=dualtree)
assert_array_almost_equal(counts, counts_true)
for dualtree in (True, False):
yield check_two_point, r, dualtree
def test_kd_tree_pickle():
import pickle
rng = check_random_state(0)
X = rng.random_sample((10, 3))
kdt1 = KDTree(X, leaf_size=1)
ind1, dist1 = kdt1.query(X)
def check_pickle_protocol(protocol):
s = pickle.dumps(kdt1, protocol=protocol)
kdt2 = pickle.loads(s)
ind2, dist2 = kdt2.query(X)
assert_array_almost_equal(ind1, ind2)
assert_array_almost_equal(dist1, dist2)
for protocol in (0, 1, 2):
yield check_pickle_protocol, protocol
def test_neighbors_heap(n_pts=5, n_nbrs=10):
heap = NeighborsHeap(n_pts, n_nbrs)
for row in range(n_pts):
d_in = rng.random_sample(2 * n_nbrs).astype(DTYPE)
i_in = np.arange(2 * n_nbrs, dtype=ITYPE)
for d, i in zip(d_in, i_in):
heap.push(row, d, i)
ind = np.argsort(d_in)
d_in = d_in[ind]
i_in = i_in[ind]
d_heap, i_heap = heap.get_arrays(sort=True)
assert_array_almost_equal(d_in[:n_nbrs], d_heap[row])
assert_array_almost_equal(i_in[:n_nbrs], i_heap[row])
def test_node_heap(n_nodes=50):
vals = rng.random_sample(n_nodes).astype(DTYPE)
i1 = np.argsort(vals)
vals2, i2 = nodeheap_sort(vals)
assert_array_almost_equal(i1, i2)
assert_array_almost_equal(vals[i1], vals2)
def test_simultaneous_sort(n_rows=10, n_pts=201):
dist = rng.random_sample((n_rows, n_pts)).astype(DTYPE)
ind = (np.arange(n_pts) + np.zeros((n_rows, 1))).astype(ITYPE)
dist2 = dist.copy()
ind2 = ind.copy()
# simultaneous sort rows using function
simultaneous_sort(dist, ind)
# simultaneous sort rows using numpy
i = np.argsort(dist2, axis=1)
row_ind = np.arange(n_rows)[:, None]
dist2 = dist2[row_ind, i]
ind2 = ind2[row_ind, i]
assert_array_almost_equal(dist, dist2)
assert_array_almost_equal(ind, ind2)
| 7,954 | 31.871901 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/tests/test_lof.py | # Authors: Nicolas Goix <[email protected]>
# Alexandre Gramfort <[email protected]>
# License: BSD 3 clause
from math import sqrt
import numpy as np
from sklearn import neighbors
from numpy.testing import assert_array_equal
from sklearn import metrics
from sklearn.metrics import roc_auc_score
from sklearn.utils import check_random_state
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_warns_message
from sklearn.datasets import load_iris
# load the iris dataset
# and randomly permute it
rng = check_random_state(0)
iris = load_iris()
perm = rng.permutation(iris.target.size)
iris.data = iris.data[perm]
iris.target = iris.target[perm]
def test_lof():
# Toy sample (the last two samples are outliers):
X = [[-2, -1], [-1, -1], [-1, -2], [1, 1], [1, 2], [2, 1], [5, 3], [-4, 2]]
# Test LocalOutlierFactor:
clf = neighbors.LocalOutlierFactor(n_neighbors=5)
score = clf.fit(X).negative_outlier_factor_
assert_array_equal(clf._fit_X, X)
# Assert largest outlier score is smaller than smallest inlier score:
assert_greater(np.min(score[:-2]), np.max(score[-2:]))
# Assert predict() works:
clf = neighbors.LocalOutlierFactor(contamination=0.25,
n_neighbors=5).fit(X)
assert_array_equal(clf._predict(), 6 * [1] + 2 * [-1])
def test_lof_performance():
# Generate train/test data
rng = check_random_state(2)
X = 0.3 * rng.randn(120, 2)
X_train = X[:100]
# Generate some abnormal novel observations
X_outliers = rng.uniform(low=-4, high=4, size=(20, 2))
X_test = np.r_[X[100:], X_outliers]
y_test = np.array([0] * 20 + [1] * 20)
# fit the model
clf = neighbors.LocalOutlierFactor().fit(X_train)
# predict scores (the lower, the more normal)
y_pred = -clf._decision_function(X_test)
# check that roc_auc is good
assert_greater(roc_auc_score(y_test, y_pred), .99)
def test_lof_values():
# toy samples:
X_train = [[1, 1], [1, 2], [2, 1]]
clf = neighbors.LocalOutlierFactor(n_neighbors=2).fit(X_train)
s_0 = 2. * sqrt(2.) / (1. + sqrt(2.))
s_1 = (1. + sqrt(2)) * (1. / (4. * sqrt(2.)) + 1. / (2. + 2. * sqrt(2)))
# check predict()
assert_array_almost_equal(-clf.negative_outlier_factor_, [s_0, s_1, s_1])
# check predict(one sample not in train)
assert_array_almost_equal(-clf._decision_function([[2., 2.]]), [s_0])
# # check predict(one sample already in train)
assert_array_almost_equal(-clf._decision_function([[1., 1.]]), [s_1])
def test_lof_precomputed(random_state=42):
"""Tests LOF with a distance matrix."""
# Note: smaller samples may result in spurious test success
rng = np.random.RandomState(random_state)
X = rng.random_sample((10, 4))
Y = rng.random_sample((3, 4))
DXX = metrics.pairwise_distances(X, metric='euclidean')
DYX = metrics.pairwise_distances(Y, X, metric='euclidean')
# As a feature matrix (n_samples by n_features)
lof_X = neighbors.LocalOutlierFactor(n_neighbors=3)
lof_X.fit(X)
pred_X_X = lof_X._predict()
pred_X_Y = lof_X._predict(Y)
# As a dense distance matrix (n_samples by n_samples)
lof_D = neighbors.LocalOutlierFactor(n_neighbors=3, algorithm='brute',
metric='precomputed')
lof_D.fit(DXX)
pred_D_X = lof_D._predict()
pred_D_Y = lof_D._predict(DYX)
assert_array_almost_equal(pred_X_X, pred_D_X)
assert_array_almost_equal(pred_X_Y, pred_D_Y)
def test_n_neighbors_attribute():
X = iris.data
clf = neighbors.LocalOutlierFactor(n_neighbors=500).fit(X)
assert_equal(clf.n_neighbors_, X.shape[0] - 1)
clf = neighbors.LocalOutlierFactor(n_neighbors=500)
assert_warns_message(UserWarning,
"n_neighbors will be set to (n_samples - 1)",
clf.fit, X)
assert_equal(clf.n_neighbors_, X.shape[0] - 1)
| 4,108 | 33.241667 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/tests/test_neighbors.py | from itertools import product
import numpy as np
from scipy.sparse import (bsr_matrix, coo_matrix, csc_matrix, csr_matrix,
dok_matrix, lil_matrix)
from sklearn import metrics
from sklearn import neighbors, datasets
from sklearn.exceptions import DataConversionWarning
from sklearn.metrics.pairwise import pairwise_distances
from sklearn.model_selection import cross_val_score
from sklearn.model_selection import train_test_split
from sklearn.neighbors.base import VALID_METRICS_SPARSE, VALID_METRICS
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_false
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_in
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.validation import check_random_state
rng = np.random.RandomState(0)
# load and shuffle iris dataset
iris = datasets.load_iris()
perm = rng.permutation(iris.target.size)
iris.data = iris.data[perm]
iris.target = iris.target[perm]
# load and shuffle digits
digits = datasets.load_digits()
perm = rng.permutation(digits.target.size)
digits.data = digits.data[perm]
digits.target = digits.target[perm]
SPARSE_TYPES = (bsr_matrix, coo_matrix, csc_matrix, csr_matrix, dok_matrix,
lil_matrix)
SPARSE_OR_DENSE = SPARSE_TYPES + (np.asarray,)
ALGORITHMS = ('ball_tree', 'brute', 'kd_tree', 'auto')
P = (1, 2, 3, 4, np.inf)
# Filter deprecation warnings.
neighbors.kneighbors_graph = ignore_warnings(neighbors.kneighbors_graph)
neighbors.radius_neighbors_graph = ignore_warnings(
neighbors.radius_neighbors_graph)
def _weight_func(dist):
""" Weight function to replace lambda d: d ** -2.
The lambda function is not valid because:
if d==0 then 0^-2 is not valid. """
# Dist could be multidimensional, flatten it so all values
# can be looped
with np.errstate(divide='ignore'):
retval = 1. / dist
return retval ** 2
def test_unsupervised_kneighbors(n_samples=20, n_features=5,
n_query_pts=2, n_neighbors=5):
# Test unsupervised neighbors methods
X = rng.rand(n_samples, n_features)
test = rng.rand(n_query_pts, n_features)
for p in P:
results_nodist = []
results = []
for algorithm in ALGORITHMS:
neigh = neighbors.NearestNeighbors(n_neighbors=n_neighbors,
algorithm=algorithm,
p=p)
neigh.fit(X)
results_nodist.append(neigh.kneighbors(test,
return_distance=False))
results.append(neigh.kneighbors(test, return_distance=True))
for i in range(len(results) - 1):
assert_array_almost_equal(results_nodist[i], results[i][1])
assert_array_almost_equal(results[i][0], results[i + 1][0])
assert_array_almost_equal(results[i][1], results[i + 1][1])
def test_unsupervised_inputs():
# test the types of valid input into NearestNeighbors
X = rng.random_sample((10, 3))
nbrs_fid = neighbors.NearestNeighbors(n_neighbors=1)
nbrs_fid.fit(X)
dist1, ind1 = nbrs_fid.kneighbors(X)
nbrs = neighbors.NearestNeighbors(n_neighbors=1)
for input in (nbrs_fid, neighbors.BallTree(X), neighbors.KDTree(X)):
nbrs.fit(input)
dist2, ind2 = nbrs.kneighbors(X)
assert_array_almost_equal(dist1, dist2)
assert_array_almost_equal(ind1, ind2)
def test_precomputed(random_state=42):
"""Tests unsupervised NearestNeighbors with a distance matrix."""
# Note: smaller samples may result in spurious test success
rng = np.random.RandomState(random_state)
X = rng.random_sample((10, 4))
Y = rng.random_sample((3, 4))
DXX = metrics.pairwise_distances(X, metric='euclidean')
DYX = metrics.pairwise_distances(Y, X, metric='euclidean')
for method in ['kneighbors']:
# TODO: also test radius_neighbors, but requires different assertion
# As a feature matrix (n_samples by n_features)
nbrs_X = neighbors.NearestNeighbors(n_neighbors=3)
nbrs_X.fit(X)
dist_X, ind_X = getattr(nbrs_X, method)(Y)
# As a dense distance matrix (n_samples by n_samples)
nbrs_D = neighbors.NearestNeighbors(n_neighbors=3, algorithm='brute',
metric='precomputed')
nbrs_D.fit(DXX)
dist_D, ind_D = getattr(nbrs_D, method)(DYX)
assert_array_almost_equal(dist_X, dist_D)
assert_array_almost_equal(ind_X, ind_D)
# Check auto works too
nbrs_D = neighbors.NearestNeighbors(n_neighbors=3, algorithm='auto',
metric='precomputed')
nbrs_D.fit(DXX)
dist_D, ind_D = getattr(nbrs_D, method)(DYX)
assert_array_almost_equal(dist_X, dist_D)
assert_array_almost_equal(ind_X, ind_D)
# Check X=None in prediction
dist_X, ind_X = getattr(nbrs_X, method)(None)
dist_D, ind_D = getattr(nbrs_D, method)(None)
assert_array_almost_equal(dist_X, dist_D)
assert_array_almost_equal(ind_X, ind_D)
# Must raise a ValueError if the matrix is not of correct shape
assert_raises(ValueError, getattr(nbrs_D, method), X)
target = np.arange(X.shape[0])
for Est in (neighbors.KNeighborsClassifier,
neighbors.RadiusNeighborsClassifier,
neighbors.KNeighborsRegressor,
neighbors.RadiusNeighborsRegressor):
print(Est)
est = Est(metric='euclidean')
est.radius = est.n_neighbors = 1
pred_X = est.fit(X, target).predict(Y)
est.metric = 'precomputed'
pred_D = est.fit(DXX, target).predict(DYX)
assert_array_almost_equal(pred_X, pred_D)
def test_precomputed_cross_validation():
# Ensure array is split correctly
rng = np.random.RandomState(0)
X = rng.rand(20, 2)
D = pairwise_distances(X, metric='euclidean')
y = rng.randint(3, size=20)
for Est in (neighbors.KNeighborsClassifier,
neighbors.RadiusNeighborsClassifier,
neighbors.KNeighborsRegressor,
neighbors.RadiusNeighborsRegressor):
metric_score = cross_val_score(Est(), X, y)
precomp_score = cross_val_score(Est(metric='precomputed'), D, y)
assert_array_equal(metric_score, precomp_score)
def test_unsupervised_radius_neighbors(n_samples=20, n_features=5,
n_query_pts=2, radius=0.5,
random_state=0):
# Test unsupervised radius-based query
rng = np.random.RandomState(random_state)
X = rng.rand(n_samples, n_features)
test = rng.rand(n_query_pts, n_features)
for p in P:
results = []
for algorithm in ALGORITHMS:
neigh = neighbors.NearestNeighbors(radius=radius,
algorithm=algorithm,
p=p)
neigh.fit(X)
ind1 = neigh.radius_neighbors(test, return_distance=False)
# sort the results: this is not done automatically for
# radius searches
dist, ind = neigh.radius_neighbors(test, return_distance=True)
for (d, i, i1) in zip(dist, ind, ind1):
j = d.argsort()
d[:] = d[j]
i[:] = i[j]
i1[:] = i1[j]
results.append((dist, ind))
assert_array_almost_equal(np.concatenate(list(ind)),
np.concatenate(list(ind1)))
for i in range(len(results) - 1):
assert_array_almost_equal(np.concatenate(list(results[i][0])),
np.concatenate(list(results[i + 1][0]))),
assert_array_almost_equal(np.concatenate(list(results[i][1])),
np.concatenate(list(results[i + 1][1])))
def test_kneighbors_classifier(n_samples=40,
n_features=5,
n_test_pts=10,
n_neighbors=5,
random_state=0):
# Test k-neighbors classification
rng = np.random.RandomState(random_state)
X = 2 * rng.rand(n_samples, n_features) - 1
y = ((X ** 2).sum(axis=1) < .5).astype(np.int)
y_str = y.astype(str)
weight_func = _weight_func
for algorithm in ALGORITHMS:
for weights in ['uniform', 'distance', weight_func]:
knn = neighbors.KNeighborsClassifier(n_neighbors=n_neighbors,
weights=weights,
algorithm=algorithm)
knn.fit(X, y)
epsilon = 1e-5 * (2 * rng.rand(1, n_features) - 1)
y_pred = knn.predict(X[:n_test_pts] + epsilon)
assert_array_equal(y_pred, y[:n_test_pts])
# Test prediction with y_str
knn.fit(X, y_str)
y_pred = knn.predict(X[:n_test_pts] + epsilon)
assert_array_equal(y_pred, y_str[:n_test_pts])
def test_kneighbors_classifier_float_labels(n_samples=40, n_features=5,
n_test_pts=10, n_neighbors=5,
random_state=0):
# Test k-neighbors classification
rng = np.random.RandomState(random_state)
X = 2 * rng.rand(n_samples, n_features) - 1
y = ((X ** 2).sum(axis=1) < .5).astype(np.int)
knn = neighbors.KNeighborsClassifier(n_neighbors=n_neighbors)
knn.fit(X, y.astype(np.float))
epsilon = 1e-5 * (2 * rng.rand(1, n_features) - 1)
y_pred = knn.predict(X[:n_test_pts] + epsilon)
assert_array_equal(y_pred, y[:n_test_pts])
def test_kneighbors_classifier_predict_proba():
# Test KNeighborsClassifier.predict_proba() method
X = np.array([[0, 2, 0],
[0, 2, 1],
[2, 0, 0],
[2, 2, 0],
[0, 0, 2],
[0, 0, 1]])
y = np.array([4, 4, 5, 5, 1, 1])
cls = neighbors.KNeighborsClassifier(n_neighbors=3, p=1) # cityblock dist
cls.fit(X, y)
y_prob = cls.predict_proba(X)
real_prob = np.array([[0, 2. / 3, 1. / 3],
[1. / 3, 2. / 3, 0],
[1. / 3, 0, 2. / 3],
[0, 1. / 3, 2. / 3],
[2. / 3, 1. / 3, 0],
[2. / 3, 1. / 3, 0]])
assert_array_equal(real_prob, y_prob)
# Check that it also works with non integer labels
cls.fit(X, y.astype(str))
y_prob = cls.predict_proba(X)
assert_array_equal(real_prob, y_prob)
# Check that it works with weights='distance'
cls = neighbors.KNeighborsClassifier(
n_neighbors=2, p=1, weights='distance')
cls.fit(X, y)
y_prob = cls.predict_proba(np.array([[0, 2, 0], [2, 2, 2]]))
real_prob = np.array([[0, 1, 0], [0, 0.4, 0.6]])
assert_array_almost_equal(real_prob, y_prob)
def test_radius_neighbors_classifier(n_samples=40,
n_features=5,
n_test_pts=10,
radius=0.5,
random_state=0):
# Test radius-based classification
rng = np.random.RandomState(random_state)
X = 2 * rng.rand(n_samples, n_features) - 1
y = ((X ** 2).sum(axis=1) < .5).astype(np.int)
y_str = y.astype(str)
weight_func = _weight_func
for algorithm in ALGORITHMS:
for weights in ['uniform', 'distance', weight_func]:
neigh = neighbors.RadiusNeighborsClassifier(radius=radius,
weights=weights,
algorithm=algorithm)
neigh.fit(X, y)
epsilon = 1e-5 * (2 * rng.rand(1, n_features) - 1)
y_pred = neigh.predict(X[:n_test_pts] + epsilon)
assert_array_equal(y_pred, y[:n_test_pts])
neigh.fit(X, y_str)
y_pred = neigh.predict(X[:n_test_pts] + epsilon)
assert_array_equal(y_pred, y_str[:n_test_pts])
def test_radius_neighbors_classifier_when_no_neighbors():
# Test radius-based classifier when no neighbors found.
# In this case it should rise an informative exception
X = np.array([[1.0, 1.0], [2.0, 2.0]])
y = np.array([1, 2])
radius = 0.1
z1 = np.array([[1.01, 1.01], [2.01, 2.01]]) # no outliers
z2 = np.array([[1.01, 1.01], [1.4, 1.4]]) # one outlier
weight_func = _weight_func
for outlier_label in [0, -1, None]:
for algorithm in ALGORITHMS:
for weights in ['uniform', 'distance', weight_func]:
rnc = neighbors.RadiusNeighborsClassifier
clf = rnc(radius=radius, weights=weights, algorithm=algorithm,
outlier_label=outlier_label)
clf.fit(X, y)
assert_array_equal(np.array([1, 2]),
clf.predict(z1))
if outlier_label is None:
assert_raises(ValueError, clf.predict, z2)
elif False:
assert_array_equal(np.array([1, outlier_label]),
clf.predict(z2))
def test_radius_neighbors_classifier_outlier_labeling():
# Test radius-based classifier when no neighbors found and outliers
# are labeled.
X = np.array([[1.0, 1.0], [2.0, 2.0], [0.99, 0.99],
[0.98, 0.98], [2.01, 2.01]])
y = np.array([1, 2, 1, 1, 2])
radius = 0.1
z1 = np.array([[1.01, 1.01], [2.01, 2.01]]) # no outliers
z2 = np.array([[1.4, 1.4], [1.01, 1.01], [2.01, 2.01]]) # one outlier
correct_labels1 = np.array([1, 2])
correct_labels2 = np.array([-1, 1, 2])
weight_func = _weight_func
for algorithm in ALGORITHMS:
for weights in ['uniform', 'distance', weight_func]:
clf = neighbors.RadiusNeighborsClassifier(radius=radius,
weights=weights,
algorithm=algorithm,
outlier_label=-1)
clf.fit(X, y)
assert_array_equal(correct_labels1, clf.predict(z1))
assert_array_equal(correct_labels2, clf.predict(z2))
def test_radius_neighbors_classifier_zero_distance():
# Test radius-based classifier, when distance to a sample is zero.
X = np.array([[1.0, 1.0], [2.0, 2.0]])
y = np.array([1, 2])
radius = 0.1
z1 = np.array([[1.01, 1.01], [2.0, 2.0]])
correct_labels1 = np.array([1, 2])
weight_func = _weight_func
for algorithm in ALGORITHMS:
for weights in ['uniform', 'distance', weight_func]:
clf = neighbors.RadiusNeighborsClassifier(radius=radius,
weights=weights,
algorithm=algorithm)
clf.fit(X, y)
assert_array_equal(correct_labels1, clf.predict(z1))
def test_neighbors_regressors_zero_distance():
# Test radius-based regressor, when distance to a sample is zero.
X = np.array([[1.0, 1.0], [1.0, 1.0], [2.0, 2.0], [2.5, 2.5]])
y = np.array([1.0, 1.5, 2.0, 0.0])
radius = 0.2
z = np.array([[1.1, 1.1], [2.0, 2.0]])
rnn_correct_labels = np.array([1.25, 2.0])
knn_correct_unif = np.array([1.25, 1.0])
knn_correct_dist = np.array([1.25, 2.0])
for algorithm in ALGORITHMS:
# we don't test for weights=_weight_func since user will be expected
# to handle zero distances themselves in the function.
for weights in ['uniform', 'distance']:
rnn = neighbors.RadiusNeighborsRegressor(radius=radius,
weights=weights,
algorithm=algorithm)
rnn.fit(X, y)
assert_array_almost_equal(rnn_correct_labels, rnn.predict(z))
for weights, corr_labels in zip(['uniform', 'distance'],
[knn_correct_unif, knn_correct_dist]):
knn = neighbors.KNeighborsRegressor(n_neighbors=2,
weights=weights,
algorithm=algorithm)
knn.fit(X, y)
assert_array_almost_equal(corr_labels, knn.predict(z))
def test_radius_neighbors_boundary_handling():
"""Test whether points lying on boundary are handled consistently
Also ensures that even with only one query point, an object array
is returned rather than a 2d array.
"""
X = np.array([[1.5], [3.0], [3.01]])
radius = 3.0
for algorithm in ALGORITHMS:
nbrs = neighbors.NearestNeighbors(radius=radius,
algorithm=algorithm).fit(X)
results = nbrs.radius_neighbors([[0.0]], return_distance=False)
assert_equal(results.shape, (1,))
assert_equal(results.dtype, object)
assert_array_equal(results[0], [0, 1])
def test_RadiusNeighborsClassifier_multioutput():
# Test k-NN classifier on multioutput data
rng = check_random_state(0)
n_features = 2
n_samples = 40
n_output = 3
X = rng.rand(n_samples, n_features)
y = rng.randint(0, 3, (n_samples, n_output))
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
weights = [None, 'uniform', 'distance', _weight_func]
for algorithm, weights in product(ALGORITHMS, weights):
# Stack single output prediction
y_pred_so = []
for o in range(n_output):
rnn = neighbors.RadiusNeighborsClassifier(weights=weights,
algorithm=algorithm)
rnn.fit(X_train, y_train[:, o])
y_pred_so.append(rnn.predict(X_test))
y_pred_so = np.vstack(y_pred_so).T
assert_equal(y_pred_so.shape, y_test.shape)
# Multioutput prediction
rnn_mo = neighbors.RadiusNeighborsClassifier(weights=weights,
algorithm=algorithm)
rnn_mo.fit(X_train, y_train)
y_pred_mo = rnn_mo.predict(X_test)
assert_equal(y_pred_mo.shape, y_test.shape)
assert_array_almost_equal(y_pred_mo, y_pred_so)
def test_kneighbors_classifier_sparse(n_samples=40,
n_features=5,
n_test_pts=10,
n_neighbors=5,
random_state=0):
# Test k-NN classifier on sparse matrices
# Like the above, but with various types of sparse matrices
rng = np.random.RandomState(random_state)
X = 2 * rng.rand(n_samples, n_features) - 1
X *= X > .2
y = ((X ** 2).sum(axis=1) < .5).astype(np.int)
for sparsemat in SPARSE_TYPES:
knn = neighbors.KNeighborsClassifier(n_neighbors=n_neighbors,
algorithm='auto')
knn.fit(sparsemat(X), y)
epsilon = 1e-5 * (2 * rng.rand(1, n_features) - 1)
for sparsev in SPARSE_TYPES + (np.asarray,):
X_eps = sparsev(X[:n_test_pts] + epsilon)
y_pred = knn.predict(X_eps)
assert_array_equal(y_pred, y[:n_test_pts])
def test_KNeighborsClassifier_multioutput():
# Test k-NN classifier on multioutput data
rng = check_random_state(0)
n_features = 5
n_samples = 50
n_output = 3
X = rng.rand(n_samples, n_features)
y = rng.randint(0, 3, (n_samples, n_output))
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
weights = [None, 'uniform', 'distance', _weight_func]
for algorithm, weights in product(ALGORITHMS, weights):
# Stack single output prediction
y_pred_so = []
y_pred_proba_so = []
for o in range(n_output):
knn = neighbors.KNeighborsClassifier(weights=weights,
algorithm=algorithm)
knn.fit(X_train, y_train[:, o])
y_pred_so.append(knn.predict(X_test))
y_pred_proba_so.append(knn.predict_proba(X_test))
y_pred_so = np.vstack(y_pred_so).T
assert_equal(y_pred_so.shape, y_test.shape)
assert_equal(len(y_pred_proba_so), n_output)
# Multioutput prediction
knn_mo = neighbors.KNeighborsClassifier(weights=weights,
algorithm=algorithm)
knn_mo.fit(X_train, y_train)
y_pred_mo = knn_mo.predict(X_test)
assert_equal(y_pred_mo.shape, y_test.shape)
assert_array_almost_equal(y_pred_mo, y_pred_so)
# Check proba
y_pred_proba_mo = knn_mo.predict_proba(X_test)
assert_equal(len(y_pred_proba_mo), n_output)
for proba_mo, proba_so in zip(y_pred_proba_mo, y_pred_proba_so):
assert_array_almost_equal(proba_mo, proba_so)
def test_kneighbors_regressor(n_samples=40,
n_features=5,
n_test_pts=10,
n_neighbors=3,
random_state=0):
# Test k-neighbors regression
rng = np.random.RandomState(random_state)
X = 2 * rng.rand(n_samples, n_features) - 1
y = np.sqrt((X ** 2).sum(1))
y /= y.max()
y_target = y[:n_test_pts]
weight_func = _weight_func
for algorithm in ALGORITHMS:
for weights in ['uniform', 'distance', weight_func]:
knn = neighbors.KNeighborsRegressor(n_neighbors=n_neighbors,
weights=weights,
algorithm=algorithm)
knn.fit(X, y)
epsilon = 1E-5 * (2 * rng.rand(1, n_features) - 1)
y_pred = knn.predict(X[:n_test_pts] + epsilon)
assert_true(np.all(abs(y_pred - y_target) < 0.3))
def test_KNeighborsRegressor_multioutput_uniform_weight():
# Test k-neighbors in multi-output regression with uniform weight
rng = check_random_state(0)
n_features = 5
n_samples = 40
n_output = 4
X = rng.rand(n_samples, n_features)
y = rng.rand(n_samples, n_output)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
for algorithm, weights in product(ALGORITHMS, [None, 'uniform']):
knn = neighbors.KNeighborsRegressor(weights=weights,
algorithm=algorithm)
knn.fit(X_train, y_train)
neigh_idx = knn.kneighbors(X_test, return_distance=False)
y_pred_idx = np.array([np.mean(y_train[idx], axis=0)
for idx in neigh_idx])
y_pred = knn.predict(X_test)
assert_equal(y_pred.shape, y_test.shape)
assert_equal(y_pred_idx.shape, y_test.shape)
assert_array_almost_equal(y_pred, y_pred_idx)
def test_kneighbors_regressor_multioutput(n_samples=40,
n_features=5,
n_test_pts=10,
n_neighbors=3,
random_state=0):
# Test k-neighbors in multi-output regression
rng = np.random.RandomState(random_state)
X = 2 * rng.rand(n_samples, n_features) - 1
y = np.sqrt((X ** 2).sum(1))
y /= y.max()
y = np.vstack([y, y]).T
y_target = y[:n_test_pts]
weights = ['uniform', 'distance', _weight_func]
for algorithm, weights in product(ALGORITHMS, weights):
knn = neighbors.KNeighborsRegressor(n_neighbors=n_neighbors,
weights=weights,
algorithm=algorithm)
knn.fit(X, y)
epsilon = 1E-5 * (2 * rng.rand(1, n_features) - 1)
y_pred = knn.predict(X[:n_test_pts] + epsilon)
assert_equal(y_pred.shape, y_target.shape)
assert_true(np.all(np.abs(y_pred - y_target) < 0.3))
def test_radius_neighbors_regressor(n_samples=40,
n_features=3,
n_test_pts=10,
radius=0.5,
random_state=0):
# Test radius-based neighbors regression
rng = np.random.RandomState(random_state)
X = 2 * rng.rand(n_samples, n_features) - 1
y = np.sqrt((X ** 2).sum(1))
y /= y.max()
y_target = y[:n_test_pts]
weight_func = _weight_func
for algorithm in ALGORITHMS:
for weights in ['uniform', 'distance', weight_func]:
neigh = neighbors.RadiusNeighborsRegressor(radius=radius,
weights=weights,
algorithm=algorithm)
neigh.fit(X, y)
epsilon = 1E-5 * (2 * rng.rand(1, n_features) - 1)
y_pred = neigh.predict(X[:n_test_pts] + epsilon)
assert_true(np.all(abs(y_pred - y_target) < radius / 2))
def test_RadiusNeighborsRegressor_multioutput_with_uniform_weight():
# Test radius neighbors in multi-output regression (uniform weight)
rng = check_random_state(0)
n_features = 5
n_samples = 40
n_output = 4
X = rng.rand(n_samples, n_features)
y = rng.rand(n_samples, n_output)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
for algorithm, weights in product(ALGORITHMS, [None, 'uniform']):
rnn = neighbors. RadiusNeighborsRegressor(weights=weights,
algorithm=algorithm)
rnn.fit(X_train, y_train)
neigh_idx = rnn.radius_neighbors(X_test, return_distance=False)
y_pred_idx = np.array([np.mean(y_train[idx], axis=0)
for idx in neigh_idx])
y_pred_idx = np.array(y_pred_idx)
y_pred = rnn.predict(X_test)
assert_equal(y_pred_idx.shape, y_test.shape)
assert_equal(y_pred.shape, y_test.shape)
assert_array_almost_equal(y_pred, y_pred_idx)
def test_RadiusNeighborsRegressor_multioutput(n_samples=40,
n_features=5,
n_test_pts=10,
n_neighbors=3,
random_state=0):
# Test k-neighbors in multi-output regression with various weight
rng = np.random.RandomState(random_state)
X = 2 * rng.rand(n_samples, n_features) - 1
y = np.sqrt((X ** 2).sum(1))
y /= y.max()
y = np.vstack([y, y]).T
y_target = y[:n_test_pts]
weights = ['uniform', 'distance', _weight_func]
for algorithm, weights in product(ALGORITHMS, weights):
rnn = neighbors.RadiusNeighborsRegressor(n_neighbors=n_neighbors,
weights=weights,
algorithm=algorithm)
rnn.fit(X, y)
epsilon = 1E-5 * (2 * rng.rand(1, n_features) - 1)
y_pred = rnn.predict(X[:n_test_pts] + epsilon)
assert_equal(y_pred.shape, y_target.shape)
assert_true(np.all(np.abs(y_pred - y_target) < 0.3))
def test_kneighbors_regressor_sparse(n_samples=40,
n_features=5,
n_test_pts=10,
n_neighbors=5,
random_state=0):
# Test radius-based regression on sparse matrices
# Like the above, but with various types of sparse matrices
rng = np.random.RandomState(random_state)
X = 2 * rng.rand(n_samples, n_features) - 1
y = ((X ** 2).sum(axis=1) < .25).astype(np.int)
for sparsemat in SPARSE_TYPES:
knn = neighbors.KNeighborsRegressor(n_neighbors=n_neighbors,
algorithm='auto')
knn.fit(sparsemat(X), y)
for sparsev in SPARSE_OR_DENSE:
X2 = sparsev(X)
assert_true(np.mean(knn.predict(X2).round() == y) > 0.95)
def test_neighbors_iris():
# Sanity checks on the iris dataset
# Puts three points of each label in the plane and performs a
# nearest neighbor query on points near the decision boundary.
for algorithm in ALGORITHMS:
clf = neighbors.KNeighborsClassifier(n_neighbors=1,
algorithm=algorithm)
clf.fit(iris.data, iris.target)
assert_array_equal(clf.predict(iris.data), iris.target)
clf.set_params(n_neighbors=9, algorithm=algorithm)
clf.fit(iris.data, iris.target)
assert_true(np.mean(clf.predict(iris.data) == iris.target) > 0.95)
rgs = neighbors.KNeighborsRegressor(n_neighbors=5, algorithm=algorithm)
rgs.fit(iris.data, iris.target)
assert_greater(np.mean(rgs.predict(iris.data).round() == iris.target),
0.95)
def test_neighbors_digits():
# Sanity check on the digits dataset
# the 'brute' algorithm has been observed to fail if the input
# dtype is uint8 due to overflow in distance calculations.
X = digits.data.astype('uint8')
Y = digits.target
(n_samples, n_features) = X.shape
train_test_boundary = int(n_samples * 0.8)
train = np.arange(0, train_test_boundary)
test = np.arange(train_test_boundary, n_samples)
(X_train, Y_train, X_test, Y_test) = X[train], Y[train], X[test], Y[test]
clf = neighbors.KNeighborsClassifier(n_neighbors=1, algorithm='brute')
score_uint8 = clf.fit(X_train, Y_train).score(X_test, Y_test)
score_float = clf.fit(X_train.astype(float), Y_train).score(
X_test.astype(float), Y_test)
assert_equal(score_uint8, score_float)
def test_kneighbors_graph():
# Test kneighbors_graph to build the k-Nearest Neighbor graph.
X = np.array([[0, 1], [1.01, 1.], [2, 0]])
# n_neighbors = 1
A = neighbors.kneighbors_graph(X, 1, mode='connectivity',
include_self=True)
assert_array_equal(A.toarray(), np.eye(A.shape[0]))
A = neighbors.kneighbors_graph(X, 1, mode='distance')
assert_array_almost_equal(
A.toarray(),
[[0.00, 1.01, 0.],
[1.01, 0., 0.],
[0.00, 1.40716026, 0.]])
# n_neighbors = 2
A = neighbors.kneighbors_graph(X, 2, mode='connectivity',
include_self=True)
assert_array_equal(
A.toarray(),
[[1., 1., 0.],
[1., 1., 0.],
[0., 1., 1.]])
A = neighbors.kneighbors_graph(X, 2, mode='distance')
assert_array_almost_equal(
A.toarray(),
[[0., 1.01, 2.23606798],
[1.01, 0., 1.40716026],
[2.23606798, 1.40716026, 0.]])
# n_neighbors = 3
A = neighbors.kneighbors_graph(X, 3, mode='connectivity',
include_self=True)
assert_array_almost_equal(
A.toarray(),
[[1, 1, 1], [1, 1, 1], [1, 1, 1]])
def test_kneighbors_graph_sparse(seed=36):
# Test kneighbors_graph to build the k-Nearest Neighbor graph
# for sparse input.
rng = np.random.RandomState(seed)
X = rng.randn(10, 10)
Xcsr = csr_matrix(X)
for n_neighbors in [1, 2, 3]:
for mode in ["connectivity", "distance"]:
assert_array_almost_equal(
neighbors.kneighbors_graph(X,
n_neighbors,
mode=mode).toarray(),
neighbors.kneighbors_graph(Xcsr,
n_neighbors,
mode=mode).toarray())
def test_radius_neighbors_graph():
# Test radius_neighbors_graph to build the Nearest Neighbor graph.
X = np.array([[0, 1], [1.01, 1.], [2, 0]])
A = neighbors.radius_neighbors_graph(X, 1.5, mode='connectivity',
include_self=True)
assert_array_equal(
A.toarray(),
[[1., 1., 0.],
[1., 1., 1.],
[0., 1., 1.]])
A = neighbors.radius_neighbors_graph(X, 1.5, mode='distance')
assert_array_almost_equal(
A.toarray(),
[[0., 1.01, 0.],
[1.01, 0., 1.40716026],
[0., 1.40716026, 0.]])
def test_radius_neighbors_graph_sparse(seed=36):
# Test radius_neighbors_graph to build the Nearest Neighbor graph
# for sparse input.
rng = np.random.RandomState(seed)
X = rng.randn(10, 10)
Xcsr = csr_matrix(X)
for n_neighbors in [1, 2, 3]:
for mode in ["connectivity", "distance"]:
assert_array_almost_equal(
neighbors.radius_neighbors_graph(X,
n_neighbors,
mode=mode).toarray(),
neighbors.radius_neighbors_graph(Xcsr,
n_neighbors,
mode=mode).toarray())
def test_neighbors_badargs():
# Test bad argument values: these should all raise ValueErrors
assert_raises(ValueError,
neighbors.NearestNeighbors,
algorithm='blah')
X = rng.random_sample((10, 2))
Xsparse = csr_matrix(X)
y = np.ones(10)
for cls in (neighbors.KNeighborsClassifier,
neighbors.RadiusNeighborsClassifier,
neighbors.KNeighborsRegressor,
neighbors.RadiusNeighborsRegressor):
assert_raises(ValueError,
cls,
weights='blah')
assert_raises(ValueError,
cls, p=-1)
assert_raises(ValueError,
cls, algorithm='blah')
nbrs = cls(algorithm='ball_tree', metric='haversine')
assert_raises(ValueError,
nbrs.predict,
X)
assert_raises(ValueError,
ignore_warnings(nbrs.fit),
Xsparse, y)
nbrs = cls()
assert_raises(ValueError,
nbrs.fit,
np.ones((0, 2)), np.ones(0))
assert_raises(ValueError,
nbrs.fit,
X[:, :, None], y)
nbrs.fit(X, y)
assert_raises(ValueError,
nbrs.predict,
[[]])
if (isinstance(cls, neighbors.KNeighborsClassifier) or
isinstance(cls, neighbors.KNeighborsRegressor)):
nbrs = cls(n_neighbors=-1)
assert_raises(ValueError, nbrs.fit, X, y)
nbrs = neighbors.NearestNeighbors().fit(X)
assert_raises(ValueError, nbrs.kneighbors_graph, X, mode='blah')
assert_raises(ValueError, nbrs.radius_neighbors_graph, X, mode='blah')
def test_neighbors_metrics(n_samples=20, n_features=3,
n_query_pts=2, n_neighbors=5):
# Test computing the neighbors for various metrics
# create a symmetric matrix
V = rng.rand(n_features, n_features)
VI = np.dot(V, V.T)
metrics = [('euclidean', {}),
('manhattan', {}),
('minkowski', dict(p=1)),
('minkowski', dict(p=2)),
('minkowski', dict(p=3)),
('minkowski', dict(p=np.inf)),
('chebyshev', {}),
('seuclidean', dict(V=rng.rand(n_features))),
('wminkowski', dict(p=3, w=rng.rand(n_features))),
('mahalanobis', dict(VI=VI))]
algorithms = ['brute', 'ball_tree', 'kd_tree']
X = rng.rand(n_samples, n_features)
test = rng.rand(n_query_pts, n_features)
for metric, metric_params in metrics:
results = {}
p = metric_params.pop('p', 2)
for algorithm in algorithms:
# KD tree doesn't support all metrics
if (algorithm == 'kd_tree' and
metric not in neighbors.KDTree.valid_metrics):
assert_raises(ValueError,
neighbors.NearestNeighbors,
algorithm=algorithm,
metric=metric, metric_params=metric_params)
continue
neigh = neighbors.NearestNeighbors(n_neighbors=n_neighbors,
algorithm=algorithm,
metric=metric, p=p,
metric_params=metric_params)
neigh.fit(X)
results[algorithm] = neigh.kneighbors(test, return_distance=True)
assert_array_almost_equal(results['brute'][0], results['ball_tree'][0])
assert_array_almost_equal(results['brute'][1], results['ball_tree'][1])
if 'kd_tree' in results:
assert_array_almost_equal(results['brute'][0],
results['kd_tree'][0])
assert_array_almost_equal(results['brute'][1],
results['kd_tree'][1])
def test_callable_metric():
def custom_metric(x1, x2):
return np.sqrt(np.sum(x1 ** 2 + x2 ** 2))
X = np.random.RandomState(42).rand(20, 2)
nbrs1 = neighbors.NearestNeighbors(3, algorithm='auto',
metric=custom_metric)
nbrs2 = neighbors.NearestNeighbors(3, algorithm='brute',
metric=custom_metric)
nbrs1.fit(X)
nbrs2.fit(X)
dist1, ind1 = nbrs1.kneighbors(X)
dist2, ind2 = nbrs2.kneighbors(X)
assert_array_almost_equal(dist1, dist2)
def test_valid_brute_metric_for_auto_algorithm():
X = rng.rand(12, 12)
Xcsr = csr_matrix(X)
# check that there is a metric that is valid for brute
# but not ball_tree (so we actually test something)
assert_in("cosine", VALID_METRICS['brute'])
assert_false("cosine" in VALID_METRICS['ball_tree'])
# Metric which don't required any additional parameter
require_params = ['mahalanobis', 'wminkowski', 'seuclidean']
for metric in VALID_METRICS['brute']:
if metric != 'precomputed' and metric not in require_params:
nn = neighbors.NearestNeighbors(n_neighbors=3, algorithm='auto',
metric=metric).fit(X)
nn.kneighbors(X)
elif metric == 'precomputed':
X_precomputed = rng.random_sample((10, 4))
Y_precomputed = rng.random_sample((3, 4))
DXX = metrics.pairwise_distances(X_precomputed, metric='euclidean')
DYX = metrics.pairwise_distances(Y_precomputed, X_precomputed,
metric='euclidean')
nb_p = neighbors.NearestNeighbors(n_neighbors=3)
nb_p.fit(DXX)
nb_p.kneighbors(DYX)
for metric in VALID_METRICS_SPARSE['brute']:
if metric != 'precomputed' and metric not in require_params:
nn = neighbors.NearestNeighbors(n_neighbors=3, algorithm='auto',
metric=metric).fit(Xcsr)
nn.kneighbors(Xcsr)
# Metric with parameter
VI = np.dot(X, X.T)
list_metrics = [('seuclidean', dict(V=rng.rand(12))),
('wminkowski', dict(w=rng.rand(12))),
('mahalanobis', dict(VI=VI))]
for metric, params in list_metrics:
nn = neighbors.NearestNeighbors(n_neighbors=3, algorithm='auto',
metric=metric,
metric_params=params).fit(X)
nn.kneighbors(X)
def test_metric_params_interface():
assert_warns(SyntaxWarning, neighbors.KNeighborsClassifier,
metric_params={'p': 3})
def test_predict_sparse_ball_kd_tree():
rng = np.random.RandomState(0)
X = rng.rand(5, 5)
y = rng.randint(0, 2, 5)
nbrs1 = neighbors.KNeighborsClassifier(1, algorithm='kd_tree')
nbrs2 = neighbors.KNeighborsRegressor(1, algorithm='ball_tree')
for model in [nbrs1, nbrs2]:
model.fit(X, y)
assert_raises(ValueError, model.predict, csr_matrix(X))
def test_non_euclidean_kneighbors():
rng = np.random.RandomState(0)
X = rng.rand(5, 5)
# Find a reasonable radius.
dist_array = pairwise_distances(X).flatten()
np.sort(dist_array)
radius = dist_array[15]
# Test kneighbors_graph
for metric in ['manhattan', 'chebyshev']:
nbrs_graph = neighbors.kneighbors_graph(
X, 3, metric=metric, mode='connectivity',
include_self=True).toarray()
nbrs1 = neighbors.NearestNeighbors(3, metric=metric).fit(X)
assert_array_equal(nbrs_graph, nbrs1.kneighbors_graph(X).toarray())
# Test radiusneighbors_graph
for metric in ['manhattan', 'chebyshev']:
nbrs_graph = neighbors.radius_neighbors_graph(
X, radius, metric=metric, mode='connectivity',
include_self=True).toarray()
nbrs1 = neighbors.NearestNeighbors(metric=metric, radius=radius).fit(X)
assert_array_equal(nbrs_graph, nbrs1.radius_neighbors_graph(X).A)
# Raise error when wrong parameters are supplied,
X_nbrs = neighbors.NearestNeighbors(3, metric='manhattan')
X_nbrs.fit(X)
assert_raises(ValueError, neighbors.kneighbors_graph, X_nbrs, 3,
metric='euclidean')
X_nbrs = neighbors.NearestNeighbors(radius=radius, metric='manhattan')
X_nbrs.fit(X)
assert_raises(ValueError, neighbors.radius_neighbors_graph, X_nbrs,
radius, metric='euclidean')
def check_object_arrays(nparray, list_check):
for ind, ele in enumerate(nparray):
assert_array_equal(ele, list_check[ind])
def test_k_and_radius_neighbors_train_is_not_query():
# Test kneighbors et.al when query is not training data
for algorithm in ALGORITHMS:
nn = neighbors.NearestNeighbors(n_neighbors=1, algorithm=algorithm)
X = [[0], [1]]
nn.fit(X)
test_data = [[2], [1]]
# Test neighbors.
dist, ind = nn.kneighbors(test_data)
assert_array_equal(dist, [[1], [0]])
assert_array_equal(ind, [[1], [1]])
dist, ind = nn.radius_neighbors([[2], [1]], radius=1.5)
check_object_arrays(dist, [[1], [1, 0]])
check_object_arrays(ind, [[1], [0, 1]])
# Test the graph variants.
assert_array_equal(
nn.kneighbors_graph(test_data).A, [[0., 1.], [0., 1.]])
assert_array_equal(
nn.kneighbors_graph([[2], [1]], mode='distance').A,
np.array([[0., 1.], [0., 0.]]))
rng = nn.radius_neighbors_graph([[2], [1]], radius=1.5)
assert_array_equal(rng.A, [[0, 1], [1, 1]])
def test_k_and_radius_neighbors_X_None():
# Test kneighbors et.al when query is None
for algorithm in ALGORITHMS:
nn = neighbors.NearestNeighbors(n_neighbors=1, algorithm=algorithm)
X = [[0], [1]]
nn.fit(X)
dist, ind = nn.kneighbors()
assert_array_equal(dist, [[1], [1]])
assert_array_equal(ind, [[1], [0]])
dist, ind = nn.radius_neighbors(None, radius=1.5)
check_object_arrays(dist, [[1], [1]])
check_object_arrays(ind, [[1], [0]])
# Test the graph variants.
rng = nn.radius_neighbors_graph(None, radius=1.5)
kng = nn.kneighbors_graph(None)
for graph in [rng, kng]:
assert_array_equal(rng.A, [[0, 1], [1, 0]])
assert_array_equal(rng.data, [1, 1])
assert_array_equal(rng.indices, [1, 0])
X = [[0, 1], [0, 1], [1, 1]]
nn = neighbors.NearestNeighbors(n_neighbors=2, algorithm=algorithm)
nn.fit(X)
assert_array_equal(
nn.kneighbors_graph().A,
np.array([[0., 1., 1.], [1., 0., 1.], [1., 1., 0]]))
def test_k_and_radius_neighbors_duplicates():
# Test behavior of kneighbors when duplicates are present in query
for algorithm in ALGORITHMS:
nn = neighbors.NearestNeighbors(n_neighbors=1, algorithm=algorithm)
nn.fit([[0], [1]])
# Do not do anything special to duplicates.
kng = nn.kneighbors_graph([[0], [1]], mode='distance')
assert_array_equal(
kng.A,
np.array([[0., 0.], [0., 0.]]))
assert_array_equal(kng.data, [0., 0.])
assert_array_equal(kng.indices, [0, 1])
dist, ind = nn.radius_neighbors([[0], [1]], radius=1.5)
check_object_arrays(dist, [[0, 1], [1, 0]])
check_object_arrays(ind, [[0, 1], [0, 1]])
rng = nn.radius_neighbors_graph([[0], [1]], radius=1.5)
assert_array_equal(rng.A, np.ones((2, 2)))
rng = nn.radius_neighbors_graph([[0], [1]], radius=1.5,
mode='distance')
assert_array_equal(rng.A, [[0, 1], [1, 0]])
assert_array_equal(rng.indices, [0, 1, 0, 1])
assert_array_equal(rng.data, [0, 1, 1, 0])
# Mask the first duplicates when n_duplicates > n_neighbors.
X = np.ones((3, 1))
nn = neighbors.NearestNeighbors(n_neighbors=1)
nn.fit(X)
dist, ind = nn.kneighbors()
assert_array_equal(dist, np.zeros((3, 1)))
assert_array_equal(ind, [[1], [0], [1]])
# Test that zeros are explicitly marked in kneighbors_graph.
kng = nn.kneighbors_graph(mode='distance')
assert_array_equal(
kng.A, np.zeros((3, 3)))
assert_array_equal(kng.data, np.zeros(3))
assert_array_equal(kng.indices, [1., 0., 1.])
assert_array_equal(
nn.kneighbors_graph().A,
np.array([[0., 1., 0.], [1., 0., 0.], [0., 1., 0.]]))
def test_include_self_neighbors_graph():
# Test include_self parameter in neighbors_graph
X = [[2, 3], [4, 5]]
kng = neighbors.kneighbors_graph(X, 1, include_self=True).A
kng_not_self = neighbors.kneighbors_graph(X, 1, include_self=False).A
assert_array_equal(kng, [[1., 0.], [0., 1.]])
assert_array_equal(kng_not_self, [[0., 1.], [1., 0.]])
rng = neighbors.radius_neighbors_graph(X, 5.0, include_self=True).A
rng_not_self = neighbors.radius_neighbors_graph(
X, 5.0, include_self=False).A
assert_array_equal(rng, [[1., 1.], [1., 1.]])
assert_array_equal(rng_not_self, [[0., 1.], [1., 0.]])
def test_same_knn_parallel():
X, y = datasets.make_classification(n_samples=30, n_features=5,
n_redundant=0, random_state=0)
X_train, X_test, y_train, y_test = train_test_split(X, y)
def check_same_knn_parallel(algorithm):
clf = neighbors.KNeighborsClassifier(n_neighbors=3,
algorithm=algorithm)
clf.fit(X_train, y_train)
y = clf.predict(X_test)
dist, ind = clf.kneighbors(X_test)
graph = clf.kneighbors_graph(X_test, mode='distance').toarray()
clf.set_params(n_jobs=3)
clf.fit(X_train, y_train)
y_parallel = clf.predict(X_test)
dist_parallel, ind_parallel = clf.kneighbors(X_test)
graph_parallel = \
clf.kneighbors_graph(X_test, mode='distance').toarray()
assert_array_equal(y, y_parallel)
assert_array_almost_equal(dist, dist_parallel)
assert_array_equal(ind, ind_parallel)
assert_array_almost_equal(graph, graph_parallel)
for algorithm in ALGORITHMS:
yield check_same_knn_parallel, algorithm
def test_dtype_convert():
classifier = neighbors.KNeighborsClassifier(n_neighbors=1)
CLASSES = 15
X = np.eye(CLASSES)
y = [ch for ch in 'ABCDEFGHIJKLMNOPQRSTU'[:CLASSES]]
result = classifier.fit(X, y).predict(X)
assert_array_equal(result, y)
# ignore conversion to boolean in pairwise_distances
@ignore_warnings(category=DataConversionWarning)
def test_pairwise_boolean_distance():
# Non-regression test for #4523
# 'brute': uses scipy.spatial.distance through pairwise_distances
# 'ball_tree': uses sklearn.neighbors.dist_metrics
rng = np.random.RandomState(0)
X = rng.uniform(size=(6, 5))
NN = neighbors.NearestNeighbors
nn1 = NN(metric="jaccard", algorithm='brute').fit(X)
nn2 = NN(metric="jaccard", algorithm='ball_tree').fit(X)
assert_array_equal(nn1.kneighbors(X)[0], nn2.kneighbors(X)[0])
| 48,928 | 37.496459 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/tests/test_ball_tree.py | import pickle
import numpy as np
from numpy.testing import assert_array_almost_equal
from sklearn.neighbors.ball_tree import (BallTree, NeighborsHeap,
simultaneous_sort, kernel_norm,
nodeheap_sort, DTYPE, ITYPE)
from sklearn.neighbors.dist_metrics import DistanceMetric
from sklearn.utils import check_random_state
from sklearn.utils.testing import SkipTest, assert_allclose
rng = np.random.RandomState(10)
V_mahalanobis = rng.rand(3, 3)
V_mahalanobis = np.dot(V_mahalanobis, V_mahalanobis.T)
DIMENSION = 3
METRICS = {'euclidean': {},
'manhattan': {},
'minkowski': dict(p=3),
'chebyshev': {},
'seuclidean': dict(V=rng.random_sample(DIMENSION)),
'wminkowski': dict(p=3, w=rng.random_sample(DIMENSION)),
'mahalanobis': dict(V=V_mahalanobis)}
DISCRETE_METRICS = ['hamming',
'canberra',
'braycurtis']
BOOLEAN_METRICS = ['matching', 'jaccard', 'dice', 'kulsinski',
'rogerstanimoto', 'russellrao', 'sokalmichener',
'sokalsneath']
def dist_func(x1, x2, p):
return np.sum((x1 - x2) ** p) ** (1. / p)
def brute_force_neighbors(X, Y, k, metric, **kwargs):
D = DistanceMetric.get_metric(metric, **kwargs).pairwise(Y, X)
ind = np.argsort(D, axis=1)[:, :k]
dist = D[np.arange(Y.shape[0])[:, None], ind]
return dist, ind
def test_ball_tree_query():
rng = check_random_state(0)
X = rng.random_sample((40, DIMENSION))
Y = rng.random_sample((10, DIMENSION))
def check_neighbors(dualtree, breadth_first, k, metric, kwargs):
bt = BallTree(X, leaf_size=1, metric=metric, **kwargs)
dist1, ind1 = bt.query(Y, k, dualtree=dualtree,
breadth_first=breadth_first)
dist2, ind2 = brute_force_neighbors(X, Y, k, metric, **kwargs)
# don't check indices here: if there are any duplicate distances,
# the indices may not match. Distances should not have this problem.
assert_array_almost_equal(dist1, dist2)
for (metric, kwargs) in METRICS.items():
for k in (1, 3, 5):
for dualtree in (True, False):
for breadth_first in (True, False):
yield (check_neighbors,
dualtree, breadth_first,
k, metric, kwargs)
def test_ball_tree_query_boolean_metrics():
rng = check_random_state(0)
X = rng.random_sample((40, 10)).round(0)
Y = rng.random_sample((10, 10)).round(0)
k = 5
def check_neighbors(metric):
bt = BallTree(X, leaf_size=1, metric=metric)
dist1, ind1 = bt.query(Y, k)
dist2, ind2 = brute_force_neighbors(X, Y, k, metric)
assert_array_almost_equal(dist1, dist2)
for metric in BOOLEAN_METRICS:
yield check_neighbors, metric
def test_ball_tree_query_discrete_metrics():
rng = check_random_state(0)
X = (4 * rng.random_sample((40, 10))).round(0)
Y = (4 * rng.random_sample((10, 10))).round(0)
k = 5
def check_neighbors(metric):
bt = BallTree(X, leaf_size=1, metric=metric)
dist1, ind1 = bt.query(Y, k)
dist2, ind2 = brute_force_neighbors(X, Y, k, metric)
assert_array_almost_equal(dist1, dist2)
for metric in DISCRETE_METRICS:
yield check_neighbors, metric
def test_ball_tree_query_radius(n_samples=100, n_features=10):
rng = check_random_state(0)
X = 2 * rng.random_sample(size=(n_samples, n_features)) - 1
query_pt = np.zeros(n_features, dtype=float)
eps = 1E-15 # roundoff error can cause test to fail
bt = BallTree(X, leaf_size=5)
rad = np.sqrt(((X - query_pt) ** 2).sum(1))
for r in np.linspace(rad[0], rad[-1], 100):
ind = bt.query_radius([query_pt], r + eps)[0]
i = np.where(rad <= r + eps)[0]
ind.sort()
i.sort()
assert_array_almost_equal(i, ind)
def test_ball_tree_query_radius_distance(n_samples=100, n_features=10):
rng = check_random_state(0)
X = 2 * rng.random_sample(size=(n_samples, n_features)) - 1
query_pt = np.zeros(n_features, dtype=float)
eps = 1E-15 # roundoff error can cause test to fail
bt = BallTree(X, leaf_size=5)
rad = np.sqrt(((X - query_pt) ** 2).sum(1))
for r in np.linspace(rad[0], rad[-1], 100):
ind, dist = bt.query_radius([query_pt], r + eps, return_distance=True)
ind = ind[0]
dist = dist[0]
d = np.sqrt(((query_pt - X[ind]) ** 2).sum(1))
assert_array_almost_equal(d, dist)
def compute_kernel_slow(Y, X, kernel, h):
d = np.sqrt(((Y[:, None, :] - X) ** 2).sum(-1))
norm = kernel_norm(h, X.shape[1], kernel)
if kernel == 'gaussian':
return norm * np.exp(-0.5 * (d * d) / (h * h)).sum(-1)
elif kernel == 'tophat':
return norm * (d < h).sum(-1)
elif kernel == 'epanechnikov':
return norm * ((1.0 - (d * d) / (h * h)) * (d < h)).sum(-1)
elif kernel == 'exponential':
return norm * (np.exp(-d / h)).sum(-1)
elif kernel == 'linear':
return norm * ((1 - d / h) * (d < h)).sum(-1)
elif kernel == 'cosine':
return norm * (np.cos(0.5 * np.pi * d / h) * (d < h)).sum(-1)
else:
raise ValueError('kernel not recognized')
def check_results(kernel, h, atol, rtol, breadth_first, bt, Y, dens_true):
dens = bt.kernel_density(Y, h, atol=atol, rtol=rtol,
kernel=kernel,
breadth_first=breadth_first)
assert_allclose(dens, dens_true,
atol=atol, rtol=max(rtol, 1e-7))
def test_ball_tree_kde(n_samples=100, n_features=3):
rng = check_random_state(0)
X = rng.random_sample((n_samples, n_features))
Y = rng.random_sample((n_samples, n_features))
bt = BallTree(X, leaf_size=10)
for kernel in ['gaussian', 'tophat', 'epanechnikov',
'exponential', 'linear', 'cosine']:
for h in [0.01, 0.1, 1]:
dens_true = compute_kernel_slow(Y, X, kernel, h)
for rtol in [0, 1E-5]:
for atol in [1E-6, 1E-2]:
for breadth_first in (True, False):
yield (check_results, kernel, h, atol, rtol,
breadth_first, bt, Y, dens_true)
def test_gaussian_kde(n_samples=1000):
# Compare gaussian KDE results to scipy.stats.gaussian_kde
from scipy.stats import gaussian_kde
rng = check_random_state(0)
x_in = rng.normal(0, 1, n_samples)
x_out = np.linspace(-5, 5, 30)
for h in [0.01, 0.1, 1]:
bt = BallTree(x_in[:, None])
try:
gkde = gaussian_kde(x_in, bw_method=h / np.std(x_in))
except TypeError:
raise SkipTest("Old version of scipy, doesn't accept "
"explicit bandwidth.")
dens_bt = bt.kernel_density(x_out[:, None], h) / n_samples
dens_gkde = gkde.evaluate(x_out)
assert_array_almost_equal(dens_bt, dens_gkde, decimal=3)
def test_ball_tree_two_point(n_samples=100, n_features=3):
rng = check_random_state(0)
X = rng.random_sample((n_samples, n_features))
Y = rng.random_sample((n_samples, n_features))
r = np.linspace(0, 1, 10)
bt = BallTree(X, leaf_size=10)
D = DistanceMetric.get_metric("euclidean").pairwise(Y, X)
counts_true = [(D <= ri).sum() for ri in r]
def check_two_point(r, dualtree):
counts = bt.two_point_correlation(Y, r=r, dualtree=dualtree)
assert_array_almost_equal(counts, counts_true)
for dualtree in (True, False):
yield check_two_point, r, dualtree
def test_ball_tree_pickle():
rng = check_random_state(0)
X = rng.random_sample((10, 3))
bt1 = BallTree(X, leaf_size=1)
# Test if BallTree with callable metric is picklable
bt1_pyfunc = BallTree(X, metric=dist_func, leaf_size=1, p=2)
ind1, dist1 = bt1.query(X)
ind1_pyfunc, dist1_pyfunc = bt1_pyfunc.query(X)
def check_pickle_protocol(protocol):
s = pickle.dumps(bt1, protocol=protocol)
bt2 = pickle.loads(s)
s_pyfunc = pickle.dumps(bt1_pyfunc, protocol=protocol)
bt2_pyfunc = pickle.loads(s_pyfunc)
ind2, dist2 = bt2.query(X)
ind2_pyfunc, dist2_pyfunc = bt2_pyfunc.query(X)
assert_array_almost_equal(ind1, ind2)
assert_array_almost_equal(dist1, dist2)
assert_array_almost_equal(ind1_pyfunc, ind2_pyfunc)
assert_array_almost_equal(dist1_pyfunc, dist2_pyfunc)
for protocol in (0, 1, 2):
yield check_pickle_protocol, protocol
def test_neighbors_heap(n_pts=5, n_nbrs=10):
heap = NeighborsHeap(n_pts, n_nbrs)
for row in range(n_pts):
d_in = rng.random_sample(2 * n_nbrs).astype(DTYPE)
i_in = np.arange(2 * n_nbrs, dtype=ITYPE)
for d, i in zip(d_in, i_in):
heap.push(row, d, i)
ind = np.argsort(d_in)
d_in = d_in[ind]
i_in = i_in[ind]
d_heap, i_heap = heap.get_arrays(sort=True)
assert_array_almost_equal(d_in[:n_nbrs], d_heap[row])
assert_array_almost_equal(i_in[:n_nbrs], i_heap[row])
def test_node_heap(n_nodes=50):
vals = rng.random_sample(n_nodes).astype(DTYPE)
i1 = np.argsort(vals)
vals2, i2 = nodeheap_sort(vals)
assert_array_almost_equal(i1, i2)
assert_array_almost_equal(vals[i1], vals2)
def test_simultaneous_sort(n_rows=10, n_pts=201):
dist = rng.random_sample((n_rows, n_pts)).astype(DTYPE)
ind = (np.arange(n_pts) + np.zeros((n_rows, 1))).astype(ITYPE)
dist2 = dist.copy()
ind2 = ind.copy()
# simultaneous sort rows using function
simultaneous_sort(dist, ind)
# simultaneous sort rows using numpy
i = np.argsort(dist2, axis=1)
row_ind = np.arange(n_rows)[:, None]
dist2 = dist2[row_ind, i]
ind2 = ind2[row_ind, i]
assert_array_almost_equal(dist, dist2)
assert_array_almost_equal(ind, ind2)
def test_query_haversine():
rng = check_random_state(0)
X = 2 * np.pi * rng.random_sample((40, 2))
bt = BallTree(X, leaf_size=1, metric='haversine')
dist1, ind1 = bt.query(X, k=5)
dist2, ind2 = brute_force_neighbors(X, X, k=5, metric='haversine')
assert_array_almost_equal(dist1, dist2)
assert_array_almost_equal(ind1, ind2)
| 10,379 | 32.057325 | 78 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/tests/test_quad_tree.py | import pickle
import numpy as np
from sklearn.neighbors.quad_tree import _QuadTree
from sklearn.utils import check_random_state
def test_quadtree_boundary_computation():
# Introduce a point into a quad tree with boundaries not easy to compute.
Xs = []
# check a random case
Xs.append(np.array([[-1, 1], [-4, -1]], dtype=np.float32))
# check the case where only 0 are inserted
Xs.append(np.array([[0, 0], [0, 0]], dtype=np.float32))
# check the case where only negative are inserted
Xs.append(np.array([[-1, -2], [-4, 0]], dtype=np.float32))
# check the case where only small numbers are inserted
Xs.append(np.array([[-1e-6, 1e-6], [-4e-6, -1e-6]], dtype=np.float32))
for X in Xs:
tree = _QuadTree(n_dimensions=2, verbose=0)
tree.build_tree(X)
tree._check_coherence()
def test_quadtree_similar_point():
# Introduce a point into a quad tree where a similar point already exists.
# Test will hang if it doesn't complete.
Xs = []
# check the case where points are actually different
Xs.append(np.array([[1, 2], [3, 4]], dtype=np.float32))
# check the case where points are the same on X axis
Xs.append(np.array([[1.0, 2.0], [1.0, 3.0]], dtype=np.float32))
# check the case where points are arbitrarily close on X axis
Xs.append(np.array([[1.00001, 2.0], [1.00002, 3.0]], dtype=np.float32))
# check the case where points are the same on Y axis
Xs.append(np.array([[1.0, 2.0], [3.0, 2.0]], dtype=np.float32))
# check the case where points are arbitrarily close on Y axis
Xs.append(np.array([[1.0, 2.00001], [3.0, 2.00002]], dtype=np.float32))
# check the case where points are arbitrarily close on both axes
Xs.append(np.array([[1.00001, 2.00001], [1.00002, 2.00002]],
dtype=np.float32))
# check the case where points are arbitrarily close on both axes
# close to machine epsilon - x axis
Xs.append(np.array([[1, 0.0003817754041], [2, 0.0003817753750]],
dtype=np.float32))
# check the case where points are arbitrarily close on both axes
# close to machine epsilon - y axis
Xs.append(np.array([[0.0003817754041, 1.0], [0.0003817753750, 2.0]],
dtype=np.float32))
for X in Xs:
tree = _QuadTree(n_dimensions=2, verbose=0)
tree.build_tree(X)
tree._check_coherence()
def test_quad_tree_pickle():
rng = check_random_state(0)
for n_dimensions in (2, 3):
X = rng.random_sample((10, n_dimensions))
tree = _QuadTree(n_dimensions=n_dimensions, verbose=0)
tree.build_tree(X)
def check_pickle_protocol(protocol):
s = pickle.dumps(tree, protocol=protocol)
bt2 = pickle.loads(s)
for x in X:
cell_x_tree = tree.get_cell(x)
cell_x_bt2 = bt2.get_cell(x)
assert cell_x_tree == cell_x_bt2
for protocol in (0, 1, 2):
yield check_pickle_protocol, protocol
def test_qt_insert_duplicate():
rng = check_random_state(0)
def check_insert_duplicate(n_dimensions=2):
X = rng.random_sample((10, n_dimensions))
Xd = np.r_[X, X[:5]]
tree = _QuadTree(n_dimensions=n_dimensions, verbose=0)
tree.build_tree(Xd)
cumulative_size = tree.cumulative_size
leafs = tree.leafs
# Assert that the first 5 are indeed duplicated and that the next
# ones are single point leaf
for i, x in enumerate(X):
cell_id = tree.get_cell(x)
assert leafs[cell_id]
assert cumulative_size[cell_id] == 1 + (i < 5)
for n_dimensions in (2, 3):
yield check_insert_duplicate, n_dimensions
def test_summarize():
_QuadTree.test_summarize()
| 3,789 | 33.770642 | 78 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/tests/test_dist_metrics.py | import itertools
import pickle
import numpy as np
from numpy.testing import assert_array_almost_equal
from scipy.spatial.distance import cdist
from sklearn.neighbors.dist_metrics import DistanceMetric
from sklearn.neighbors import BallTree
from sklearn.utils import check_random_state
from sklearn.utils.testing import assert_raises_regex
def dist_func(x1, x2, p):
return np.sum((x1 - x2) ** p) ** (1. / p)
class TestMetrics:
def __init__(self, n1=20, n2=25, d=4, zero_frac=0.5,
rseed=0, dtype=np.float64):
rng = check_random_state(rseed)
self.X1 = rng.random_sample((n1, d)).astype(dtype)
self.X2 = rng.random_sample((n2, d)).astype(dtype)
# make boolean arrays: ones and zeros
self.X1_bool = self.X1.round(0)
self.X2_bool = self.X2.round(0)
V = rng.random_sample((d, d))
VI = np.dot(V, V.T)
self.metrics = {'euclidean': {},
'cityblock': {},
'minkowski': dict(p=(1, 1.5, 2, 3)),
'chebyshev': {},
'seuclidean': dict(V=(rng.random_sample(d),)),
'wminkowski': dict(p=(1, 1.5, 3),
w=(rng.random_sample(d),)),
'mahalanobis': dict(VI=(VI,)),
'hamming': {},
'canberra': {},
'braycurtis': {}}
self.bool_metrics = ['matching', 'jaccard', 'dice',
'kulsinski', 'rogerstanimoto', 'russellrao',
'sokalmichener', 'sokalsneath']
def test_cdist(self):
for metric, argdict in self.metrics.items():
keys = argdict.keys()
for vals in itertools.product(*argdict.values()):
kwargs = dict(zip(keys, vals))
D_true = cdist(self.X1, self.X2, metric, **kwargs)
yield self.check_cdist, metric, kwargs, D_true
for metric in self.bool_metrics:
D_true = cdist(self.X1_bool, self.X2_bool, metric)
yield self.check_cdist_bool, metric, D_true
def check_cdist(self, metric, kwargs, D_true):
dm = DistanceMetric.get_metric(metric, **kwargs)
D12 = dm.pairwise(self.X1, self.X2)
assert_array_almost_equal(D12, D_true)
def check_cdist_bool(self, metric, D_true):
dm = DistanceMetric.get_metric(metric)
D12 = dm.pairwise(self.X1_bool, self.X2_bool)
assert_array_almost_equal(D12, D_true)
def test_pdist(self):
for metric, argdict in self.metrics.items():
keys = argdict.keys()
for vals in itertools.product(*argdict.values()):
kwargs = dict(zip(keys, vals))
D_true = cdist(self.X1, self.X1, metric, **kwargs)
yield self.check_pdist, metric, kwargs, D_true
for metric in self.bool_metrics:
D_true = cdist(self.X1_bool, self.X1_bool, metric)
yield self.check_pdist_bool, metric, D_true
def check_pdist(self, metric, kwargs, D_true):
dm = DistanceMetric.get_metric(metric, **kwargs)
D12 = dm.pairwise(self.X1)
assert_array_almost_equal(D12, D_true)
def check_pdist_bool(self, metric, D_true):
dm = DistanceMetric.get_metric(metric)
D12 = dm.pairwise(self.X1_bool)
assert_array_almost_equal(D12, D_true)
def test_pickle(self):
for metric, argdict in self.metrics.items():
keys = argdict.keys()
for vals in itertools.product(*argdict.values()):
kwargs = dict(zip(keys, vals))
yield self.check_pickle, metric, kwargs
for metric in self.bool_metrics:
yield self.check_pickle_bool, metric
def check_pickle_bool(self, metric):
dm = DistanceMetric.get_metric(metric)
D1 = dm.pairwise(self.X1_bool)
dm2 = pickle.loads(pickle.dumps(dm))
D2 = dm2.pairwise(self.X1_bool)
assert_array_almost_equal(D1, D2)
def check_pickle(self, metric, kwargs):
dm = DistanceMetric.get_metric(metric, **kwargs)
D1 = dm.pairwise(self.X1)
dm2 = pickle.loads(pickle.dumps(dm))
D2 = dm2.pairwise(self.X1)
assert_array_almost_equal(D1, D2)
def test_haversine_metric():
def haversine_slow(x1, x2):
return 2 * np.arcsin(np.sqrt(np.sin(0.5 * (x1[0] - x2[0])) ** 2
+ np.cos(x1[0]) * np.cos(x2[0]) *
np.sin(0.5 * (x1[1] - x2[1])) ** 2))
X = np.random.random((10, 2))
haversine = DistanceMetric.get_metric("haversine")
D1 = haversine.pairwise(X)
D2 = np.zeros_like(D1)
for i, x1 in enumerate(X):
for j, x2 in enumerate(X):
D2[i, j] = haversine_slow(x1, x2)
assert_array_almost_equal(D1, D2)
assert_array_almost_equal(haversine.dist_to_rdist(D1),
np.sin(0.5 * D2) ** 2)
def test_pyfunc_metric():
X = np.random.random((10, 3))
euclidean = DistanceMetric.get_metric("euclidean")
pyfunc = DistanceMetric.get_metric("pyfunc", func=dist_func, p=2)
# Check if both callable metric and predefined metric initialized
# DistanceMetric object is picklable
euclidean_pkl = pickle.loads(pickle.dumps(euclidean))
pyfunc_pkl = pickle.loads(pickle.dumps(pyfunc))
D1 = euclidean.pairwise(X)
D2 = pyfunc.pairwise(X)
D1_pkl = euclidean_pkl.pairwise(X)
D2_pkl = pyfunc_pkl.pairwise(X)
assert_array_almost_equal(D1, D2)
assert_array_almost_equal(D1_pkl, D2_pkl)
def test_bad_pyfunc_metric():
def wrong_distance(x, y):
return "1"
X = np.ones((5, 2))
assert_raises_regex(TypeError,
"Custom distance function must accept two vectors",
BallTree, X, metric=wrong_distance)
def test_input_data_size():
# Regression test for #6288
# Previoulsly, a metric requiring a particular input dimension would fail
def custom_metric(x, y):
assert x.shape[0] == 3
return np.sum((x - y) ** 2)
rng = check_random_state(0)
X = rng.rand(10, 3)
pyfunc = DistanceMetric.get_metric("pyfunc", func=dist_func, p=2)
eucl = DistanceMetric.get_metric("euclidean")
assert_array_almost_equal(pyfunc.pairwise(X), eucl.pairwise(X))
| 6,413 | 34.241758 | 77 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/tests/test_kde.py | import numpy as np
from sklearn.utils.testing import (assert_allclose, assert_raises,
assert_equal)
from sklearn.neighbors import KernelDensity, KDTree, NearestNeighbors
from sklearn.neighbors.ball_tree import kernel_norm
from sklearn.pipeline import make_pipeline
from sklearn.datasets import make_blobs
from sklearn.model_selection import GridSearchCV
from sklearn.preprocessing import StandardScaler
def compute_kernel_slow(Y, X, kernel, h):
d = np.sqrt(((Y[:, None, :] - X) ** 2).sum(-1))
norm = kernel_norm(h, X.shape[1], kernel) / X.shape[0]
if kernel == 'gaussian':
return norm * np.exp(-0.5 * (d * d) / (h * h)).sum(-1)
elif kernel == 'tophat':
return norm * (d < h).sum(-1)
elif kernel == 'epanechnikov':
return norm * ((1.0 - (d * d) / (h * h)) * (d < h)).sum(-1)
elif kernel == 'exponential':
return norm * (np.exp(-d / h)).sum(-1)
elif kernel == 'linear':
return norm * ((1 - d / h) * (d < h)).sum(-1)
elif kernel == 'cosine':
return norm * (np.cos(0.5 * np.pi * d / h) * (d < h)).sum(-1)
else:
raise ValueError('kernel not recognized')
def check_results(kernel, bandwidth, atol, rtol, X, Y, dens_true):
kde = KernelDensity(kernel=kernel, bandwidth=bandwidth,
atol=atol, rtol=rtol)
log_dens = kde.fit(X).score_samples(Y)
assert_allclose(np.exp(log_dens), dens_true,
atol=atol, rtol=max(1E-7, rtol))
assert_allclose(np.exp(kde.score(Y)),
np.prod(dens_true),
atol=atol, rtol=max(1E-7, rtol))
def test_kernel_density(n_samples=100, n_features=3):
rng = np.random.RandomState(0)
X = rng.randn(n_samples, n_features)
Y = rng.randn(n_samples, n_features)
for kernel in ['gaussian', 'tophat', 'epanechnikov',
'exponential', 'linear', 'cosine']:
for bandwidth in [0.01, 0.1, 1]:
dens_true = compute_kernel_slow(Y, X, kernel, bandwidth)
for rtol in [0, 1E-5]:
for atol in [1E-6, 1E-2]:
for breadth_first in (True, False):
yield (check_results, kernel, bandwidth, atol, rtol,
X, Y, dens_true)
def test_kernel_density_sampling(n_samples=100, n_features=3):
rng = np.random.RandomState(0)
X = rng.randn(n_samples, n_features)
bandwidth = 0.2
for kernel in ['gaussian', 'tophat']:
# draw a tophat sample
kde = KernelDensity(bandwidth, kernel=kernel).fit(X)
samp = kde.sample(100)
assert_equal(X.shape, samp.shape)
# check that samples are in the right range
nbrs = NearestNeighbors(n_neighbors=1).fit(X)
dist, ind = nbrs.kneighbors(X, return_distance=True)
if kernel == 'tophat':
assert np.all(dist < bandwidth)
elif kernel == 'gaussian':
# 5 standard deviations is safe for 100 samples, but there's a
# very small chance this test could fail.
assert np.all(dist < 5 * bandwidth)
# check unsupported kernels
for kernel in ['epanechnikov', 'exponential', 'linear', 'cosine']:
kde = KernelDensity(bandwidth, kernel=kernel).fit(X)
assert_raises(NotImplementedError, kde.sample, 100)
# non-regression test: used to return a scalar
X = rng.randn(4, 1)
kde = KernelDensity(kernel="gaussian").fit(X)
assert_equal(kde.sample().shape, (1, 1))
def test_kde_algorithm_metric_choice():
# Smoke test for various metrics and algorithms
rng = np.random.RandomState(0)
X = rng.randn(10, 2) # 2 features required for haversine dist.
Y = rng.randn(10, 2)
for algorithm in ['auto', 'ball_tree', 'kd_tree']:
for metric in ['euclidean', 'minkowski', 'manhattan',
'chebyshev', 'haversine']:
if algorithm == 'kd_tree' and metric not in KDTree.valid_metrics:
assert_raises(ValueError, KernelDensity,
algorithm=algorithm, metric=metric)
else:
kde = KernelDensity(algorithm=algorithm, metric=metric)
kde.fit(X)
y_dens = kde.score_samples(Y)
assert_equal(y_dens.shape, Y.shape[:1])
def test_kde_score(n_samples=100, n_features=3):
pass
# FIXME
# rng = np.random.RandomState(0)
# X = rng.random_sample((n_samples, n_features))
# Y = rng.random_sample((n_samples, n_features))
def test_kde_badargs():
assert_raises(ValueError, KernelDensity,
algorithm='blah')
assert_raises(ValueError, KernelDensity,
bandwidth=0)
assert_raises(ValueError, KernelDensity,
kernel='blah')
assert_raises(ValueError, KernelDensity,
metric='blah')
assert_raises(ValueError, KernelDensity,
algorithm='kd_tree', metric='blah')
def test_kde_pipeline_gridsearch():
# test that kde plays nice in pipelines and grid-searches
X, _ = make_blobs(cluster_std=.1, random_state=1,
centers=[[0, 1], [1, 0], [0, 0]])
pipe1 = make_pipeline(StandardScaler(with_mean=False, with_std=False),
KernelDensity(kernel="gaussian"))
params = dict(kerneldensity__bandwidth=[0.001, 0.01, 0.1, 1, 10])
search = GridSearchCV(pipe1, param_grid=params, cv=5)
search.fit(X)
assert_equal(search.best_params_['kerneldensity__bandwidth'], .1)
| 5,537 | 37.458333 | 77 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/tests/__init__.py | 0 | 0 | 0 | py |
|
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/neighbors/tests/test_nearest_centroid.py | """
Testing for the nearest centroid module.
"""
import numpy as np
from scipy import sparse as sp
from numpy.testing import assert_array_equal
from numpy.testing import assert_equal
from numpy.testing import assert_raises
from sklearn.neighbors import NearestCentroid
from sklearn import datasets
# toy sample
X = [[-2, -1], [-1, -1], [-1, -2], [1, 1], [1, 2], [2, 1]]
X_csr = sp.csr_matrix(X) # Sparse matrix
y = [-1, -1, -1, 1, 1, 1]
T = [[-1, -1], [2, 2], [3, 2]]
T_csr = sp.csr_matrix(T)
true_result = [-1, 1, 1]
# also load the iris dataset
# and randomly permute it
iris = datasets.load_iris()
rng = np.random.RandomState(1)
perm = rng.permutation(iris.target.size)
iris.data = iris.data[perm]
iris.target = iris.target[perm]
def test_classification_toy():
# Check classification on a toy dataset, including sparse versions.
clf = NearestCentroid()
clf.fit(X, y)
assert_array_equal(clf.predict(T), true_result)
# Same test, but with a sparse matrix to fit and test.
clf = NearestCentroid()
clf.fit(X_csr, y)
assert_array_equal(clf.predict(T_csr), true_result)
# Fit with sparse, test with non-sparse
clf = NearestCentroid()
clf.fit(X_csr, y)
assert_array_equal(clf.predict(T), true_result)
# Fit with non-sparse, test with sparse
clf = NearestCentroid()
clf.fit(X, y)
assert_array_equal(clf.predict(T_csr), true_result)
# Fit and predict with non-CSR sparse matrices
clf = NearestCentroid()
clf.fit(X_csr.tocoo(), y)
assert_array_equal(clf.predict(T_csr.tolil()), true_result)
def test_precomputed():
clf = NearestCentroid(metric='precomputed')
with assert_raises(ValueError) as context:
clf.fit(X, y)
assert_equal(ValueError, type(context.exception))
def test_iris():
# Check consistency on dataset iris.
for metric in ('euclidean', 'cosine'):
clf = NearestCentroid(metric=metric).fit(iris.data, iris.target)
score = np.mean(clf.predict(iris.data) == iris.target)
assert score > 0.9, "Failed with score = " + str(score)
def test_iris_shrinkage():
# Check consistency on dataset iris, when using shrinkage.
for metric in ('euclidean', 'cosine'):
for shrink_threshold in [None, 0.1, 0.5]:
clf = NearestCentroid(metric=metric,
shrink_threshold=shrink_threshold)
clf = clf.fit(iris.data, iris.target)
score = np.mean(clf.predict(iris.data) == iris.target)
assert score > 0.8, "Failed with score = " + str(score)
def test_pickle():
import pickle
# classification
obj = NearestCentroid()
obj.fit(iris.data, iris.target)
score = obj.score(iris.data, iris.target)
s = pickle.dumps(obj)
obj2 = pickle.loads(s)
assert_equal(type(obj2), obj.__class__)
score2 = obj2.score(iris.data, iris.target)
assert_array_equal(score, score2,
"Failed to generate same score"
" after pickling (classification).")
def test_shrinkage_correct():
# Ensure that the shrinking is correct.
# The expected result is calculated by R (pamr),
# which is implemented by the author of the original paper.
# (One need to modify the code to output the new centroid in pamr.predict)
X = np.array([[0, 1], [1, 0], [1, 1], [2, 0], [6, 8]])
y = np.array([1, 1, 2, 2, 2])
clf = NearestCentroid(shrink_threshold=0.1)
clf.fit(X, y)
expected_result = np.array([[0.7787310, 0.8545292], [2.814179, 2.763647]])
np.testing.assert_array_almost_equal(clf.centroids_, expected_result)
def test_shrinkage_threshold_decoded_y():
clf = NearestCentroid(shrink_threshold=0.01)
y_ind = np.asarray(y)
y_ind[y_ind == -1] = 0
clf.fit(X, y_ind)
centroid_encoded = clf.centroids_
clf.fit(X, y)
assert_array_equal(centroid_encoded, clf.centroids_)
def test_predict_translated_data():
# Test that NearestCentroid gives same results on translated data
rng = np.random.RandomState(0)
X = rng.rand(50, 50)
y = rng.randint(0, 3, 50)
noise = rng.rand(50)
clf = NearestCentroid(shrink_threshold=0.1)
clf.fit(X, y)
y_init = clf.predict(X)
clf = NearestCentroid(shrink_threshold=0.1)
X_noise = X + noise
clf.fit(X_noise, y)
y_translate = clf.predict(X_noise)
assert_array_equal(y_init, y_translate)
def test_manhattan_metric():
# Test the manhattan metric.
clf = NearestCentroid(metric='manhattan')
clf.fit(X, y)
dense_centroid = clf.centroids_
clf.fit(X_csr, y)
assert_array_equal(clf.centroids_, dense_centroid)
assert_array_equal(dense_centroid, [[-1, -1], [1, 1]])
| 4,696 | 30.313333 | 78 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/base.py | """
Common code for all metrics
"""
# Authors: Alexandre Gramfort <[email protected]>
# Mathieu Blondel <[email protected]>
# Olivier Grisel <[email protected]>
# Arnaud Joly <[email protected]>
# Jochen Wersdorfer <[email protected]>
# Lars Buitinck
# Joel Nothman <[email protected]>
# Noel Dawe <[email protected]>
# License: BSD 3 clause
from __future__ import division
import numpy as np
from ..utils import check_array, check_consistent_length
from ..utils.multiclass import type_of_target
def _average_binary_score(binary_metric, y_true, y_score, average,
sample_weight=None):
"""Average a binary metric for multilabel classification
Parameters
----------
y_true : array, shape = [n_samples] or [n_samples, n_classes]
True binary labels in binary label indicators.
y_score : array, shape = [n_samples] or [n_samples, n_classes]
Target scores, can either be probability estimates of the positive
class, confidence values, or binary decisions.
average : string, [None, 'micro', 'macro' (default), 'samples', 'weighted']
If ``None``, the scores for each class are returned. Otherwise,
this determines the type of averaging performed on the data:
``'micro'``:
Calculate metrics globally by considering each element of the label
indicator matrix as a label.
``'macro'``:
Calculate metrics for each label, and find their unweighted
mean. This does not take label imbalance into account.
``'weighted'``:
Calculate metrics for each label, and find their average, weighted
by support (the number of true instances for each label).
``'samples'``:
Calculate metrics for each instance, and find their average.
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
binary_metric : callable, returns shape [n_classes]
The binary metric function to use.
Returns
-------
score : float or array of shape [n_classes]
If not ``None``, average the score, else return the score for each
classes.
"""
average_options = (None, 'micro', 'macro', 'weighted', 'samples')
if average not in average_options:
raise ValueError('average has to be one of {0}'
''.format(average_options))
y_type = type_of_target(y_true)
if y_type not in ("binary", "multilabel-indicator"):
raise ValueError("{0} format is not supported".format(y_type))
if y_type == "binary":
return binary_metric(y_true, y_score, sample_weight=sample_weight)
check_consistent_length(y_true, y_score, sample_weight)
y_true = check_array(y_true)
y_score = check_array(y_score)
not_average_axis = 1
score_weight = sample_weight
average_weight = None
if average == "micro":
if score_weight is not None:
score_weight = np.repeat(score_weight, y_true.shape[1])
y_true = y_true.ravel()
y_score = y_score.ravel()
elif average == 'weighted':
if score_weight is not None:
average_weight = np.sum(np.multiply(
y_true, np.reshape(score_weight, (-1, 1))), axis=0)
else:
average_weight = np.sum(y_true, axis=0)
if average_weight.sum() == 0:
return 0
elif average == 'samples':
# swap average_weight <-> score_weight
average_weight = score_weight
score_weight = None
not_average_axis = 0
if y_true.ndim == 1:
y_true = y_true.reshape((-1, 1))
if y_score.ndim == 1:
y_score = y_score.reshape((-1, 1))
n_classes = y_score.shape[not_average_axis]
score = np.zeros((n_classes,))
for c in range(n_classes):
y_true_c = y_true.take([c], axis=not_average_axis).ravel()
y_score_c = y_score.take([c], axis=not_average_axis).ravel()
score[c] = binary_metric(y_true_c, y_score_c,
sample_weight=score_weight)
# Average the results
if average is not None:
return np.average(score, weights=average_weight)
else:
return score
| 4,302 | 33.424 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/classification.py | """Metrics to assess performance on classification task given class prediction
Functions named as ``*_score`` return a scalar value to maximize: the higher
the better
Function named as ``*_error`` or ``*_loss`` return a scalar value to minimize:
the lower the better
"""
# Authors: Alexandre Gramfort <[email protected]>
# Mathieu Blondel <[email protected]>
# Olivier Grisel <[email protected]>
# Arnaud Joly <[email protected]>
# Jochen Wersdorfer <[email protected]>
# Lars Buitinck
# Joel Nothman <[email protected]>
# Noel Dawe <[email protected]>
# Jatin Shah <[email protected]>
# Saurabh Jha <[email protected]>
# Bernardo Stein <[email protected]>
# License: BSD 3 clause
from __future__ import division
import warnings
import numpy as np
from scipy.sparse import coo_matrix
from scipy.sparse import csr_matrix
from ..preprocessing import LabelBinarizer, label_binarize
from ..preprocessing import LabelEncoder
from ..utils import assert_all_finite
from ..utils import check_array
from ..utils import check_consistent_length
from ..utils import column_or_1d
from ..utils.multiclass import unique_labels
from ..utils.multiclass import type_of_target
from ..utils.validation import _num_samples
from ..utils.sparsefuncs import count_nonzero
from ..exceptions import UndefinedMetricWarning
def _check_targets(y_true, y_pred):
"""Check that y_true and y_pred belong to the same classification task
This converts multiclass or binary types to a common shape, and raises a
ValueError for a mix of multilabel and multiclass targets, a mix of
multilabel formats, for the presence of continuous-valued or multioutput
targets, or for targets of different lengths.
Column vectors are squeezed to 1d, while multilabel formats are returned
as CSR sparse label indicators.
Parameters
----------
y_true : array-like
y_pred : array-like
Returns
-------
type_true : one of {'multilabel-indicator', 'multiclass', 'binary'}
The type of the true target data, as output by
``utils.multiclass.type_of_target``
y_true : array or indicator matrix
y_pred : array or indicator matrix
"""
check_consistent_length(y_true, y_pred)
type_true = type_of_target(y_true)
type_pred = type_of_target(y_pred)
y_type = set([type_true, type_pred])
if y_type == set(["binary", "multiclass"]):
y_type = set(["multiclass"])
if len(y_type) > 1:
raise ValueError("Classification metrics can't handle a mix of {0} "
"and {1} targets".format(type_true, type_pred))
# We can't have more than one value on y_type => The set is no more needed
y_type = y_type.pop()
# No metrics support "multiclass-multioutput" format
if (y_type not in ["binary", "multiclass", "multilabel-indicator"]):
raise ValueError("{0} is not supported".format(y_type))
if y_type in ["binary", "multiclass"]:
y_true = column_or_1d(y_true)
y_pred = column_or_1d(y_pred)
if y_type == "binary":
unique_values = np.union1d(y_true, y_pred)
if len(unique_values) > 2:
y_type = "multiclass"
if y_type.startswith('multilabel'):
y_true = csr_matrix(y_true)
y_pred = csr_matrix(y_pred)
y_type = 'multilabel-indicator'
return y_type, y_true, y_pred
def _weighted_sum(sample_score, sample_weight, normalize=False):
if normalize:
return np.average(sample_score, weights=sample_weight)
elif sample_weight is not None:
return np.dot(sample_score, sample_weight)
else:
return sample_score.sum()
def accuracy_score(y_true, y_pred, normalize=True, sample_weight=None):
"""Accuracy classification score.
In multilabel classification, this function computes subset accuracy:
the set of labels predicted for a sample must *exactly* match the
corresponding set of labels in y_true.
Read more in the :ref:`User Guide <accuracy_score>`.
Parameters
----------
y_true : 1d array-like, or label indicator array / sparse matrix
Ground truth (correct) labels.
y_pred : 1d array-like, or label indicator array / sparse matrix
Predicted labels, as returned by a classifier.
normalize : bool, optional (default=True)
If ``False``, return the number of correctly classified samples.
Otherwise, return the fraction of correctly classified samples.
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
score : float
If ``normalize == True``, return the correctly classified samples
(float), else it returns the number of correctly classified samples
(int).
The best performance is 1 with ``normalize == True`` and the number
of samples with ``normalize == False``.
See also
--------
jaccard_similarity_score, hamming_loss, zero_one_loss
Notes
-----
In binary and multiclass classification, this function is equal
to the ``jaccard_similarity_score`` function.
Examples
--------
>>> import numpy as np
>>> from sklearn.metrics import accuracy_score
>>> y_pred = [0, 2, 1, 3]
>>> y_true = [0, 1, 2, 3]
>>> accuracy_score(y_true, y_pred)
0.5
>>> accuracy_score(y_true, y_pred, normalize=False)
2
In the multilabel case with binary label indicators:
>>> accuracy_score(np.array([[0, 1], [1, 1]]), np.ones((2, 2)))
0.5
"""
# Compute accuracy for each possible representation
y_type, y_true, y_pred = _check_targets(y_true, y_pred)
if y_type.startswith('multilabel'):
differing_labels = count_nonzero(y_true - y_pred, axis=1)
score = differing_labels == 0
else:
score = y_true == y_pred
return _weighted_sum(score, sample_weight, normalize)
def confusion_matrix(y_true, y_pred, labels=None, sample_weight=None):
"""Compute confusion matrix to evaluate the accuracy of a classification
By definition a confusion matrix :math:`C` is such that :math:`C_{i, j}`
is equal to the number of observations known to be in group :math:`i` but
predicted to be in group :math:`j`.
Thus in binary classification, the count of true negatives is
:math:`C_{0,0}`, false negatives is :math:`C_{1,0}`, true positives is
:math:`C_{1,1}` and false positives is :math:`C_{0,1}`.
Read more in the :ref:`User Guide <confusion_matrix>`.
Parameters
----------
y_true : array, shape = [n_samples]
Ground truth (correct) target values.
y_pred : array, shape = [n_samples]
Estimated targets as returned by a classifier.
labels : array, shape = [n_classes], optional
List of labels to index the matrix. This may be used to reorder
or select a subset of labels.
If none is given, those that appear at least once
in ``y_true`` or ``y_pred`` are used in sorted order.
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
C : array, shape = [n_classes, n_classes]
Confusion matrix
References
----------
.. [1] `Wikipedia entry for the Confusion matrix
<https://en.wikipedia.org/wiki/Confusion_matrix>`_
Examples
--------
>>> from sklearn.metrics import confusion_matrix
>>> y_true = [2, 0, 2, 2, 0, 1]
>>> y_pred = [0, 0, 2, 2, 0, 2]
>>> confusion_matrix(y_true, y_pred)
array([[2, 0, 0],
[0, 0, 1],
[1, 0, 2]])
>>> y_true = ["cat", "ant", "cat", "cat", "ant", "bird"]
>>> y_pred = ["ant", "ant", "cat", "cat", "ant", "cat"]
>>> confusion_matrix(y_true, y_pred, labels=["ant", "bird", "cat"])
array([[2, 0, 0],
[0, 0, 1],
[1, 0, 2]])
In the binary case, we can extract true positives, etc as follows:
>>> tn, fp, fn, tp = confusion_matrix([0, 1, 0, 1], [1, 1, 1, 0]).ravel()
>>> (tn, fp, fn, tp)
(0, 2, 1, 1)
"""
y_type, y_true, y_pred = _check_targets(y_true, y_pred)
if y_type not in ("binary", "multiclass"):
raise ValueError("%s is not supported" % y_type)
if labels is None:
labels = unique_labels(y_true, y_pred)
else:
labels = np.asarray(labels)
if np.all([l not in y_true for l in labels]):
raise ValueError("At least one label specified must be in y_true")
if sample_weight is None:
sample_weight = np.ones(y_true.shape[0], dtype=np.int64)
else:
sample_weight = np.asarray(sample_weight)
check_consistent_length(sample_weight, y_true, y_pred)
n_labels = labels.size
label_to_ind = dict((y, x) for x, y in enumerate(labels))
# convert yt, yp into index
y_pred = np.array([label_to_ind.get(x, n_labels + 1) for x in y_pred])
y_true = np.array([label_to_ind.get(x, n_labels + 1) for x in y_true])
# intersect y_pred, y_true with labels, eliminate items not in labels
ind = np.logical_and(y_pred < n_labels, y_true < n_labels)
y_pred = y_pred[ind]
y_true = y_true[ind]
# also eliminate weights of eliminated items
sample_weight = sample_weight[ind]
# Choose the accumulator dtype to always have high precision
if sample_weight.dtype.kind in {'i', 'u', 'b'}:
dtype = np.int64
else:
dtype = np.float64
CM = coo_matrix((sample_weight, (y_true, y_pred)),
shape=(n_labels, n_labels), dtype=dtype,
).toarray()
return CM
def cohen_kappa_score(y1, y2, labels=None, weights=None, sample_weight=None):
"""Cohen's kappa: a statistic that measures inter-annotator agreement.
This function computes Cohen's kappa [1]_, a score that expresses the level
of agreement between two annotators on a classification problem. It is
defined as
.. math::
\kappa = (p_o - p_e) / (1 - p_e)
where :math:`p_o` is the empirical probability of agreement on the label
assigned to any sample (the observed agreement ratio), and :math:`p_e` is
the expected agreement when both annotators assign labels randomly.
:math:`p_e` is estimated using a per-annotator empirical prior over the
class labels [2]_.
Read more in the :ref:`User Guide <cohen_kappa>`.
Parameters
----------
y1 : array, shape = [n_samples]
Labels assigned by the first annotator.
y2 : array, shape = [n_samples]
Labels assigned by the second annotator. The kappa statistic is
symmetric, so swapping ``y1`` and ``y2`` doesn't change the value.
labels : array, shape = [n_classes], optional
List of labels to index the matrix. This may be used to select a
subset of labels. If None, all labels that appear at least once in
``y1`` or ``y2`` are used.
weights : str, optional
List of weighting type to calculate the score. None means no weighted;
"linear" means linear weighted; "quadratic" means quadratic weighted.
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
kappa : float
The kappa statistic, which is a number between -1 and 1. The maximum
value means complete agreement; zero or lower means chance agreement.
References
----------
.. [1] J. Cohen (1960). "A coefficient of agreement for nominal scales".
Educational and Psychological Measurement 20(1):37-46.
doi:10.1177/001316446002000104.
.. [2] `R. Artstein and M. Poesio (2008). "Inter-coder agreement for
computational linguistics". Computational Linguistics 34(4):555-596.
<http://www.mitpressjournals.org/doi/abs/10.1162/coli.07-034-R2#.V0J1MJMrIWo>`_
.. [3] `Wikipedia entry for the Cohen's kappa.
<https://en.wikipedia.org/wiki/Cohen%27s_kappa>`_
"""
confusion = confusion_matrix(y1, y2, labels=labels,
sample_weight=sample_weight)
n_classes = confusion.shape[0]
sum0 = np.sum(confusion, axis=0)
sum1 = np.sum(confusion, axis=1)
expected = np.outer(sum0, sum1) / np.sum(sum0)
if weights is None:
w_mat = np.ones([n_classes, n_classes], dtype=np.int)
w_mat.flat[:: n_classes + 1] = 0
elif weights == "linear" or weights == "quadratic":
w_mat = np.zeros([n_classes, n_classes], dtype=np.int)
w_mat += np.arange(n_classes)
if weights == "linear":
w_mat = np.abs(w_mat - w_mat.T)
else:
w_mat = (w_mat - w_mat.T) ** 2
else:
raise ValueError("Unknown kappa weighting type.")
k = np.sum(w_mat * confusion) / np.sum(w_mat * expected)
return 1 - k
def jaccard_similarity_score(y_true, y_pred, normalize=True,
sample_weight=None):
"""Jaccard similarity coefficient score
The Jaccard index [1], or Jaccard similarity coefficient, defined as
the size of the intersection divided by the size of the union of two label
sets, is used to compare set of predicted labels for a sample to the
corresponding set of labels in ``y_true``.
Read more in the :ref:`User Guide <jaccard_similarity_score>`.
Parameters
----------
y_true : 1d array-like, or label indicator array / sparse matrix
Ground truth (correct) labels.
y_pred : 1d array-like, or label indicator array / sparse matrix
Predicted labels, as returned by a classifier.
normalize : bool, optional (default=True)
If ``False``, return the sum of the Jaccard similarity coefficient
over the sample set. Otherwise, return the average of Jaccard
similarity coefficient.
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
score : float
If ``normalize == True``, return the average Jaccard similarity
coefficient, else it returns the sum of the Jaccard similarity
coefficient over the sample set.
The best performance is 1 with ``normalize == True`` and the number
of samples with ``normalize == False``.
See also
--------
accuracy_score, hamming_loss, zero_one_loss
Notes
-----
In binary and multiclass classification, this function is equivalent
to the ``accuracy_score``. It differs in the multilabel classification
problem.
References
----------
.. [1] `Wikipedia entry for the Jaccard index
<https://en.wikipedia.org/wiki/Jaccard_index>`_
Examples
--------
>>> import numpy as np
>>> from sklearn.metrics import jaccard_similarity_score
>>> y_pred = [0, 2, 1, 3]
>>> y_true = [0, 1, 2, 3]
>>> jaccard_similarity_score(y_true, y_pred)
0.5
>>> jaccard_similarity_score(y_true, y_pred, normalize=False)
2
In the multilabel case with binary label indicators:
>>> jaccard_similarity_score(np.array([[0, 1], [1, 1]]),\
np.ones((2, 2)))
0.75
"""
# Compute accuracy for each possible representation
y_type, y_true, y_pred = _check_targets(y_true, y_pred)
if y_type.startswith('multilabel'):
with np.errstate(divide='ignore', invalid='ignore'):
# oddly, we may get an "invalid" rather than a "divide" error here
pred_or_true = count_nonzero(y_true + y_pred, axis=1)
pred_and_true = count_nonzero(y_true.multiply(y_pred), axis=1)
score = pred_and_true / pred_or_true
score[pred_or_true == 0.0] = 1.0
else:
score = y_true == y_pred
return _weighted_sum(score, sample_weight, normalize)
def matthews_corrcoef(y_true, y_pred, sample_weight=None):
"""Compute the Matthews correlation coefficient (MCC)
The Matthews correlation coefficient is used in machine learning as a
measure of the quality of binary (two-class) classifications. It takes into
account true and false positives and negatives and is generally regarded as
a balanced measure which can be used even if the classes are of very
different sizes. The MCC is in essence a correlation coefficient value
between -1 and +1. A coefficient of +1 represents a perfect prediction, 0
an average random prediction and -1 an inverse prediction. The statistic
is also known as the phi coefficient. [source: Wikipedia]
Binary and multiclass labels are supported. Only in the binary case does
this relate to information about true and false positives and negatives.
See references below.
Read more in the :ref:`User Guide <matthews_corrcoef>`.
Parameters
----------
y_true : array, shape = [n_samples]
Ground truth (correct) target values.
y_pred : array, shape = [n_samples]
Estimated targets as returned by a classifier.
sample_weight : array-like of shape = [n_samples], default None
Sample weights.
Returns
-------
mcc : float
The Matthews correlation coefficient (+1 represents a perfect
prediction, 0 an average random prediction and -1 and inverse
prediction).
References
----------
.. [1] `Baldi, Brunak, Chauvin, Andersen and Nielsen, (2000). Assessing the
accuracy of prediction algorithms for classification: an overview
<http://dx.doi.org/10.1093/bioinformatics/16.5.412>`_
.. [2] `Wikipedia entry for the Matthews Correlation Coefficient
<https://en.wikipedia.org/wiki/Matthews_correlation_coefficient>`_
.. [3] `Gorodkin, (2004). Comparing two K-category assignments by a
K-category correlation coefficient
<http://www.sciencedirect.com/science/article/pii/S1476927104000799>`_
.. [4] `Jurman, Riccadonna, Furlanello, (2012). A Comparison of MCC and CEN
Error Measures in MultiClass Prediction
<http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0041882>`_
Examples
--------
>>> from sklearn.metrics import matthews_corrcoef
>>> y_true = [+1, +1, +1, -1]
>>> y_pred = [+1, -1, +1, +1]
>>> matthews_corrcoef(y_true, y_pred) # doctest: +ELLIPSIS
-0.33...
"""
y_type, y_true, y_pred = _check_targets(y_true, y_pred)
if y_type not in {"binary", "multiclass"}:
raise ValueError("%s is not supported" % y_type)
lb = LabelEncoder()
lb.fit(np.hstack([y_true, y_pred]))
y_true = lb.transform(y_true)
y_pred = lb.transform(y_pred)
C = confusion_matrix(y_true, y_pred, sample_weight=sample_weight)
t_sum = C.sum(axis=1, dtype=np.float64)
p_sum = C.sum(axis=0, dtype=np.float64)
n_correct = np.trace(C, dtype=np.float64)
n_samples = p_sum.sum()
cov_ytyp = n_correct * n_samples - np.dot(t_sum, p_sum)
cov_ypyp = n_samples ** 2 - np.dot(p_sum, p_sum)
cov_ytyt = n_samples ** 2 - np.dot(t_sum, t_sum)
mcc = cov_ytyp / np.sqrt(cov_ytyt * cov_ypyp)
if np.isnan(mcc):
return 0.
else:
return mcc
def zero_one_loss(y_true, y_pred, normalize=True, sample_weight=None):
"""Zero-one classification loss.
If normalize is ``True``, return the fraction of misclassifications
(float), else it returns the number of misclassifications (int). The best
performance is 0.
Read more in the :ref:`User Guide <zero_one_loss>`.
Parameters
----------
y_true : 1d array-like, or label indicator array / sparse matrix
Ground truth (correct) labels.
y_pred : 1d array-like, or label indicator array / sparse matrix
Predicted labels, as returned by a classifier.
normalize : bool, optional (default=True)
If ``False``, return the number of misclassifications.
Otherwise, return the fraction of misclassifications.
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
loss : float or int,
If ``normalize == True``, return the fraction of misclassifications
(float), else it returns the number of misclassifications (int).
Notes
-----
In multilabel classification, the zero_one_loss function corresponds to
the subset zero-one loss: for each sample, the entire set of labels must be
correctly predicted, otherwise the loss for that sample is equal to one.
See also
--------
accuracy_score, hamming_loss, jaccard_similarity_score
Examples
--------
>>> from sklearn.metrics import zero_one_loss
>>> y_pred = [1, 2, 3, 4]
>>> y_true = [2, 2, 3, 4]
>>> zero_one_loss(y_true, y_pred)
0.25
>>> zero_one_loss(y_true, y_pred, normalize=False)
1
In the multilabel case with binary label indicators:
>>> zero_one_loss(np.array([[0, 1], [1, 1]]), np.ones((2, 2)))
0.5
"""
score = accuracy_score(y_true, y_pred,
normalize=normalize,
sample_weight=sample_weight)
if normalize:
return 1 - score
else:
if sample_weight is not None:
n_samples = np.sum(sample_weight)
else:
n_samples = _num_samples(y_true)
return n_samples - score
def f1_score(y_true, y_pred, labels=None, pos_label=1, average='binary',
sample_weight=None):
"""Compute the F1 score, also known as balanced F-score or F-measure
The F1 score can be interpreted as a weighted average of the precision and
recall, where an F1 score reaches its best value at 1 and worst score at 0.
The relative contribution of precision and recall to the F1 score are
equal. The formula for the F1 score is::
F1 = 2 * (precision * recall) / (precision + recall)
In the multi-class and multi-label case, this is the weighted average of
the F1 score of each class.
Read more in the :ref:`User Guide <precision_recall_f_measure_metrics>`.
Parameters
----------
y_true : 1d array-like, or label indicator array / sparse matrix
Ground truth (correct) target values.
y_pred : 1d array-like, or label indicator array / sparse matrix
Estimated targets as returned by a classifier.
labels : list, optional
The set of labels to include when ``average != 'binary'``, and their
order if ``average is None``. Labels present in the data can be
excluded, for example to calculate a multiclass average ignoring a
majority negative class, while labels not present in the data will
result in 0 components in a macro average. For multilabel targets,
labels are column indices. By default, all labels in ``y_true`` and
``y_pred`` are used in sorted order.
.. versionchanged:: 0.17
parameter *labels* improved for multiclass problem.
pos_label : str or int, 1 by default
The class to report if ``average='binary'`` and the data is binary.
If the data are multiclass or multilabel, this will be ignored;
setting ``labels=[pos_label]`` and ``average != 'binary'`` will report
scores for that label only.
average : string, [None, 'binary' (default), 'micro', 'macro', 'samples', \
'weighted']
This parameter is required for multiclass/multilabel targets.
If ``None``, the scores for each class are returned. Otherwise, this
determines the type of averaging performed on the data:
``'binary'``:
Only report results for the class specified by ``pos_label``.
This is applicable only if targets (``y_{true,pred}``) are binary.
``'micro'``:
Calculate metrics globally by counting the total true positives,
false negatives and false positives.
``'macro'``:
Calculate metrics for each label, and find their unweighted
mean. This does not take label imbalance into account.
``'weighted'``:
Calculate metrics for each label, and find their average, weighted
by support (the number of true instances for each label). This
alters 'macro' to account for label imbalance; it can result in an
F-score that is not between precision and recall.
``'samples'``:
Calculate metrics for each instance, and find their average (only
meaningful for multilabel classification where this differs from
:func:`accuracy_score`).
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
f1_score : float or array of float, shape = [n_unique_labels]
F1 score of the positive class in binary classification or weighted
average of the F1 scores of each class for the multiclass task.
References
----------
.. [1] `Wikipedia entry for the F1-score
<https://en.wikipedia.org/wiki/F1_score>`_
Examples
--------
>>> from sklearn.metrics import f1_score
>>> y_true = [0, 1, 2, 0, 1, 2]
>>> y_pred = [0, 2, 1, 0, 0, 1]
>>> f1_score(y_true, y_pred, average='macro') # doctest: +ELLIPSIS
0.26...
>>> f1_score(y_true, y_pred, average='micro') # doctest: +ELLIPSIS
0.33...
>>> f1_score(y_true, y_pred, average='weighted') # doctest: +ELLIPSIS
0.26...
>>> f1_score(y_true, y_pred, average=None)
array([ 0.8, 0. , 0. ])
"""
return fbeta_score(y_true, y_pred, 1, labels=labels,
pos_label=pos_label, average=average,
sample_weight=sample_weight)
def fbeta_score(y_true, y_pred, beta, labels=None, pos_label=1,
average='binary', sample_weight=None):
"""Compute the F-beta score
The F-beta score is the weighted harmonic mean of precision and recall,
reaching its optimal value at 1 and its worst value at 0.
The `beta` parameter determines the weight of precision in the combined
score. ``beta < 1`` lends more weight to precision, while ``beta > 1``
favors recall (``beta -> 0`` considers only precision, ``beta -> inf``
only recall).
Read more in the :ref:`User Guide <precision_recall_f_measure_metrics>`.
Parameters
----------
y_true : 1d array-like, or label indicator array / sparse matrix
Ground truth (correct) target values.
y_pred : 1d array-like, or label indicator array / sparse matrix
Estimated targets as returned by a classifier.
beta : float
Weight of precision in harmonic mean.
labels : list, optional
The set of labels to include when ``average != 'binary'``, and their
order if ``average is None``. Labels present in the data can be
excluded, for example to calculate a multiclass average ignoring a
majority negative class, while labels not present in the data will
result in 0 components in a macro average. For multilabel targets,
labels are column indices. By default, all labels in ``y_true`` and
``y_pred`` are used in sorted order.
.. versionchanged:: 0.17
parameter *labels* improved for multiclass problem.
pos_label : str or int, 1 by default
The class to report if ``average='binary'`` and the data is binary.
If the data are multiclass or multilabel, this will be ignored;
setting ``labels=[pos_label]`` and ``average != 'binary'`` will report
scores for that label only.
average : string, [None, 'binary' (default), 'micro', 'macro', 'samples', \
'weighted']
This parameter is required for multiclass/multilabel targets.
If ``None``, the scores for each class are returned. Otherwise, this
determines the type of averaging performed on the data:
``'binary'``:
Only report results for the class specified by ``pos_label``.
This is applicable only if targets (``y_{true,pred}``) are binary.
``'micro'``:
Calculate metrics globally by counting the total true positives,
false negatives and false positives.
``'macro'``:
Calculate metrics for each label, and find their unweighted
mean. This does not take label imbalance into account.
``'weighted'``:
Calculate metrics for each label, and find their average, weighted
by support (the number of true instances for each label). This
alters 'macro' to account for label imbalance; it can result in an
F-score that is not between precision and recall.
``'samples'``:
Calculate metrics for each instance, and find their average (only
meaningful for multilabel classification where this differs from
:func:`accuracy_score`).
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
fbeta_score : float (if average is not None) or array of float, shape =\
[n_unique_labels]
F-beta score of the positive class in binary classification or weighted
average of the F-beta score of each class for the multiclass task.
References
----------
.. [1] R. Baeza-Yates and B. Ribeiro-Neto (2011).
Modern Information Retrieval. Addison Wesley, pp. 327-328.
.. [2] `Wikipedia entry for the F1-score
<https://en.wikipedia.org/wiki/F1_score>`_
Examples
--------
>>> from sklearn.metrics import fbeta_score
>>> y_true = [0, 1, 2, 0, 1, 2]
>>> y_pred = [0, 2, 1, 0, 0, 1]
>>> fbeta_score(y_true, y_pred, average='macro', beta=0.5)
... # doctest: +ELLIPSIS
0.23...
>>> fbeta_score(y_true, y_pred, average='micro', beta=0.5)
... # doctest: +ELLIPSIS
0.33...
>>> fbeta_score(y_true, y_pred, average='weighted', beta=0.5)
... # doctest: +ELLIPSIS
0.23...
>>> fbeta_score(y_true, y_pred, average=None, beta=0.5)
... # doctest: +ELLIPSIS
array([ 0.71..., 0. , 0. ])
"""
_, _, f, _ = precision_recall_fscore_support(y_true, y_pred,
beta=beta,
labels=labels,
pos_label=pos_label,
average=average,
warn_for=('f-score',),
sample_weight=sample_weight)
return f
def _prf_divide(numerator, denominator, metric, modifier, average, warn_for):
"""Performs division and handles divide-by-zero.
On zero-division, sets the corresponding result elements to zero
and raises a warning.
The metric, modifier and average arguments are used only for determining
an appropriate warning.
"""
result = numerator / denominator
mask = denominator == 0.0
if not np.any(mask):
return result
# remove infs
result[mask] = 0.0
# build appropriate warning
# E.g. "Precision and F-score are ill-defined and being set to 0.0 in
# labels with no predicted samples"
axis0 = 'sample'
axis1 = 'label'
if average == 'samples':
axis0, axis1 = axis1, axis0
if metric in warn_for and 'f-score' in warn_for:
msg_start = '{0} and F-score are'.format(metric.title())
elif metric in warn_for:
msg_start = '{0} is'.format(metric.title())
elif 'f-score' in warn_for:
msg_start = 'F-score is'
else:
return result
msg = ('{0} ill-defined and being set to 0.0 {{0}} '
'no {1} {2}s.'.format(msg_start, modifier, axis0))
if len(mask) == 1:
msg = msg.format('due to')
else:
msg = msg.format('in {0}s with'.format(axis1))
warnings.warn(msg, UndefinedMetricWarning, stacklevel=2)
return result
def precision_recall_fscore_support(y_true, y_pred, beta=1.0, labels=None,
pos_label=1, average=None,
warn_for=('precision', 'recall',
'f-score'),
sample_weight=None):
"""Compute precision, recall, F-measure and support for each class
The precision is the ratio ``tp / (tp + fp)`` where ``tp`` is the number of
true positives and ``fp`` the number of false positives. The precision is
intuitively the ability of the classifier not to label as positive a sample
that is negative.
The recall is the ratio ``tp / (tp + fn)`` where ``tp`` is the number of
true positives and ``fn`` the number of false negatives. The recall is
intuitively the ability of the classifier to find all the positive samples.
The F-beta score can be interpreted as a weighted harmonic mean of
the precision and recall, where an F-beta score reaches its best
value at 1 and worst score at 0.
The F-beta score weights recall more than precision by a factor of
``beta``. ``beta == 1.0`` means recall and precision are equally important.
The support is the number of occurrences of each class in ``y_true``.
If ``pos_label is None`` and in binary classification, this function
returns the average precision, recall and F-measure if ``average``
is one of ``'micro'``, ``'macro'``, ``'weighted'`` or ``'samples'``.
Read more in the :ref:`User Guide <precision_recall_f_measure_metrics>`.
Parameters
----------
y_true : 1d array-like, or label indicator array / sparse matrix
Ground truth (correct) target values.
y_pred : 1d array-like, or label indicator array / sparse matrix
Estimated targets as returned by a classifier.
beta : float, 1.0 by default
The strength of recall versus precision in the F-score.
labels : list, optional
The set of labels to include when ``average != 'binary'``, and their
order if ``average is None``. Labels present in the data can be
excluded, for example to calculate a multiclass average ignoring a
majority negative class, while labels not present in the data will
result in 0 components in a macro average. For multilabel targets,
labels are column indices. By default, all labels in ``y_true`` and
``y_pred`` are used in sorted order.
pos_label : str or int, 1 by default
The class to report if ``average='binary'`` and the data is binary.
If the data are multiclass or multilabel, this will be ignored;
setting ``labels=[pos_label]`` and ``average != 'binary'`` will report
scores for that label only.
average : string, [None (default), 'binary', 'micro', 'macro', 'samples', \
'weighted']
If ``None``, the scores for each class are returned. Otherwise, this
determines the type of averaging performed on the data:
``'binary'``:
Only report results for the class specified by ``pos_label``.
This is applicable only if targets (``y_{true,pred}``) are binary.
``'micro'``:
Calculate metrics globally by counting the total true positives,
false negatives and false positives.
``'macro'``:
Calculate metrics for each label, and find their unweighted
mean. This does not take label imbalance into account.
``'weighted'``:
Calculate metrics for each label, and find their average, weighted
by support (the number of true instances for each label). This
alters 'macro' to account for label imbalance; it can result in an
F-score that is not between precision and recall.
``'samples'``:
Calculate metrics for each instance, and find their average (only
meaningful for multilabel classification where this differs from
:func:`accuracy_score`).
warn_for : tuple or set, for internal use
This determines which warnings will be made in the case that this
function is being used to return only one of its metrics.
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
precision : float (if average is not None) or array of float, shape =\
[n_unique_labels]
recall : float (if average is not None) or array of float, , shape =\
[n_unique_labels]
fbeta_score : float (if average is not None) or array of float, shape =\
[n_unique_labels]
support : int (if average is not None) or array of int, shape =\
[n_unique_labels]
The number of occurrences of each label in ``y_true``.
References
----------
.. [1] `Wikipedia entry for the Precision and recall
<https://en.wikipedia.org/wiki/Precision_and_recall>`_
.. [2] `Wikipedia entry for the F1-score
<https://en.wikipedia.org/wiki/F1_score>`_
.. [3] `Discriminative Methods for Multi-labeled Classification Advances
in Knowledge Discovery and Data Mining (2004), pp. 22-30 by Shantanu
Godbole, Sunita Sarawagi
<http://www.godbole.net/shantanu/pubs/multilabelsvm-pakdd04.pdf>`_
Examples
--------
>>> from sklearn.metrics import precision_recall_fscore_support
>>> y_true = np.array(['cat', 'dog', 'pig', 'cat', 'dog', 'pig'])
>>> y_pred = np.array(['cat', 'pig', 'dog', 'cat', 'cat', 'dog'])
>>> precision_recall_fscore_support(y_true, y_pred, average='macro')
... # doctest: +ELLIPSIS
(0.22..., 0.33..., 0.26..., None)
>>> precision_recall_fscore_support(y_true, y_pred, average='micro')
... # doctest: +ELLIPSIS
(0.33..., 0.33..., 0.33..., None)
>>> precision_recall_fscore_support(y_true, y_pred, average='weighted')
... # doctest: +ELLIPSIS
(0.22..., 0.33..., 0.26..., None)
It is possible to compute per-label precisions, recalls, F1-scores and
supports instead of averaging:
>>> precision_recall_fscore_support(y_true, y_pred, average=None,
... labels=['pig', 'dog', 'cat'])
... # doctest: +ELLIPSIS,+NORMALIZE_WHITESPACE
(array([ 0. , 0. , 0.66...]),
array([ 0., 0., 1.]),
array([ 0. , 0. , 0.8]),
array([2, 2, 2]))
"""
average_options = (None, 'micro', 'macro', 'weighted', 'samples')
if average not in average_options and average != 'binary':
raise ValueError('average has to be one of ' +
str(average_options))
if beta <= 0:
raise ValueError("beta should be >0 in the F-beta score")
y_type, y_true, y_pred = _check_targets(y_true, y_pred)
present_labels = unique_labels(y_true, y_pred)
if average == 'binary':
if y_type == 'binary':
if pos_label not in present_labels:
if len(present_labels) < 2:
# Only negative labels
return (0., 0., 0., 0)
else:
raise ValueError("pos_label=%r is not a valid label: %r" %
(pos_label, present_labels))
labels = [pos_label]
else:
raise ValueError("Target is %s but average='binary'. Please "
"choose another average setting." % y_type)
elif pos_label not in (None, 1):
warnings.warn("Note that pos_label (set to %r) is ignored when "
"average != 'binary' (got %r). You may use "
"labels=[pos_label] to specify a single positive class."
% (pos_label, average), UserWarning)
if labels is None:
labels = present_labels
n_labels = None
else:
n_labels = len(labels)
labels = np.hstack([labels, np.setdiff1d(present_labels, labels,
assume_unique=True)])
# Calculate tp_sum, pred_sum, true_sum ###
if y_type.startswith('multilabel'):
sum_axis = 1 if average == 'samples' else 0
# All labels are index integers for multilabel.
# Select labels:
if not np.all(labels == present_labels):
if np.max(labels) > np.max(present_labels):
raise ValueError('All labels must be in [0, n labels). '
'Got %d > %d' %
(np.max(labels), np.max(present_labels)))
if np.min(labels) < 0:
raise ValueError('All labels must be in [0, n labels). '
'Got %d < 0' % np.min(labels))
y_true = y_true[:, labels[:n_labels]]
y_pred = y_pred[:, labels[:n_labels]]
# calculate weighted counts
true_and_pred = y_true.multiply(y_pred)
tp_sum = count_nonzero(true_and_pred, axis=sum_axis,
sample_weight=sample_weight)
pred_sum = count_nonzero(y_pred, axis=sum_axis,
sample_weight=sample_weight)
true_sum = count_nonzero(y_true, axis=sum_axis,
sample_weight=sample_weight)
elif average == 'samples':
raise ValueError("Sample-based precision, recall, fscore is "
"not meaningful outside multilabel "
"classification. See the accuracy_score instead.")
else:
le = LabelEncoder()
le.fit(labels)
y_true = le.transform(y_true)
y_pred = le.transform(y_pred)
sorted_labels = le.classes_
# labels are now from 0 to len(labels) - 1 -> use bincount
tp = y_true == y_pred
tp_bins = y_true[tp]
if sample_weight is not None:
tp_bins_weights = np.asarray(sample_weight)[tp]
else:
tp_bins_weights = None
if len(tp_bins):
tp_sum = np.bincount(tp_bins, weights=tp_bins_weights,
minlength=len(labels))
else:
# Pathological case
true_sum = pred_sum = tp_sum = np.zeros(len(labels))
if len(y_pred):
pred_sum = np.bincount(y_pred, weights=sample_weight,
minlength=len(labels))
if len(y_true):
true_sum = np.bincount(y_true, weights=sample_weight,
minlength=len(labels))
# Retain only selected labels
indices = np.searchsorted(sorted_labels, labels[:n_labels])
tp_sum = tp_sum[indices]
true_sum = true_sum[indices]
pred_sum = pred_sum[indices]
if average == 'micro':
tp_sum = np.array([tp_sum.sum()])
pred_sum = np.array([pred_sum.sum()])
true_sum = np.array([true_sum.sum()])
# Finally, we have all our sufficient statistics. Divide! #
beta2 = beta ** 2
with np.errstate(divide='ignore', invalid='ignore'):
# Divide, and on zero-division, set scores to 0 and warn:
# Oddly, we may get an "invalid" rather than a "divide" error
# here.
precision = _prf_divide(tp_sum, pred_sum,
'precision', 'predicted', average, warn_for)
recall = _prf_divide(tp_sum, true_sum,
'recall', 'true', average, warn_for)
# Don't need to warn for F: either P or R warned, or tp == 0 where pos
# and true are nonzero, in which case, F is well-defined and zero
f_score = ((1 + beta2) * precision * recall /
(beta2 * precision + recall))
f_score[tp_sum == 0] = 0.0
# Average the results
if average == 'weighted':
weights = true_sum
if weights.sum() == 0:
return 0, 0, 0, None
elif average == 'samples':
weights = sample_weight
else:
weights = None
if average is not None:
assert average != 'binary' or len(precision) == 1
precision = np.average(precision, weights=weights)
recall = np.average(recall, weights=weights)
f_score = np.average(f_score, weights=weights)
true_sum = None # return no support
return precision, recall, f_score, true_sum
def precision_score(y_true, y_pred, labels=None, pos_label=1,
average='binary', sample_weight=None):
"""Compute the precision
The precision is the ratio ``tp / (tp + fp)`` where ``tp`` is the number of
true positives and ``fp`` the number of false positives. The precision is
intuitively the ability of the classifier not to label as positive a sample
that is negative.
The best value is 1 and the worst value is 0.
Read more in the :ref:`User Guide <precision_recall_f_measure_metrics>`.
Parameters
----------
y_true : 1d array-like, or label indicator array / sparse matrix
Ground truth (correct) target values.
y_pred : 1d array-like, or label indicator array / sparse matrix
Estimated targets as returned by a classifier.
labels : list, optional
The set of labels to include when ``average != 'binary'``, and their
order if ``average is None``. Labels present in the data can be
excluded, for example to calculate a multiclass average ignoring a
majority negative class, while labels not present in the data will
result in 0 components in a macro average. For multilabel targets,
labels are column indices. By default, all labels in ``y_true`` and
``y_pred`` are used in sorted order.
.. versionchanged:: 0.17
parameter *labels* improved for multiclass problem.
pos_label : str or int, 1 by default
The class to report if ``average='binary'`` and the data is binary.
If the data are multiclass or multilabel, this will be ignored;
setting ``labels=[pos_label]`` and ``average != 'binary'`` will report
scores for that label only.
average : string, [None, 'binary' (default), 'micro', 'macro', 'samples', \
'weighted']
This parameter is required for multiclass/multilabel targets.
If ``None``, the scores for each class are returned. Otherwise, this
determines the type of averaging performed on the data:
``'binary'``:
Only report results for the class specified by ``pos_label``.
This is applicable only if targets (``y_{true,pred}``) are binary.
``'micro'``:
Calculate metrics globally by counting the total true positives,
false negatives and false positives.
``'macro'``:
Calculate metrics for each label, and find their unweighted
mean. This does not take label imbalance into account.
``'weighted'``:
Calculate metrics for each label, and find their average, weighted
by support (the number of true instances for each label). This
alters 'macro' to account for label imbalance; it can result in an
F-score that is not between precision and recall.
``'samples'``:
Calculate metrics for each instance, and find their average (only
meaningful for multilabel classification where this differs from
:func:`accuracy_score`).
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
precision : float (if average is not None) or array of float, shape =\
[n_unique_labels]
Precision of the positive class in binary classification or weighted
average of the precision of each class for the multiclass task.
Examples
--------
>>> from sklearn.metrics import precision_score
>>> y_true = [0, 1, 2, 0, 1, 2]
>>> y_pred = [0, 2, 1, 0, 0, 1]
>>> precision_score(y_true, y_pred, average='macro') # doctest: +ELLIPSIS
0.22...
>>> precision_score(y_true, y_pred, average='micro') # doctest: +ELLIPSIS
0.33...
>>> precision_score(y_true, y_pred, average='weighted')
... # doctest: +ELLIPSIS
0.22...
>>> precision_score(y_true, y_pred, average=None) # doctest: +ELLIPSIS
array([ 0.66..., 0. , 0. ])
"""
p, _, _, _ = precision_recall_fscore_support(y_true, y_pred,
labels=labels,
pos_label=pos_label,
average=average,
warn_for=('precision',),
sample_weight=sample_weight)
return p
def recall_score(y_true, y_pred, labels=None, pos_label=1, average='binary',
sample_weight=None):
"""Compute the recall
The recall is the ratio ``tp / (tp + fn)`` where ``tp`` is the number of
true positives and ``fn`` the number of false negatives. The recall is
intuitively the ability of the classifier to find all the positive samples.
The best value is 1 and the worst value is 0.
Read more in the :ref:`User Guide <precision_recall_f_measure_metrics>`.
Parameters
----------
y_true : 1d array-like, or label indicator array / sparse matrix
Ground truth (correct) target values.
y_pred : 1d array-like, or label indicator array / sparse matrix
Estimated targets as returned by a classifier.
labels : list, optional
The set of labels to include when ``average != 'binary'``, and their
order if ``average is None``. Labels present in the data can be
excluded, for example to calculate a multiclass average ignoring a
majority negative class, while labels not present in the data will
result in 0 components in a macro average. For multilabel targets,
labels are column indices. By default, all labels in ``y_true`` and
``y_pred`` are used in sorted order.
.. versionchanged:: 0.17
parameter *labels* improved for multiclass problem.
pos_label : str or int, 1 by default
The class to report if ``average='binary'`` and the data is binary.
If the data are multiclass or multilabel, this will be ignored;
setting ``labels=[pos_label]`` and ``average != 'binary'`` will report
scores for that label only.
average : string, [None, 'binary' (default), 'micro', 'macro', 'samples', \
'weighted']
This parameter is required for multiclass/multilabel targets.
If ``None``, the scores for each class are returned. Otherwise, this
determines the type of averaging performed on the data:
``'binary'``:
Only report results for the class specified by ``pos_label``.
This is applicable only if targets (``y_{true,pred}``) are binary.
``'micro'``:
Calculate metrics globally by counting the total true positives,
false negatives and false positives.
``'macro'``:
Calculate metrics for each label, and find their unweighted
mean. This does not take label imbalance into account.
``'weighted'``:
Calculate metrics for each label, and find their average, weighted
by support (the number of true instances for each label). This
alters 'macro' to account for label imbalance; it can result in an
F-score that is not between precision and recall.
``'samples'``:
Calculate metrics for each instance, and find their average (only
meaningful for multilabel classification where this differs from
:func:`accuracy_score`).
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
recall : float (if average is not None) or array of float, shape =\
[n_unique_labels]
Recall of the positive class in binary classification or weighted
average of the recall of each class for the multiclass task.
Examples
--------
>>> from sklearn.metrics import recall_score
>>> y_true = [0, 1, 2, 0, 1, 2]
>>> y_pred = [0, 2, 1, 0, 0, 1]
>>> recall_score(y_true, y_pred, average='macro') # doctest: +ELLIPSIS
0.33...
>>> recall_score(y_true, y_pred, average='micro') # doctest: +ELLIPSIS
0.33...
>>> recall_score(y_true, y_pred, average='weighted') # doctest: +ELLIPSIS
0.33...
>>> recall_score(y_true, y_pred, average=None)
array([ 1., 0., 0.])
"""
_, r, _, _ = precision_recall_fscore_support(y_true, y_pred,
labels=labels,
pos_label=pos_label,
average=average,
warn_for=('recall',),
sample_weight=sample_weight)
return r
def classification_report(y_true, y_pred, labels=None, target_names=None,
sample_weight=None, digits=2):
"""Build a text report showing the main classification metrics
Read more in the :ref:`User Guide <classification_report>`.
Parameters
----------
y_true : 1d array-like, or label indicator array / sparse matrix
Ground truth (correct) target values.
y_pred : 1d array-like, or label indicator array / sparse matrix
Estimated targets as returned by a classifier.
labels : array, shape = [n_labels]
Optional list of label indices to include in the report.
target_names : list of strings
Optional display names matching the labels (same order).
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
digits : int
Number of digits for formatting output floating point values
Returns
-------
report : string
Text summary of the precision, recall, F1 score for each class.
The reported averages are a prevalence-weighted macro-average across
classes (equivalent to :func:`precision_recall_fscore_support` with
``average='weighted'``).
Note that in binary classification, recall of the positive class
is also known as "sensitivity"; recall of the negative class is
"specificity".
Examples
--------
>>> from sklearn.metrics import classification_report
>>> y_true = [0, 1, 2, 2, 2]
>>> y_pred = [0, 0, 2, 2, 1]
>>> target_names = ['class 0', 'class 1', 'class 2']
>>> print(classification_report(y_true, y_pred, target_names=target_names))
precision recall f1-score support
<BLANKLINE>
class 0 0.50 1.00 0.67 1
class 1 0.00 0.00 0.00 1
class 2 1.00 0.67 0.80 3
<BLANKLINE>
avg / total 0.70 0.60 0.61 5
<BLANKLINE>
"""
if labels is None:
labels = unique_labels(y_true, y_pred)
else:
labels = np.asarray(labels)
if target_names is not None and len(labels) != len(target_names):
warnings.warn(
"labels size, {0}, does not match size of target_names, {1}"
.format(len(labels), len(target_names))
)
last_line_heading = 'avg / total'
if target_names is None:
target_names = [u'%s' % l for l in labels]
name_width = max(len(cn) for cn in target_names)
width = max(name_width, len(last_line_heading), digits)
headers = ["precision", "recall", "f1-score", "support"]
head_fmt = u'{:>{width}s} ' + u' {:>9}' * len(headers)
report = head_fmt.format(u'', *headers, width=width)
report += u'\n\n'
p, r, f1, s = precision_recall_fscore_support(y_true, y_pred,
labels=labels,
average=None,
sample_weight=sample_weight)
row_fmt = u'{:>{width}s} ' + u' {:>9.{digits}f}' * 3 + u' {:>9}\n'
rows = zip(target_names, p, r, f1, s)
for row in rows:
report += row_fmt.format(*row, width=width, digits=digits)
report += u'\n'
# compute averages
report += row_fmt.format(last_line_heading,
np.average(p, weights=s),
np.average(r, weights=s),
np.average(f1, weights=s),
np.sum(s),
width=width, digits=digits)
return report
def hamming_loss(y_true, y_pred, labels=None, sample_weight=None,
classes=None):
"""Compute the average Hamming loss.
The Hamming loss is the fraction of labels that are incorrectly predicted.
Read more in the :ref:`User Guide <hamming_loss>`.
Parameters
----------
y_true : 1d array-like, or label indicator array / sparse matrix
Ground truth (correct) labels.
y_pred : 1d array-like, or label indicator array / sparse matrix
Predicted labels, as returned by a classifier.
labels : array, shape = [n_labels], optional (default=None)
Integer array of labels. If not provided, labels will be inferred
from y_true and y_pred.
.. versionadded:: 0.18
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
.. versionadded:: 0.18
classes : array, shape = [n_labels], optional
Integer array of labels.
.. deprecated:: 0.18
This parameter has been deprecated in favor of ``labels`` in
version 0.18 and will be removed in 0.20. Use ``labels`` instead.
Returns
-------
loss : float or int,
Return the average Hamming loss between element of ``y_true`` and
``y_pred``.
See Also
--------
accuracy_score, jaccard_similarity_score, zero_one_loss
Notes
-----
In multiclass classification, the Hamming loss correspond to the Hamming
distance between ``y_true`` and ``y_pred`` which is equivalent to the
subset ``zero_one_loss`` function.
In multilabel classification, the Hamming loss is different from the
subset zero-one loss. The zero-one loss considers the entire set of labels
for a given sample incorrect if it does entirely match the true set of
labels. Hamming loss is more forgiving in that it penalizes the individual
labels.
The Hamming loss is upperbounded by the subset zero-one loss. When
normalized over samples, the Hamming loss is always between 0 and 1.
References
----------
.. [1] Grigorios Tsoumakas, Ioannis Katakis. Multi-Label Classification:
An Overview. International Journal of Data Warehousing & Mining,
3(3), 1-13, July-September 2007.
.. [2] `Wikipedia entry on the Hamming distance
<https://en.wikipedia.org/wiki/Hamming_distance>`_
Examples
--------
>>> from sklearn.metrics import hamming_loss
>>> y_pred = [1, 2, 3, 4]
>>> y_true = [2, 2, 3, 4]
>>> hamming_loss(y_true, y_pred)
0.25
In the multilabel case with binary label indicators:
>>> hamming_loss(np.array([[0, 1], [1, 1]]), np.zeros((2, 2)))
0.75
"""
if classes is not None:
warnings.warn("'classes' was renamed to 'labels' in version 0.18 and "
"will be removed in 0.20.", DeprecationWarning)
labels = classes
y_type, y_true, y_pred = _check_targets(y_true, y_pred)
if labels is None:
labels = unique_labels(y_true, y_pred)
else:
labels = np.asarray(labels)
if sample_weight is None:
weight_average = 1.
else:
weight_average = np.mean(sample_weight)
if y_type.startswith('multilabel'):
n_differences = count_nonzero(y_true - y_pred,
sample_weight=sample_weight)
return (n_differences /
(y_true.shape[0] * len(labels) * weight_average))
elif y_type in ["binary", "multiclass"]:
return _weighted_sum(y_true != y_pred, sample_weight, normalize=True)
else:
raise ValueError("{0} is not supported".format(y_type))
def log_loss(y_true, y_pred, eps=1e-15, normalize=True, sample_weight=None,
labels=None):
"""Log loss, aka logistic loss or cross-entropy loss.
This is the loss function used in (multinomial) logistic regression
and extensions of it such as neural networks, defined as the negative
log-likelihood of the true labels given a probabilistic classifier's
predictions. The log loss is only defined for two or more labels.
For a single sample with true label yt in {0,1} and
estimated probability yp that yt = 1, the log loss is
-log P(yt|yp) = -(yt log(yp) + (1 - yt) log(1 - yp))
Read more in the :ref:`User Guide <log_loss>`.
Parameters
----------
y_true : array-like or label indicator matrix
Ground truth (correct) labels for n_samples samples.
y_pred : array-like of float, shape = (n_samples, n_classes) or (n_samples,)
Predicted probabilities, as returned by a classifier's
predict_proba method. If ``y_pred.shape = (n_samples,)``
the probabilities provided are assumed to be that of the
positive class. The labels in ``y_pred`` are assumed to be
ordered alphabetically, as done by
:class:`preprocessing.LabelBinarizer`.
eps : float
Log loss is undefined for p=0 or p=1, so probabilities are
clipped to max(eps, min(1 - eps, p)).
normalize : bool, optional (default=True)
If true, return the mean loss per sample.
Otherwise, return the sum of the per-sample losses.
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
labels : array-like, optional (default=None)
If not provided, labels will be inferred from y_true. If ``labels``
is ``None`` and ``y_pred`` has shape (n_samples,) the labels are
assumed to be binary and are inferred from ``y_true``.
.. versionadded:: 0.18
Returns
-------
loss : float
Examples
--------
>>> log_loss(["spam", "ham", "ham", "spam"], # doctest: +ELLIPSIS
... [[.1, .9], [.9, .1], [.8, .2], [.35, .65]])
0.21616...
References
----------
C.M. Bishop (2006). Pattern Recognition and Machine Learning. Springer,
p. 209.
Notes
-----
The logarithm used is the natural logarithm (base-e).
"""
y_pred = check_array(y_pred, ensure_2d=False)
check_consistent_length(y_pred, y_true)
lb = LabelBinarizer()
if labels is not None:
lb.fit(labels)
else:
lb.fit(y_true)
if len(lb.classes_) == 1:
if labels is None:
raise ValueError('y_true contains only one label ({0}). Please '
'provide the true labels explicitly through the '
'labels argument.'.format(lb.classes_[0]))
else:
raise ValueError('The labels array needs to contain at least two '
'labels for log_loss, '
'got {0}.'.format(lb.classes_))
transformed_labels = lb.transform(y_true)
if transformed_labels.shape[1] == 1:
transformed_labels = np.append(1 - transformed_labels,
transformed_labels, axis=1)
# Clipping
y_pred = np.clip(y_pred, eps, 1 - eps)
# If y_pred is of single dimension, assume y_true to be binary
# and then check.
if y_pred.ndim == 1:
y_pred = y_pred[:, np.newaxis]
if y_pred.shape[1] == 1:
y_pred = np.append(1 - y_pred, y_pred, axis=1)
# Check if dimensions are consistent.
transformed_labels = check_array(transformed_labels)
if len(lb.classes_) != y_pred.shape[1]:
if labels is None:
raise ValueError("y_true and y_pred contain different number of "
"classes {0}, {1}. Please provide the true "
"labels explicitly through the labels argument. "
"Classes found in "
"y_true: {2}".format(transformed_labels.shape[1],
y_pred.shape[1],
lb.classes_))
else:
raise ValueError('The number of classes in labels is different '
'from that in y_pred. Classes found in '
'labels: {0}'.format(lb.classes_))
# Renormalize
y_pred /= y_pred.sum(axis=1)[:, np.newaxis]
loss = -(transformed_labels * np.log(y_pred)).sum(axis=1)
return _weighted_sum(loss, sample_weight, normalize)
def hinge_loss(y_true, pred_decision, labels=None, sample_weight=None):
"""Average hinge loss (non-regularized)
In binary class case, assuming labels in y_true are encoded with +1 and -1,
when a prediction mistake is made, ``margin = y_true * pred_decision`` is
always negative (since the signs disagree), implying ``1 - margin`` is
always greater than 1. The cumulated hinge loss is therefore an upper
bound of the number of mistakes made by the classifier.
In multiclass case, the function expects that either all the labels are
included in y_true or an optional labels argument is provided which
contains all the labels. The multilabel margin is calculated according
to Crammer-Singer's method. As in the binary case, the cumulated hinge loss
is an upper bound of the number of mistakes made by the classifier.
Read more in the :ref:`User Guide <hinge_loss>`.
Parameters
----------
y_true : array, shape = [n_samples]
True target, consisting of integers of two values. The positive label
must be greater than the negative label.
pred_decision : array, shape = [n_samples] or [n_samples, n_classes]
Predicted decisions, as output by decision_function (floats).
labels : array, optional, default None
Contains all the labels for the problem. Used in multiclass hinge loss.
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
loss : float
References
----------
.. [1] `Wikipedia entry on the Hinge loss
<https://en.wikipedia.org/wiki/Hinge_loss>`_
.. [2] Koby Crammer, Yoram Singer. On the Algorithmic
Implementation of Multiclass Kernel-based Vector
Machines. Journal of Machine Learning Research 2,
(2001), 265-292
.. [3] `L1 AND L2 Regularization for Multiclass Hinge Loss Models
by Robert C. Moore, John DeNero.
<http://www.ttic.edu/sigml/symposium2011/papers/
Moore+DeNero_Regularization.pdf>`_
Examples
--------
>>> from sklearn import svm
>>> from sklearn.metrics import hinge_loss
>>> X = [[0], [1]]
>>> y = [-1, 1]
>>> est = svm.LinearSVC(random_state=0)
>>> est.fit(X, y)
LinearSVC(C=1.0, class_weight=None, dual=True, fit_intercept=True,
intercept_scaling=1, loss='squared_hinge', max_iter=1000,
multi_class='ovr', penalty='l2', random_state=0, tol=0.0001,
verbose=0)
>>> pred_decision = est.decision_function([[-2], [3], [0.5]])
>>> pred_decision # doctest: +ELLIPSIS
array([-2.18..., 2.36..., 0.09...])
>>> hinge_loss([-1, 1, 1], pred_decision) # doctest: +ELLIPSIS
0.30...
In the multiclass case:
>>> X = np.array([[0], [1], [2], [3]])
>>> Y = np.array([0, 1, 2, 3])
>>> labels = np.array([0, 1, 2, 3])
>>> est = svm.LinearSVC()
>>> est.fit(X, Y)
LinearSVC(C=1.0, class_weight=None, dual=True, fit_intercept=True,
intercept_scaling=1, loss='squared_hinge', max_iter=1000,
multi_class='ovr', penalty='l2', random_state=None, tol=0.0001,
verbose=0)
>>> pred_decision = est.decision_function([[-1], [2], [3]])
>>> y_true = [0, 2, 3]
>>> hinge_loss(y_true, pred_decision, labels) #doctest: +ELLIPSIS
0.56...
"""
check_consistent_length(y_true, pred_decision, sample_weight)
pred_decision = check_array(pred_decision, ensure_2d=False)
y_true = column_or_1d(y_true)
y_true_unique = np.unique(y_true)
if y_true_unique.size > 2:
if (labels is None and pred_decision.ndim > 1 and
(np.size(y_true_unique) != pred_decision.shape[1])):
raise ValueError("Please include all labels in y_true "
"or pass labels as third argument")
if labels is None:
labels = y_true_unique
le = LabelEncoder()
le.fit(labels)
y_true = le.transform(y_true)
mask = np.ones_like(pred_decision, dtype=bool)
mask[np.arange(y_true.shape[0]), y_true] = False
margin = pred_decision[~mask]
margin -= np.max(pred_decision[mask].reshape(y_true.shape[0], -1),
axis=1)
else:
# Handles binary class case
# this code assumes that positive and negative labels
# are encoded as +1 and -1 respectively
pred_decision = column_or_1d(pred_decision)
pred_decision = np.ravel(pred_decision)
lbin = LabelBinarizer(neg_label=-1)
y_true = lbin.fit_transform(y_true)[:, 0]
try:
margin = y_true * pred_decision
except TypeError:
raise TypeError("pred_decision should be an array of floats.")
losses = 1 - margin
# The hinge_loss doesn't penalize good enough predictions.
losses[losses <= 0] = 0
return np.average(losses, weights=sample_weight)
def _check_binary_probabilistic_predictions(y_true, y_prob):
"""Check that y_true is binary and y_prob contains valid probabilities"""
check_consistent_length(y_true, y_prob)
labels = np.unique(y_true)
if len(labels) > 2:
raise ValueError("Only binary classification is supported. "
"Provided labels %s." % labels)
if y_prob.max() > 1:
raise ValueError("y_prob contains values greater than 1.")
if y_prob.min() < 0:
raise ValueError("y_prob contains values less than 0.")
return label_binarize(y_true, labels)[:, 0]
def brier_score_loss(y_true, y_prob, sample_weight=None, pos_label=None):
"""Compute the Brier score.
The smaller the Brier score, the better, hence the naming with "loss".
Across all items in a set N predictions, the Brier score measures the
mean squared difference between (1) the predicted probability assigned
to the possible outcomes for item i, and (2) the actual outcome.
Therefore, the lower the Brier score is for a set of predictions, the
better the predictions are calibrated. Note that the Brier score always
takes on a value between zero and one, since this is the largest
possible difference between a predicted probability (which must be
between zero and one) and the actual outcome (which can take on values
of only 0 and 1).
The Brier score is appropriate for binary and categorical outcomes that
can be structured as true or false, but is inappropriate for ordinal
variables which can take on three or more values (this is because the
Brier score assumes that all possible outcomes are equivalently
"distant" from one another). Which label is considered to be the positive
label is controlled via the parameter pos_label, which defaults to 1.
Read more in the :ref:`User Guide <calibration>`.
Parameters
----------
y_true : array, shape (n_samples,)
True targets.
y_prob : array, shape (n_samples,)
Probabilities of the positive class.
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
pos_label : int or str, default=None
Label of the positive class. If None, the maximum label is used as
positive class
Returns
-------
score : float
Brier score
Examples
--------
>>> import numpy as np
>>> from sklearn.metrics import brier_score_loss
>>> y_true = np.array([0, 1, 1, 0])
>>> y_true_categorical = np.array(["spam", "ham", "ham", "spam"])
>>> y_prob = np.array([0.1, 0.9, 0.8, 0.3])
>>> brier_score_loss(y_true, y_prob) # doctest: +ELLIPSIS
0.037...
>>> brier_score_loss(y_true, 1-y_prob, pos_label=0) # doctest: +ELLIPSIS
0.037...
>>> brier_score_loss(y_true_categorical, y_prob, \
pos_label="ham") # doctest: +ELLIPSIS
0.037...
>>> brier_score_loss(y_true, np.array(y_prob) > 0.5)
0.0
References
----------
.. [1] `Wikipedia entry for the Brier score.
<https://en.wikipedia.org/wiki/Brier_score>`_
"""
y_true = column_or_1d(y_true)
y_prob = column_or_1d(y_prob)
assert_all_finite(y_true)
assert_all_finite(y_prob)
if pos_label is None:
pos_label = y_true.max()
y_true = np.array(y_true == pos_label, int)
y_true = _check_binary_probabilistic_predictions(y_true, y_prob)
return np.average((y_true - y_prob) ** 2, weights=sample_weight)
| 73,449 | 37.255208 | 90 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/setup.py | import os
import os.path
import numpy
from numpy.distutils.misc_util import Configuration
from sklearn._build_utils import get_blas_info
def configuration(parent_package="", top_path=None):
config = Configuration("metrics", parent_package, top_path)
cblas_libs, blas_info = get_blas_info()
if os.name == 'posix':
cblas_libs.append('m')
config.add_extension("pairwise_fast",
sources=["pairwise_fast.pyx"],
include_dirs=[os.path.join('..', 'src', 'cblas'),
numpy.get_include(),
blas_info.pop('include_dirs', [])],
libraries=cblas_libs,
extra_compile_args=blas_info.pop('extra_compile_args',
[]),
**blas_info)
config.add_subpackage('tests')
return config
if __name__ == "__main__":
from numpy.distutils.core import setup
setup(**configuration().todict())
| 1,061 | 31.181818 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/scorer.py | """
The :mod:`sklearn.metrics.scorer` submodule implements a flexible
interface for model selection and evaluation using
arbitrary score functions.
A scorer object is a callable that can be passed to
:class:`sklearn.model_selection.GridSearchCV` or
:func:`sklearn.model_selection.cross_val_score` as the ``scoring``
parameter, to specify how a model should be evaluated.
The signature of the call is ``(estimator, X, y)`` where ``estimator``
is the model to be evaluated, ``X`` is the test data and ``y`` is the
ground truth labeling (or ``None`` in the case of unsupervised models).
"""
# Authors: Andreas Mueller <[email protected]>
# Lars Buitinck
# Arnaud Joly <[email protected]>
# License: Simplified BSD
from abc import ABCMeta, abstractmethod
import warnings
import numpy as np
from . import (r2_score, median_absolute_error, mean_absolute_error,
mean_squared_error, mean_squared_log_error, accuracy_score,
f1_score, roc_auc_score, average_precision_score,
precision_score, recall_score, log_loss,
explained_variance_score)
from .cluster import adjusted_rand_score
from .cluster import homogeneity_score
from .cluster import completeness_score
from .cluster import v_measure_score
from .cluster import mutual_info_score
from .cluster import adjusted_mutual_info_score
from .cluster import normalized_mutual_info_score
from .cluster import fowlkes_mallows_score
from ..utils.multiclass import type_of_target
from ..externals import six
from ..base import is_regressor
class _BaseScorer(six.with_metaclass(ABCMeta, object)):
def __init__(self, score_func, sign, kwargs):
self._kwargs = kwargs
self._score_func = score_func
self._sign = sign
# XXX After removing the deprecated scorers (v0.20) remove the
# XXX deprecation_msg property again and remove __call__'s body again
self._deprecation_msg = None
@abstractmethod
def __call__(self, estimator, X, y, sample_weight=None):
if self._deprecation_msg is not None:
warnings.warn(self._deprecation_msg,
category=DeprecationWarning,
stacklevel=2)
def __repr__(self):
kwargs_string = "".join([", %s=%s" % (str(k), str(v))
for k, v in self._kwargs.items()])
return ("make_scorer(%s%s%s%s)"
% (self._score_func.__name__,
"" if self._sign > 0 else ", greater_is_better=False",
self._factory_args(), kwargs_string))
def _factory_args(self):
"""Return non-default make_scorer arguments for repr."""
return ""
class _PredictScorer(_BaseScorer):
def __call__(self, estimator, X, y_true, sample_weight=None):
"""Evaluate predicted target values for X relative to y_true.
Parameters
----------
estimator : object
Trained estimator to use for scoring. Must have a predict_proba
method; the output of that is used to compute the score.
X : array-like or sparse matrix
Test data that will be fed to estimator.predict.
y_true : array-like
Gold standard target values for X.
sample_weight : array-like, optional (default=None)
Sample weights.
Returns
-------
score : float
Score function applied to prediction of estimator on X.
"""
super(_PredictScorer, self).__call__(estimator, X, y_true,
sample_weight=sample_weight)
y_pred = estimator.predict(X)
if sample_weight is not None:
return self._sign * self._score_func(y_true, y_pred,
sample_weight=sample_weight,
**self._kwargs)
else:
return self._sign * self._score_func(y_true, y_pred,
**self._kwargs)
class _ProbaScorer(_BaseScorer):
def __call__(self, clf, X, y, sample_weight=None):
"""Evaluate predicted probabilities for X relative to y_true.
Parameters
----------
clf : object
Trained classifier to use for scoring. Must have a predict_proba
method; the output of that is used to compute the score.
X : array-like or sparse matrix
Test data that will be fed to clf.predict_proba.
y : array-like
Gold standard target values for X. These must be class labels,
not probabilities.
sample_weight : array-like, optional (default=None)
Sample weights.
Returns
-------
score : float
Score function applied to prediction of estimator on X.
"""
super(_ProbaScorer, self).__call__(clf, X, y,
sample_weight=sample_weight)
y_pred = clf.predict_proba(X)
if sample_weight is not None:
return self._sign * self._score_func(y, y_pred,
sample_weight=sample_weight,
**self._kwargs)
else:
return self._sign * self._score_func(y, y_pred, **self._kwargs)
def _factory_args(self):
return ", needs_proba=True"
class _ThresholdScorer(_BaseScorer):
def __call__(self, clf, X, y, sample_weight=None):
"""Evaluate decision function output for X relative to y_true.
Parameters
----------
clf : object
Trained classifier to use for scoring. Must have either a
decision_function method or a predict_proba method; the output of
that is used to compute the score.
X : array-like or sparse matrix
Test data that will be fed to clf.decision_function or
clf.predict_proba.
y : array-like
Gold standard target values for X. These must be class labels,
not decision function values.
sample_weight : array-like, optional (default=None)
Sample weights.
Returns
-------
score : float
Score function applied to prediction of estimator on X.
"""
super(_ThresholdScorer, self).__call__(clf, X, y,
sample_weight=sample_weight)
y_type = type_of_target(y)
if y_type not in ("binary", "multilabel-indicator"):
raise ValueError("{0} format is not supported".format(y_type))
if is_regressor(clf):
y_pred = clf.predict(X)
else:
try:
y_pred = clf.decision_function(X)
# For multi-output multi-class estimator
if isinstance(y_pred, list):
y_pred = np.vstack(p for p in y_pred).T
except (NotImplementedError, AttributeError):
y_pred = clf.predict_proba(X)
if y_type == "binary":
y_pred = y_pred[:, 1]
elif isinstance(y_pred, list):
y_pred = np.vstack([p[:, -1] for p in y_pred]).T
if sample_weight is not None:
return self._sign * self._score_func(y, y_pred,
sample_weight=sample_weight,
**self._kwargs)
else:
return self._sign * self._score_func(y, y_pred, **self._kwargs)
def _factory_args(self):
return ", needs_threshold=True"
def get_scorer(scoring):
"""Get a scorer from string
Parameters
----------
scoring : str | callable
scoring method as string. If callable it is returned as is.
Returns
-------
scorer : callable
The scorer.
"""
valid = True
if isinstance(scoring, six.string_types):
try:
scorer = SCORERS[scoring]
except KeyError:
scorers = [scorer for scorer in SCORERS
if SCORERS[scorer]._deprecation_msg is None]
valid = False # Don't raise here to make the error message elegant
if not valid:
raise ValueError('%r is not a valid scoring value. '
'Valid options are %s'
% (scoring, sorted(scorers)))
else:
scorer = scoring
return scorer
def _passthrough_scorer(estimator, *args, **kwargs):
"""Function that wraps estimator.score"""
return estimator.score(*args, **kwargs)
def check_scoring(estimator, scoring=None, allow_none=False):
"""Determine scorer from user options.
A TypeError will be thrown if the estimator cannot be scored.
Parameters
----------
estimator : estimator object implementing 'fit'
The object to use to fit the data.
scoring : string, callable or None, optional, default: None
A string (see model evaluation documentation) or
a scorer callable object / function with signature
``scorer(estimator, X, y)``.
allow_none : boolean, optional, default: False
If no scoring is specified and the estimator has no score function, we
can either return None or raise an exception.
Returns
-------
scoring : callable
A scorer callable object / function with signature
``scorer(estimator, X, y)``.
"""
if not hasattr(estimator, 'fit'):
raise TypeError("estimator should be an estimator implementing "
"'fit' method, %r was passed" % estimator)
if isinstance(scoring, six.string_types):
return get_scorer(scoring)
elif callable(scoring):
# Heuristic to ensure user has not passed a metric
module = getattr(scoring, '__module__', None)
if hasattr(module, 'startswith') and \
module.startswith('sklearn.metrics.') and \
not module.startswith('sklearn.metrics.scorer') and \
not module.startswith('sklearn.metrics.tests.'):
raise ValueError('scoring value %r looks like it is a metric '
'function rather than a scorer. A scorer should '
'require an estimator as its first parameter. '
'Please use `make_scorer` to convert a metric '
'to a scorer.' % scoring)
return get_scorer(scoring)
elif scoring is None:
if hasattr(estimator, 'score'):
return _passthrough_scorer
elif allow_none:
return None
else:
raise TypeError(
"If no scoring is specified, the estimator passed should "
"have a 'score' method. The estimator %r does not."
% estimator)
else:
raise ValueError("scoring value should either be a callable, string or"
" None. %r was passed" % scoring)
def _check_multimetric_scoring(estimator, scoring=None):
"""Check the scoring parameter in cases when multiple metrics are allowed
Parameters
----------
estimator : sklearn estimator instance
The estimator for which the scoring will be applied.
scoring : string, callable, list/tuple, dict or None, default: None
A single string (see :ref:`scoring_parameter`) or a callable
(see :ref:`scoring`) to evaluate the predictions on the test set.
For evaluating multiple metrics, either give a list of (unique) strings
or a dict with names as keys and callables as values.
NOTE that when using custom scorers, each scorer should return a single
value. Metric functions returning a list/array of values can be wrapped
into multiple scorers that return one value each.
See :ref:`multimetric_grid_search` for an example.
If None the estimator's default scorer (if available) is used.
The return value in that case will be ``{'score': <default_scorer>}``.
If the estimator's default scorer is not available, a ``TypeError``
is raised.
Returns
-------
scorers_dict : dict
A dict mapping each scorer name to its validated scorer.
is_multimetric : bool
True if scorer is a list/tuple or dict of callables
False if scorer is None/str/callable
"""
if callable(scoring) or scoring is None or isinstance(scoring,
six.string_types):
scorers = {"score": check_scoring(estimator, scoring=scoring)}
return scorers, False
else:
err_msg_generic = ("scoring should either be a single string or "
"callable for single metric evaluation or a "
"list/tuple of strings or a dict of scorer name "
"mapped to the callable for multiple metric "
"evaluation. Got %s of type %s"
% (repr(scoring), type(scoring)))
if isinstance(scoring, (list, tuple, set)):
err_msg = ("The list/tuple elements must be unique "
"strings of predefined scorers. ")
invalid = False
try:
keys = set(scoring)
except TypeError:
invalid = True
if invalid:
raise ValueError(err_msg)
if len(keys) != len(scoring):
raise ValueError(err_msg + "Duplicate elements were found in"
" the given list. %r" % repr(scoring))
elif len(keys) > 0:
if not all(isinstance(k, six.string_types) for k in keys):
if any(callable(k) for k in keys):
raise ValueError(err_msg +
"One or more of the elements were "
"callables. Use a dict of score name "
"mapped to the scorer callable. "
"Got %r" % repr(scoring))
else:
raise ValueError(err_msg +
"Non-string types were found in "
"the given list. Got %r"
% repr(scoring))
scorers = {scorer: check_scoring(estimator, scoring=scorer)
for scorer in scoring}
else:
raise ValueError(err_msg +
"Empty list was given. %r" % repr(scoring))
elif isinstance(scoring, dict):
keys = set(scoring)
if not all(isinstance(k, six.string_types) for k in keys):
raise ValueError("Non-string types were found in the keys of "
"the given dict. scoring=%r" % repr(scoring))
if len(keys) == 0:
raise ValueError("An empty dict was passed. %r"
% repr(scoring))
scorers = {key: check_scoring(estimator, scoring=scorer)
for key, scorer in scoring.items()}
else:
raise ValueError(err_msg_generic)
return scorers, True
def make_scorer(score_func, greater_is_better=True, needs_proba=False,
needs_threshold=False, **kwargs):
"""Make a scorer from a performance metric or loss function.
This factory function wraps scoring functions for use in GridSearchCV
and cross_val_score. It takes a score function, such as ``accuracy_score``,
``mean_squared_error``, ``adjusted_rand_index`` or ``average_precision``
and returns a callable that scores an estimator's output.
Read more in the :ref:`User Guide <scoring>`.
Parameters
----------
score_func : callable,
Score function (or loss function) with signature
``score_func(y, y_pred, **kwargs)``.
greater_is_better : boolean, default=True
Whether score_func is a score function (default), meaning high is good,
or a loss function, meaning low is good. In the latter case, the
scorer object will sign-flip the outcome of the score_func.
needs_proba : boolean, default=False
Whether score_func requires predict_proba to get probability estimates
out of a classifier.
needs_threshold : boolean, default=False
Whether score_func takes a continuous decision certainty.
This only works for binary classification using estimators that
have either a decision_function or predict_proba method.
For example ``average_precision`` or the area under the roc curve
can not be computed using discrete predictions alone.
**kwargs : additional arguments
Additional parameters to be passed to score_func.
Returns
-------
scorer : callable
Callable object that returns a scalar score; greater is better.
Examples
--------
>>> from sklearn.metrics import fbeta_score, make_scorer
>>> ftwo_scorer = make_scorer(fbeta_score, beta=2)
>>> ftwo_scorer
make_scorer(fbeta_score, beta=2)
>>> from sklearn.model_selection import GridSearchCV
>>> from sklearn.svm import LinearSVC
>>> grid = GridSearchCV(LinearSVC(), param_grid={'C': [1, 10]},
... scoring=ftwo_scorer)
"""
sign = 1 if greater_is_better else -1
if needs_proba and needs_threshold:
raise ValueError("Set either needs_proba or needs_threshold to True,"
" but not both.")
if needs_proba:
cls = _ProbaScorer
elif needs_threshold:
cls = _ThresholdScorer
else:
cls = _PredictScorer
return cls(score_func, sign, kwargs)
# Standard regression scores
explained_variance_scorer = make_scorer(explained_variance_score)
r2_scorer = make_scorer(r2_score)
neg_mean_squared_error_scorer = make_scorer(mean_squared_error,
greater_is_better=False)
deprecation_msg = ('Scoring method mean_squared_error was renamed to '
'neg_mean_squared_error in version 0.18 and will '
'be removed in 0.20.')
mean_squared_error_scorer = make_scorer(mean_squared_error,
greater_is_better=False)
mean_squared_error_scorer._deprecation_msg = deprecation_msg
neg_mean_squared_log_error_scorer = make_scorer(mean_squared_log_error,
greater_is_better=False)
neg_mean_absolute_error_scorer = make_scorer(mean_absolute_error,
greater_is_better=False)
deprecation_msg = ('Scoring method mean_absolute_error was renamed to '
'neg_mean_absolute_error in version 0.18 and will '
'be removed in 0.20.')
mean_absolute_error_scorer = make_scorer(mean_absolute_error,
greater_is_better=False)
mean_absolute_error_scorer._deprecation_msg = deprecation_msg
neg_median_absolute_error_scorer = make_scorer(median_absolute_error,
greater_is_better=False)
deprecation_msg = ('Scoring method median_absolute_error was renamed to '
'neg_median_absolute_error in version 0.18 and will '
'be removed in 0.20.')
median_absolute_error_scorer = make_scorer(median_absolute_error,
greater_is_better=False)
median_absolute_error_scorer._deprecation_msg = deprecation_msg
# Standard Classification Scores
accuracy_scorer = make_scorer(accuracy_score)
f1_scorer = make_scorer(f1_score)
# Score functions that need decision values
roc_auc_scorer = make_scorer(roc_auc_score, greater_is_better=True,
needs_threshold=True)
average_precision_scorer = make_scorer(average_precision_score,
needs_threshold=True)
precision_scorer = make_scorer(precision_score)
recall_scorer = make_scorer(recall_score)
# Score function for probabilistic classification
neg_log_loss_scorer = make_scorer(log_loss, greater_is_better=False,
needs_proba=True)
deprecation_msg = ('Scoring method log_loss was renamed to '
'neg_log_loss in version 0.18 and will be removed in 0.20.')
log_loss_scorer = make_scorer(log_loss, greater_is_better=False,
needs_proba=True)
log_loss_scorer._deprecation_msg = deprecation_msg
# Clustering scores
adjusted_rand_scorer = make_scorer(adjusted_rand_score)
homogeneity_scorer = make_scorer(homogeneity_score)
completeness_scorer = make_scorer(completeness_score)
v_measure_scorer = make_scorer(v_measure_score)
mutual_info_scorer = make_scorer(mutual_info_score)
adjusted_mutual_info_scorer = make_scorer(adjusted_mutual_info_score)
normalized_mutual_info_scorer = make_scorer(normalized_mutual_info_score)
fowlkes_mallows_scorer = make_scorer(fowlkes_mallows_score)
SCORERS = dict(explained_variance=explained_variance_scorer,
r2=r2_scorer,
neg_median_absolute_error=neg_median_absolute_error_scorer,
neg_mean_absolute_error=neg_mean_absolute_error_scorer,
neg_mean_squared_error=neg_mean_squared_error_scorer,
neg_mean_squared_log_error=neg_mean_squared_log_error_scorer,
median_absolute_error=median_absolute_error_scorer,
mean_absolute_error=mean_absolute_error_scorer,
mean_squared_error=mean_squared_error_scorer,
accuracy=accuracy_scorer, roc_auc=roc_auc_scorer,
average_precision=average_precision_scorer,
log_loss=log_loss_scorer,
neg_log_loss=neg_log_loss_scorer,
# Cluster metrics that use supervised evaluation
adjusted_rand_score=adjusted_rand_scorer,
homogeneity_score=homogeneity_scorer,
completeness_score=completeness_scorer,
v_measure_score=v_measure_scorer,
mutual_info_score=mutual_info_scorer,
adjusted_mutual_info_score=adjusted_mutual_info_scorer,
normalized_mutual_info_score=normalized_mutual_info_scorer,
fowlkes_mallows_score=fowlkes_mallows_scorer)
for name, metric in [('precision', precision_score),
('recall', recall_score), ('f1', f1_score)]:
SCORERS[name] = make_scorer(metric)
for average in ['macro', 'micro', 'samples', 'weighted']:
qualified_name = '{0}_{1}'.format(name, average)
SCORERS[qualified_name] = make_scorer(metric, pos_label=None,
average=average)
| 23,011 | 40.019608 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/regression.py | """Metrics to assess performance on regression task
Functions named as ``*_score`` return a scalar value to maximize: the higher
the better
Function named as ``*_error`` or ``*_loss`` return a scalar value to minimize:
the lower the better
"""
# Authors: Alexandre Gramfort <[email protected]>
# Mathieu Blondel <[email protected]>
# Olivier Grisel <[email protected]>
# Arnaud Joly <[email protected]>
# Jochen Wersdorfer <[email protected]>
# Lars Buitinck
# Joel Nothman <[email protected]>
# Karan Desai <[email protected]>
# Noel Dawe <[email protected]>
# Manoj Kumar <[email protected]>
# Michael Eickenberg <[email protected]>
# Konstantin Shmelkov <[email protected]>
# License: BSD 3 clause
from __future__ import division
import numpy as np
from ..utils.validation import check_array, check_consistent_length
from ..utils.validation import column_or_1d
from ..externals.six import string_types
__ALL__ = [
"mean_absolute_error",
"mean_squared_error",
"mean_squared_log_error",
"median_absolute_error",
"r2_score",
"explained_variance_score"
]
def _check_reg_targets(y_true, y_pred, multioutput):
"""Check that y_true and y_pred belong to the same regression task
Parameters
----------
y_true : array-like,
y_pred : array-like,
multioutput : array-like or string in ['raw_values', uniform_average',
'variance_weighted'] or None
None is accepted due to backward compatibility of r2_score().
Returns
-------
type_true : one of {'continuous', continuous-multioutput'}
The type of the true target data, as output by
'utils.multiclass.type_of_target'
y_true : array-like of shape = (n_samples, n_outputs)
Ground truth (correct) target values.
y_pred : array-like of shape = (n_samples, n_outputs)
Estimated target values.
multioutput : array-like of shape = (n_outputs) or string in ['raw_values',
uniform_average', 'variance_weighted'] or None
Custom output weights if ``multioutput`` is array-like or
just the corresponding argument if ``multioutput`` is a
correct keyword.
"""
check_consistent_length(y_true, y_pred)
y_true = check_array(y_true, ensure_2d=False)
y_pred = check_array(y_pred, ensure_2d=False)
if y_true.ndim == 1:
y_true = y_true.reshape((-1, 1))
if y_pred.ndim == 1:
y_pred = y_pred.reshape((-1, 1))
if y_true.shape[1] != y_pred.shape[1]:
raise ValueError("y_true and y_pred have different number of output "
"({0}!={1})".format(y_true.shape[1], y_pred.shape[1]))
n_outputs = y_true.shape[1]
allowed_multioutput_str = ('raw_values', 'uniform_average',
'variance_weighted')
if isinstance(multioutput, string_types):
if multioutput not in allowed_multioutput_str:
raise ValueError("Allowed 'multioutput' string values are {}. "
"You provided multioutput={!r}".format(
allowed_multioutput_str,
multioutput))
elif multioutput is not None:
multioutput = check_array(multioutput, ensure_2d=False)
if n_outputs == 1:
raise ValueError("Custom weights are useful only in "
"multi-output cases.")
elif n_outputs != len(multioutput):
raise ValueError(("There must be equally many custom weights "
"(%d) as outputs (%d).") %
(len(multioutput), n_outputs))
y_type = 'continuous' if n_outputs == 1 else 'continuous-multioutput'
return y_type, y_true, y_pred, multioutput
def mean_absolute_error(y_true, y_pred,
sample_weight=None,
multioutput='uniform_average'):
"""Mean absolute error regression loss
Read more in the :ref:`User Guide <mean_absolute_error>`.
Parameters
----------
y_true : array-like of shape = (n_samples) or (n_samples, n_outputs)
Ground truth (correct) target values.
y_pred : array-like of shape = (n_samples) or (n_samples, n_outputs)
Estimated target values.
sample_weight : array-like of shape = (n_samples), optional
Sample weights.
multioutput : string in ['raw_values', 'uniform_average']
or array-like of shape (n_outputs)
Defines aggregating of multiple output values.
Array-like value defines weights used to average errors.
'raw_values' :
Returns a full set of errors in case of multioutput input.
'uniform_average' :
Errors of all outputs are averaged with uniform weight.
Returns
-------
loss : float or ndarray of floats
If multioutput is 'raw_values', then mean absolute error is returned
for each output separately.
If multioutput is 'uniform_average' or an ndarray of weights, then the
weighted average of all output errors is returned.
MAE output is non-negative floating point. The best value is 0.0.
Examples
--------
>>> from sklearn.metrics import mean_absolute_error
>>> y_true = [3, -0.5, 2, 7]
>>> y_pred = [2.5, 0.0, 2, 8]
>>> mean_absolute_error(y_true, y_pred)
0.5
>>> y_true = [[0.5, 1], [-1, 1], [7, -6]]
>>> y_pred = [[0, 2], [-1, 2], [8, -5]]
>>> mean_absolute_error(y_true, y_pred)
0.75
>>> mean_absolute_error(y_true, y_pred, multioutput='raw_values')
array([ 0.5, 1. ])
>>> mean_absolute_error(y_true, y_pred, multioutput=[0.3, 0.7])
... # doctest: +ELLIPSIS
0.849...
"""
y_type, y_true, y_pred, multioutput = _check_reg_targets(
y_true, y_pred, multioutput)
output_errors = np.average(np.abs(y_pred - y_true),
weights=sample_weight, axis=0)
if isinstance(multioutput, string_types):
if multioutput == 'raw_values':
return output_errors
elif multioutput == 'uniform_average':
# pass None as weights to np.average: uniform mean
multioutput = None
return np.average(output_errors, weights=multioutput)
def mean_squared_error(y_true, y_pred,
sample_weight=None,
multioutput='uniform_average'):
"""Mean squared error regression loss
Read more in the :ref:`User Guide <mean_squared_error>`.
Parameters
----------
y_true : array-like of shape = (n_samples) or (n_samples, n_outputs)
Ground truth (correct) target values.
y_pred : array-like of shape = (n_samples) or (n_samples, n_outputs)
Estimated target values.
sample_weight : array-like of shape = (n_samples), optional
Sample weights.
multioutput : string in ['raw_values', 'uniform_average']
or array-like of shape (n_outputs)
Defines aggregating of multiple output values.
Array-like value defines weights used to average errors.
'raw_values' :
Returns a full set of errors in case of multioutput input.
'uniform_average' :
Errors of all outputs are averaged with uniform weight.
Returns
-------
loss : float or ndarray of floats
A non-negative floating point value (the best value is 0.0), or an
array of floating point values, one for each individual target.
Examples
--------
>>> from sklearn.metrics import mean_squared_error
>>> y_true = [3, -0.5, 2, 7]
>>> y_pred = [2.5, 0.0, 2, 8]
>>> mean_squared_error(y_true, y_pred)
0.375
>>> y_true = [[0.5, 1],[-1, 1],[7, -6]]
>>> y_pred = [[0, 2],[-1, 2],[8, -5]]
>>> mean_squared_error(y_true, y_pred) # doctest: +ELLIPSIS
0.708...
>>> mean_squared_error(y_true, y_pred, multioutput='raw_values')
... # doctest: +ELLIPSIS
array([ 0.416..., 1. ])
>>> mean_squared_error(y_true, y_pred, multioutput=[0.3, 0.7])
... # doctest: +ELLIPSIS
0.824...
"""
y_type, y_true, y_pred, multioutput = _check_reg_targets(
y_true, y_pred, multioutput)
output_errors = np.average((y_true - y_pred) ** 2, axis=0,
weights=sample_weight)
if isinstance(multioutput, string_types):
if multioutput == 'raw_values':
return output_errors
elif multioutput == 'uniform_average':
# pass None as weights to np.average: uniform mean
multioutput = None
return np.average(output_errors, weights=multioutput)
def mean_squared_log_error(y_true, y_pred,
sample_weight=None,
multioutput='uniform_average'):
"""Mean squared logarithmic error regression loss
Read more in the :ref:`User Guide <mean_squared_log_error>`.
Parameters
----------
y_true : array-like of shape = (n_samples) or (n_samples, n_outputs)
Ground truth (correct) target values.
y_pred : array-like of shape = (n_samples) or (n_samples, n_outputs)
Estimated target values.
sample_weight : array-like of shape = (n_samples), optional
Sample weights.
multioutput : string in ['raw_values', 'uniform_average'] \
or array-like of shape = (n_outputs)
Defines aggregating of multiple output values.
Array-like value defines weights used to average errors.
'raw_values' :
Returns a full set of errors when the input is of multioutput
format.
'uniform_average' :
Errors of all outputs are averaged with uniform weight.
Returns
-------
loss : float or ndarray of floats
A non-negative floating point value (the best value is 0.0), or an
array of floating point values, one for each individual target.
Examples
--------
>>> from sklearn.metrics import mean_squared_log_error
>>> y_true = [3, 5, 2.5, 7]
>>> y_pred = [2.5, 5, 4, 8]
>>> mean_squared_log_error(y_true, y_pred) # doctest: +ELLIPSIS
0.039...
>>> y_true = [[0.5, 1], [1, 2], [7, 6]]
>>> y_pred = [[0.5, 2], [1, 2.5], [8, 8]]
>>> mean_squared_log_error(y_true, y_pred) # doctest: +ELLIPSIS
0.044...
>>> mean_squared_log_error(y_true, y_pred, multioutput='raw_values')
... # doctest: +ELLIPSIS
array([ 0.004..., 0.083...])
>>> mean_squared_log_error(y_true, y_pred, multioutput=[0.3, 0.7])
... # doctest: +ELLIPSIS
0.060...
"""
y_type, y_true, y_pred, multioutput = _check_reg_targets(
y_true, y_pred, multioutput)
if not (y_true >= 0).all() and not (y_pred >= 0).all():
raise ValueError("Mean Squared Logarithmic Error cannot be used when "
"targets contain negative values.")
return mean_squared_error(np.log(y_true + 1), np.log(y_pred + 1),
sample_weight, multioutput)
def median_absolute_error(y_true, y_pred):
"""Median absolute error regression loss
Read more in the :ref:`User Guide <median_absolute_error>`.
Parameters
----------
y_true : array-like of shape = (n_samples)
Ground truth (correct) target values.
y_pred : array-like of shape = (n_samples)
Estimated target values.
Returns
-------
loss : float
A positive floating point value (the best value is 0.0).
Examples
--------
>>> from sklearn.metrics import median_absolute_error
>>> y_true = [3, -0.5, 2, 7]
>>> y_pred = [2.5, 0.0, 2, 8]
>>> median_absolute_error(y_true, y_pred)
0.5
"""
y_type, y_true, y_pred, _ = _check_reg_targets(y_true, y_pred,
'uniform_average')
if y_type == 'continuous-multioutput':
raise ValueError("Multioutput not supported in median_absolute_error")
return np.median(np.abs(y_pred - y_true))
def explained_variance_score(y_true, y_pred,
sample_weight=None,
multioutput='uniform_average'):
"""Explained variance regression score function
Best possible score is 1.0, lower values are worse.
Read more in the :ref:`User Guide <explained_variance_score>`.
Parameters
----------
y_true : array-like of shape = (n_samples) or (n_samples, n_outputs)
Ground truth (correct) target values.
y_pred : array-like of shape = (n_samples) or (n_samples, n_outputs)
Estimated target values.
sample_weight : array-like of shape = (n_samples), optional
Sample weights.
multioutput : string in ['raw_values', 'uniform_average', \
'variance_weighted'] or array-like of shape (n_outputs)
Defines aggregating of multiple output scores.
Array-like value defines weights used to average scores.
'raw_values' :
Returns a full set of scores in case of multioutput input.
'uniform_average' :
Scores of all outputs are averaged with uniform weight.
'variance_weighted' :
Scores of all outputs are averaged, weighted by the variances
of each individual output.
Returns
-------
score : float or ndarray of floats
The explained variance or ndarray if 'multioutput' is 'raw_values'.
Notes
-----
This is not a symmetric function.
Examples
--------
>>> from sklearn.metrics import explained_variance_score
>>> y_true = [3, -0.5, 2, 7]
>>> y_pred = [2.5, 0.0, 2, 8]
>>> explained_variance_score(y_true, y_pred) # doctest: +ELLIPSIS
0.957...
>>> y_true = [[0.5, 1], [-1, 1], [7, -6]]
>>> y_pred = [[0, 2], [-1, 2], [8, -5]]
>>> explained_variance_score(y_true, y_pred, multioutput='uniform_average')
... # doctest: +ELLIPSIS
0.983...
"""
y_type, y_true, y_pred, multioutput = _check_reg_targets(
y_true, y_pred, multioutput)
y_diff_avg = np.average(y_true - y_pred, weights=sample_weight, axis=0)
numerator = np.average((y_true - y_pred - y_diff_avg) ** 2,
weights=sample_weight, axis=0)
y_true_avg = np.average(y_true, weights=sample_weight, axis=0)
denominator = np.average((y_true - y_true_avg) ** 2,
weights=sample_weight, axis=0)
nonzero_numerator = numerator != 0
nonzero_denominator = denominator != 0
valid_score = nonzero_numerator & nonzero_denominator
output_scores = np.ones(y_true.shape[1])
output_scores[valid_score] = 1 - (numerator[valid_score] /
denominator[valid_score])
output_scores[nonzero_numerator & ~nonzero_denominator] = 0.
if isinstance(multioutput, string_types):
if multioutput == 'raw_values':
# return scores individually
return output_scores
elif multioutput == 'uniform_average':
# passing to np.average() None as weights results is uniform mean
avg_weights = None
elif multioutput == 'variance_weighted':
avg_weights = denominator
else:
avg_weights = multioutput
return np.average(output_scores, weights=avg_weights)
def r2_score(y_true, y_pred, sample_weight=None,
multioutput="uniform_average"):
"""R^2 (coefficient of determination) regression score function.
Best possible score is 1.0 and it can be negative (because the
model can be arbitrarily worse). A constant model that always
predicts the expected value of y, disregarding the input features,
would get a R^2 score of 0.0.
Read more in the :ref:`User Guide <r2_score>`.
Parameters
----------
y_true : array-like of shape = (n_samples) or (n_samples, n_outputs)
Ground truth (correct) target values.
y_pred : array-like of shape = (n_samples) or (n_samples, n_outputs)
Estimated target values.
sample_weight : array-like of shape = (n_samples), optional
Sample weights.
multioutput : string in ['raw_values', 'uniform_average', \
'variance_weighted'] or None or array-like of shape (n_outputs)
Defines aggregating of multiple output scores.
Array-like value defines weights used to average scores.
Default is "uniform_average".
'raw_values' :
Returns a full set of scores in case of multioutput input.
'uniform_average' :
Scores of all outputs are averaged with uniform weight.
'variance_weighted' :
Scores of all outputs are averaged, weighted by the variances
of each individual output.
.. versionchanged:: 0.19
Default value of multioutput is 'uniform_average'.
Returns
-------
z : float or ndarray of floats
The R^2 score or ndarray of scores if 'multioutput' is
'raw_values'.
Notes
-----
This is not a symmetric function.
Unlike most other scores, R^2 score may be negative (it need not actually
be the square of a quantity R).
References
----------
.. [1] `Wikipedia entry on the Coefficient of determination
<https://en.wikipedia.org/wiki/Coefficient_of_determination>`_
Examples
--------
>>> from sklearn.metrics import r2_score
>>> y_true = [3, -0.5, 2, 7]
>>> y_pred = [2.5, 0.0, 2, 8]
>>> r2_score(y_true, y_pred) # doctest: +ELLIPSIS
0.948...
>>> y_true = [[0.5, 1], [-1, 1], [7, -6]]
>>> y_pred = [[0, 2], [-1, 2], [8, -5]]
>>> r2_score(y_true, y_pred, multioutput='variance_weighted')
... # doctest: +ELLIPSIS
0.938...
>>> y_true = [1,2,3]
>>> y_pred = [1,2,3]
>>> r2_score(y_true, y_pred)
1.0
>>> y_true = [1,2,3]
>>> y_pred = [2,2,2]
>>> r2_score(y_true, y_pred)
0.0
>>> y_true = [1,2,3]
>>> y_pred = [3,2,1]
>>> r2_score(y_true, y_pred)
-3.0
"""
y_type, y_true, y_pred, multioutput = _check_reg_targets(
y_true, y_pred, multioutput)
if sample_weight is not None:
sample_weight = column_or_1d(sample_weight)
weight = sample_weight[:, np.newaxis]
else:
weight = 1.
numerator = (weight * (y_true - y_pred) ** 2).sum(axis=0,
dtype=np.float64)
denominator = (weight * (y_true - np.average(
y_true, axis=0, weights=sample_weight)) ** 2).sum(axis=0,
dtype=np.float64)
nonzero_denominator = denominator != 0
nonzero_numerator = numerator != 0
valid_score = nonzero_denominator & nonzero_numerator
output_scores = np.ones([y_true.shape[1]])
output_scores[valid_score] = 1 - (numerator[valid_score] /
denominator[valid_score])
# arbitrary set to zero to avoid -inf scores, having a constant
# y_true is not interesting for scoring a regression anyway
output_scores[nonzero_numerator & ~nonzero_denominator] = 0.
if isinstance(multioutput, string_types):
if multioutput == 'raw_values':
# return scores individually
return output_scores
elif multioutput == 'uniform_average':
# passing None as weights results is uniform mean
avg_weights = None
elif multioutput == 'variance_weighted':
avg_weights = denominator
# avoid fail on constant y or one-element arrays
if not np.any(nonzero_denominator):
if not np.any(nonzero_numerator):
return 1.0
else:
return 0.0
else:
avg_weights = multioutput
return np.average(output_scores, weights=avg_weights)
| 19,967 | 33.970228 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/pairwise.py | # -*- coding: utf-8 -*-
# Authors: Alexandre Gramfort <[email protected]>
# Mathieu Blondel <[email protected]>
# Robert Layton <[email protected]>
# Andreas Mueller <[email protected]>
# Philippe Gervais <[email protected]>
# Lars Buitinck
# Joel Nothman <[email protected]>
# License: BSD 3 clause
import itertools
from functools import partial
import warnings
import numpy as np
from scipy.spatial import distance
from scipy.sparse import csr_matrix
from scipy.sparse import issparse
from ..utils import check_array
from ..utils import gen_even_slices
from ..utils import gen_batches
from ..utils.extmath import row_norms, safe_sparse_dot
from ..preprocessing import normalize
from ..externals.joblib import Parallel
from ..externals.joblib import delayed
from ..externals.joblib import cpu_count
from .pairwise_fast import _chi2_kernel_fast, _sparse_manhattan
# Utility Functions
def _return_float_dtype(X, Y):
"""
1. If dtype of X and Y is float32, then dtype float32 is returned.
2. Else dtype float is returned.
"""
if not issparse(X) and not isinstance(X, np.ndarray):
X = np.asarray(X)
if Y is None:
Y_dtype = X.dtype
elif not issparse(Y) and not isinstance(Y, np.ndarray):
Y = np.asarray(Y)
Y_dtype = Y.dtype
else:
Y_dtype = Y.dtype
if X.dtype == Y_dtype == np.float32:
dtype = np.float32
else:
dtype = np.float
return X, Y, dtype
def check_pairwise_arrays(X, Y, precomputed=False, dtype=None):
""" Set X and Y appropriately and checks inputs
If Y is None, it is set as a pointer to X (i.e. not a copy).
If Y is given, this does not happen.
All distance metrics should use this function first to assert that the
given parameters are correct and safe to use.
Specifically, this function first ensures that both X and Y are arrays,
then checks that they are at least two dimensional while ensuring that
their elements are floats (or dtype if provided). Finally, the function
checks that the size of the second dimension of the two arrays is equal, or
the equivalent check for a precomputed distance matrix.
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples_a, n_features)
Y : {array-like, sparse matrix}, shape (n_samples_b, n_features)
precomputed : bool
True if X is to be treated as precomputed distances to the samples in
Y.
dtype : string, type, list of types or None (default=None)
Data type required for X and Y. If None, the dtype will be an
appropriate float type selected by _return_float_dtype.
.. versionadded:: 0.18
Returns
-------
safe_X : {array-like, sparse matrix}, shape (n_samples_a, n_features)
An array equal to X, guaranteed to be a numpy array.
safe_Y : {array-like, sparse matrix}, shape (n_samples_b, n_features)
An array equal to Y if Y was not None, guaranteed to be a numpy array.
If Y was None, safe_Y will be a pointer to X.
"""
X, Y, dtype_float = _return_float_dtype(X, Y)
warn_on_dtype = dtype is not None
estimator = 'check_pairwise_arrays'
if dtype is None:
dtype = dtype_float
if Y is X or Y is None:
X = Y = check_array(X, accept_sparse='csr', dtype=dtype,
warn_on_dtype=warn_on_dtype, estimator=estimator)
else:
X = check_array(X, accept_sparse='csr', dtype=dtype,
warn_on_dtype=warn_on_dtype, estimator=estimator)
Y = check_array(Y, accept_sparse='csr', dtype=dtype,
warn_on_dtype=warn_on_dtype, estimator=estimator)
if precomputed:
if X.shape[1] != Y.shape[0]:
raise ValueError("Precomputed metric requires shape "
"(n_queries, n_indexed). Got (%d, %d) "
"for %d indexed." %
(X.shape[0], X.shape[1], Y.shape[0]))
elif X.shape[1] != Y.shape[1]:
raise ValueError("Incompatible dimension for X and Y matrices: "
"X.shape[1] == %d while Y.shape[1] == %d" % (
X.shape[1], Y.shape[1]))
return X, Y
def check_paired_arrays(X, Y):
""" Set X and Y appropriately and checks inputs for paired distances
All paired distance metrics should use this function first to assert that
the given parameters are correct and safe to use.
Specifically, this function first ensures that both X and Y are arrays,
then checks that they are at least two dimensional while ensuring that
their elements are floats. Finally, the function checks that the size
of the dimensions of the two arrays are equal.
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples_a, n_features)
Y : {array-like, sparse matrix}, shape (n_samples_b, n_features)
Returns
-------
safe_X : {array-like, sparse matrix}, shape (n_samples_a, n_features)
An array equal to X, guaranteed to be a numpy array.
safe_Y : {array-like, sparse matrix}, shape (n_samples_b, n_features)
An array equal to Y if Y was not None, guaranteed to be a numpy array.
If Y was None, safe_Y will be a pointer to X.
"""
X, Y = check_pairwise_arrays(X, Y)
if X.shape != Y.shape:
raise ValueError("X and Y should be of same shape. They were "
"respectively %r and %r long." % (X.shape, Y.shape))
return X, Y
# Pairwise distances
def euclidean_distances(X, Y=None, Y_norm_squared=None, squared=False,
X_norm_squared=None):
"""
Considering the rows of X (and Y=X) as vectors, compute the
distance matrix between each pair of vectors.
For efficiency reasons, the euclidean distance between a pair of row
vector x and y is computed as::
dist(x, y) = sqrt(dot(x, x) - 2 * dot(x, y) + dot(y, y))
This formulation has two advantages over other ways of computing distances.
First, it is computationally efficient when dealing with sparse data.
Second, if one argument varies but the other remains unchanged, then
`dot(x, x)` and/or `dot(y, y)` can be pre-computed.
However, this is not the most precise way of doing this computation, and
the distance matrix returned by this function may not be exactly
symmetric as required by, e.g., ``scipy.spatial.distance`` functions.
Read more in the :ref:`User Guide <metrics>`.
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples_1, n_features)
Y : {array-like, sparse matrix}, shape (n_samples_2, n_features)
Y_norm_squared : array-like, shape (n_samples_2, ), optional
Pre-computed dot-products of vectors in Y (e.g.,
``(Y**2).sum(axis=1)``)
squared : boolean, optional
Return squared Euclidean distances.
X_norm_squared : array-like, shape = [n_samples_1], optional
Pre-computed dot-products of vectors in X (e.g.,
``(X**2).sum(axis=1)``)
Returns
-------
distances : {array, sparse matrix}, shape (n_samples_1, n_samples_2)
Examples
--------
>>> from sklearn.metrics.pairwise import euclidean_distances
>>> X = [[0, 1], [1, 1]]
>>> # distance between rows of X
>>> euclidean_distances(X, X)
array([[ 0., 1.],
[ 1., 0.]])
>>> # get distance to origin
>>> euclidean_distances(X, [[0, 0]])
array([[ 1. ],
[ 1.41421356]])
See also
--------
paired_distances : distances betweens pairs of elements of X and Y.
"""
X, Y = check_pairwise_arrays(X, Y)
if X_norm_squared is not None:
XX = check_array(X_norm_squared)
if XX.shape == (1, X.shape[0]):
XX = XX.T
elif XX.shape != (X.shape[0], 1):
raise ValueError(
"Incompatible dimensions for X and X_norm_squared")
else:
XX = row_norms(X, squared=True)[:, np.newaxis]
if X is Y: # shortcut in the common case euclidean_distances(X, X)
YY = XX.T
elif Y_norm_squared is not None:
YY = np.atleast_2d(Y_norm_squared)
if YY.shape != (1, Y.shape[0]):
raise ValueError(
"Incompatible dimensions for Y and Y_norm_squared")
else:
YY = row_norms(Y, squared=True)[np.newaxis, :]
distances = safe_sparse_dot(X, Y.T, dense_output=True)
distances *= -2
distances += XX
distances += YY
np.maximum(distances, 0, out=distances)
if X is Y:
# Ensure that distances between vectors and themselves are set to 0.0.
# This may not be the case due to floating point rounding errors.
distances.flat[::distances.shape[0] + 1] = 0.0
return distances if squared else np.sqrt(distances, out=distances)
def pairwise_distances_argmin_min(X, Y, axis=1, metric="euclidean",
batch_size=500, metric_kwargs=None):
"""Compute minimum distances between one point and a set of points.
This function computes for each row in X, the index of the row of Y which
is closest (according to the specified distance). The minimal distances are
also returned.
This is mostly equivalent to calling:
(pairwise_distances(X, Y=Y, metric=metric).argmin(axis=axis),
pairwise_distances(X, Y=Y, metric=metric).min(axis=axis))
but uses much less memory, and is faster for large arrays.
Parameters
----------
X : {array-like, sparse matrix}, shape (n_samples1, n_features)
Array containing points.
Y : {array-like, sparse matrix}, shape (n_samples2, n_features)
Arrays containing points.
axis : int, optional, default 1
Axis along which the argmin and distances are to be computed.
metric : string or callable, default 'euclidean'
metric to use for distance computation. Any metric from scikit-learn
or scipy.spatial.distance can be used.
If metric is a callable function, it is called on each
pair of instances (rows) and the resulting value recorded. The callable
should take two arrays as input and return one value indicating the
distance between them. This works for Scipy's metrics, but is less
efficient than passing the metric name as a string.
Distance matrices are not supported.
Valid values for metric are:
- from scikit-learn: ['cityblock', 'cosine', 'euclidean', 'l1', 'l2',
'manhattan']
- from scipy.spatial.distance: ['braycurtis', 'canberra', 'chebyshev',
'correlation', 'dice', 'hamming', 'jaccard', 'kulsinski',
'mahalanobis', 'matching', 'minkowski', 'rogerstanimoto',
'russellrao', 'seuclidean', 'sokalmichener', 'sokalsneath',
'sqeuclidean', 'yule']
See the documentation for scipy.spatial.distance for details on these
metrics.
batch_size : integer
To reduce memory consumption over the naive solution, data are
processed in batches, comprising batch_size rows of X and
batch_size rows of Y. The default value is quite conservative, but
can be changed for fine-tuning. The larger the number, the larger the
memory usage.
metric_kwargs : dict, optional
Keyword arguments to pass to specified metric function.
Returns
-------
argmin : numpy.ndarray
Y[argmin[i], :] is the row in Y that is closest to X[i, :].
distances : numpy.ndarray
distances[i] is the distance between the i-th row in X and the
argmin[i]-th row in Y.
See also
--------
sklearn.metrics.pairwise_distances
sklearn.metrics.pairwise_distances_argmin
"""
dist_func = None
if metric in PAIRWISE_DISTANCE_FUNCTIONS:
dist_func = PAIRWISE_DISTANCE_FUNCTIONS[metric]
elif not callable(metric) and not isinstance(metric, str):
raise ValueError("'metric' must be a string or a callable")
X, Y = check_pairwise_arrays(X, Y)
if metric_kwargs is None:
metric_kwargs = {}
if axis == 0:
X, Y = Y, X
# Allocate output arrays
indices = np.empty(X.shape[0], dtype=np.intp)
values = np.empty(X.shape[0])
values.fill(np.infty)
for chunk_x in gen_batches(X.shape[0], batch_size):
X_chunk = X[chunk_x, :]
for chunk_y in gen_batches(Y.shape[0], batch_size):
Y_chunk = Y[chunk_y, :]
if dist_func is not None:
if metric == 'euclidean': # special case, for speed
d_chunk = safe_sparse_dot(X_chunk, Y_chunk.T,
dense_output=True)
d_chunk *= -2
d_chunk += row_norms(X_chunk, squared=True)[:, np.newaxis]
d_chunk += row_norms(Y_chunk, squared=True)[np.newaxis, :]
np.maximum(d_chunk, 0, d_chunk)
else:
d_chunk = dist_func(X_chunk, Y_chunk, **metric_kwargs)
else:
d_chunk = pairwise_distances(X_chunk, Y_chunk,
metric=metric, **metric_kwargs)
# Update indices and minimum values using chunk
min_indices = d_chunk.argmin(axis=1)
min_values = d_chunk[np.arange(chunk_x.stop - chunk_x.start),
min_indices]
flags = values[chunk_x] > min_values
indices[chunk_x][flags] = min_indices[flags] + chunk_y.start
values[chunk_x][flags] = min_values[flags]
if metric == "euclidean" and not metric_kwargs.get("squared", False):
np.sqrt(values, values)
return indices, values
def pairwise_distances_argmin(X, Y, axis=1, metric="euclidean",
batch_size=500, metric_kwargs=None):
"""Compute minimum distances between one point and a set of points.
This function computes for each row in X, the index of the row of Y which
is closest (according to the specified distance).
This is mostly equivalent to calling:
pairwise_distances(X, Y=Y, metric=metric).argmin(axis=axis)
but uses much less memory, and is faster for large arrays.
This function works with dense 2D arrays only.
Parameters
----------
X : array-like
Arrays containing points. Respective shapes (n_samples1, n_features)
and (n_samples2, n_features)
Y : array-like
Arrays containing points. Respective shapes (n_samples1, n_features)
and (n_samples2, n_features)
axis : int, optional, default 1
Axis along which the argmin and distances are to be computed.
metric : string or callable
metric to use for distance computation. Any metric from scikit-learn
or scipy.spatial.distance can be used.
If metric is a callable function, it is called on each
pair of instances (rows) and the resulting value recorded. The callable
should take two arrays as input and return one value indicating the
distance between them. This works for Scipy's metrics, but is less
efficient than passing the metric name as a string.
Distance matrices are not supported.
Valid values for metric are:
- from scikit-learn: ['cityblock', 'cosine', 'euclidean', 'l1', 'l2',
'manhattan']
- from scipy.spatial.distance: ['braycurtis', 'canberra', 'chebyshev',
'correlation', 'dice', 'hamming', 'jaccard', 'kulsinski',
'mahalanobis', 'matching', 'minkowski', 'rogerstanimoto',
'russellrao', 'seuclidean', 'sokalmichener', 'sokalsneath',
'sqeuclidean', 'yule']
See the documentation for scipy.spatial.distance for details on these
metrics.
batch_size : integer
To reduce memory consumption over the naive solution, data are
processed in batches, comprising batch_size rows of X and
batch_size rows of Y. The default value is quite conservative, but
can be changed for fine-tuning. The larger the number, the larger the
memory usage.
metric_kwargs : dict
keyword arguments to pass to specified metric function.
Returns
-------
argmin : numpy.ndarray
Y[argmin[i], :] is the row in Y that is closest to X[i, :].
See also
--------
sklearn.metrics.pairwise_distances
sklearn.metrics.pairwise_distances_argmin_min
"""
if metric_kwargs is None:
metric_kwargs = {}
return pairwise_distances_argmin_min(X, Y, axis, metric, batch_size,
metric_kwargs)[0]
def manhattan_distances(X, Y=None, sum_over_features=True,
size_threshold=None):
""" Compute the L1 distances between the vectors in X and Y.
With sum_over_features equal to False it returns the componentwise
distances.
Read more in the :ref:`User Guide <metrics>`.
Parameters
----------
X : array_like
An array with shape (n_samples_X, n_features).
Y : array_like, optional
An array with shape (n_samples_Y, n_features).
sum_over_features : bool, default=True
If True the function returns the pairwise distance matrix
else it returns the componentwise L1 pairwise-distances.
Not supported for sparse matrix inputs.
size_threshold : int, default=5e8
Unused parameter.
Returns
-------
D : array
If sum_over_features is False shape is
(n_samples_X * n_samples_Y, n_features) and D contains the
componentwise L1 pairwise-distances (ie. absolute difference),
else shape is (n_samples_X, n_samples_Y) and D contains
the pairwise L1 distances.
Examples
--------
>>> from sklearn.metrics.pairwise import manhattan_distances
>>> manhattan_distances([[3]], [[3]])#doctest:+ELLIPSIS
array([[ 0.]])
>>> manhattan_distances([[3]], [[2]])#doctest:+ELLIPSIS
array([[ 1.]])
>>> manhattan_distances([[2]], [[3]])#doctest:+ELLIPSIS
array([[ 1.]])
>>> manhattan_distances([[1, 2], [3, 4]],\
[[1, 2], [0, 3]])#doctest:+ELLIPSIS
array([[ 0., 2.],
[ 4., 4.]])
>>> import numpy as np
>>> X = np.ones((1, 2))
>>> y = 2 * np.ones((2, 2))
>>> manhattan_distances(X, y, sum_over_features=False)#doctest:+ELLIPSIS
array([[ 1., 1.],
[ 1., 1.]]...)
"""
if size_threshold is not None:
warnings.warn('Use of the "size_threshold" is deprecated '
'in 0.19 and it will be removed version '
'0.21 of scikit-learn', DeprecationWarning)
X, Y = check_pairwise_arrays(X, Y)
if issparse(X) or issparse(Y):
if not sum_over_features:
raise TypeError("sum_over_features=%r not supported"
" for sparse matrices" % sum_over_features)
X = csr_matrix(X, copy=False)
Y = csr_matrix(Y, copy=False)
D = np.zeros((X.shape[0], Y.shape[0]))
_sparse_manhattan(X.data, X.indices, X.indptr,
Y.data, Y.indices, Y.indptr,
X.shape[1], D)
return D
if sum_over_features:
return distance.cdist(X, Y, 'cityblock')
D = X[:, np.newaxis, :] - Y[np.newaxis, :, :]
D = np.abs(D, D)
return D.reshape((-1, X.shape[1]))
def cosine_distances(X, Y=None):
"""Compute cosine distance between samples in X and Y.
Cosine distance is defined as 1.0 minus the cosine similarity.
Read more in the :ref:`User Guide <metrics>`.
Parameters
----------
X : array_like, sparse matrix
with shape (n_samples_X, n_features).
Y : array_like, sparse matrix (optional)
with shape (n_samples_Y, n_features).
Returns
-------
distance matrix : array
An array with shape (n_samples_X, n_samples_Y).
See also
--------
sklearn.metrics.pairwise.cosine_similarity
scipy.spatial.distance.cosine (dense matrices only)
"""
# 1.0 - cosine_similarity(X, Y) without copy
S = cosine_similarity(X, Y)
S *= -1
S += 1
np.clip(S, 0, 2, out=S)
if X is Y or Y is None:
# Ensure that distances between vectors and themselves are set to 0.0.
# This may not be the case due to floating point rounding errors.
S[np.diag_indices_from(S)] = 0.0
return S
# Paired distances
def paired_euclidean_distances(X, Y):
"""
Computes the paired euclidean distances between X and Y
Read more in the :ref:`User Guide <metrics>`.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Y : array-like, shape (n_samples, n_features)
Returns
-------
distances : ndarray (n_samples, )
"""
X, Y = check_paired_arrays(X, Y)
return row_norms(X - Y)
def paired_manhattan_distances(X, Y):
"""Compute the L1 distances between the vectors in X and Y.
Read more in the :ref:`User Guide <metrics>`.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Y : array-like, shape (n_samples, n_features)
Returns
-------
distances : ndarray (n_samples, )
"""
X, Y = check_paired_arrays(X, Y)
diff = X - Y
if issparse(diff):
diff.data = np.abs(diff.data)
return np.squeeze(np.array(diff.sum(axis=1)))
else:
return np.abs(diff).sum(axis=-1)
def paired_cosine_distances(X, Y):
"""
Computes the paired cosine distances between X and Y
Read more in the :ref:`User Guide <metrics>`.
Parameters
----------
X : array-like, shape (n_samples, n_features)
Y : array-like, shape (n_samples, n_features)
Returns
-------
distances : ndarray, shape (n_samples, )
Notes
------
The cosine distance is equivalent to the half the squared
euclidean distance if each sample is normalized to unit norm
"""
X, Y = check_paired_arrays(X, Y)
return .5 * row_norms(normalize(X) - normalize(Y), squared=True)
PAIRED_DISTANCES = {
'cosine': paired_cosine_distances,
'euclidean': paired_euclidean_distances,
'l2': paired_euclidean_distances,
'l1': paired_manhattan_distances,
'manhattan': paired_manhattan_distances,
'cityblock': paired_manhattan_distances}
def paired_distances(X, Y, metric="euclidean", **kwds):
"""
Computes the paired distances between X and Y.
Computes the distances between (X[0], Y[0]), (X[1], Y[1]), etc...
Read more in the :ref:`User Guide <metrics>`.
Parameters
----------
X : ndarray (n_samples, n_features)
Array 1 for distance computation.
Y : ndarray (n_samples, n_features)
Array 2 for distance computation.
metric : string or callable
The metric to use when calculating distance between instances in a
feature array. If metric is a string, it must be one of the options
specified in PAIRED_DISTANCES, including "euclidean",
"manhattan", or "cosine".
Alternatively, if metric is a callable function, it is called on each
pair of instances (rows) and the resulting value recorded. The callable
should take two arrays from X as input and return a value indicating
the distance between them.
Returns
-------
distances : ndarray (n_samples, )
Examples
--------
>>> from sklearn.metrics.pairwise import paired_distances
>>> X = [[0, 1], [1, 1]]
>>> Y = [[0, 1], [2, 1]]
>>> paired_distances(X, Y)
array([ 0., 1.])
See also
--------
pairwise_distances : pairwise distances.
"""
if metric in PAIRED_DISTANCES:
func = PAIRED_DISTANCES[metric]
return func(X, Y)
elif callable(metric):
# Check the matrix first (it is usually done by the metric)
X, Y = check_paired_arrays(X, Y)
distances = np.zeros(len(X))
for i in range(len(X)):
distances[i] = metric(X[i], Y[i])
return distances
else:
raise ValueError('Unknown distance %s' % metric)
# Kernels
def linear_kernel(X, Y=None):
"""
Compute the linear kernel between X and Y.
Read more in the :ref:`User Guide <linear_kernel>`.
Parameters
----------
X : array of shape (n_samples_1, n_features)
Y : array of shape (n_samples_2, n_features)
Returns
-------
Gram matrix : array of shape (n_samples_1, n_samples_2)
"""
X, Y = check_pairwise_arrays(X, Y)
return safe_sparse_dot(X, Y.T, dense_output=True)
def polynomial_kernel(X, Y=None, degree=3, gamma=None, coef0=1):
"""
Compute the polynomial kernel between X and Y::
K(X, Y) = (gamma <X, Y> + coef0)^degree
Read more in the :ref:`User Guide <polynomial_kernel>`.
Parameters
----------
X : ndarray of shape (n_samples_1, n_features)
Y : ndarray of shape (n_samples_2, n_features)
degree : int, default 3
gamma : float, default None
if None, defaults to 1.0 / n_features
coef0 : int, default 1
Returns
-------
Gram matrix : array of shape (n_samples_1, n_samples_2)
"""
X, Y = check_pairwise_arrays(X, Y)
if gamma is None:
gamma = 1.0 / X.shape[1]
K = safe_sparse_dot(X, Y.T, dense_output=True)
K *= gamma
K += coef0
K **= degree
return K
def sigmoid_kernel(X, Y=None, gamma=None, coef0=1):
"""
Compute the sigmoid kernel between X and Y::
K(X, Y) = tanh(gamma <X, Y> + coef0)
Read more in the :ref:`User Guide <sigmoid_kernel>`.
Parameters
----------
X : ndarray of shape (n_samples_1, n_features)
Y : ndarray of shape (n_samples_2, n_features)
gamma : float, default None
If None, defaults to 1.0 / n_features
coef0 : int, default 1
Returns
-------
Gram matrix : array of shape (n_samples_1, n_samples_2)
"""
X, Y = check_pairwise_arrays(X, Y)
if gamma is None:
gamma = 1.0 / X.shape[1]
K = safe_sparse_dot(X, Y.T, dense_output=True)
K *= gamma
K += coef0
np.tanh(K, K) # compute tanh in-place
return K
def rbf_kernel(X, Y=None, gamma=None):
"""
Compute the rbf (gaussian) kernel between X and Y::
K(x, y) = exp(-gamma ||x-y||^2)
for each pair of rows x in X and y in Y.
Read more in the :ref:`User Guide <rbf_kernel>`.
Parameters
----------
X : array of shape (n_samples_X, n_features)
Y : array of shape (n_samples_Y, n_features)
gamma : float, default None
If None, defaults to 1.0 / n_features
Returns
-------
kernel_matrix : array of shape (n_samples_X, n_samples_Y)
"""
X, Y = check_pairwise_arrays(X, Y)
if gamma is None:
gamma = 1.0 / X.shape[1]
K = euclidean_distances(X, Y, squared=True)
K *= -gamma
np.exp(K, K) # exponentiate K in-place
return K
def laplacian_kernel(X, Y=None, gamma=None):
"""Compute the laplacian kernel between X and Y.
The laplacian kernel is defined as::
K(x, y) = exp(-gamma ||x-y||_1)
for each pair of rows x in X and y in Y.
Read more in the :ref:`User Guide <laplacian_kernel>`.
.. versionadded:: 0.17
Parameters
----------
X : array of shape (n_samples_X, n_features)
Y : array of shape (n_samples_Y, n_features)
gamma : float, default None
If None, defaults to 1.0 / n_features
Returns
-------
kernel_matrix : array of shape (n_samples_X, n_samples_Y)
"""
X, Y = check_pairwise_arrays(X, Y)
if gamma is None:
gamma = 1.0 / X.shape[1]
K = -gamma * manhattan_distances(X, Y)
np.exp(K, K) # exponentiate K in-place
return K
def cosine_similarity(X, Y=None, dense_output=True):
"""Compute cosine similarity between samples in X and Y.
Cosine similarity, or the cosine kernel, computes similarity as the
normalized dot product of X and Y:
K(X, Y) = <X, Y> / (||X||*||Y||)
On L2-normalized data, this function is equivalent to linear_kernel.
Read more in the :ref:`User Guide <cosine_similarity>`.
Parameters
----------
X : ndarray or sparse array, shape: (n_samples_X, n_features)
Input data.
Y : ndarray or sparse array, shape: (n_samples_Y, n_features)
Input data. If ``None``, the output will be the pairwise
similarities between all samples in ``X``.
dense_output : boolean (optional), default True
Whether to return dense output even when the input is sparse. If
``False``, the output is sparse if both input arrays are sparse.
.. versionadded:: 0.17
parameter ``dense_output`` for dense output.
Returns
-------
kernel matrix : array
An array with shape (n_samples_X, n_samples_Y).
"""
# to avoid recursive import
X, Y = check_pairwise_arrays(X, Y)
X_normalized = normalize(X, copy=True)
if X is Y:
Y_normalized = X_normalized
else:
Y_normalized = normalize(Y, copy=True)
K = safe_sparse_dot(X_normalized, Y_normalized.T, dense_output=dense_output)
return K
def additive_chi2_kernel(X, Y=None):
"""Computes the additive chi-squared kernel between observations in X and Y
The chi-squared kernel is computed between each pair of rows in X and Y. X
and Y have to be non-negative. This kernel is most commonly applied to
histograms.
The chi-squared kernel is given by::
k(x, y) = -Sum [(x - y)^2 / (x + y)]
It can be interpreted as a weighted difference per entry.
Read more in the :ref:`User Guide <chi2_kernel>`.
Notes
-----
As the negative of a distance, this kernel is only conditionally positive
definite.
Parameters
----------
X : array-like of shape (n_samples_X, n_features)
Y : array of shape (n_samples_Y, n_features)
Returns
-------
kernel_matrix : array of shape (n_samples_X, n_samples_Y)
References
----------
* Zhang, J. and Marszalek, M. and Lazebnik, S. and Schmid, C.
Local features and kernels for classification of texture and object
categories: A comprehensive study
International Journal of Computer Vision 2007
http://research.microsoft.com/en-us/um/people/manik/projects/trade-off/papers/ZhangIJCV06.pdf
See also
--------
chi2_kernel : The exponentiated version of the kernel, which is usually
preferable.
sklearn.kernel_approximation.AdditiveChi2Sampler : A Fourier approximation
to this kernel.
"""
if issparse(X) or issparse(Y):
raise ValueError("additive_chi2 does not support sparse matrices.")
X, Y = check_pairwise_arrays(X, Y)
if (X < 0).any():
raise ValueError("X contains negative values.")
if Y is not X and (Y < 0).any():
raise ValueError("Y contains negative values.")
result = np.zeros((X.shape[0], Y.shape[0]), dtype=X.dtype)
_chi2_kernel_fast(X, Y, result)
return result
def chi2_kernel(X, Y=None, gamma=1.):
"""Computes the exponential chi-squared kernel X and Y.
The chi-squared kernel is computed between each pair of rows in X and Y. X
and Y have to be non-negative. This kernel is most commonly applied to
histograms.
The chi-squared kernel is given by::
k(x, y) = exp(-gamma Sum [(x - y)^2 / (x + y)])
It can be interpreted as a weighted difference per entry.
Read more in the :ref:`User Guide <chi2_kernel>`.
Parameters
----------
X : array-like of shape (n_samples_X, n_features)
Y : array of shape (n_samples_Y, n_features)
gamma : float, default=1.
Scaling parameter of the chi2 kernel.
Returns
-------
kernel_matrix : array of shape (n_samples_X, n_samples_Y)
References
----------
* Zhang, J. and Marszalek, M. and Lazebnik, S. and Schmid, C.
Local features and kernels for classification of texture and object
categories: A comprehensive study
International Journal of Computer Vision 2007
http://research.microsoft.com/en-us/um/people/manik/projects/trade-off/papers/ZhangIJCV06.pdf
See also
--------
additive_chi2_kernel : The additive version of this kernel
sklearn.kernel_approximation.AdditiveChi2Sampler : A Fourier approximation
to the additive version of this kernel.
"""
K = additive_chi2_kernel(X, Y)
K *= gamma
return np.exp(K, K)
# Helper functions - distance
PAIRWISE_DISTANCE_FUNCTIONS = {
# If updating this dictionary, update the doc in both distance_metrics()
# and also in pairwise_distances()!
'cityblock': manhattan_distances,
'cosine': cosine_distances,
'euclidean': euclidean_distances,
'l2': euclidean_distances,
'l1': manhattan_distances,
'manhattan': manhattan_distances,
'precomputed': None, # HACK: precomputed is always allowed, never called
}
def distance_metrics():
"""Valid metrics for pairwise_distances.
This function simply returns the valid pairwise distance metrics.
It exists to allow for a description of the mapping for
each of the valid strings.
The valid distance metrics, and the function they map to, are:
============ ====================================
metric Function
============ ====================================
'cityblock' metrics.pairwise.manhattan_distances
'cosine' metrics.pairwise.cosine_distances
'euclidean' metrics.pairwise.euclidean_distances
'l1' metrics.pairwise.manhattan_distances
'l2' metrics.pairwise.euclidean_distances
'manhattan' metrics.pairwise.manhattan_distances
============ ====================================
Read more in the :ref:`User Guide <metrics>`.
"""
return PAIRWISE_DISTANCE_FUNCTIONS
def _parallel_pairwise(X, Y, func, n_jobs, **kwds):
"""Break the pairwise matrix in n_jobs even slices
and compute them in parallel"""
if n_jobs < 0:
n_jobs = max(cpu_count() + 1 + n_jobs, 1)
if Y is None:
Y = X
if n_jobs == 1:
# Special case to avoid picklability checks in delayed
return func(X, Y, **kwds)
# TODO: in some cases, backend='threading' may be appropriate
fd = delayed(func)
ret = Parallel(n_jobs=n_jobs, verbose=0)(
fd(X, Y[s], **kwds)
for s in gen_even_slices(Y.shape[0], n_jobs))
return np.hstack(ret)
def _pairwise_callable(X, Y, metric, **kwds):
"""Handle the callable case for pairwise_{distances,kernels}
"""
X, Y = check_pairwise_arrays(X, Y)
if X is Y:
# Only calculate metric for upper triangle
out = np.zeros((X.shape[0], Y.shape[0]), dtype='float')
iterator = itertools.combinations(range(X.shape[0]), 2)
for i, j in iterator:
out[i, j] = metric(X[i], Y[j], **kwds)
# Make symmetric
# NB: out += out.T will produce incorrect results
out = out + out.T
# Calculate diagonal
# NB: nonzero diagonals are allowed for both metrics and kernels
for i in range(X.shape[0]):
x = X[i]
out[i, i] = metric(x, x, **kwds)
else:
# Calculate all cells
out = np.empty((X.shape[0], Y.shape[0]), dtype='float')
iterator = itertools.product(range(X.shape[0]), range(Y.shape[0]))
for i, j in iterator:
out[i, j] = metric(X[i], Y[j], **kwds)
return out
_VALID_METRICS = ['euclidean', 'l2', 'l1', 'manhattan', 'cityblock',
'braycurtis', 'canberra', 'chebyshev', 'correlation',
'cosine', 'dice', 'hamming', 'jaccard', 'kulsinski',
'mahalanobis', 'matching', 'minkowski', 'rogerstanimoto',
'russellrao', 'seuclidean', 'sokalmichener',
'sokalsneath', 'sqeuclidean', 'yule', "wminkowski"]
def pairwise_distances(X, Y=None, metric="euclidean", n_jobs=1, **kwds):
""" Compute the distance matrix from a vector array X and optional Y.
This method takes either a vector array or a distance matrix, and returns
a distance matrix. If the input is a vector array, the distances are
computed. If the input is a distances matrix, it is returned instead.
This method provides a safe way to take a distance matrix as input, while
preserving compatibility with many other algorithms that take a vector
array.
If Y is given (default is None), then the returned matrix is the pairwise
distance between the arrays from both X and Y.
Valid values for metric are:
- From scikit-learn: ['cityblock', 'cosine', 'euclidean', 'l1', 'l2',
'manhattan']. These metrics support sparse matrix inputs.
- From scipy.spatial.distance: ['braycurtis', 'canberra', 'chebyshev',
'correlation', 'dice', 'hamming', 'jaccard', 'kulsinski', 'mahalanobis',
'matching', 'minkowski', 'rogerstanimoto', 'russellrao', 'seuclidean',
'sokalmichener', 'sokalsneath', 'sqeuclidean', 'yule']
See the documentation for scipy.spatial.distance for details on these
metrics. These metrics do not support sparse matrix inputs.
Note that in the case of 'cityblock', 'cosine' and 'euclidean' (which are
valid scipy.spatial.distance metrics), the scikit-learn implementation
will be used, which is faster and has support for sparse matrices (except
for 'cityblock'). For a verbose description of the metrics from
scikit-learn, see the __doc__ of the sklearn.pairwise.distance_metrics
function.
Read more in the :ref:`User Guide <metrics>`.
Parameters
----------
X : array [n_samples_a, n_samples_a] if metric == "precomputed", or, \
[n_samples_a, n_features] otherwise
Array of pairwise distances between samples, or a feature array.
Y : array [n_samples_b, n_features], optional
An optional second feature array. Only allowed if metric != "precomputed".
metric : string, or callable
The metric to use when calculating distance between instances in a
feature array. If metric is a string, it must be one of the options
allowed by scipy.spatial.distance.pdist for its metric parameter, or
a metric listed in pairwise.PAIRWISE_DISTANCE_FUNCTIONS.
If metric is "precomputed", X is assumed to be a distance matrix.
Alternatively, if metric is a callable function, it is called on each
pair of instances (rows) and the resulting value recorded. The callable
should take two arrays from X as input and return a value indicating
the distance between them.
n_jobs : int
The number of jobs to use for the computation. This works by breaking
down the pairwise matrix into n_jobs even slices and computing them in
parallel.
If -1 all CPUs are used. If 1 is given, no parallel computing code is
used at all, which is useful for debugging. For n_jobs below -1,
(n_cpus + 1 + n_jobs) are used. Thus for n_jobs = -2, all CPUs but one
are used.
**kwds : optional keyword parameters
Any further parameters are passed directly to the distance function.
If using a scipy.spatial.distance metric, the parameters are still
metric dependent. See the scipy docs for usage examples.
Returns
-------
D : array [n_samples_a, n_samples_a] or [n_samples_a, n_samples_b]
A distance matrix D such that D_{i, j} is the distance between the
ith and jth vectors of the given matrix X, if Y is None.
If Y is not None, then D_{i, j} is the distance between the ith array
from X and the jth array from Y.
"""
if (metric not in _VALID_METRICS and
not callable(metric) and metric != "precomputed"):
raise ValueError("Unknown metric %s. "
"Valid metrics are %s, or 'precomputed', or a "
"callable" % (metric, _VALID_METRICS))
if metric == "precomputed":
X, _ = check_pairwise_arrays(X, Y, precomputed=True)
return X
elif metric in PAIRWISE_DISTANCE_FUNCTIONS:
func = PAIRWISE_DISTANCE_FUNCTIONS[metric]
elif callable(metric):
func = partial(_pairwise_callable, metric=metric, **kwds)
else:
if issparse(X) or issparse(Y):
raise TypeError("scipy distance metrics do not"
" support sparse matrices.")
dtype = bool if metric in PAIRWISE_BOOLEAN_FUNCTIONS else None
X, Y = check_pairwise_arrays(X, Y, dtype=dtype)
if n_jobs == 1 and X is Y:
return distance.squareform(distance.pdist(X, metric=metric,
**kwds))
func = partial(distance.cdist, metric=metric, **kwds)
return _parallel_pairwise(X, Y, func, n_jobs, **kwds)
# These distances recquire boolean arrays, when using scipy.spatial.distance
PAIRWISE_BOOLEAN_FUNCTIONS = [
'dice',
'jaccard',
'kulsinski',
'matching',
'rogerstanimoto',
'russellrao',
'sokalmichener',
'sokalsneath',
'yule',
]
# Helper functions - distance
PAIRWISE_KERNEL_FUNCTIONS = {
# If updating this dictionary, update the doc in both distance_metrics()
# and also in pairwise_distances()!
'additive_chi2': additive_chi2_kernel,
'chi2': chi2_kernel,
'linear': linear_kernel,
'polynomial': polynomial_kernel,
'poly': polynomial_kernel,
'rbf': rbf_kernel,
'laplacian': laplacian_kernel,
'sigmoid': sigmoid_kernel,
'cosine': cosine_similarity, }
def kernel_metrics():
""" Valid metrics for pairwise_kernels
This function simply returns the valid pairwise distance metrics.
It exists, however, to allow for a verbose description of the mapping for
each of the valid strings.
The valid distance metrics, and the function they map to, are:
=============== ========================================
metric Function
=============== ========================================
'additive_chi2' sklearn.pairwise.additive_chi2_kernel
'chi2' sklearn.pairwise.chi2_kernel
'linear' sklearn.pairwise.linear_kernel
'poly' sklearn.pairwise.polynomial_kernel
'polynomial' sklearn.pairwise.polynomial_kernel
'rbf' sklearn.pairwise.rbf_kernel
'laplacian' sklearn.pairwise.laplacian_kernel
'sigmoid' sklearn.pairwise.sigmoid_kernel
'cosine' sklearn.pairwise.cosine_similarity
=============== ========================================
Read more in the :ref:`User Guide <metrics>`.
"""
return PAIRWISE_KERNEL_FUNCTIONS
KERNEL_PARAMS = {
"additive_chi2": (),
"chi2": frozenset(["gamma"]),
"cosine": (),
"linear": (),
"poly": frozenset(["gamma", "degree", "coef0"]),
"polynomial": frozenset(["gamma", "degree", "coef0"]),
"rbf": frozenset(["gamma"]),
"laplacian": frozenset(["gamma"]),
"sigmoid": frozenset(["gamma", "coef0"]),
}
def pairwise_kernels(X, Y=None, metric="linear", filter_params=False,
n_jobs=1, **kwds):
"""Compute the kernel between arrays X and optional array Y.
This method takes either a vector array or a kernel matrix, and returns
a kernel matrix. If the input is a vector array, the kernels are
computed. If the input is a kernel matrix, it is returned instead.
This method provides a safe way to take a kernel matrix as input, while
preserving compatibility with many other algorithms that take a vector
array.
If Y is given (default is None), then the returned matrix is the pairwise
kernel between the arrays from both X and Y.
Valid values for metric are::
['rbf', 'sigmoid', 'polynomial', 'poly', 'linear', 'cosine']
Read more in the :ref:`User Guide <metrics>`.
Parameters
----------
X : array [n_samples_a, n_samples_a] if metric == "precomputed", or, \
[n_samples_a, n_features] otherwise
Array of pairwise kernels between samples, or a feature array.
Y : array [n_samples_b, n_features]
A second feature array only if X has shape [n_samples_a, n_features].
metric : string, or callable
The metric to use when calculating kernel between instances in a
feature array. If metric is a string, it must be one of the metrics
in pairwise.PAIRWISE_KERNEL_FUNCTIONS.
If metric is "precomputed", X is assumed to be a kernel matrix.
Alternatively, if metric is a callable function, it is called on each
pair of instances (rows) and the resulting value recorded. The callable
should take two arrays from X as input and return a value indicating
the distance between them.
filter_params : boolean
Whether to filter invalid parameters or not.
n_jobs : int
The number of jobs to use for the computation. This works by breaking
down the pairwise matrix into n_jobs even slices and computing them in
parallel.
If -1 all CPUs are used. If 1 is given, no parallel computing code is
used at all, which is useful for debugging. For n_jobs below -1,
(n_cpus + 1 + n_jobs) are used. Thus for n_jobs = -2, all CPUs but one
are used.
**kwds : optional keyword parameters
Any further parameters are passed directly to the kernel function.
Returns
-------
K : array [n_samples_a, n_samples_a] or [n_samples_a, n_samples_b]
A kernel matrix K such that K_{i, j} is the kernel between the
ith and jth vectors of the given matrix X, if Y is None.
If Y is not None, then K_{i, j} is the kernel between the ith array
from X and the jth array from Y.
Notes
-----
If metric is 'precomputed', Y is ignored and X is returned.
"""
# import GPKernel locally to prevent circular imports
from ..gaussian_process.kernels import Kernel as GPKernel
if metric == "precomputed":
X, _ = check_pairwise_arrays(X, Y, precomputed=True)
return X
elif isinstance(metric, GPKernel):
func = metric.__call__
elif metric in PAIRWISE_KERNEL_FUNCTIONS:
if filter_params:
kwds = dict((k, kwds[k]) for k in kwds
if k in KERNEL_PARAMS[metric])
func = PAIRWISE_KERNEL_FUNCTIONS[metric]
elif callable(metric):
func = partial(_pairwise_callable, metric=metric, **kwds)
else:
raise ValueError("Unknown kernel %r" % metric)
return _parallel_pairwise(X, Y, func, n_jobs, **kwds)
| 47,000 | 32.428876 | 99 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/__init__.py | """
The :mod:`sklearn.metrics` module includes score functions, performance metrics
and pairwise metrics and distance computations.
"""
from .ranking import auc
from .ranking import average_precision_score
from .ranking import coverage_error
from .ranking import label_ranking_average_precision_score
from .ranking import label_ranking_loss
from .ranking import precision_recall_curve
from .ranking import roc_auc_score
from .ranking import roc_curve
from .classification import accuracy_score
from .classification import classification_report
from .classification import cohen_kappa_score
from .classification import confusion_matrix
from .classification import f1_score
from .classification import fbeta_score
from .classification import hamming_loss
from .classification import hinge_loss
from .classification import jaccard_similarity_score
from .classification import log_loss
from .classification import matthews_corrcoef
from .classification import precision_recall_fscore_support
from .classification import precision_score
from .classification import recall_score
from .classification import zero_one_loss
from .classification import brier_score_loss
from . import cluster
from .cluster import adjusted_mutual_info_score
from .cluster import adjusted_rand_score
from .cluster import completeness_score
from .cluster import consensus_score
from .cluster import homogeneity_completeness_v_measure
from .cluster import homogeneity_score
from .cluster import mutual_info_score
from .cluster import normalized_mutual_info_score
from .cluster import fowlkes_mallows_score
from .cluster import silhouette_samples
from .cluster import silhouette_score
from .cluster import calinski_harabaz_score
from .cluster import v_measure_score
from .pairwise import euclidean_distances
from .pairwise import pairwise_distances
from .pairwise import pairwise_distances_argmin
from .pairwise import pairwise_distances_argmin_min
from .pairwise import pairwise_kernels
from .regression import explained_variance_score
from .regression import mean_absolute_error
from .regression import mean_squared_error
from .regression import mean_squared_log_error
from .regression import median_absolute_error
from .regression import r2_score
from .scorer import make_scorer
from .scorer import SCORERS
from .scorer import get_scorer
__all__ = [
'accuracy_score',
'adjusted_mutual_info_score',
'adjusted_rand_score',
'auc',
'average_precision_score',
'calinski_harabaz_score',
'classification_report',
'cluster',
'cohen_kappa_score',
'completeness_score',
'confusion_matrix',
'consensus_score',
'coverage_error',
'euclidean_distances',
'explained_variance_score',
'f1_score',
'fbeta_score',
'fowlkes_mallows_score',
'get_scorer',
'hamming_loss',
'hinge_loss',
'homogeneity_completeness_v_measure',
'homogeneity_score',
'jaccard_similarity_score',
'label_ranking_average_precision_score',
'label_ranking_loss',
'log_loss',
'make_scorer',
'matthews_corrcoef',
'mean_absolute_error',
'mean_squared_error',
'mean_squared_log_error',
'median_absolute_error',
'mutual_info_score',
'normalized_mutual_info_score',
'pairwise_distances',
'pairwise_distances_argmin',
'pairwise_distances_argmin_min',
'pairwise_distances_argmin_min',
'pairwise_kernels',
'precision_recall_curve',
'precision_recall_fscore_support',
'precision_score',
'r2_score',
'recall_score',
'roc_auc_score',
'roc_curve',
'SCORERS',
'silhouette_samples',
'silhouette_score',
'v_measure_score',
'zero_one_loss',
'brier_score_loss',
]
| 3,688 | 29.741667 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/ranking.py | """Metrics to assess performance on classification task given scores
Functions named as ``*_score`` return a scalar value to maximize: the higher
the better
Function named as ``*_error`` or ``*_loss`` return a scalar value to minimize:
the lower the better
"""
# Authors: Alexandre Gramfort <[email protected]>
# Mathieu Blondel <[email protected]>
# Olivier Grisel <[email protected]>
# Arnaud Joly <[email protected]>
# Jochen Wersdorfer <[email protected]>
# Lars Buitinck
# Joel Nothman <[email protected]>
# Noel Dawe <[email protected]>
# License: BSD 3 clause
from __future__ import division
import warnings
import numpy as np
from scipy.sparse import csr_matrix
from scipy.stats import rankdata
from ..utils import assert_all_finite
from ..utils import check_consistent_length
from ..utils import column_or_1d, check_array
from ..utils.multiclass import type_of_target
from ..utils.extmath import stable_cumsum
from ..utils.sparsefuncs import count_nonzero
from ..exceptions import UndefinedMetricWarning
from ..preprocessing import LabelBinarizer
from .base import _average_binary_score
def auc(x, y, reorder=False):
"""Compute Area Under the Curve (AUC) using the trapezoidal rule
This is a general function, given points on a curve. For computing the
area under the ROC-curve, see :func:`roc_auc_score`. For an alternative
way to summarize a precision-recall curve, see
:func:`average_precision_score`.
Parameters
----------
x : array, shape = [n]
x coordinates.
y : array, shape = [n]
y coordinates.
reorder : boolean, optional (default=False)
If True, assume that the curve is ascending in the case of ties, as for
an ROC curve. If the curve is non-ascending, the result will be wrong.
Returns
-------
auc : float
Examples
--------
>>> import numpy as np
>>> from sklearn import metrics
>>> y = np.array([1, 1, 2, 2])
>>> pred = np.array([0.1, 0.4, 0.35, 0.8])
>>> fpr, tpr, thresholds = metrics.roc_curve(y, pred, pos_label=2)
>>> metrics.auc(fpr, tpr)
0.75
See also
--------
roc_auc_score : Compute the area under the ROC curve
average_precision_score : Compute average precision from prediction scores
precision_recall_curve :
Compute precision-recall pairs for different probability thresholds
"""
check_consistent_length(x, y)
x = column_or_1d(x)
y = column_or_1d(y)
if x.shape[0] < 2:
raise ValueError('At least 2 points are needed to compute'
' area under curve, but x.shape = %s' % x.shape)
direction = 1
if reorder:
# reorder the data points according to the x axis and using y to
# break ties
order = np.lexsort((y, x))
x, y = x[order], y[order]
else:
dx = np.diff(x)
if np.any(dx < 0):
if np.all(dx <= 0):
direction = -1
else:
raise ValueError("Reordering is not turned on, and "
"the x array is not increasing: %s" % x)
area = direction * np.trapz(y, x)
if isinstance(area, np.memmap):
# Reductions such as .sum used internally in np.trapz do not return a
# scalar by default for numpy.memmap instances contrary to
# regular numpy.ndarray instances.
area = area.dtype.type(area)
return area
def average_precision_score(y_true, y_score, average="macro",
sample_weight=None):
"""Compute average precision (AP) from prediction scores
AP summarizes a precision-recall curve as the weighted mean of precisions
achieved at each threshold, with the increase in recall from the previous
threshold used as the weight:
.. math::
\\text{AP} = \\sum_n (R_n - R_{n-1}) P_n
where :math:`P_n` and :math:`R_n` are the precision and recall at the nth
threshold [1]_. This implementation is not interpolated and is different
from computing the area under the precision-recall curve with the
trapezoidal rule, which uses linear interpolation and can be too
optimistic.
Note: this implementation is restricted to the binary classification task
or multilabel classification task.
Read more in the :ref:`User Guide <precision_recall_f_measure_metrics>`.
Parameters
----------
y_true : array, shape = [n_samples] or [n_samples, n_classes]
True binary labels in binary label indicators.
y_score : array, shape = [n_samples] or [n_samples, n_classes]
Target scores, can either be probability estimates of the positive
class, confidence values, or non-thresholded measure of decisions
(as returned by "decision_function" on some classifiers).
average : string, [None, 'micro', 'macro' (default), 'samples', 'weighted']
If ``None``, the scores for each class are returned. Otherwise,
this determines the type of averaging performed on the data:
``'micro'``:
Calculate metrics globally by considering each element of the label
indicator matrix as a label.
``'macro'``:
Calculate metrics for each label, and find their unweighted
mean. This does not take label imbalance into account.
``'weighted'``:
Calculate metrics for each label, and find their average, weighted
by support (the number of true instances for each label).
``'samples'``:
Calculate metrics for each instance, and find their average.
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
average_precision : float
References
----------
.. [1] `Wikipedia entry for the Average precision
<http://en.wikipedia.org/w/index.php?title=Information_retrieval&
oldid=793358396#Average_precision>`_
See also
--------
roc_auc_score : Compute the area under the ROC curve
precision_recall_curve :
Compute precision-recall pairs for different probability thresholds
Examples
--------
>>> import numpy as np
>>> from sklearn.metrics import average_precision_score
>>> y_true = np.array([0, 0, 1, 1])
>>> y_scores = np.array([0.1, 0.4, 0.35, 0.8])
>>> average_precision_score(y_true, y_scores) # doctest: +ELLIPSIS
0.83...
"""
def _binary_uninterpolated_average_precision(
y_true, y_score, sample_weight=None):
precision, recall, thresholds = precision_recall_curve(
y_true, y_score, sample_weight=sample_weight)
# Return the step function integral
# The following works because the last entry of precision is
# guaranteed to be 1, as returned by precision_recall_curve
return -np.sum(np.diff(recall) * np.array(precision)[:-1])
return _average_binary_score(_binary_uninterpolated_average_precision,
y_true, y_score, average,
sample_weight=sample_weight)
def roc_auc_score(y_true, y_score, average="macro", sample_weight=None):
"""Compute Area Under the Receiver Operating Characteristic Curve (ROC AUC)
from prediction scores.
Note: this implementation is restricted to the binary classification task
or multilabel classification task in label indicator format.
Read more in the :ref:`User Guide <roc_metrics>`.
Parameters
----------
y_true : array, shape = [n_samples] or [n_samples, n_classes]
True binary labels in binary label indicators.
y_score : array, shape = [n_samples] or [n_samples, n_classes]
Target scores, can either be probability estimates of the positive
class, confidence values, or non-thresholded measure of decisions
(as returned by "decision_function" on some classifiers).
average : string, [None, 'micro', 'macro' (default), 'samples', 'weighted']
If ``None``, the scores for each class are returned. Otherwise,
this determines the type of averaging performed on the data:
``'micro'``:
Calculate metrics globally by considering each element of the label
indicator matrix as a label.
``'macro'``:
Calculate metrics for each label, and find their unweighted
mean. This does not take label imbalance into account.
``'weighted'``:
Calculate metrics for each label, and find their average, weighted
by support (the number of true instances for each label).
``'samples'``:
Calculate metrics for each instance, and find their average.
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
auc : float
References
----------
.. [1] `Wikipedia entry for the Receiver operating characteristic
<https://en.wikipedia.org/wiki/Receiver_operating_characteristic>`_
See also
--------
average_precision_score : Area under the precision-recall curve
roc_curve : Compute Receiver operating characteristic (ROC) curve
Examples
--------
>>> import numpy as np
>>> from sklearn.metrics import roc_auc_score
>>> y_true = np.array([0, 0, 1, 1])
>>> y_scores = np.array([0.1, 0.4, 0.35, 0.8])
>>> roc_auc_score(y_true, y_scores)
0.75
"""
def _binary_roc_auc_score(y_true, y_score, sample_weight=None):
if len(np.unique(y_true)) != 2:
raise ValueError("Only one class present in y_true. ROC AUC score "
"is not defined in that case.")
fpr, tpr, tresholds = roc_curve(y_true, y_score,
sample_weight=sample_weight)
return auc(fpr, tpr, reorder=True)
return _average_binary_score(
_binary_roc_auc_score, y_true, y_score, average,
sample_weight=sample_weight)
def _binary_clf_curve(y_true, y_score, pos_label=None, sample_weight=None):
"""Calculate true and false positives per binary classification threshold.
Parameters
----------
y_true : array, shape = [n_samples]
True targets of binary classification
y_score : array, shape = [n_samples]
Estimated probabilities or decision function
pos_label : int or str, default=None
The label of the positive class
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
fps : array, shape = [n_thresholds]
A count of false positives, at index i being the number of negative
samples assigned a score >= thresholds[i]. The total number of
negative samples is equal to fps[-1] (thus true negatives are given by
fps[-1] - fps).
tps : array, shape = [n_thresholds <= len(np.unique(y_score))]
An increasing count of true positives, at index i being the number
of positive samples assigned a score >= thresholds[i]. The total
number of positive samples is equal to tps[-1] (thus false negatives
are given by tps[-1] - tps).
thresholds : array, shape = [n_thresholds]
Decreasing score values.
"""
# Check to make sure y_true is valid
y_type = type_of_target(y_true)
if not (y_type == "binary" or
(y_type == "multiclass" and pos_label is not None)):
raise ValueError("{0} format is not supported".format(y_type))
check_consistent_length(y_true, y_score, sample_weight)
y_true = column_or_1d(y_true)
y_score = column_or_1d(y_score)
assert_all_finite(y_true)
assert_all_finite(y_score)
if sample_weight is not None:
sample_weight = column_or_1d(sample_weight)
# ensure binary classification if pos_label is not specified
classes = np.unique(y_true)
if (pos_label is None and
not (np.array_equal(classes, [0, 1]) or
np.array_equal(classes, [-1, 1]) or
np.array_equal(classes, [0]) or
np.array_equal(classes, [-1]) or
np.array_equal(classes, [1]))):
raise ValueError("Data is not binary and pos_label is not specified")
elif pos_label is None:
pos_label = 1.
# make y_true a boolean vector
y_true = (y_true == pos_label)
# sort scores and corresponding truth values
desc_score_indices = np.argsort(y_score, kind="mergesort")[::-1]
y_score = y_score[desc_score_indices]
y_true = y_true[desc_score_indices]
if sample_weight is not None:
weight = sample_weight[desc_score_indices]
else:
weight = 1.
# y_score typically has many tied values. Here we extract
# the indices associated with the distinct values. We also
# concatenate a value for the end of the curve.
distinct_value_indices = np.where(np.diff(y_score))[0]
threshold_idxs = np.r_[distinct_value_indices, y_true.size - 1]
# accumulate the true positives with decreasing threshold
tps = stable_cumsum(y_true * weight)[threshold_idxs]
if sample_weight is not None:
fps = stable_cumsum(weight)[threshold_idxs] - tps
else:
fps = 1 + threshold_idxs - tps
return fps, tps, y_score[threshold_idxs]
def precision_recall_curve(y_true, probas_pred, pos_label=None,
sample_weight=None):
"""Compute precision-recall pairs for different probability thresholds
Note: this implementation is restricted to the binary classification task.
The precision is the ratio ``tp / (tp + fp)`` where ``tp`` is the number of
true positives and ``fp`` the number of false positives. The precision is
intuitively the ability of the classifier not to label as positive a sample
that is negative.
The recall is the ratio ``tp / (tp + fn)`` where ``tp`` is the number of
true positives and ``fn`` the number of false negatives. The recall is
intuitively the ability of the classifier to find all the positive samples.
The last precision and recall values are 1. and 0. respectively and do not
have a corresponding threshold. This ensures that the graph starts on the
x axis.
Read more in the :ref:`User Guide <precision_recall_f_measure_metrics>`.
Parameters
----------
y_true : array, shape = [n_samples]
True targets of binary classification in range {-1, 1} or {0, 1}.
probas_pred : array, shape = [n_samples]
Estimated probabilities or decision function.
pos_label : int or str, default=None
The label of the positive class
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
precision : array, shape = [n_thresholds + 1]
Precision values such that element i is the precision of
predictions with score >= thresholds[i] and the last element is 1.
recall : array, shape = [n_thresholds + 1]
Decreasing recall values such that element i is the recall of
predictions with score >= thresholds[i] and the last element is 0.
thresholds : array, shape = [n_thresholds <= len(np.unique(probas_pred))]
Increasing thresholds on the decision function used to compute
precision and recall.
See also
--------
average_precision_score : Compute average precision from prediction scores
roc_curve : Compute Receiver operating characteristic (ROC) curve
Examples
--------
>>> import numpy as np
>>> from sklearn.metrics import precision_recall_curve
>>> y_true = np.array([0, 0, 1, 1])
>>> y_scores = np.array([0.1, 0.4, 0.35, 0.8])
>>> precision, recall, thresholds = precision_recall_curve(
... y_true, y_scores)
>>> precision # doctest: +ELLIPSIS
array([ 0.66..., 0.5 , 1. , 1. ])
>>> recall
array([ 1. , 0.5, 0.5, 0. ])
>>> thresholds
array([ 0.35, 0.4 , 0.8 ])
"""
fps, tps, thresholds = _binary_clf_curve(y_true, probas_pred,
pos_label=pos_label,
sample_weight=sample_weight)
precision = tps / (tps + fps)
recall = tps / tps[-1]
# stop when full recall attained
# and reverse the outputs so recall is decreasing
last_ind = tps.searchsorted(tps[-1])
sl = slice(last_ind, None, -1)
return np.r_[precision[sl], 1], np.r_[recall[sl], 0], thresholds[sl]
def roc_curve(y_true, y_score, pos_label=None, sample_weight=None,
drop_intermediate=True):
"""Compute Receiver operating characteristic (ROC)
Note: this implementation is restricted to the binary classification task.
Read more in the :ref:`User Guide <roc_metrics>`.
Parameters
----------
y_true : array, shape = [n_samples]
True binary labels in range {0, 1} or {-1, 1}. If labels are not
binary, pos_label should be explicitly given.
y_score : array, shape = [n_samples]
Target scores, can either be probability estimates of the positive
class, confidence values, or non-thresholded measure of decisions
(as returned by "decision_function" on some classifiers).
pos_label : int or str, default=None
Label considered as positive and others are considered negative.
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
drop_intermediate : boolean, optional (default=True)
Whether to drop some suboptimal thresholds which would not appear
on a plotted ROC curve. This is useful in order to create lighter
ROC curves.
.. versionadded:: 0.17
parameter *drop_intermediate*.
Returns
-------
fpr : array, shape = [>2]
Increasing false positive rates such that element i is the false
positive rate of predictions with score >= thresholds[i].
tpr : array, shape = [>2]
Increasing true positive rates such that element i is the true
positive rate of predictions with score >= thresholds[i].
thresholds : array, shape = [n_thresholds]
Decreasing thresholds on the decision function used to compute
fpr and tpr. `thresholds[0]` represents no instances being predicted
and is arbitrarily set to `max(y_score) + 1`.
See also
--------
roc_auc_score : Compute the area under the ROC curve
Notes
-----
Since the thresholds are sorted from low to high values, they
are reversed upon returning them to ensure they correspond to both ``fpr``
and ``tpr``, which are sorted in reversed order during their calculation.
References
----------
.. [1] `Wikipedia entry for the Receiver operating characteristic
<https://en.wikipedia.org/wiki/Receiver_operating_characteristic>`_
Examples
--------
>>> import numpy as np
>>> from sklearn import metrics
>>> y = np.array([1, 1, 2, 2])
>>> scores = np.array([0.1, 0.4, 0.35, 0.8])
>>> fpr, tpr, thresholds = metrics.roc_curve(y, scores, pos_label=2)
>>> fpr
array([ 0. , 0.5, 0.5, 1. ])
>>> tpr
array([ 0.5, 0.5, 1. , 1. ])
>>> thresholds
array([ 0.8 , 0.4 , 0.35, 0.1 ])
"""
fps, tps, thresholds = _binary_clf_curve(
y_true, y_score, pos_label=pos_label, sample_weight=sample_weight)
# Attempt to drop thresholds corresponding to points in between and
# collinear with other points. These are always suboptimal and do not
# appear on a plotted ROC curve (and thus do not affect the AUC).
# Here np.diff(_, 2) is used as a "second derivative" to tell if there
# is a corner at the point. Both fps and tps must be tested to handle
# thresholds with multiple data points (which are combined in
# _binary_clf_curve). This keeps all cases where the point should be kept,
# but does not drop more complicated cases like fps = [1, 3, 7],
# tps = [1, 2, 4]; there is no harm in keeping too many thresholds.
if drop_intermediate and len(fps) > 2:
optimal_idxs = np.where(np.r_[True,
np.logical_or(np.diff(fps, 2),
np.diff(tps, 2)),
True])[0]
fps = fps[optimal_idxs]
tps = tps[optimal_idxs]
thresholds = thresholds[optimal_idxs]
if tps.size == 0 or fps[0] != 0:
# Add an extra threshold position if necessary
tps = np.r_[0, tps]
fps = np.r_[0, fps]
thresholds = np.r_[thresholds[0] + 1, thresholds]
if fps[-1] <= 0:
warnings.warn("No negative samples in y_true, "
"false positive value should be meaningless",
UndefinedMetricWarning)
fpr = np.repeat(np.nan, fps.shape)
else:
fpr = fps / fps[-1]
if tps[-1] <= 0:
warnings.warn("No positive samples in y_true, "
"true positive value should be meaningless",
UndefinedMetricWarning)
tpr = np.repeat(np.nan, tps.shape)
else:
tpr = tps / tps[-1]
return fpr, tpr, thresholds
def label_ranking_average_precision_score(y_true, y_score):
"""Compute ranking-based average precision
Label ranking average precision (LRAP) is the average over each ground
truth label assigned to each sample, of the ratio of true vs. total
labels with lower score.
This metric is used in multilabel ranking problem, where the goal
is to give better rank to the labels associated to each sample.
The obtained score is always strictly greater than 0 and
the best value is 1.
Read more in the :ref:`User Guide <label_ranking_average_precision>`.
Parameters
----------
y_true : array or sparse matrix, shape = [n_samples, n_labels]
True binary labels in binary indicator format.
y_score : array, shape = [n_samples, n_labels]
Target scores, can either be probability estimates of the positive
class, confidence values, or non-thresholded measure of decisions
(as returned by "decision_function" on some classifiers).
Returns
-------
score : float
Examples
--------
>>> import numpy as np
>>> from sklearn.metrics import label_ranking_average_precision_score
>>> y_true = np.array([[1, 0, 0], [0, 0, 1]])
>>> y_score = np.array([[0.75, 0.5, 1], [1, 0.2, 0.1]])
>>> label_ranking_average_precision_score(y_true, y_score) \
# doctest: +ELLIPSIS
0.416...
"""
check_consistent_length(y_true, y_score)
y_true = check_array(y_true, ensure_2d=False)
y_score = check_array(y_score, ensure_2d=False)
if y_true.shape != y_score.shape:
raise ValueError("y_true and y_score have different shape")
# Handle badly formatted array and the degenerate case with one label
y_type = type_of_target(y_true)
if (y_type != "multilabel-indicator" and
not (y_type == "binary" and y_true.ndim == 2)):
raise ValueError("{0} format is not supported".format(y_type))
y_true = csr_matrix(y_true)
y_score = -y_score
n_samples, n_labels = y_true.shape
out = 0.
for i, (start, stop) in enumerate(zip(y_true.indptr, y_true.indptr[1:])):
relevant = y_true.indices[start:stop]
if (relevant.size == 0 or relevant.size == n_labels):
# If all labels are relevant or unrelevant, the score is also
# equal to 1. The label ranking has no meaning.
out += 1.
continue
scores_i = y_score[i]
rank = rankdata(scores_i, 'max')[relevant]
L = rankdata(scores_i[relevant], 'max')
out += (L / rank).mean()
return out / n_samples
def coverage_error(y_true, y_score, sample_weight=None):
"""Coverage error measure
Compute how far we need to go through the ranked scores to cover all
true labels. The best value is equal to the average number
of labels in ``y_true`` per sample.
Ties in ``y_scores`` are broken by giving maximal rank that would have
been assigned to all tied values.
Note: Our implementation's score is 1 greater than the one given in
Tsoumakas et al., 2010. This extends it to handle the degenerate case
in which an instance has 0 true labels.
Read more in the :ref:`User Guide <coverage_error>`.
Parameters
----------
y_true : array, shape = [n_samples, n_labels]
True binary labels in binary indicator format.
y_score : array, shape = [n_samples, n_labels]
Target scores, can either be probability estimates of the positive
class, confidence values, or non-thresholded measure of decisions
(as returned by "decision_function" on some classifiers).
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
coverage_error : float
References
----------
.. [1] Tsoumakas, G., Katakis, I., & Vlahavas, I. (2010).
Mining multi-label data. In Data mining and knowledge discovery
handbook (pp. 667-685). Springer US.
"""
y_true = check_array(y_true, ensure_2d=False)
y_score = check_array(y_score, ensure_2d=False)
check_consistent_length(y_true, y_score, sample_weight)
y_type = type_of_target(y_true)
if y_type != "multilabel-indicator":
raise ValueError("{0} format is not supported".format(y_type))
if y_true.shape != y_score.shape:
raise ValueError("y_true and y_score have different shape")
y_score_mask = np.ma.masked_array(y_score, mask=np.logical_not(y_true))
y_min_relevant = y_score_mask.min(axis=1).reshape((-1, 1))
coverage = (y_score >= y_min_relevant).sum(axis=1)
coverage = coverage.filled(0)
return np.average(coverage, weights=sample_weight)
def label_ranking_loss(y_true, y_score, sample_weight=None):
"""Compute Ranking loss measure
Compute the average number of label pairs that are incorrectly ordered
given y_score weighted by the size of the label set and the number of
labels not in the label set.
This is similar to the error set size, but weighted by the number of
relevant and irrelevant labels. The best performance is achieved with
a ranking loss of zero.
Read more in the :ref:`User Guide <label_ranking_loss>`.
.. versionadded:: 0.17
A function *label_ranking_loss*
Parameters
----------
y_true : array or sparse matrix, shape = [n_samples, n_labels]
True binary labels in binary indicator format.
y_score : array, shape = [n_samples, n_labels]
Target scores, can either be probability estimates of the positive
class, confidence values, or non-thresholded measure of decisions
(as returned by "decision_function" on some classifiers).
sample_weight : array-like of shape = [n_samples], optional
Sample weights.
Returns
-------
loss : float
References
----------
.. [1] Tsoumakas, G., Katakis, I., & Vlahavas, I. (2010).
Mining multi-label data. In Data mining and knowledge discovery
handbook (pp. 667-685). Springer US.
"""
y_true = check_array(y_true, ensure_2d=False, accept_sparse='csr')
y_score = check_array(y_score, ensure_2d=False)
check_consistent_length(y_true, y_score, sample_weight)
y_type = type_of_target(y_true)
if y_type not in ("multilabel-indicator",):
raise ValueError("{0} format is not supported".format(y_type))
if y_true.shape != y_score.shape:
raise ValueError("y_true and y_score have different shape")
n_samples, n_labels = y_true.shape
y_true = csr_matrix(y_true)
loss = np.zeros(n_samples)
for i, (start, stop) in enumerate(zip(y_true.indptr, y_true.indptr[1:])):
# Sort and bin the label scores
unique_scores, unique_inverse = np.unique(y_score[i],
return_inverse=True)
true_at_reversed_rank = np.bincount(
unique_inverse[y_true.indices[start:stop]],
minlength=len(unique_scores))
all_at_reversed_rank = np.bincount(unique_inverse,
minlength=len(unique_scores))
false_at_reversed_rank = all_at_reversed_rank - true_at_reversed_rank
# if the scores are ordered, it's possible to count the number of
# incorrectly ordered paires in linear time by cumulatively counting
# how many false labels of a given score have a score higher than the
# accumulated true labels with lower score.
loss[i] = np.dot(true_at_reversed_rank.cumsum(),
false_at_reversed_rank)
n_positives = count_nonzero(y_true, axis=1)
with np.errstate(divide="ignore", invalid="ignore"):
loss /= ((n_labels - n_positives) * n_positives)
# When there is no positive or no negative labels, those values should
# be consider as correct, i.e. the ranking doesn't matter.
loss[np.logical_or(n_positives == 0, n_positives == n_labels)] = 0.
return np.average(loss, weights=sample_weight)
| 29,356 | 35.834379 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/tests/test_regression.py | from __future__ import division, print_function
import numpy as np
from itertools import product
from sklearn.utils.testing import assert_raises, assert_raises_regex
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.metrics import explained_variance_score
from sklearn.metrics import mean_absolute_error
from sklearn.metrics import mean_squared_error
from sklearn.metrics import mean_squared_log_error
from sklearn.metrics import median_absolute_error
from sklearn.metrics import r2_score
from sklearn.metrics.regression import _check_reg_targets
def test_regression_metrics(n_samples=50):
y_true = np.arange(n_samples)
y_pred = y_true + 1
assert_almost_equal(mean_squared_error(y_true, y_pred), 1.)
assert_almost_equal(mean_squared_log_error(y_true, y_pred),
mean_squared_error(np.log(1 + y_true),
np.log(1 + y_pred)))
assert_almost_equal(mean_absolute_error(y_true, y_pred), 1.)
assert_almost_equal(median_absolute_error(y_true, y_pred), 1.)
assert_almost_equal(r2_score(y_true, y_pred), 0.995, 2)
assert_almost_equal(explained_variance_score(y_true, y_pred), 1.)
def test_multioutput_regression():
y_true = np.array([[1, 0, 0, 1], [0, 1, 1, 1], [1, 1, 0, 1]])
y_pred = np.array([[0, 0, 0, 1], [1, 0, 1, 1], [0, 0, 0, 1]])
error = mean_squared_error(y_true, y_pred)
assert_almost_equal(error, (1. / 3 + 2. / 3 + 2. / 3) / 4.)
error = mean_squared_log_error(y_true, y_pred)
assert_almost_equal(error, 0.200, decimal=2)
# mean_absolute_error and mean_squared_error are equal because
# it is a binary problem.
error = mean_absolute_error(y_true, y_pred)
assert_almost_equal(error, (1. / 3 + 2. / 3 + 2. / 3) / 4.)
error = r2_score(y_true, y_pred, multioutput='variance_weighted')
assert_almost_equal(error, 1. - 5. / 2)
error = r2_score(y_true, y_pred, multioutput='uniform_average')
assert_almost_equal(error, -.875)
def test_regression_metrics_at_limits():
assert_almost_equal(mean_squared_error([0.], [0.]), 0.00, 2)
assert_almost_equal(mean_squared_log_error([0.], [0.]), 0.00, 2)
assert_almost_equal(mean_absolute_error([0.], [0.]), 0.00, 2)
assert_almost_equal(median_absolute_error([0.], [0.]), 0.00, 2)
assert_almost_equal(explained_variance_score([0.], [0.]), 1.00, 2)
assert_almost_equal(r2_score([0., 1], [0., 1]), 1.00, 2)
assert_raises_regex(ValueError, "Mean Squared Logarithmic Error cannot be "
"used when targets contain negative values.",
mean_squared_log_error, [-1.], [-1.])
def test__check_reg_targets():
# All of length 3
EXAMPLES = [
("continuous", [1, 2, 3], 1),
("continuous", [[1], [2], [3]], 1),
("continuous-multioutput", [[1, 1], [2, 2], [3, 1]], 2),
("continuous-multioutput", [[5, 1], [4, 2], [3, 1]], 2),
("continuous-multioutput", [[1, 3, 4], [2, 2, 2], [3, 1, 1]], 3),
]
for (type1, y1, n_out1), (type2, y2, n_out2) in product(EXAMPLES,
repeat=2):
if type1 == type2 and n_out1 == n_out2:
y_type, y_check1, y_check2, multioutput = _check_reg_targets(
y1, y2, None)
assert_equal(type1, y_type)
if type1 == 'continuous':
assert_array_equal(y_check1, np.reshape(y1, (-1, 1)))
assert_array_equal(y_check2, np.reshape(y2, (-1, 1)))
else:
assert_array_equal(y_check1, y1)
assert_array_equal(y_check2, y2)
else:
assert_raises(ValueError, _check_reg_targets, y1, y2, None)
def test__check_reg_targets_exception():
invalid_multioutput = 'this_value_is_not_valid'
expected_message = ("Allowed 'multioutput' string values are.+"
"You provided multioutput={!r}".format(
invalid_multioutput))
assert_raises_regex(ValueError, expected_message,
_check_reg_targets,
[1, 2, 3],
[[1], [2], [3]],
invalid_multioutput)
def test_regression_multioutput_array():
y_true = [[1, 2], [2.5, -1], [4.5, 3], [5, 7]]
y_pred = [[1, 1], [2, -1], [5, 4], [5, 6.5]]
mse = mean_squared_error(y_true, y_pred, multioutput='raw_values')
mae = mean_absolute_error(y_true, y_pred, multioutput='raw_values')
r = r2_score(y_true, y_pred, multioutput='raw_values')
evs = explained_variance_score(y_true, y_pred, multioutput='raw_values')
assert_array_almost_equal(mse, [0.125, 0.5625], decimal=2)
assert_array_almost_equal(mae, [0.25, 0.625], decimal=2)
assert_array_almost_equal(r, [0.95, 0.93], decimal=2)
assert_array_almost_equal(evs, [0.95, 0.93], decimal=2)
# mean_absolute_error and mean_squared_error are equal because
# it is a binary problem.
y_true = [[0, 0]]*4
y_pred = [[1, 1]]*4
mse = mean_squared_error(y_true, y_pred, multioutput='raw_values')
mae = mean_absolute_error(y_true, y_pred, multioutput='raw_values')
r = r2_score(y_true, y_pred, multioutput='raw_values')
assert_array_almost_equal(mse, [1., 1.], decimal=2)
assert_array_almost_equal(mae, [1., 1.], decimal=2)
assert_array_almost_equal(r, [0., 0.], decimal=2)
r = r2_score([[0, -1], [0, 1]], [[2, 2], [1, 1]], multioutput='raw_values')
assert_array_almost_equal(r, [0, -3.5], decimal=2)
assert_equal(np.mean(r), r2_score([[0, -1], [0, 1]], [[2, 2], [1, 1]],
multioutput='uniform_average'))
evs = explained_variance_score([[0, -1], [0, 1]], [[2, 2], [1, 1]],
multioutput='raw_values')
assert_array_almost_equal(evs, [0, -1.25], decimal=2)
# Checking for the condition in which both numerator and denominator is
# zero.
y_true = [[1, 3], [-1, 2]]
y_pred = [[1, 4], [-1, 1]]
r2 = r2_score(y_true, y_pred, multioutput='raw_values')
assert_array_almost_equal(r2, [1., -3.], decimal=2)
assert_equal(np.mean(r2), r2_score(y_true, y_pred,
multioutput='uniform_average'))
evs = explained_variance_score(y_true, y_pred, multioutput='raw_values')
assert_array_almost_equal(evs, [1., -3.], decimal=2)
assert_equal(np.mean(evs), explained_variance_score(y_true, y_pred))
# Handling msle separately as it does not accept negative inputs.
y_true = np.array([[0.5, 1], [1, 2], [7, 6]])
y_pred = np.array([[0.5, 2], [1, 2.5], [8, 8]])
msle = mean_squared_log_error(y_true, y_pred, multioutput='raw_values')
msle2 = mean_squared_error(np.log(1 + y_true), np.log(1 + y_pred),
multioutput='raw_values')
assert_array_almost_equal(msle, msle2, decimal=2)
def test_regression_custom_weights():
y_true = [[1, 2], [2.5, -1], [4.5, 3], [5, 7]]
y_pred = [[1, 1], [2, -1], [5, 4], [5, 6.5]]
msew = mean_squared_error(y_true, y_pred, multioutput=[0.4, 0.6])
maew = mean_absolute_error(y_true, y_pred, multioutput=[0.4, 0.6])
rw = r2_score(y_true, y_pred, multioutput=[0.4, 0.6])
evsw = explained_variance_score(y_true, y_pred, multioutput=[0.4, 0.6])
assert_almost_equal(msew, 0.39, decimal=2)
assert_almost_equal(maew, 0.475, decimal=3)
assert_almost_equal(rw, 0.94, decimal=2)
assert_almost_equal(evsw, 0.94, decimal=2)
# Handling msle separately as it does not accept negative inputs.
y_true = np.array([[0.5, 1], [1, 2], [7, 6]])
y_pred = np.array([[0.5, 2], [1, 2.5], [8, 8]])
msle = mean_squared_log_error(y_true, y_pred, multioutput=[0.3, 0.7])
msle2 = mean_squared_error(np.log(1 + y_true), np.log(1 + y_pred),
multioutput=[0.3, 0.7])
assert_almost_equal(msle, msle2, decimal=2)
| 8,058 | 43.038251 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/tests/test_common.py | from __future__ import division, print_function
from functools import partial
from itertools import product
import numpy as np
import scipy.sparse as sp
from sklearn.datasets import make_multilabel_classification
from sklearn.preprocessing import LabelBinarizer
from sklearn.utils.multiclass import type_of_target
from sklearn.utils.validation import check_random_state
from sklearn.utils import shuffle
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_not_equal
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_raise_message
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.testing import _named_check
from sklearn.metrics import accuracy_score
from sklearn.metrics import average_precision_score
from sklearn.metrics import brier_score_loss
from sklearn.metrics import cohen_kappa_score
from sklearn.metrics import confusion_matrix
from sklearn.metrics import coverage_error
from sklearn.metrics import explained_variance_score
from sklearn.metrics import f1_score
from sklearn.metrics import fbeta_score
from sklearn.metrics import hamming_loss
from sklearn.metrics import hinge_loss
from sklearn.metrics import jaccard_similarity_score
from sklearn.metrics import label_ranking_average_precision_score
from sklearn.metrics import label_ranking_loss
from sklearn.metrics import log_loss
from sklearn.metrics import matthews_corrcoef
from sklearn.metrics import mean_absolute_error
from sklearn.metrics import mean_squared_error
from sklearn.metrics import median_absolute_error
from sklearn.metrics import precision_score
from sklearn.metrics import r2_score
from sklearn.metrics import recall_score
from sklearn.metrics import roc_auc_score
from sklearn.metrics import zero_one_loss
# TODO Curve are currently not covered by invariance test
# from sklearn.metrics import precision_recall_curve
# from sklearn.metrics import roc_curve
from sklearn.metrics.base import _average_binary_score
# Note toward developers about metric testing
# -------------------------------------------
# It is often possible to write one general test for several metrics:
#
# - invariance properties, e.g. invariance to sample order
# - common behavior for an argument, e.g. the "normalize" with value True
# will return the mean of the metrics and with value False will return
# the sum of the metrics.
#
# In order to improve the overall metric testing, it is a good idea to write
# first a specific test for the given metric and then add a general test for
# all metrics that have the same behavior.
#
# Two types of datastructures are used in order to implement this system:
# dictionaries of metrics and lists of metrics wit common properties.
#
# Dictionaries of metrics
# ------------------------
# The goal of having those dictionaries is to have an easy way to call a
# particular metric and associate a name to each function:
#
# - REGRESSION_METRICS: all regression metrics.
# - CLASSIFICATION_METRICS: all classification metrics
# which compare a ground truth and the estimated targets as returned by a
# classifier.
# - THRESHOLDED_METRICS: all classification metrics which
# compare a ground truth and a score, e.g. estimated probabilities or
# decision function (format might vary)
#
# Those dictionaries will be used to test systematically some invariance
# properties, e.g. invariance toward several input layout.
#
REGRESSION_METRICS = {
"mean_absolute_error": mean_absolute_error,
"mean_squared_error": mean_squared_error,
"median_absolute_error": median_absolute_error,
"explained_variance_score": explained_variance_score,
"r2_score": partial(r2_score, multioutput='variance_weighted'),
}
CLASSIFICATION_METRICS = {
"accuracy_score": accuracy_score,
"unnormalized_accuracy_score": partial(accuracy_score, normalize=False),
"confusion_matrix": confusion_matrix,
"hamming_loss": hamming_loss,
"jaccard_similarity_score": jaccard_similarity_score,
"unnormalized_jaccard_similarity_score":
partial(jaccard_similarity_score, normalize=False),
"zero_one_loss": zero_one_loss,
"unnormalized_zero_one_loss": partial(zero_one_loss, normalize=False),
# These are needed to test averaging
"precision_score": precision_score,
"recall_score": recall_score,
"f1_score": f1_score,
"f2_score": partial(fbeta_score, beta=2),
"f0.5_score": partial(fbeta_score, beta=0.5),
"matthews_corrcoef_score": matthews_corrcoef,
"weighted_f0.5_score": partial(fbeta_score, average="weighted", beta=0.5),
"weighted_f1_score": partial(f1_score, average="weighted"),
"weighted_f2_score": partial(fbeta_score, average="weighted", beta=2),
"weighted_precision_score": partial(precision_score, average="weighted"),
"weighted_recall_score": partial(recall_score, average="weighted"),
"micro_f0.5_score": partial(fbeta_score, average="micro", beta=0.5),
"micro_f1_score": partial(f1_score, average="micro"),
"micro_f2_score": partial(fbeta_score, average="micro", beta=2),
"micro_precision_score": partial(precision_score, average="micro"),
"micro_recall_score": partial(recall_score, average="micro"),
"macro_f0.5_score": partial(fbeta_score, average="macro", beta=0.5),
"macro_f1_score": partial(f1_score, average="macro"),
"macro_f2_score": partial(fbeta_score, average="macro", beta=2),
"macro_precision_score": partial(precision_score, average="macro"),
"macro_recall_score": partial(recall_score, average="macro"),
"samples_f0.5_score": partial(fbeta_score, average="samples", beta=0.5),
"samples_f1_score": partial(f1_score, average="samples"),
"samples_f2_score": partial(fbeta_score, average="samples", beta=2),
"samples_precision_score": partial(precision_score, average="samples"),
"samples_recall_score": partial(recall_score, average="samples"),
"cohen_kappa_score": cohen_kappa_score,
}
THRESHOLDED_METRICS = {
"coverage_error": coverage_error,
"label_ranking_loss": label_ranking_loss,
"log_loss": log_loss,
"unnormalized_log_loss": partial(log_loss, normalize=False),
"hinge_loss": hinge_loss,
"brier_score_loss": brier_score_loss,
"roc_auc_score": roc_auc_score,
"weighted_roc_auc": partial(roc_auc_score, average="weighted"),
"samples_roc_auc": partial(roc_auc_score, average="samples"),
"micro_roc_auc": partial(roc_auc_score, average="micro"),
"macro_roc_auc": partial(roc_auc_score, average="macro"),
"average_precision_score": average_precision_score,
"weighted_average_precision_score":
partial(average_precision_score, average="weighted"),
"samples_average_precision_score":
partial(average_precision_score, average="samples"),
"micro_average_precision_score":
partial(average_precision_score, average="micro"),
"macro_average_precision_score":
partial(average_precision_score, average="macro"),
"label_ranking_average_precision_score":
label_ranking_average_precision_score,
}
ALL_METRICS = dict()
ALL_METRICS.update(THRESHOLDED_METRICS)
ALL_METRICS.update(CLASSIFICATION_METRICS)
ALL_METRICS.update(REGRESSION_METRICS)
# Lists of metrics with common properties
# ---------------------------------------
# Lists of metrics with common properties are used to test systematically some
# functionalities and invariance, e.g. SYMMETRIC_METRICS lists all metrics that
# are symmetric with respect to their input argument y_true and y_pred.
#
# When you add a new metric or functionality, check if a general test
# is already written.
# Those metrics don't support binary inputs
METRIC_UNDEFINED_BINARY = [
"samples_f0.5_score",
"samples_f1_score",
"samples_f2_score",
"samples_precision_score",
"samples_recall_score",
"coverage_error",
"roc_auc_score",
"micro_roc_auc",
"weighted_roc_auc",
"macro_roc_auc",
"samples_roc_auc",
"average_precision_score",
"weighted_average_precision_score",
"micro_average_precision_score",
"macro_average_precision_score",
"samples_average_precision_score",
"label_ranking_loss",
"label_ranking_average_precision_score",
]
# Those metrics don't support multiclass inputs
METRIC_UNDEFINED_MULTICLASS = [
"brier_score_loss",
# with default average='binary', multiclass is prohibited
"precision_score",
"recall_score",
"f1_score",
"f2_score",
"f0.5_score",
]
# Metric undefined with "binary" or "multiclass" input
METRIC_UNDEFINED_BINARY_MULTICLASS = set(METRIC_UNDEFINED_BINARY).union(
set(METRIC_UNDEFINED_MULTICLASS))
# Metrics with an "average" argument
METRICS_WITH_AVERAGING = [
"precision_score", "recall_score", "f1_score", "f2_score", "f0.5_score"
]
# Threshold-based metrics with an "average" argument
THRESHOLDED_METRICS_WITH_AVERAGING = [
"roc_auc_score", "average_precision_score",
]
# Metrics with a "pos_label" argument
METRICS_WITH_POS_LABEL = [
"roc_curve",
"brier_score_loss",
"precision_score", "recall_score", "f1_score", "f2_score", "f0.5_score",
# pos_label support deprecated; to be removed in 0.18:
"weighted_f0.5_score", "weighted_f1_score", "weighted_f2_score",
"weighted_precision_score", "weighted_recall_score",
"micro_f0.5_score", "micro_f1_score", "micro_f2_score",
"micro_precision_score", "micro_recall_score",
"macro_f0.5_score", "macro_f1_score", "macro_f2_score",
"macro_precision_score", "macro_recall_score",
]
# Metrics with a "labels" argument
# TODO: Handle multi_class metrics that has a labels argument as well as a
# decision function argument. e.g hinge_loss
METRICS_WITH_LABELS = [
"confusion_matrix",
"hamming_loss",
"precision_score", "recall_score", "f1_score", "f2_score", "f0.5_score",
"weighted_f0.5_score", "weighted_f1_score", "weighted_f2_score",
"weighted_precision_score", "weighted_recall_score",
"micro_f0.5_score", "micro_f1_score", "micro_f2_score",
"micro_precision_score", "micro_recall_score",
"macro_f0.5_score", "macro_f1_score", "macro_f2_score",
"macro_precision_score", "macro_recall_score",
"cohen_kappa_score",
]
# Metrics with a "normalize" option
METRICS_WITH_NORMALIZE_OPTION = [
"accuracy_score",
"jaccard_similarity_score",
"zero_one_loss",
]
# Threshold-based metrics with "multilabel-indicator" format support
THRESHOLDED_MULTILABEL_METRICS = [
"log_loss",
"unnormalized_log_loss",
"roc_auc_score", "weighted_roc_auc", "samples_roc_auc",
"micro_roc_auc", "macro_roc_auc",
"average_precision_score", "weighted_average_precision_score",
"samples_average_precision_score", "micro_average_precision_score",
"macro_average_precision_score",
"coverage_error", "label_ranking_loss",
]
# Classification metrics with "multilabel-indicator" format
MULTILABELS_METRICS = [
"accuracy_score", "unnormalized_accuracy_score",
"hamming_loss",
"jaccard_similarity_score", "unnormalized_jaccard_similarity_score",
"zero_one_loss", "unnormalized_zero_one_loss",
"weighted_f0.5_score", "weighted_f1_score", "weighted_f2_score",
"weighted_precision_score", "weighted_recall_score",
"macro_f0.5_score", "macro_f1_score", "macro_f2_score",
"macro_precision_score", "macro_recall_score",
"micro_f0.5_score", "micro_f1_score", "micro_f2_score",
"micro_precision_score", "micro_recall_score",
"samples_f0.5_score", "samples_f1_score", "samples_f2_score",
"samples_precision_score", "samples_recall_score",
]
# Regression metrics with "multioutput-continuous" format support
MULTIOUTPUT_METRICS = [
"mean_absolute_error", "mean_squared_error", "r2_score",
"explained_variance_score"
]
# Symmetric with respect to their input arguments y_true and y_pred
# metric(y_true, y_pred) == metric(y_pred, y_true).
SYMMETRIC_METRICS = [
"accuracy_score", "unnormalized_accuracy_score",
"hamming_loss",
"jaccard_similarity_score", "unnormalized_jaccard_similarity_score",
"zero_one_loss", "unnormalized_zero_one_loss",
"f1_score", "micro_f1_score", "macro_f1_score",
"weighted_recall_score",
# P = R = F = accuracy in multiclass case
"micro_f0.5_score", "micro_f1_score", "micro_f2_score",
"micro_precision_score", "micro_recall_score",
"matthews_corrcoef_score", "mean_absolute_error", "mean_squared_error",
"median_absolute_error",
"cohen_kappa_score",
]
# Asymmetric with respect to their input arguments y_true and y_pred
# metric(y_true, y_pred) != metric(y_pred, y_true).
NOT_SYMMETRIC_METRICS = [
"explained_variance_score",
"r2_score",
"confusion_matrix",
"precision_score", "recall_score", "f2_score", "f0.5_score",
"weighted_f0.5_score", "weighted_f1_score", "weighted_f2_score",
"weighted_precision_score",
"macro_f0.5_score", "macro_f2_score", "macro_precision_score",
"macro_recall_score", "log_loss", "hinge_loss"
]
# No Sample weight support
METRICS_WITHOUT_SAMPLE_WEIGHT = [
"confusion_matrix", # Left this one here because the tests in this file do
# not work for confusion_matrix, as its output is a
# matrix instead of a number. Testing of
# confusion_matrix with sample_weight is in
# test_classification.py
"median_absolute_error",
]
@ignore_warnings
def test_symmetry():
# Test the symmetry of score and loss functions
random_state = check_random_state(0)
y_true = random_state.randint(0, 2, size=(20, ))
y_pred = random_state.randint(0, 2, size=(20, ))
# We shouldn't forget any metrics
assert_equal(set(SYMMETRIC_METRICS).union(
NOT_SYMMETRIC_METRICS, THRESHOLDED_METRICS,
METRIC_UNDEFINED_BINARY_MULTICLASS),
set(ALL_METRICS))
assert_equal(
set(SYMMETRIC_METRICS).intersection(set(NOT_SYMMETRIC_METRICS)),
set([]))
# Symmetric metric
for name in SYMMETRIC_METRICS:
metric = ALL_METRICS[name]
assert_almost_equal(metric(y_true, y_pred),
metric(y_pred, y_true),
err_msg="%s is not symmetric" % name)
# Not symmetric metrics
for name in NOT_SYMMETRIC_METRICS:
metric = ALL_METRICS[name]
assert_true(np.any(metric(y_true, y_pred) != metric(y_pred, y_true)),
msg="%s seems to be symmetric" % name)
@ignore_warnings
def test_sample_order_invariance():
random_state = check_random_state(0)
y_true = random_state.randint(0, 2, size=(20, ))
y_pred = random_state.randint(0, 2, size=(20, ))
y_true_shuffle, y_pred_shuffle = shuffle(y_true, y_pred, random_state=0)
for name, metric in ALL_METRICS.items():
if name in METRIC_UNDEFINED_BINARY_MULTICLASS:
continue
assert_almost_equal(metric(y_true, y_pred),
metric(y_true_shuffle, y_pred_shuffle),
err_msg="%s is not sample order invariant"
% name)
@ignore_warnings
def test_sample_order_invariance_multilabel_and_multioutput():
random_state = check_random_state(0)
# Generate some data
y_true = random_state.randint(0, 2, size=(20, 25))
y_pred = random_state.randint(0, 2, size=(20, 25))
y_score = random_state.normal(size=y_true.shape)
y_true_shuffle, y_pred_shuffle, y_score_shuffle = shuffle(y_true,
y_pred,
y_score,
random_state=0)
for name in MULTILABELS_METRICS:
metric = ALL_METRICS[name]
assert_almost_equal(metric(y_true, y_pred),
metric(y_true_shuffle, y_pred_shuffle),
err_msg="%s is not sample order invariant"
% name)
for name in THRESHOLDED_MULTILABEL_METRICS:
metric = ALL_METRICS[name]
assert_almost_equal(metric(y_true, y_score),
metric(y_true_shuffle, y_score_shuffle),
err_msg="%s is not sample order invariant"
% name)
for name in MULTIOUTPUT_METRICS:
metric = ALL_METRICS[name]
assert_almost_equal(metric(y_true, y_score),
metric(y_true_shuffle, y_score_shuffle),
err_msg="%s is not sample order invariant"
% name)
assert_almost_equal(metric(y_true, y_pred),
metric(y_true_shuffle, y_pred_shuffle),
err_msg="%s is not sample order invariant"
% name)
@ignore_warnings
def test_format_invariance_with_1d_vectors():
random_state = check_random_state(0)
y1 = random_state.randint(0, 2, size=(20, ))
y2 = random_state.randint(0, 2, size=(20, ))
y1_list = list(y1)
y2_list = list(y2)
y1_1d, y2_1d = np.array(y1), np.array(y2)
assert_equal(y1_1d.ndim, 1)
assert_equal(y2_1d.ndim, 1)
y1_column = np.reshape(y1_1d, (-1, 1))
y2_column = np.reshape(y2_1d, (-1, 1))
y1_row = np.reshape(y1_1d, (1, -1))
y2_row = np.reshape(y2_1d, (1, -1))
for name, metric in ALL_METRICS.items():
if name in METRIC_UNDEFINED_BINARY_MULTICLASS:
continue
measure = metric(y1, y2)
assert_almost_equal(metric(y1_list, y2_list), measure,
err_msg="%s is not representation invariant "
"with list" % name)
assert_almost_equal(metric(y1_1d, y2_1d), measure,
err_msg="%s is not representation invariant "
"with np-array-1d" % name)
assert_almost_equal(metric(y1_column, y2_column), measure,
err_msg="%s is not representation invariant "
"with np-array-column" % name)
# Mix format support
assert_almost_equal(metric(y1_1d, y2_list), measure,
err_msg="%s is not representation invariant "
"with mix np-array-1d and list" % name)
assert_almost_equal(metric(y1_list, y2_1d), measure,
err_msg="%s is not representation invariant "
"with mix np-array-1d and list" % name)
assert_almost_equal(metric(y1_1d, y2_column), measure,
err_msg="%s is not representation invariant "
"with mix np-array-1d and np-array-column"
% name)
assert_almost_equal(metric(y1_column, y2_1d), measure,
err_msg="%s is not representation invariant "
"with mix np-array-1d and np-array-column"
% name)
assert_almost_equal(metric(y1_list, y2_column), measure,
err_msg="%s is not representation invariant "
"with mix list and np-array-column"
% name)
assert_almost_equal(metric(y1_column, y2_list), measure,
err_msg="%s is not representation invariant "
"with mix list and np-array-column"
% name)
# These mix representations aren't allowed
assert_raises(ValueError, metric, y1_1d, y2_row)
assert_raises(ValueError, metric, y1_row, y2_1d)
assert_raises(ValueError, metric, y1_list, y2_row)
assert_raises(ValueError, metric, y1_row, y2_list)
assert_raises(ValueError, metric, y1_column, y2_row)
assert_raises(ValueError, metric, y1_row, y2_column)
# NB: We do not test for y1_row, y2_row as these may be
# interpreted as multilabel or multioutput data.
if (name not in (MULTIOUTPUT_METRICS + THRESHOLDED_MULTILABEL_METRICS +
MULTILABELS_METRICS)):
assert_raises(ValueError, metric, y1_row, y2_row)
@ignore_warnings
def test_invariance_string_vs_numbers_labels():
# Ensure that classification metrics with string labels
random_state = check_random_state(0)
y1 = random_state.randint(0, 2, size=(20, ))
y2 = random_state.randint(0, 2, size=(20, ))
y1_str = np.array(["eggs", "spam"])[y1]
y2_str = np.array(["eggs", "spam"])[y2]
pos_label_str = "spam"
labels_str = ["eggs", "spam"]
for name, metric in CLASSIFICATION_METRICS.items():
if name in METRIC_UNDEFINED_BINARY_MULTICLASS:
continue
measure_with_number = metric(y1, y2)
# Ugly, but handle case with a pos_label and label
metric_str = metric
if name in METRICS_WITH_POS_LABEL:
metric_str = partial(metric_str, pos_label=pos_label_str)
measure_with_str = metric_str(y1_str, y2_str)
assert_array_equal(measure_with_number, measure_with_str,
err_msg="{0} failed string vs number invariance "
"test".format(name))
measure_with_strobj = metric_str(y1_str.astype('O'),
y2_str.astype('O'))
assert_array_equal(measure_with_number, measure_with_strobj,
err_msg="{0} failed string object vs number "
"invariance test".format(name))
if name in METRICS_WITH_LABELS:
metric_str = partial(metric_str, labels=labels_str)
measure_with_str = metric_str(y1_str, y2_str)
assert_array_equal(measure_with_number, measure_with_str,
err_msg="{0} failed string vs number "
"invariance test".format(name))
measure_with_strobj = metric_str(y1_str.astype('O'),
y2_str.astype('O'))
assert_array_equal(measure_with_number, measure_with_strobj,
err_msg="{0} failed string vs number "
"invariance test".format(name))
for name, metric in THRESHOLDED_METRICS.items():
if name in ("log_loss", "hinge_loss", "unnormalized_log_loss",
"brier_score_loss"):
# Ugly, but handle case with a pos_label and label
metric_str = metric
if name in METRICS_WITH_POS_LABEL:
metric_str = partial(metric_str, pos_label=pos_label_str)
measure_with_number = metric(y1, y2)
measure_with_str = metric_str(y1_str, y2)
assert_array_equal(measure_with_number, measure_with_str,
err_msg="{0} failed string vs number "
"invariance test".format(name))
measure_with_strobj = metric(y1_str.astype('O'), y2)
assert_array_equal(measure_with_number, measure_with_strobj,
err_msg="{0} failed string object vs number "
"invariance test".format(name))
else:
# TODO those metrics doesn't support string label yet
assert_raises(ValueError, metric, y1_str, y2)
assert_raises(ValueError, metric, y1_str.astype('O'), y2)
def test_inf_nan_input():
invalids =[([0, 1], [np.inf, np.inf]),
([0, 1], [np.nan, np.nan]),
([0, 1], [np.nan, np.inf])]
METRICS = dict()
METRICS.update(THRESHOLDED_METRICS)
METRICS.update(REGRESSION_METRICS)
for metric in METRICS.values():
for y_true, y_score in invalids:
assert_raise_message(ValueError,
"contains NaN, infinity",
metric, y_true, y_score)
# Classification metrics all raise a mixed input exception
for metric in CLASSIFICATION_METRICS.values():
for y_true, y_score in invalids:
assert_raise_message(ValueError,
"Classification metrics can't handle a mix "
"of binary and continuous targets",
metric, y_true, y_score)
@ignore_warnings
def check_single_sample(name):
# Non-regression test: scores should work with a single sample.
# This is important for leave-one-out cross validation.
# Score functions tested are those that formerly called np.squeeze,
# which turns an array of size 1 into a 0-d array (!).
metric = ALL_METRICS[name]
# assert that no exception is thrown
for i, j in product([0, 1], repeat=2):
metric([i], [j])
@ignore_warnings
def check_single_sample_multioutput(name):
metric = ALL_METRICS[name]
for i, j, k, l in product([0, 1], repeat=4):
metric(np.array([[i, j]]), np.array([[k, l]]))
def test_single_sample():
for name in ALL_METRICS:
if (name in METRIC_UNDEFINED_BINARY_MULTICLASS or
name in THRESHOLDED_METRICS):
# Those metrics are not always defined with one sample
# or in multiclass classification
continue
yield check_single_sample, name
for name in MULTIOUTPUT_METRICS + MULTILABELS_METRICS:
yield check_single_sample_multioutput, name
def test_multioutput_number_of_output_differ():
y_true = np.array([[1, 0, 0, 1], [0, 1, 1, 1], [1, 1, 0, 1]])
y_pred = np.array([[0, 0], [1, 0], [0, 0]])
for name in MULTIOUTPUT_METRICS:
metric = ALL_METRICS[name]
assert_raises(ValueError, metric, y_true, y_pred)
def test_multioutput_regression_invariance_to_dimension_shuffling():
# test invariance to dimension shuffling
random_state = check_random_state(0)
y_true = random_state.uniform(0, 2, size=(20, 5))
y_pred = random_state.uniform(0, 2, size=(20, 5))
for name in MULTIOUTPUT_METRICS:
metric = ALL_METRICS[name]
error = metric(y_true, y_pred)
for _ in range(3):
perm = random_state.permutation(y_true.shape[1])
assert_almost_equal(metric(y_true[:, perm], y_pred[:, perm]),
error,
err_msg="%s is not dimension shuffling "
"invariant" % name)
@ignore_warnings
def test_multilabel_representation_invariance():
# Generate some data
n_classes = 4
n_samples = 50
_, y1 = make_multilabel_classification(n_features=1, n_classes=n_classes,
random_state=0, n_samples=n_samples,
allow_unlabeled=True)
_, y2 = make_multilabel_classification(n_features=1, n_classes=n_classes,
random_state=1, n_samples=n_samples,
allow_unlabeled=True)
# To make sure at least one empty label is present
y1 = np.vstack([y1, [[0] * n_classes]])
y2 = np.vstack([y2, [[0] * n_classes]])
y1_sparse_indicator = sp.coo_matrix(y1)
y2_sparse_indicator = sp.coo_matrix(y2)
for name in MULTILABELS_METRICS:
metric = ALL_METRICS[name]
# XXX cruel hack to work with partial functions
if isinstance(metric, partial):
metric.__module__ = 'tmp'
metric.__name__ = name
measure = metric(y1, y2)
# Check representation invariance
assert_almost_equal(metric(y1_sparse_indicator,
y2_sparse_indicator),
measure,
err_msg="%s failed representation invariance "
"between dense and sparse indicator "
"formats." % name)
def test_raise_value_error_multilabel_sequences():
# make sure the multilabel-sequence format raises ValueError
multilabel_sequences = [
[[0, 1]],
[[1], [2], [0, 1]],
[(), (2), (0, 1)],
[[]],
[()],
np.array([[], [1, 2]], dtype='object')]
for name in MULTILABELS_METRICS:
metric = ALL_METRICS[name]
for seq in multilabel_sequences:
assert_raises(ValueError, metric, seq, seq)
def test_normalize_option_binary_classification(n_samples=20):
# Test in the binary case
random_state = check_random_state(0)
y_true = random_state.randint(0, 2, size=(n_samples, ))
y_pred = random_state.randint(0, 2, size=(n_samples, ))
for name in METRICS_WITH_NORMALIZE_OPTION:
metrics = ALL_METRICS[name]
measure = metrics(y_true, y_pred, normalize=True)
assert_greater(measure, 0,
msg="We failed to test correctly the normalize option")
assert_almost_equal(metrics(y_true, y_pred, normalize=False)
/ n_samples, measure)
def test_normalize_option_multiclass_classification():
# Test in the multiclass case
random_state = check_random_state(0)
y_true = random_state.randint(0, 4, size=(20, ))
y_pred = random_state.randint(0, 4, size=(20, ))
n_samples = y_true.shape[0]
for name in METRICS_WITH_NORMALIZE_OPTION:
metrics = ALL_METRICS[name]
measure = metrics(y_true, y_pred, normalize=True)
assert_greater(measure, 0,
msg="We failed to test correctly the normalize option")
assert_almost_equal(metrics(y_true, y_pred, normalize=False)
/ n_samples, measure)
def test_normalize_option_multilabel_classification():
# Test in the multilabel case
n_classes = 4
n_samples = 100
# for both random_state 0 and 1, y_true and y_pred has at least one
# unlabelled entry
_, y_true = make_multilabel_classification(n_features=1,
n_classes=n_classes,
random_state=0,
allow_unlabeled=True,
n_samples=n_samples)
_, y_pred = make_multilabel_classification(n_features=1,
n_classes=n_classes,
random_state=1,
allow_unlabeled=True,
n_samples=n_samples)
# To make sure at least one empty label is present
y_true += [0]*n_classes
y_pred += [0]*n_classes
for name in METRICS_WITH_NORMALIZE_OPTION:
metrics = ALL_METRICS[name]
measure = metrics(y_true, y_pred, normalize=True)
assert_greater(measure, 0,
msg="We failed to test correctly the normalize option")
assert_almost_equal(metrics(y_true, y_pred, normalize=False)
/ n_samples, measure,
err_msg="Failed with %s" % name)
@ignore_warnings
def _check_averaging(metric, y_true, y_pred, y_true_binarize, y_pred_binarize,
is_multilabel):
n_samples, n_classes = y_true_binarize.shape
# No averaging
label_measure = metric(y_true, y_pred, average=None)
assert_array_almost_equal(label_measure,
[metric(y_true_binarize[:, i],
y_pred_binarize[:, i])
for i in range(n_classes)])
# Micro measure
micro_measure = metric(y_true, y_pred, average="micro")
assert_almost_equal(micro_measure, metric(y_true_binarize.ravel(),
y_pred_binarize.ravel()))
# Macro measure
macro_measure = metric(y_true, y_pred, average="macro")
assert_almost_equal(macro_measure, np.mean(label_measure))
# Weighted measure
weights = np.sum(y_true_binarize, axis=0, dtype=int)
if np.sum(weights) != 0:
weighted_measure = metric(y_true, y_pred, average="weighted")
assert_almost_equal(weighted_measure, np.average(label_measure,
weights=weights))
else:
weighted_measure = metric(y_true, y_pred, average="weighted")
assert_almost_equal(weighted_measure, 0)
# Sample measure
if is_multilabel:
sample_measure = metric(y_true, y_pred, average="samples")
assert_almost_equal(sample_measure,
np.mean([metric(y_true_binarize[i],
y_pred_binarize[i])
for i in range(n_samples)]))
assert_raises(ValueError, metric, y_true, y_pred, average="unknown")
assert_raises(ValueError, metric, y_true, y_pred, average="garbage")
def check_averaging(name, y_true, y_true_binarize, y_pred, y_pred_binarize,
y_score):
is_multilabel = type_of_target(y_true).startswith("multilabel")
metric = ALL_METRICS[name]
if name in METRICS_WITH_AVERAGING:
_check_averaging(metric, y_true, y_pred, y_true_binarize,
y_pred_binarize, is_multilabel)
elif name in THRESHOLDED_METRICS_WITH_AVERAGING:
_check_averaging(metric, y_true, y_score, y_true_binarize,
y_score, is_multilabel)
else:
raise ValueError("Metric is not recorded as having an average option")
def test_averaging_multiclass(n_samples=50, n_classes=3):
random_state = check_random_state(0)
y_true = random_state.randint(0, n_classes, size=(n_samples, ))
y_pred = random_state.randint(0, n_classes, size=(n_samples, ))
y_score = random_state.uniform(size=(n_samples, n_classes))
lb = LabelBinarizer().fit(y_true)
y_true_binarize = lb.transform(y_true)
y_pred_binarize = lb.transform(y_pred)
for name in METRICS_WITH_AVERAGING:
yield (_named_check(check_averaging, name), name, y_true,
y_true_binarize, y_pred, y_pred_binarize, y_score)
def test_averaging_multilabel(n_classes=5, n_samples=40):
_, y = make_multilabel_classification(n_features=1, n_classes=n_classes,
random_state=5, n_samples=n_samples,
allow_unlabeled=False)
y_true = y[:20]
y_pred = y[20:]
y_score = check_random_state(0).normal(size=(20, n_classes))
y_true_binarize = y_true
y_pred_binarize = y_pred
for name in METRICS_WITH_AVERAGING + THRESHOLDED_METRICS_WITH_AVERAGING:
yield (_named_check(check_averaging, name), name, y_true,
y_true_binarize, y_pred, y_pred_binarize, y_score)
def test_averaging_multilabel_all_zeroes():
y_true = np.zeros((20, 3))
y_pred = np.zeros((20, 3))
y_score = np.zeros((20, 3))
y_true_binarize = y_true
y_pred_binarize = y_pred
for name in METRICS_WITH_AVERAGING:
yield (_named_check(check_averaging, name), name, y_true,
y_true_binarize, y_pred, y_pred_binarize, y_score)
# Test _average_binary_score for weight.sum() == 0
binary_metric = (lambda y_true, y_score, average="macro":
_average_binary_score(
precision_score, y_true, y_score, average))
_check_averaging(binary_metric, y_true, y_pred, y_true_binarize,
y_pred_binarize, is_multilabel=True)
def test_averaging_multilabel_all_ones():
y_true = np.ones((20, 3))
y_pred = np.ones((20, 3))
y_score = np.ones((20, 3))
y_true_binarize = y_true
y_pred_binarize = y_pred
for name in METRICS_WITH_AVERAGING:
yield (_named_check(check_averaging, name), name, y_true,
y_true_binarize, y_pred, y_pred_binarize, y_score)
@ignore_warnings
def check_sample_weight_invariance(name, metric, y1, y2):
rng = np.random.RandomState(0)
sample_weight = rng.randint(1, 10, size=len(y1))
# check that unit weights gives the same score as no weight
unweighted_score = metric(y1, y2, sample_weight=None)
assert_almost_equal(
unweighted_score,
metric(y1, y2, sample_weight=np.ones(shape=len(y1))),
err_msg="For %s sample_weight=None is not equivalent to "
"sample_weight=ones" % name)
# check that the weighted and unweighted scores are unequal
weighted_score = metric(y1, y2, sample_weight=sample_weight)
assert_not_equal(
unweighted_score, weighted_score,
msg="Unweighted and weighted scores are unexpectedly "
"equal (%f) for %s" % (weighted_score, name))
# check that sample_weight can be a list
weighted_score_list = metric(y1, y2,
sample_weight=sample_weight.tolist())
assert_almost_equal(
weighted_score, weighted_score_list,
err_msg=("Weighted scores for array and list "
"sample_weight input are not equal (%f != %f) for %s") % (
weighted_score, weighted_score_list, name))
# check that integer weights is the same as repeated samples
repeat_weighted_score = metric(
np.repeat(y1, sample_weight, axis=0),
np.repeat(y2, sample_weight, axis=0), sample_weight=None)
assert_almost_equal(
weighted_score, repeat_weighted_score,
err_msg="Weighting %s is not equal to repeating samples" % name)
# check that ignoring a fraction of the samples is equivalent to setting
# the corresponding weights to zero
sample_weight_subset = sample_weight[1::2]
sample_weight_zeroed = np.copy(sample_weight)
sample_weight_zeroed[::2] = 0
y1_subset = y1[1::2]
y2_subset = y2[1::2]
weighted_score_subset = metric(y1_subset, y2_subset,
sample_weight=sample_weight_subset)
weighted_score_zeroed = metric(y1, y2,
sample_weight=sample_weight_zeroed)
assert_almost_equal(
weighted_score_subset, weighted_score_zeroed,
err_msg=("Zeroing weights does not give the same result as "
"removing the corresponding samples (%f != %f) for %s" %
(weighted_score_zeroed, weighted_score_subset, name)))
if not name.startswith('unnormalized'):
# check that the score is invariant under scaling of the weights by a
# common factor
for scaling in [2, 0.3]:
assert_almost_equal(
weighted_score,
metric(y1, y2, sample_weight=sample_weight * scaling),
err_msg="%s sample_weight is not invariant "
"under scaling" % name)
# Check that if sample_weight.shape[0] != y_true.shape[0], it raised an
# error
assert_raises(Exception, metric, y1, y2,
sample_weight=np.hstack([sample_weight, sample_weight]))
def test_sample_weight_invariance(n_samples=50):
random_state = check_random_state(0)
# regression
y_true = random_state.random_sample(size=(n_samples,))
y_pred = random_state.random_sample(size=(n_samples,))
for name in ALL_METRICS:
if name not in REGRESSION_METRICS:
continue
if name in METRICS_WITHOUT_SAMPLE_WEIGHT:
continue
metric = ALL_METRICS[name]
yield _named_check(check_sample_weight_invariance, name), name,\
metric, y_true, y_pred
# binary
random_state = check_random_state(0)
y_true = random_state.randint(0, 2, size=(n_samples, ))
y_pred = random_state.randint(0, 2, size=(n_samples, ))
y_score = random_state.random_sample(size=(n_samples,))
for name in ALL_METRICS:
if name in REGRESSION_METRICS:
continue
if (name in METRICS_WITHOUT_SAMPLE_WEIGHT or
name in METRIC_UNDEFINED_BINARY):
continue
metric = ALL_METRICS[name]
if name in THRESHOLDED_METRICS:
yield _named_check(check_sample_weight_invariance, name), name,\
metric, y_true, y_score
else:
yield _named_check(check_sample_weight_invariance, name), name,\
metric, y_true, y_pred
# multiclass
random_state = check_random_state(0)
y_true = random_state.randint(0, 5, size=(n_samples, ))
y_pred = random_state.randint(0, 5, size=(n_samples, ))
y_score = random_state.random_sample(size=(n_samples, 5))
for name in ALL_METRICS:
if name in REGRESSION_METRICS:
continue
if (name in METRICS_WITHOUT_SAMPLE_WEIGHT or
name in METRIC_UNDEFINED_BINARY_MULTICLASS):
continue
metric = ALL_METRICS[name]
if name in THRESHOLDED_METRICS:
yield _named_check(check_sample_weight_invariance, name), name,\
metric, y_true, y_score
else:
yield _named_check(check_sample_weight_invariance, name), name,\
metric, y_true, y_pred
# multilabel indicator
_, ya = make_multilabel_classification(n_features=1, n_classes=20,
random_state=0, n_samples=100,
allow_unlabeled=False)
_, yb = make_multilabel_classification(n_features=1, n_classes=20,
random_state=1, n_samples=100,
allow_unlabeled=False)
y_true = np.vstack([ya, yb])
y_pred = np.vstack([ya, ya])
y_score = random_state.randint(1, 4, size=y_true.shape)
for name in (MULTILABELS_METRICS + THRESHOLDED_MULTILABEL_METRICS +
MULTIOUTPUT_METRICS):
if name in METRICS_WITHOUT_SAMPLE_WEIGHT:
continue
metric = ALL_METRICS[name]
if name in THRESHOLDED_METRICS:
yield (_named_check(check_sample_weight_invariance, name), name,
metric, y_true, y_score)
else:
yield (_named_check(check_sample_weight_invariance, name), name,
metric, y_true, y_pred)
@ignore_warnings
def test_no_averaging_labels():
# test labels argument when not using averaging
# in multi-class and multi-label cases
y_true_multilabel = np.array([[1, 1, 0, 0], [1, 1, 0, 0]])
y_pred_multilabel = np.array([[0, 0, 1, 1], [0, 1, 1, 0]])
y_true_multiclass = np.array([0, 1, 2])
y_pred_multiclass = np.array([0, 2, 3])
labels = np.array([3, 0, 1, 2])
_, inverse_labels = np.unique(labels, return_inverse=True)
for name in METRICS_WITH_AVERAGING:
for y_true, y_pred in [[y_true_multiclass, y_pred_multiclass],
[y_true_multilabel, y_pred_multilabel]]:
if name not in MULTILABELS_METRICS and y_pred.ndim > 1:
continue
metric = ALL_METRICS[name]
score_labels = metric(y_true, y_pred, labels=labels, average=None)
score = metric(y_true, y_pred, average=None)
assert_array_equal(score_labels, score[inverse_labels])
| 43,668 | 38.2354 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/tests/test_ranking.py | from __future__ import division, print_function
import numpy as np
from itertools import product
import warnings
from scipy.sparse import csr_matrix
from sklearn import datasets
from sklearn import svm
from sklearn.datasets import make_multilabel_classification
from sklearn.random_projection import sparse_random_matrix
from sklearn.utils.validation import check_array, check_consistent_length
from sklearn.utils.validation import check_random_state
from sklearn.utils.testing import assert_raises, clean_warning_registry
from sklearn.utils.testing import assert_raise_message
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_warns
from sklearn.metrics import auc
from sklearn.metrics import average_precision_score
from sklearn.metrics import coverage_error
from sklearn.metrics import label_ranking_average_precision_score
from sklearn.metrics import precision_recall_curve
from sklearn.metrics import label_ranking_loss
from sklearn.metrics import roc_auc_score
from sklearn.metrics import roc_curve
from sklearn.exceptions import UndefinedMetricWarning
###############################################################################
# Utilities for testing
def make_prediction(dataset=None, binary=False):
"""Make some classification predictions on a toy dataset using a SVC
If binary is True restrict to a binary classification problem instead of a
multiclass classification problem
"""
if dataset is None:
# import some data to play with
dataset = datasets.load_iris()
X = dataset.data
y = dataset.target
if binary:
# restrict to a binary classification task
X, y = X[y < 2], y[y < 2]
n_samples, n_features = X.shape
p = np.arange(n_samples)
rng = check_random_state(37)
rng.shuffle(p)
X, y = X[p], y[p]
half = int(n_samples / 2)
# add noisy features to make the problem harder and avoid perfect results
rng = np.random.RandomState(0)
X = np.c_[X, rng.randn(n_samples, 200 * n_features)]
# run classifier, get class probabilities and label predictions
clf = svm.SVC(kernel='linear', probability=True, random_state=0)
probas_pred = clf.fit(X[:half], y[:half]).predict_proba(X[half:])
if binary:
# only interested in probabilities of the positive case
# XXX: do we really want a special API for the binary case?
probas_pred = probas_pred[:, 1]
y_pred = clf.predict(X[half:])
y_true = y[half:]
return y_true, y_pred, probas_pred
###############################################################################
# Tests
def _auc(y_true, y_score):
"""Alternative implementation to check for correctness of
`roc_auc_score`."""
pos_label = np.unique(y_true)[1]
# Count the number of times positive samples are correctly ranked above
# negative samples.
pos = y_score[y_true == pos_label]
neg = y_score[y_true != pos_label]
diff_matrix = pos.reshape(1, -1) - neg.reshape(-1, 1)
n_correct = np.sum(diff_matrix > 0)
return n_correct / float(len(pos) * len(neg))
def _average_precision(y_true, y_score):
"""Alternative implementation to check for correctness of
`average_precision_score`.
Note that this implementation fails on some edge cases.
For example, for constant predictions e.g. [0.5, 0.5, 0.5],
y_true = [1, 0, 0] returns an average precision of 0.33...
but y_true = [0, 0, 1] returns 1.0.
"""
pos_label = np.unique(y_true)[1]
n_pos = np.sum(y_true == pos_label)
order = np.argsort(y_score)[::-1]
y_score = y_score[order]
y_true = y_true[order]
score = 0
for i in range(len(y_score)):
if y_true[i] == pos_label:
# Compute precision up to document i
# i.e, percentage of relevant documents up to document i.
prec = 0
for j in range(0, i + 1):
if y_true[j] == pos_label:
prec += 1.0
prec /= (i + 1.0)
score += prec
return score / n_pos
def _average_precision_slow(y_true, y_score):
"""A second alternative implementation of average precision that closely
follows the Wikipedia article's definition (see References). This should
give identical results as `average_precision_score` for all inputs.
References
----------
.. [1] `Wikipedia entry for the Average precision
<http://en.wikipedia.org/wiki/Average_precision>`_
"""
precision, recall, threshold = precision_recall_curve(y_true, y_score)
precision = list(reversed(precision))
recall = list(reversed(recall))
average_precision = 0
for i in range(1, len(precision)):
average_precision += precision[i] * (recall[i] - recall[i - 1])
return average_precision
def test_roc_curve():
# Test Area under Receiver Operating Characteristic (ROC) curve
y_true, _, probas_pred = make_prediction(binary=True)
expected_auc = _auc(y_true, probas_pred)
for drop in [True, False]:
fpr, tpr, thresholds = roc_curve(y_true, probas_pred,
drop_intermediate=drop)
roc_auc = auc(fpr, tpr)
assert_array_almost_equal(roc_auc, expected_auc, decimal=2)
assert_almost_equal(roc_auc, roc_auc_score(y_true, probas_pred))
assert_equal(fpr.shape, tpr.shape)
assert_equal(fpr.shape, thresholds.shape)
def test_roc_curve_end_points():
# Make sure that roc_curve returns a curve start at 0 and ending and
# 1 even in corner cases
rng = np.random.RandomState(0)
y_true = np.array([0] * 50 + [1] * 50)
y_pred = rng.randint(3, size=100)
fpr, tpr, thr = roc_curve(y_true, y_pred, drop_intermediate=True)
assert_equal(fpr[0], 0)
assert_equal(fpr[-1], 1)
assert_equal(fpr.shape, tpr.shape)
assert_equal(fpr.shape, thr.shape)
def test_roc_returns_consistency():
# Test whether the returned threshold matches up with tpr
# make small toy dataset
y_true, _, probas_pred = make_prediction(binary=True)
fpr, tpr, thresholds = roc_curve(y_true, probas_pred)
# use the given thresholds to determine the tpr
tpr_correct = []
for t in thresholds:
tp = np.sum((probas_pred >= t) & y_true)
p = np.sum(y_true)
tpr_correct.append(1.0 * tp / p)
# compare tpr and tpr_correct to see if the thresholds' order was correct
assert_array_almost_equal(tpr, tpr_correct, decimal=2)
assert_equal(fpr.shape, tpr.shape)
assert_equal(fpr.shape, thresholds.shape)
def test_roc_curve_multi():
# roc_curve not applicable for multi-class problems
y_true, _, probas_pred = make_prediction(binary=False)
assert_raises(ValueError, roc_curve, y_true, probas_pred)
def test_roc_curve_confidence():
# roc_curve for confidence scores
y_true, _, probas_pred = make_prediction(binary=True)
fpr, tpr, thresholds = roc_curve(y_true, probas_pred - 0.5)
roc_auc = auc(fpr, tpr)
assert_array_almost_equal(roc_auc, 0.90, decimal=2)
assert_equal(fpr.shape, tpr.shape)
assert_equal(fpr.shape, thresholds.shape)
def test_roc_curve_hard():
# roc_curve for hard decisions
y_true, pred, probas_pred = make_prediction(binary=True)
# always predict one
trivial_pred = np.ones(y_true.shape)
fpr, tpr, thresholds = roc_curve(y_true, trivial_pred)
roc_auc = auc(fpr, tpr)
assert_array_almost_equal(roc_auc, 0.50, decimal=2)
assert_equal(fpr.shape, tpr.shape)
assert_equal(fpr.shape, thresholds.shape)
# always predict zero
trivial_pred = np.zeros(y_true.shape)
fpr, tpr, thresholds = roc_curve(y_true, trivial_pred)
roc_auc = auc(fpr, tpr)
assert_array_almost_equal(roc_auc, 0.50, decimal=2)
assert_equal(fpr.shape, tpr.shape)
assert_equal(fpr.shape, thresholds.shape)
# hard decisions
fpr, tpr, thresholds = roc_curve(y_true, pred)
roc_auc = auc(fpr, tpr)
assert_array_almost_equal(roc_auc, 0.78, decimal=2)
assert_equal(fpr.shape, tpr.shape)
assert_equal(fpr.shape, thresholds.shape)
def test_roc_curve_one_label():
y_true = [1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
y_pred = [0, 1, 0, 1, 0, 1, 0, 1, 0, 1]
# assert there are warnings
w = UndefinedMetricWarning
fpr, tpr, thresholds = assert_warns(w, roc_curve, y_true, y_pred)
# all true labels, all fpr should be nan
assert_array_equal(fpr,
np.nan * np.ones(len(thresholds)))
assert_equal(fpr.shape, tpr.shape)
assert_equal(fpr.shape, thresholds.shape)
# assert there are warnings
fpr, tpr, thresholds = assert_warns(w, roc_curve,
[1 - x for x in y_true],
y_pred)
# all negative labels, all tpr should be nan
assert_array_equal(tpr,
np.nan * np.ones(len(thresholds)))
assert_equal(fpr.shape, tpr.shape)
assert_equal(fpr.shape, thresholds.shape)
def test_roc_curve_toydata():
# Binary classification
y_true = [0, 1]
y_score = [0, 1]
tpr, fpr, _ = roc_curve(y_true, y_score)
roc_auc = roc_auc_score(y_true, y_score)
assert_array_almost_equal(tpr, [0, 1])
assert_array_almost_equal(fpr, [1, 1])
assert_almost_equal(roc_auc, 1.)
y_true = [0, 1]
y_score = [1, 0]
tpr, fpr, _ = roc_curve(y_true, y_score)
roc_auc = roc_auc_score(y_true, y_score)
assert_array_almost_equal(tpr, [0, 1, 1])
assert_array_almost_equal(fpr, [0, 0, 1])
assert_almost_equal(roc_auc, 0.)
y_true = [1, 0]
y_score = [1, 1]
tpr, fpr, _ = roc_curve(y_true, y_score)
roc_auc = roc_auc_score(y_true, y_score)
assert_array_almost_equal(tpr, [0, 1])
assert_array_almost_equal(fpr, [0, 1])
assert_almost_equal(roc_auc, 0.5)
y_true = [1, 0]
y_score = [1, 0]
tpr, fpr, _ = roc_curve(y_true, y_score)
roc_auc = roc_auc_score(y_true, y_score)
assert_array_almost_equal(tpr, [0, 1])
assert_array_almost_equal(fpr, [1, 1])
assert_almost_equal(roc_auc, 1.)
y_true = [1, 0]
y_score = [0.5, 0.5]
tpr, fpr, _ = roc_curve(y_true, y_score)
roc_auc = roc_auc_score(y_true, y_score)
assert_array_almost_equal(tpr, [0, 1])
assert_array_almost_equal(fpr, [0, 1])
assert_almost_equal(roc_auc, .5)
y_true = [0, 0]
y_score = [0.25, 0.75]
# assert UndefinedMetricWarning because of no positive sample in y_true
tpr, fpr, _ = assert_warns(UndefinedMetricWarning, roc_curve, y_true, y_score)
assert_raises(ValueError, roc_auc_score, y_true, y_score)
assert_array_almost_equal(tpr, [0., 0.5, 1.])
assert_array_almost_equal(fpr, [np.nan, np.nan, np.nan])
y_true = [1, 1]
y_score = [0.25, 0.75]
# assert UndefinedMetricWarning because of no negative sample in y_true
tpr, fpr, _ = assert_warns(UndefinedMetricWarning, roc_curve, y_true, y_score)
assert_raises(ValueError, roc_auc_score, y_true, y_score)
assert_array_almost_equal(tpr, [np.nan, np.nan])
assert_array_almost_equal(fpr, [0.5, 1.])
# Multi-label classification task
y_true = np.array([[0, 1], [0, 1]])
y_score = np.array([[0, 1], [0, 1]])
assert_raises(ValueError, roc_auc_score, y_true, y_score, average="macro")
assert_raises(ValueError, roc_auc_score, y_true, y_score,
average="weighted")
assert_almost_equal(roc_auc_score(y_true, y_score, average="samples"), 1.)
assert_almost_equal(roc_auc_score(y_true, y_score, average="micro"), 1.)
y_true = np.array([[0, 1], [0, 1]])
y_score = np.array([[0, 1], [1, 0]])
assert_raises(ValueError, roc_auc_score, y_true, y_score, average="macro")
assert_raises(ValueError, roc_auc_score, y_true, y_score,
average="weighted")
assert_almost_equal(roc_auc_score(y_true, y_score, average="samples"), 0.5)
assert_almost_equal(roc_auc_score(y_true, y_score, average="micro"), 0.5)
y_true = np.array([[1, 0], [0, 1]])
y_score = np.array([[0, 1], [1, 0]])
assert_almost_equal(roc_auc_score(y_true, y_score, average="macro"), 0)
assert_almost_equal(roc_auc_score(y_true, y_score, average="weighted"), 0)
assert_almost_equal(roc_auc_score(y_true, y_score, average="samples"), 0)
assert_almost_equal(roc_auc_score(y_true, y_score, average="micro"), 0)
y_true = np.array([[1, 0], [0, 1]])
y_score = np.array([[0.5, 0.5], [0.5, 0.5]])
assert_almost_equal(roc_auc_score(y_true, y_score, average="macro"), .5)
assert_almost_equal(roc_auc_score(y_true, y_score, average="weighted"), .5)
assert_almost_equal(roc_auc_score(y_true, y_score, average="samples"), .5)
assert_almost_equal(roc_auc_score(y_true, y_score, average="micro"), .5)
def test_roc_curve_drop_intermediate():
# Test that drop_intermediate drops the correct thresholds
y_true = [0, 0, 0, 0, 1, 1]
y_score = [0., 0.2, 0.5, 0.6, 0.7, 1.0]
tpr, fpr, thresholds = roc_curve(y_true, y_score, drop_intermediate=True)
assert_array_almost_equal(thresholds, [1., 0.7, 0.])
# Test dropping thresholds with repeating scores
y_true = [0, 0, 0, 0, 0, 0, 0,
1, 1, 1, 1, 1, 1]
y_score = [0., 0.1, 0.6, 0.6, 0.7, 0.8, 0.9,
0.6, 0.7, 0.8, 0.9, 0.9, 1.0]
tpr, fpr, thresholds = roc_curve(y_true, y_score, drop_intermediate=True)
assert_array_almost_equal(thresholds,
[1.0, 0.9, 0.7, 0.6, 0.])
def test_auc():
# Test Area Under Curve (AUC) computation
x = [0, 1]
y = [0, 1]
assert_array_almost_equal(auc(x, y), 0.5)
x = [1, 0]
y = [0, 1]
assert_array_almost_equal(auc(x, y), 0.5)
x = [1, 0, 0]
y = [0, 1, 1]
assert_array_almost_equal(auc(x, y), 0.5)
x = [0, 1]
y = [1, 1]
assert_array_almost_equal(auc(x, y), 1)
x = [0, 0.5, 1]
y = [0, 0.5, 1]
assert_array_almost_equal(auc(x, y), 0.5)
def test_auc_duplicate_values():
# Test Area Under Curve (AUC) computation with duplicate values
# auc() was previously sorting the x and y arrays according to the indices
# from numpy.argsort(x), which was reordering the tied 0's in this example
# and resulting in an incorrect area computation. This test detects the
# error.
x = [-2.0, 0.0, 0.0, 0.0, 1.0]
y1 = [2.0, 0.0, 0.5, 1.0, 1.0]
y2 = [2.0, 1.0, 0.0, 0.5, 1.0]
y3 = [2.0, 1.0, 0.5, 0.0, 1.0]
for y in (y1, y2, y3):
assert_array_almost_equal(auc(x, y, reorder=True), 3.0)
def test_auc_errors():
# Incompatible shapes
assert_raises(ValueError, auc, [0.0, 0.5, 1.0], [0.1, 0.2])
# Too few x values
assert_raises(ValueError, auc, [0.0], [0.1])
# x is not in order
assert_raises(ValueError, auc, [1.0, 0.0, 0.5], [0.0, 0.0, 0.0])
def test_auc_score_non_binary_class():
# Test that roc_auc_score function returns an error when trying
# to compute AUC for non-binary class values.
rng = check_random_state(404)
y_pred = rng.rand(10)
# y_true contains only one class value
y_true = np.zeros(10, dtype="int")
assert_raise_message(ValueError, "ROC AUC score is not defined",
roc_auc_score, y_true, y_pred)
y_true = np.ones(10, dtype="int")
assert_raise_message(ValueError, "ROC AUC score is not defined",
roc_auc_score, y_true, y_pred)
y_true = -np.ones(10, dtype="int")
assert_raise_message(ValueError, "ROC AUC score is not defined",
roc_auc_score, y_true, y_pred)
# y_true contains three different class values
y_true = rng.randint(0, 3, size=10)
assert_raise_message(ValueError, "multiclass format is not supported",
roc_auc_score, y_true, y_pred)
clean_warning_registry()
with warnings.catch_warnings(record=True):
rng = check_random_state(404)
y_pred = rng.rand(10)
# y_true contains only one class value
y_true = np.zeros(10, dtype="int")
assert_raise_message(ValueError, "ROC AUC score is not defined",
roc_auc_score, y_true, y_pred)
y_true = np.ones(10, dtype="int")
assert_raise_message(ValueError, "ROC AUC score is not defined",
roc_auc_score, y_true, y_pred)
y_true = -np.ones(10, dtype="int")
assert_raise_message(ValueError, "ROC AUC score is not defined",
roc_auc_score, y_true, y_pred)
# y_true contains three different class values
y_true = rng.randint(0, 3, size=10)
assert_raise_message(ValueError, "multiclass format is not supported",
roc_auc_score, y_true, y_pred)
def test_binary_clf_curve():
rng = check_random_state(404)
y_true = rng.randint(0, 3, size=10)
y_pred = rng.rand(10)
msg = "multiclass format is not supported"
assert_raise_message(ValueError, msg, precision_recall_curve,
y_true, y_pred)
def test_precision_recall_curve():
y_true, _, probas_pred = make_prediction(binary=True)
_test_precision_recall_curve(y_true, probas_pred)
# Use {-1, 1} for labels; make sure original labels aren't modified
y_true[np.where(y_true == 0)] = -1
y_true_copy = y_true.copy()
_test_precision_recall_curve(y_true, probas_pred)
assert_array_equal(y_true_copy, y_true)
labels = [1, 0, 0, 1]
predict_probas = [1, 2, 3, 4]
p, r, t = precision_recall_curve(labels, predict_probas)
assert_array_almost_equal(p, np.array([0.5, 0.33333333, 0.5, 1., 1.]))
assert_array_almost_equal(r, np.array([1., 0.5, 0.5, 0.5, 0.]))
assert_array_almost_equal(t, np.array([1, 2, 3, 4]))
assert_equal(p.size, r.size)
assert_equal(p.size, t.size + 1)
def test_precision_recall_curve_pos_label():
y_true, _, probas_pred = make_prediction(binary=False)
pos_label = 2
p, r, thresholds = precision_recall_curve(y_true,
probas_pred[:, pos_label],
pos_label=pos_label)
p2, r2, thresholds2 = precision_recall_curve(y_true == pos_label,
probas_pred[:, pos_label])
assert_array_almost_equal(p, p2)
assert_array_almost_equal(r, r2)
assert_array_almost_equal(thresholds, thresholds2)
assert_equal(p.size, r.size)
assert_equal(p.size, thresholds.size + 1)
def _test_precision_recall_curve(y_true, probas_pred):
# Test Precision-Recall and aread under PR curve
p, r, thresholds = precision_recall_curve(y_true, probas_pred)
precision_recall_auc = _average_precision_slow(y_true, probas_pred)
assert_array_almost_equal(precision_recall_auc, 0.859, 3)
assert_array_almost_equal(precision_recall_auc,
average_precision_score(y_true, probas_pred))
assert_almost_equal(_average_precision(y_true, probas_pred),
precision_recall_auc, decimal=3)
assert_equal(p.size, r.size)
assert_equal(p.size, thresholds.size + 1)
# Smoke test in the case of proba having only one value
p, r, thresholds = precision_recall_curve(y_true,
np.zeros_like(probas_pred))
assert_equal(p.size, r.size)
assert_equal(p.size, thresholds.size + 1)
def test_precision_recall_curve_errors():
# Contains non-binary labels
assert_raises(ValueError, precision_recall_curve,
[0, 1, 2], [[0.0], [1.0], [1.0]])
def test_precision_recall_curve_toydata():
with np.errstate(all="raise"):
# Binary classification
y_true = [0, 1]
y_score = [0, 1]
p, r, _ = precision_recall_curve(y_true, y_score)
auc_prc = average_precision_score(y_true, y_score)
assert_array_almost_equal(p, [1, 1])
assert_array_almost_equal(r, [1, 0])
assert_almost_equal(auc_prc, 1.)
y_true = [0, 1]
y_score = [1, 0]
p, r, _ = precision_recall_curve(y_true, y_score)
auc_prc = average_precision_score(y_true, y_score)
assert_array_almost_equal(p, [0.5, 0., 1.])
assert_array_almost_equal(r, [1., 0., 0.])
# Here we are doing a terrible prediction: we are always getting
# it wrong, hence the average_precision_score is the accuracy at
# chance: 50%
assert_almost_equal(auc_prc, 0.5)
y_true = [1, 0]
y_score = [1, 1]
p, r, _ = precision_recall_curve(y_true, y_score)
auc_prc = average_precision_score(y_true, y_score)
assert_array_almost_equal(p, [0.5, 1])
assert_array_almost_equal(r, [1., 0])
assert_almost_equal(auc_prc, .5)
y_true = [1, 0]
y_score = [1, 0]
p, r, _ = precision_recall_curve(y_true, y_score)
auc_prc = average_precision_score(y_true, y_score)
assert_array_almost_equal(p, [1, 1])
assert_array_almost_equal(r, [1, 0])
assert_almost_equal(auc_prc, 1.)
y_true = [1, 0]
y_score = [0.5, 0.5]
p, r, _ = precision_recall_curve(y_true, y_score)
auc_prc = average_precision_score(y_true, y_score)
assert_array_almost_equal(p, [0.5, 1])
assert_array_almost_equal(r, [1, 0.])
assert_almost_equal(auc_prc, .5)
y_true = [0, 0]
y_score = [0.25, 0.75]
assert_raises(Exception, precision_recall_curve, y_true, y_score)
assert_raises(Exception, average_precision_score, y_true, y_score)
y_true = [1, 1]
y_score = [0.25, 0.75]
p, r, _ = precision_recall_curve(y_true, y_score)
assert_almost_equal(average_precision_score(y_true, y_score), 1.)
assert_array_almost_equal(p, [1., 1., 1.])
assert_array_almost_equal(r, [1, 0.5, 0.])
# Multi-label classification task
y_true = np.array([[0, 1], [0, 1]])
y_score = np.array([[0, 1], [0, 1]])
assert_raises(Exception, average_precision_score, y_true, y_score,
average="macro")
assert_raises(Exception, average_precision_score, y_true, y_score,
average="weighted")
assert_almost_equal(average_precision_score(y_true, y_score,
average="samples"), 1.)
assert_almost_equal(average_precision_score(y_true, y_score,
average="micro"), 1.)
y_true = np.array([[0, 1], [0, 1]])
y_score = np.array([[0, 1], [1, 0]])
assert_raises(Exception, average_precision_score, y_true, y_score,
average="macro")
assert_raises(Exception, average_precision_score, y_true, y_score,
average="weighted")
assert_almost_equal(average_precision_score(y_true, y_score,
average="samples"), 0.75)
assert_almost_equal(average_precision_score(y_true, y_score,
average="micro"), 0.5)
y_true = np.array([[1, 0], [0, 1]])
y_score = np.array([[0, 1], [1, 0]])
assert_almost_equal(average_precision_score(y_true, y_score,
average="macro"), 0.5)
assert_almost_equal(average_precision_score(y_true, y_score,
average="weighted"), 0.5)
assert_almost_equal(average_precision_score(y_true, y_score,
average="samples"), 0.5)
assert_almost_equal(average_precision_score(y_true, y_score,
average="micro"), 0.5)
y_true = np.array([[1, 0], [0, 1]])
y_score = np.array([[0.5, 0.5], [0.5, 0.5]])
assert_almost_equal(average_precision_score(y_true, y_score,
average="macro"), 0.5)
assert_almost_equal(average_precision_score(y_true, y_score,
average="weighted"), 0.5)
assert_almost_equal(average_precision_score(y_true, y_score,
average="samples"), 0.5)
assert_almost_equal(average_precision_score(y_true, y_score,
average="micro"), 0.5)
def test_average_precision_constant_values():
# Check the average_precision_score of a constant predictor is
# the TPR
# Generate a dataset with 25% of positives
y_true = np.zeros(100, dtype=int)
y_true[::4] = 1
# And a constant score
y_score = np.ones(100)
# The precision is then the fraction of positive whatever the recall
# is, as there is only one threshold:
assert_equal(average_precision_score(y_true, y_score), .25)
def test_score_scale_invariance():
# Test that average_precision_score and roc_auc_score are invariant by
# the scaling or shifting of probabilities
# This test was expanded (added scaled_down) in response to github
# issue #3864 (and others), where overly aggressive rounding was causing
# problems for users with very small y_score values
y_true, _, probas_pred = make_prediction(binary=True)
roc_auc = roc_auc_score(y_true, probas_pred)
roc_auc_scaled_up = roc_auc_score(y_true, 100 * probas_pred)
roc_auc_scaled_down = roc_auc_score(y_true, 1e-6 * probas_pred)
roc_auc_shifted = roc_auc_score(y_true, probas_pred - 10)
assert_equal(roc_auc, roc_auc_scaled_up)
assert_equal(roc_auc, roc_auc_scaled_down)
assert_equal(roc_auc, roc_auc_shifted)
pr_auc = average_precision_score(y_true, probas_pred)
pr_auc_scaled_up = average_precision_score(y_true, 100 * probas_pred)
pr_auc_scaled_down = average_precision_score(y_true, 1e-6 * probas_pred)
pr_auc_shifted = average_precision_score(y_true, probas_pred - 10)
assert_equal(pr_auc, pr_auc_scaled_up)
assert_equal(pr_auc, pr_auc_scaled_down)
assert_equal(pr_auc, pr_auc_shifted)
def check_lrap_toy(lrap_score):
# Check on several small example that it works
assert_almost_equal(lrap_score([[0, 1]], [[0.25, 0.75]]), 1)
assert_almost_equal(lrap_score([[0, 1]], [[0.75, 0.25]]), 1 / 2)
assert_almost_equal(lrap_score([[1, 1]], [[0.75, 0.25]]), 1)
assert_almost_equal(lrap_score([[0, 0, 1]], [[0.25, 0.5, 0.75]]), 1)
assert_almost_equal(lrap_score([[0, 1, 0]], [[0.25, 0.5, 0.75]]), 1 / 2)
assert_almost_equal(lrap_score([[0, 1, 1]], [[0.25, 0.5, 0.75]]), 1)
assert_almost_equal(lrap_score([[1, 0, 0]], [[0.25, 0.5, 0.75]]), 1 / 3)
assert_almost_equal(lrap_score([[1, 0, 1]], [[0.25, 0.5, 0.75]]),
(2 / 3 + 1 / 1) / 2)
assert_almost_equal(lrap_score([[1, 1, 0]], [[0.25, 0.5, 0.75]]),
(2 / 3 + 1 / 2) / 2)
assert_almost_equal(lrap_score([[0, 0, 1]], [[0.75, 0.5, 0.25]]), 1 / 3)
assert_almost_equal(lrap_score([[0, 1, 0]], [[0.75, 0.5, 0.25]]), 1 / 2)
assert_almost_equal(lrap_score([[0, 1, 1]], [[0.75, 0.5, 0.25]]),
(1 / 2 + 2 / 3) / 2)
assert_almost_equal(lrap_score([[1, 0, 0]], [[0.75, 0.5, 0.25]]), 1)
assert_almost_equal(lrap_score([[1, 0, 1]], [[0.75, 0.5, 0.25]]),
(1 + 2 / 3) / 2)
assert_almost_equal(lrap_score([[1, 1, 0]], [[0.75, 0.5, 0.25]]), 1)
assert_almost_equal(lrap_score([[1, 1, 1]], [[0.75, 0.5, 0.25]]), 1)
assert_almost_equal(lrap_score([[0, 0, 1]], [[0.5, 0.75, 0.25]]), 1 / 3)
assert_almost_equal(lrap_score([[0, 1, 0]], [[0.5, 0.75, 0.25]]), 1)
assert_almost_equal(lrap_score([[0, 1, 1]], [[0.5, 0.75, 0.25]]),
(1 + 2 / 3) / 2)
assert_almost_equal(lrap_score([[1, 0, 0]], [[0.5, 0.75, 0.25]]), 1 / 2)
assert_almost_equal(lrap_score([[1, 0, 1]], [[0.5, 0.75, 0.25]]),
(1 / 2 + 2 / 3) / 2)
assert_almost_equal(lrap_score([[1, 1, 0]], [[0.5, 0.75, 0.25]]), 1)
assert_almost_equal(lrap_score([[1, 1, 1]], [[0.5, 0.75, 0.25]]), 1)
# Tie handling
assert_almost_equal(lrap_score([[1, 0]], [[0.5, 0.5]]), 0.5)
assert_almost_equal(lrap_score([[0, 1]], [[0.5, 0.5]]), 0.5)
assert_almost_equal(lrap_score([[1, 1]], [[0.5, 0.5]]), 1)
assert_almost_equal(lrap_score([[0, 0, 1]], [[0.25, 0.5, 0.5]]), 0.5)
assert_almost_equal(lrap_score([[0, 1, 0]], [[0.25, 0.5, 0.5]]), 0.5)
assert_almost_equal(lrap_score([[0, 1, 1]], [[0.25, 0.5, 0.5]]), 1)
assert_almost_equal(lrap_score([[1, 0, 0]], [[0.25, 0.5, 0.5]]), 1 / 3)
assert_almost_equal(lrap_score([[1, 0, 1]], [[0.25, 0.5, 0.5]]),
(2 / 3 + 1 / 2) / 2)
assert_almost_equal(lrap_score([[1, 1, 0]], [[0.25, 0.5, 0.5]]),
(2 / 3 + 1 / 2) / 2)
assert_almost_equal(lrap_score([[1, 1, 1]], [[0.25, 0.5, 0.5]]), 1)
assert_almost_equal(lrap_score([[1, 1, 0]], [[0.5, 0.5, 0.5]]), 2 / 3)
assert_almost_equal(lrap_score([[1, 1, 1, 0]], [[0.5, 0.5, 0.5, 0.5]]),
3 / 4)
def check_zero_or_all_relevant_labels(lrap_score):
random_state = check_random_state(0)
for n_labels in range(2, 5):
y_score = random_state.uniform(size=(1, n_labels))
y_score_ties = np.zeros_like(y_score)
# No relevant labels
y_true = np.zeros((1, n_labels))
assert_equal(lrap_score(y_true, y_score), 1.)
assert_equal(lrap_score(y_true, y_score_ties), 1.)
# Only relevant labels
y_true = np.ones((1, n_labels))
assert_equal(lrap_score(y_true, y_score), 1.)
assert_equal(lrap_score(y_true, y_score_ties), 1.)
# Degenerate case: only one label
assert_almost_equal(lrap_score([[1], [0], [1], [0]],
[[0.5], [0.5], [0.5], [0.5]]), 1.)
def check_lrap_error_raised(lrap_score):
# Raise value error if not appropriate format
assert_raises(ValueError, lrap_score,
[0, 1, 0], [0.25, 0.3, 0.2])
assert_raises(ValueError, lrap_score, [0, 1, 2],
[[0.25, 0.75, 0.0], [0.7, 0.3, 0.0], [0.8, 0.2, 0.0]])
assert_raises(ValueError, lrap_score, [(0), (1), (2)],
[[0.25, 0.75, 0.0], [0.7, 0.3, 0.0], [0.8, 0.2, 0.0]])
# Check that y_true.shape != y_score.shape raise the proper exception
assert_raises(ValueError, lrap_score, [[0, 1], [0, 1]], [0, 1])
assert_raises(ValueError, lrap_score, [[0, 1], [0, 1]], [[0, 1]])
assert_raises(ValueError, lrap_score, [[0, 1], [0, 1]], [[0], [1]])
assert_raises(ValueError, lrap_score, [[0, 1]], [[0, 1], [0, 1]])
assert_raises(ValueError, lrap_score, [[0], [1]], [[0, 1], [0, 1]])
assert_raises(ValueError, lrap_score, [[0, 1], [0, 1]], [[0], [1]])
def check_lrap_only_ties(lrap_score):
# Check tie handling in score
# Basic check with only ties and increasing label space
for n_labels in range(2, 10):
y_score = np.ones((1, n_labels))
# Check for growing number of consecutive relevant
for n_relevant in range(1, n_labels):
# Check for a bunch of positions
for pos in range(n_labels - n_relevant):
y_true = np.zeros((1, n_labels))
y_true[0, pos:pos + n_relevant] = 1
assert_almost_equal(lrap_score(y_true, y_score),
n_relevant / n_labels)
def check_lrap_without_tie_and_increasing_score(lrap_score):
# Check that Label ranking average precision works for various
# Basic check with increasing label space size and decreasing score
for n_labels in range(2, 10):
y_score = n_labels - (np.arange(n_labels).reshape((1, n_labels)) + 1)
# First and last
y_true = np.zeros((1, n_labels))
y_true[0, 0] = 1
y_true[0, -1] = 1
assert_almost_equal(lrap_score(y_true, y_score),
(2 / n_labels + 1) / 2)
# Check for growing number of consecutive relevant label
for n_relevant in range(1, n_labels):
# Check for a bunch of position
for pos in range(n_labels - n_relevant):
y_true = np.zeros((1, n_labels))
y_true[0, pos:pos + n_relevant] = 1
assert_almost_equal(lrap_score(y_true, y_score),
sum((r + 1) / ((pos + r + 1) * n_relevant)
for r in range(n_relevant)))
def _my_lrap(y_true, y_score):
"""Simple implementation of label ranking average precision"""
check_consistent_length(y_true, y_score)
y_true = check_array(y_true)
y_score = check_array(y_score)
n_samples, n_labels = y_true.shape
score = np.empty((n_samples, ))
for i in range(n_samples):
# The best rank correspond to 1. Rank higher than 1 are worse.
# The best inverse ranking correspond to n_labels.
unique_rank, inv_rank = np.unique(y_score[i], return_inverse=True)
n_ranks = unique_rank.size
rank = n_ranks - inv_rank
# Rank need to be corrected to take into account ties
# ex: rank 1 ex aequo means that both label are rank 2.
corr_rank = np.bincount(rank, minlength=n_ranks + 1).cumsum()
rank = corr_rank[rank]
relevant = y_true[i].nonzero()[0]
if relevant.size == 0 or relevant.size == n_labels:
score[i] = 1
continue
score[i] = 0.
for label in relevant:
# Let's count the number of relevant label with better rank
# (smaller rank).
n_ranked_above = sum(rank[r] <= rank[label] for r in relevant)
# Weight by the rank of the actual label
score[i] += n_ranked_above / rank[label]
score[i] /= relevant.size
return score.mean()
def check_alternative_lrap_implementation(lrap_score, n_classes=5,
n_samples=20, random_state=0):
_, y_true = make_multilabel_classification(n_features=1,
allow_unlabeled=False,
random_state=random_state,
n_classes=n_classes,
n_samples=n_samples)
# Score with ties
y_score = sparse_random_matrix(n_components=y_true.shape[0],
n_features=y_true.shape[1],
random_state=random_state)
if hasattr(y_score, "toarray"):
y_score = y_score.toarray()
score_lrap = label_ranking_average_precision_score(y_true, y_score)
score_my_lrap = _my_lrap(y_true, y_score)
assert_almost_equal(score_lrap, score_my_lrap)
# Uniform score
random_state = check_random_state(random_state)
y_score = random_state.uniform(size=(n_samples, n_classes))
score_lrap = label_ranking_average_precision_score(y_true, y_score)
score_my_lrap = _my_lrap(y_true, y_score)
assert_almost_equal(score_lrap, score_my_lrap)
def test_label_ranking_avp():
for fn in [label_ranking_average_precision_score, _my_lrap]:
yield check_lrap_toy, fn
yield check_lrap_without_tie_and_increasing_score, fn
yield check_lrap_only_ties, fn
yield check_zero_or_all_relevant_labels, fn
yield check_lrap_error_raised, label_ranking_average_precision_score
for n_samples, n_classes, random_state in product((1, 2, 8, 20),
(2, 5, 10),
range(1)):
yield (check_alternative_lrap_implementation,
label_ranking_average_precision_score,
n_classes, n_samples, random_state)
def test_coverage_error():
# Toy case
assert_almost_equal(coverage_error([[0, 1]], [[0.25, 0.75]]), 1)
assert_almost_equal(coverage_error([[0, 1]], [[0.75, 0.25]]), 2)
assert_almost_equal(coverage_error([[1, 1]], [[0.75, 0.25]]), 2)
assert_almost_equal(coverage_error([[0, 0]], [[0.75, 0.25]]), 0)
assert_almost_equal(coverage_error([[0, 0, 0]], [[0.25, 0.5, 0.75]]), 0)
assert_almost_equal(coverage_error([[0, 0, 1]], [[0.25, 0.5, 0.75]]), 1)
assert_almost_equal(coverage_error([[0, 1, 0]], [[0.25, 0.5, 0.75]]), 2)
assert_almost_equal(coverage_error([[0, 1, 1]], [[0.25, 0.5, 0.75]]), 2)
assert_almost_equal(coverage_error([[1, 0, 0]], [[0.25, 0.5, 0.75]]), 3)
assert_almost_equal(coverage_error([[1, 0, 1]], [[0.25, 0.5, 0.75]]), 3)
assert_almost_equal(coverage_error([[1, 1, 0]], [[0.25, 0.5, 0.75]]), 3)
assert_almost_equal(coverage_error([[1, 1, 1]], [[0.25, 0.5, 0.75]]), 3)
assert_almost_equal(coverage_error([[0, 0, 0]], [[0.75, 0.5, 0.25]]), 0)
assert_almost_equal(coverage_error([[0, 0, 1]], [[0.75, 0.5, 0.25]]), 3)
assert_almost_equal(coverage_error([[0, 1, 0]], [[0.75, 0.5, 0.25]]), 2)
assert_almost_equal(coverage_error([[0, 1, 1]], [[0.75, 0.5, 0.25]]), 3)
assert_almost_equal(coverage_error([[1, 0, 0]], [[0.75, 0.5, 0.25]]), 1)
assert_almost_equal(coverage_error([[1, 0, 1]], [[0.75, 0.5, 0.25]]), 3)
assert_almost_equal(coverage_error([[1, 1, 0]], [[0.75, 0.5, 0.25]]), 2)
assert_almost_equal(coverage_error([[1, 1, 1]], [[0.75, 0.5, 0.25]]), 3)
assert_almost_equal(coverage_error([[0, 0, 0]], [[0.5, 0.75, 0.25]]), 0)
assert_almost_equal(coverage_error([[0, 0, 1]], [[0.5, 0.75, 0.25]]), 3)
assert_almost_equal(coverage_error([[0, 1, 0]], [[0.5, 0.75, 0.25]]), 1)
assert_almost_equal(coverage_error([[0, 1, 1]], [[0.5, 0.75, 0.25]]), 3)
assert_almost_equal(coverage_error([[1, 0, 0]], [[0.5, 0.75, 0.25]]), 2)
assert_almost_equal(coverage_error([[1, 0, 1]], [[0.5, 0.75, 0.25]]), 3)
assert_almost_equal(coverage_error([[1, 1, 0]], [[0.5, 0.75, 0.25]]), 2)
assert_almost_equal(coverage_error([[1, 1, 1]], [[0.5, 0.75, 0.25]]), 3)
# Non trival case
assert_almost_equal(coverage_error([[0, 1, 0], [1, 1, 0]],
[[0.1, 10., -3], [0, 1, 3]]),
(1 + 3) / 2.)
assert_almost_equal(coverage_error([[0, 1, 0], [1, 1, 0], [0, 1, 1]],
[[0.1, 10, -3], [0, 1, 3], [0, 2, 0]]),
(1 + 3 + 3) / 3.)
assert_almost_equal(coverage_error([[0, 1, 0], [1, 1, 0], [0, 1, 1]],
[[0.1, 10, -3], [3, 1, 3], [0, 2, 0]]),
(1 + 3 + 3) / 3.)
def test_coverage_tie_handling():
assert_almost_equal(coverage_error([[0, 0]], [[0.5, 0.5]]), 0)
assert_almost_equal(coverage_error([[1, 0]], [[0.5, 0.5]]), 2)
assert_almost_equal(coverage_error([[0, 1]], [[0.5, 0.5]]), 2)
assert_almost_equal(coverage_error([[1, 1]], [[0.5, 0.5]]), 2)
assert_almost_equal(coverage_error([[0, 0, 0]], [[0.25, 0.5, 0.5]]), 0)
assert_almost_equal(coverage_error([[0, 0, 1]], [[0.25, 0.5, 0.5]]), 2)
assert_almost_equal(coverage_error([[0, 1, 0]], [[0.25, 0.5, 0.5]]), 2)
assert_almost_equal(coverage_error([[0, 1, 1]], [[0.25, 0.5, 0.5]]), 2)
assert_almost_equal(coverage_error([[1, 0, 0]], [[0.25, 0.5, 0.5]]), 3)
assert_almost_equal(coverage_error([[1, 0, 1]], [[0.25, 0.5, 0.5]]), 3)
assert_almost_equal(coverage_error([[1, 1, 0]], [[0.25, 0.5, 0.5]]), 3)
assert_almost_equal(coverage_error([[1, 1, 1]], [[0.25, 0.5, 0.5]]), 3)
def test_label_ranking_loss():
assert_almost_equal(label_ranking_loss([[0, 1]], [[0.25, 0.75]]), 0)
assert_almost_equal(label_ranking_loss([[0, 1]], [[0.75, 0.25]]), 1)
assert_almost_equal(label_ranking_loss([[0, 0, 1]], [[0.25, 0.5, 0.75]]),
0)
assert_almost_equal(label_ranking_loss([[0, 1, 0]], [[0.25, 0.5, 0.75]]),
1 / 2)
assert_almost_equal(label_ranking_loss([[0, 1, 1]], [[0.25, 0.5, 0.75]]),
0)
assert_almost_equal(label_ranking_loss([[1, 0, 0]], [[0.25, 0.5, 0.75]]),
2 / 2)
assert_almost_equal(label_ranking_loss([[1, 0, 1]], [[0.25, 0.5, 0.75]]),
1 / 2)
assert_almost_equal(label_ranking_loss([[1, 1, 0]], [[0.25, 0.5, 0.75]]),
2 / 2)
# Undefined metrics - the ranking doesn't matter
assert_almost_equal(label_ranking_loss([[0, 0]], [[0.75, 0.25]]), 0)
assert_almost_equal(label_ranking_loss([[1, 1]], [[0.75, 0.25]]), 0)
assert_almost_equal(label_ranking_loss([[0, 0]], [[0.5, 0.5]]), 0)
assert_almost_equal(label_ranking_loss([[1, 1]], [[0.5, 0.5]]), 0)
assert_almost_equal(label_ranking_loss([[0, 0, 0]], [[0.5, 0.75, 0.25]]),
0)
assert_almost_equal(label_ranking_loss([[1, 1, 1]], [[0.5, 0.75, 0.25]]),
0)
assert_almost_equal(label_ranking_loss([[0, 0, 0]], [[0.25, 0.5, 0.5]]),
0)
assert_almost_equal(label_ranking_loss([[1, 1, 1]], [[0.25, 0.5, 0.5]]), 0)
# Non trival case
assert_almost_equal(label_ranking_loss([[0, 1, 0], [1, 1, 0]],
[[0.1, 10., -3], [0, 1, 3]]),
(0 + 2 / 2) / 2.)
assert_almost_equal(label_ranking_loss(
[[0, 1, 0], [1, 1, 0], [0, 1, 1]],
[[0.1, 10, -3], [0, 1, 3], [0, 2, 0]]),
(0 + 2 / 2 + 1 / 2) / 3.)
assert_almost_equal(label_ranking_loss(
[[0, 1, 0], [1, 1, 0], [0, 1, 1]],
[[0.1, 10, -3], [3, 1, 3], [0, 2, 0]]),
(0 + 2 / 2 + 1 / 2) / 3.)
# Sparse csr matrices
assert_almost_equal(label_ranking_loss(
csr_matrix(np.array([[0, 1, 0], [1, 1, 0]])),
[[0.1, 10, -3], [3, 1, 3]]),
(0 + 2 / 2) / 2.)
def test_ranking_appropriate_input_shape():
# Check that y_true.shape != y_score.shape raise the proper exception
assert_raises(ValueError, label_ranking_loss, [[0, 1], [0, 1]], [0, 1])
assert_raises(ValueError, label_ranking_loss, [[0, 1], [0, 1]], [[0, 1]])
assert_raises(ValueError, label_ranking_loss,
[[0, 1], [0, 1]], [[0], [1]])
assert_raises(ValueError, label_ranking_loss, [[0, 1]], [[0, 1], [0, 1]])
assert_raises(ValueError, label_ranking_loss,
[[0], [1]], [[0, 1], [0, 1]])
assert_raises(ValueError, label_ranking_loss, [[0, 1], [0, 1]], [[0], [1]])
def test_ranking_loss_ties_handling():
# Tie handling
assert_almost_equal(label_ranking_loss([[1, 0]], [[0.5, 0.5]]), 1)
assert_almost_equal(label_ranking_loss([[0, 1]], [[0.5, 0.5]]), 1)
assert_almost_equal(label_ranking_loss([[0, 0, 1]], [[0.25, 0.5, 0.5]]),
1 / 2)
assert_almost_equal(label_ranking_loss([[0, 1, 0]], [[0.25, 0.5, 0.5]]),
1 / 2)
assert_almost_equal(label_ranking_loss([[0, 1, 1]], [[0.25, 0.5, 0.5]]), 0)
assert_almost_equal(label_ranking_loss([[1, 0, 0]], [[0.25, 0.5, 0.5]]), 1)
assert_almost_equal(label_ranking_loss([[1, 0, 1]], [[0.25, 0.5, 0.5]]), 1)
assert_almost_equal(label_ranking_loss([[1, 1, 0]], [[0.25, 0.5, 0.5]]), 1)
| 43,099 | 40.885326 | 82 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/tests/test_classification.py | from __future__ import division, print_function
import numpy as np
from scipy import linalg
from functools import partial
from itertools import product
import warnings
from sklearn import datasets
from sklearn import svm
from sklearn.datasets import make_multilabel_classification
from sklearn.preprocessing import label_binarize
from sklearn.utils.validation import check_random_state
from sklearn.utils.testing import assert_raises, clean_warning_registry
from sklearn.utils.testing import assert_raise_message
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import assert_no_warnings
from sklearn.utils.testing import assert_warns_message
from sklearn.utils.testing import assert_not_equal
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.mocking import MockDataFrame
from sklearn.metrics import accuracy_score
from sklearn.metrics import average_precision_score
from sklearn.metrics import classification_report
from sklearn.metrics import cohen_kappa_score
from sklearn.metrics import confusion_matrix
from sklearn.metrics import f1_score
from sklearn.metrics import fbeta_score
from sklearn.metrics import hamming_loss
from sklearn.metrics import hinge_loss
from sklearn.metrics import jaccard_similarity_score
from sklearn.metrics import log_loss
from sklearn.metrics import matthews_corrcoef
from sklearn.metrics import precision_recall_fscore_support
from sklearn.metrics import precision_score
from sklearn.metrics import recall_score
from sklearn.metrics import zero_one_loss
from sklearn.metrics import brier_score_loss
from sklearn.metrics.classification import _check_targets
from sklearn.exceptions import UndefinedMetricWarning
from scipy.spatial.distance import hamming as sp_hamming
###############################################################################
# Utilities for testing
def make_prediction(dataset=None, binary=False):
"""Make some classification predictions on a toy dataset using a SVC
If binary is True restrict to a binary classification problem instead of a
multiclass classification problem
"""
if dataset is None:
# import some data to play with
dataset = datasets.load_iris()
X = dataset.data
y = dataset.target
if binary:
# restrict to a binary classification task
X, y = X[y < 2], y[y < 2]
n_samples, n_features = X.shape
p = np.arange(n_samples)
rng = check_random_state(37)
rng.shuffle(p)
X, y = X[p], y[p]
half = int(n_samples / 2)
# add noisy features to make the problem harder and avoid perfect results
rng = np.random.RandomState(0)
X = np.c_[X, rng.randn(n_samples, 200 * n_features)]
# run classifier, get class probabilities and label predictions
clf = svm.SVC(kernel='linear', probability=True, random_state=0)
probas_pred = clf.fit(X[:half], y[:half]).predict_proba(X[half:])
if binary:
# only interested in probabilities of the positive case
# XXX: do we really want a special API for the binary case?
probas_pred = probas_pred[:, 1]
y_pred = clf.predict(X[half:])
y_true = y[half:]
return y_true, y_pred, probas_pred
###############################################################################
# Tests
def test_multilabel_accuracy_score_subset_accuracy():
# Dense label indicator matrix format
y1 = np.array([[0, 1, 1], [1, 0, 1]])
y2 = np.array([[0, 0, 1], [1, 0, 1]])
assert_equal(accuracy_score(y1, y2), 0.5)
assert_equal(accuracy_score(y1, y1), 1)
assert_equal(accuracy_score(y2, y2), 1)
assert_equal(accuracy_score(y2, np.logical_not(y2)), 0)
assert_equal(accuracy_score(y1, np.logical_not(y1)), 0)
assert_equal(accuracy_score(y1, np.zeros(y1.shape)), 0)
assert_equal(accuracy_score(y2, np.zeros(y1.shape)), 0)
def test_precision_recall_f1_score_binary():
# Test Precision Recall and F1 Score for binary classification task
y_true, y_pred, _ = make_prediction(binary=True)
# detailed measures for each class
p, r, f, s = precision_recall_fscore_support(y_true, y_pred, average=None)
assert_array_almost_equal(p, [0.73, 0.85], 2)
assert_array_almost_equal(r, [0.88, 0.68], 2)
assert_array_almost_equal(f, [0.80, 0.76], 2)
assert_array_equal(s, [25, 25])
# individual scoring function that can be used for grid search: in the
# binary class case the score is the value of the measure for the positive
# class (e.g. label == 1). This is deprecated for average != 'binary'.
for kwargs, my_assert in [({}, assert_no_warnings),
({'average': 'binary'}, assert_no_warnings)]:
ps = my_assert(precision_score, y_true, y_pred, **kwargs)
assert_array_almost_equal(ps, 0.85, 2)
rs = my_assert(recall_score, y_true, y_pred, **kwargs)
assert_array_almost_equal(rs, 0.68, 2)
fs = my_assert(f1_score, y_true, y_pred, **kwargs)
assert_array_almost_equal(fs, 0.76, 2)
assert_almost_equal(my_assert(fbeta_score, y_true, y_pred, beta=2,
**kwargs),
(1 + 2 ** 2) * ps * rs / (2 ** 2 * ps + rs), 2)
def test_precision_recall_f_binary_single_class():
# Test precision, recall and F1 score behave with a single positive or
# negative class
# Such a case may occur with non-stratified cross-validation
assert_equal(1., precision_score([1, 1], [1, 1]))
assert_equal(1., recall_score([1, 1], [1, 1]))
assert_equal(1., f1_score([1, 1], [1, 1]))
assert_equal(0., precision_score([-1, -1], [-1, -1]))
assert_equal(0., recall_score([-1, -1], [-1, -1]))
assert_equal(0., f1_score([-1, -1], [-1, -1]))
@ignore_warnings
def test_precision_recall_f_extra_labels():
# Test handling of explicit additional (not in input) labels to PRF
y_true = [1, 3, 3, 2]
y_pred = [1, 1, 3, 2]
y_true_bin = label_binarize(y_true, classes=np.arange(5))
y_pred_bin = label_binarize(y_pred, classes=np.arange(5))
data = [(y_true, y_pred),
(y_true_bin, y_pred_bin)]
for i, (y_true, y_pred) in enumerate(data):
# No average: zeros in array
actual = recall_score(y_true, y_pred, labels=[0, 1, 2, 3, 4],
average=None)
assert_array_almost_equal([0., 1., 1., .5, 0.], actual)
# Macro average is changed
actual = recall_score(y_true, y_pred, labels=[0, 1, 2, 3, 4],
average='macro')
assert_array_almost_equal(np.mean([0., 1., 1., .5, 0.]), actual)
# No effect otheriwse
for average in ['micro', 'weighted', 'samples']:
if average == 'samples' and i == 0:
continue
assert_almost_equal(recall_score(y_true, y_pred,
labels=[0, 1, 2, 3, 4],
average=average),
recall_score(y_true, y_pred, labels=None,
average=average))
# Error when introducing invalid label in multilabel case
# (although it would only affect performance if average='macro'/None)
for average in [None, 'macro', 'micro', 'samples']:
assert_raises(ValueError, recall_score, y_true_bin, y_pred_bin,
labels=np.arange(6), average=average)
assert_raises(ValueError, recall_score, y_true_bin, y_pred_bin,
labels=np.arange(-1, 4), average=average)
@ignore_warnings
def test_precision_recall_f_ignored_labels():
# Test a subset of labels may be requested for PRF
y_true = [1, 1, 2, 3]
y_pred = [1, 3, 3, 3]
y_true_bin = label_binarize(y_true, classes=np.arange(5))
y_pred_bin = label_binarize(y_pred, classes=np.arange(5))
data = [(y_true, y_pred),
(y_true_bin, y_pred_bin)]
for i, (y_true, y_pred) in enumerate(data):
recall_13 = partial(recall_score, y_true, y_pred, labels=[1, 3])
recall_all = partial(recall_score, y_true, y_pred, labels=None)
assert_array_almost_equal([.5, 1.], recall_13(average=None))
assert_almost_equal((.5 + 1.) / 2, recall_13(average='macro'))
assert_almost_equal((.5 * 2 + 1. * 1) / 3,
recall_13(average='weighted'))
assert_almost_equal(2. / 3, recall_13(average='micro'))
# ensure the above were meaningful tests:
for average in ['macro', 'weighted', 'micro']:
assert_not_equal(recall_13(average=average),
recall_all(average=average))
def test_average_precision_score_score_non_binary_class():
# Test that average_precision_score function returns an error when trying
# to compute average_precision_score for multiclass task.
rng = check_random_state(404)
y_pred = rng.rand(10)
# y_true contains three different class values
y_true = rng.randint(0, 3, size=10)
assert_raise_message(ValueError, "multiclass format is not supported",
average_precision_score, y_true, y_pred)
def test_average_precision_score_duplicate_values():
# Duplicate values with precision-recall require a different
# processing than when computing the AUC of a ROC, because the
# precision-recall curve is a decreasing curve
# The following situation corresponds to a perfect
# test statistic, the average_precision_score should be 1
y_true = [0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1]
y_score = [0, .1, .1, .4, .5, .6, .6, .9, .9, 1, 1]
assert_equal(average_precision_score(y_true, y_score), 1)
def test_average_precision_score_tied_values():
# Here if we go from left to right in y_true, the 0 values are
# are separated from the 1 values, so it appears that we've
# Correctly sorted our classifications. But in fact the first two
# values have the same score (0.5) and so the first two values
# could be swapped around, creating an imperfect sorting. This
# imperfection should come through in the end score, making it less
# than one.
y_true = [0, 1, 1]
y_score = [.5, .5, .6]
assert_not_equal(average_precision_score(y_true, y_score), 1.)
@ignore_warnings
def test_precision_recall_fscore_support_errors():
y_true, y_pred, _ = make_prediction(binary=True)
# Bad beta
assert_raises(ValueError, precision_recall_fscore_support,
y_true, y_pred, beta=0.0)
# Bad pos_label
assert_raises(ValueError, precision_recall_fscore_support,
y_true, y_pred, pos_label=2, average='binary')
# Bad average option
assert_raises(ValueError, precision_recall_fscore_support,
[0, 1, 2], [1, 2, 0], average='mega')
def test_precision_recall_f_unused_pos_label():
# Check warning that pos_label unused when set to non-default value
# but average != 'binary'; even if data is binary.
assert_warns_message(UserWarning,
"Note that pos_label (set to 2) is "
"ignored when average != 'binary' (got 'macro'). You "
"may use labels=[pos_label] to specify a single "
"positive class.", precision_recall_fscore_support,
[1, 2, 1], [1, 2, 2], pos_label=2, average='macro')
def test_confusion_matrix_binary():
# Test confusion matrix - binary classification case
y_true, y_pred, _ = make_prediction(binary=True)
def test(y_true, y_pred):
cm = confusion_matrix(y_true, y_pred)
assert_array_equal(cm, [[22, 3], [8, 17]])
tp, fp, fn, tn = cm.flatten()
num = (tp * tn - fp * fn)
den = np.sqrt((tp + fp) * (tp + fn) * (tn + fp) * (tn + fn))
true_mcc = 0 if den == 0 else num / den
mcc = matthews_corrcoef(y_true, y_pred)
assert_array_almost_equal(mcc, true_mcc, decimal=2)
assert_array_almost_equal(mcc, 0.57, decimal=2)
test(y_true, y_pred)
test([str(y) for y in y_true],
[str(y) for y in y_pred])
def test_cohen_kappa():
# These label vectors reproduce the contingency matrix from Artstein and
# Poesio (2008), Table 1: np.array([[20, 20], [10, 50]]).
y1 = np.array([0] * 40 + [1] * 60)
y2 = np.array([0] * 20 + [1] * 20 + [0] * 10 + [1] * 50)
kappa = cohen_kappa_score(y1, y2)
assert_almost_equal(kappa, .348, decimal=3)
assert_equal(kappa, cohen_kappa_score(y2, y1))
# Add spurious labels and ignore them.
y1 = np.append(y1, [2] * 4)
y2 = np.append(y2, [2] * 4)
assert_equal(cohen_kappa_score(y1, y2, labels=[0, 1]), kappa)
assert_almost_equal(cohen_kappa_score(y1, y1), 1.)
# Multiclass example: Artstein and Poesio, Table 4.
y1 = np.array([0] * 46 + [1] * 44 + [2] * 10)
y2 = np.array([0] * 52 + [1] * 32 + [2] * 16)
assert_almost_equal(cohen_kappa_score(y1, y2), .8013, decimal=4)
# Weighting example: none, linear, quadratic.
y1 = np.array([0] * 46 + [1] * 44 + [2] * 10)
y2 = np.array([0] * 50 + [1] * 40 + [2] * 10)
assert_almost_equal(cohen_kappa_score(y1, y2), .9315, decimal=4)
assert_almost_equal(cohen_kappa_score(y1, y2, weights="linear"), .9412, decimal=4)
assert_almost_equal(cohen_kappa_score(y1, y2, weights="quadratic"), .9541, decimal=4)
@ignore_warnings
def test_matthews_corrcoef_nan():
assert_equal(matthews_corrcoef([0], [1]), 0.0)
assert_equal(matthews_corrcoef([0, 0], [0, 1]), 0.0)
def test_matthews_corrcoef_against_numpy_corrcoef():
rng = np.random.RandomState(0)
y_true = rng.randint(0, 2, size=20)
y_pred = rng.randint(0, 2, size=20)
assert_almost_equal(matthews_corrcoef(y_true, y_pred),
np.corrcoef(y_true, y_pred)[0, 1], 10)
def test_matthews_corrcoef_against_jurman():
# Check that the multiclass matthews_corrcoef agrees with the definition
# presented in Jurman, Riccadonna, Furlanello, (2012). A Comparison of MCC
# and CEN Error Measures in MultiClass Prediction
rng = np.random.RandomState(0)
y_true = rng.randint(0, 2, size=20)
y_pred = rng.randint(0, 2, size=20)
sample_weight = rng.rand(20)
C = confusion_matrix(y_true, y_pred, sample_weight=sample_weight)
N = len(C)
cov_ytyp = sum([
C[k, k] * C[m, l] - C[l, k] * C[k, m]
for k in range(N) for m in range(N) for l in range(N)
])
cov_ytyt = sum([
C[:, k].sum() *
np.sum([C[g, f] for f in range(N) for g in range(N) if f != k])
for k in range(N)
])
cov_ypyp = np.sum([
C[k, :].sum() *
np.sum([C[f, g] for f in range(N) for g in range(N) if f != k])
for k in range(N)
])
mcc_jurman = cov_ytyp / np.sqrt(cov_ytyt * cov_ypyp)
mcc_ours = matthews_corrcoef(y_true, y_pred, sample_weight)
assert_almost_equal(mcc_ours, mcc_jurman, 10)
def test_matthews_corrcoef():
rng = np.random.RandomState(0)
y_true = ["a" if i == 0 else "b" for i in rng.randint(0, 2, size=20)]
# corrcoef of same vectors must be 1
assert_almost_equal(matthews_corrcoef(y_true, y_true), 1.0)
# corrcoef, when the two vectors are opposites of each other, should be -1
y_true_inv = ["b" if i == "a" else "a" for i in y_true]
assert_almost_equal(matthews_corrcoef(y_true, y_true_inv), -1)
y_true_inv2 = label_binarize(y_true, ["a", "b"])
y_true_inv2 = np.where(y_true_inv2, 'a', 'b')
assert_almost_equal(matthews_corrcoef(y_true, y_true_inv2), -1)
# For the zero vector case, the corrcoef cannot be calculated and should
# result in a RuntimeWarning
mcc = assert_warns_message(RuntimeWarning, 'invalid value encountered',
matthews_corrcoef, [0, 0, 0, 0], [0, 0, 0, 0])
# But will output 0
assert_almost_equal(mcc, 0.)
# And also for any other vector with 0 variance
mcc = assert_warns_message(RuntimeWarning, 'invalid value encountered',
matthews_corrcoef, y_true, ['a'] * len(y_true))
# But will output 0
assert_almost_equal(mcc, 0.)
# These two vectors have 0 correlation and hence mcc should be 0
y_1 = [1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1]
y_2 = [1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1]
assert_almost_equal(matthews_corrcoef(y_1, y_2), 0.)
# Check that sample weight is able to selectively exclude
mask = [1] * 10 + [0] * 10
# Now the first half of the vector elements are alone given a weight of 1
# and hence the mcc will not be a perfect 0 as in the previous case
assert_raises(AssertionError, assert_almost_equal,
matthews_corrcoef(y_1, y_2, sample_weight=mask), 0.)
def test_matthews_corrcoef_multiclass():
rng = np.random.RandomState(0)
ord_a = ord('a')
n_classes = 4
y_true = [chr(ord_a + i) for i in rng.randint(0, n_classes, size=20)]
# corrcoef of same vectors must be 1
assert_almost_equal(matthews_corrcoef(y_true, y_true), 1.0)
# with multiclass > 2 it is not possible to achieve -1
y_true = [0, 0, 1, 1, 2, 2]
y_pred_bad = [2, 2, 0, 0, 1, 1]
assert_almost_equal(matthews_corrcoef(y_true, y_pred_bad), -.5)
# Maximizing false positives and negatives minimizes the MCC
# The minimum will be different for depending on the input
y_true = [0, 0, 1, 1, 2, 2]
y_pred_min = [1, 1, 0, 0, 0, 0]
assert_almost_equal(matthews_corrcoef(y_true, y_pred_min),
-12 / np.sqrt(24 * 16))
# Zero variance will result in an mcc of zero and a Runtime Warning
y_true = [0, 1, 2]
y_pred = [3, 3, 3]
mcc = assert_warns_message(RuntimeWarning, 'invalid value encountered',
matthews_corrcoef, y_true, y_pred)
assert_almost_equal(mcc, 0.0)
# These two vectors have 0 correlation and hence mcc should be 0
y_1 = [0, 1, 2, 0, 1, 2, 0, 1, 2]
y_2 = [1, 1, 1, 2, 2, 2, 0, 0, 0]
assert_almost_equal(matthews_corrcoef(y_1, y_2), 0.)
# We can test that binary assumptions hold using the multiclass computation
# by masking the weight of samples not in the first two classes
# Masking the last label should let us get an MCC of -1
y_true = [0, 0, 1, 1, 2]
y_pred = [1, 1, 0, 0, 2]
sample_weight = [1, 1, 1, 1, 0]
assert_almost_equal(matthews_corrcoef(y_true, y_pred, sample_weight), -1)
# For the zero vector case, the corrcoef cannot be calculated and should
# result in a RuntimeWarning
y_true = [0, 0, 1, 2]
y_pred = [0, 0, 1, 2]
sample_weight = [1, 1, 0, 0]
mcc = assert_warns_message(RuntimeWarning, 'invalid value encountered',
matthews_corrcoef, y_true, y_pred,
sample_weight)
# But will output 0
assert_almost_equal(mcc, 0.)
def test_matthews_corrcoef_overflow():
# https://github.com/scikit-learn/scikit-learn/issues/9622
rng = np.random.RandomState(20170906)
def mcc_safe(y_true, y_pred):
conf_matrix = confusion_matrix(y_true, y_pred)
true_pos = conf_matrix[1, 1]
false_pos = conf_matrix[1, 0]
false_neg = conf_matrix[0, 1]
n_points = len(y_true)
pos_rate = (true_pos + false_neg) / n_points
activity = (true_pos + false_pos) / n_points
mcc_numerator = true_pos / n_points - pos_rate * activity
mcc_denominator = activity * pos_rate * (1 - activity) * (1 - pos_rate)
return mcc_numerator / np.sqrt(mcc_denominator)
def random_ys(n_points): # binary
x_true = rng.random_sample(n_points)
x_pred = x_true + 0.2 * (rng.random_sample(n_points) - 0.5)
y_true = (x_true > 0.5)
y_pred = (x_pred > 0.5)
return y_true, y_pred
for n_points in [100, 10000, 1000000]:
arr = np.repeat([0., 1.], n_points) # binary
assert_almost_equal(matthews_corrcoef(arr, arr), 1.0)
arr = np.repeat([0., 1., 2.], n_points) # multiclass
assert_almost_equal(matthews_corrcoef(arr, arr), 1.0)
y_true, y_pred = random_ys(n_points)
assert_almost_equal(matthews_corrcoef(y_true, y_true), 1.0)
assert_almost_equal(matthews_corrcoef(y_true, y_pred),
mcc_safe(y_true, y_pred))
def test_precision_recall_f1_score_multiclass():
# Test Precision Recall and F1 Score for multiclass classification task
y_true, y_pred, _ = make_prediction(binary=False)
# compute scores with default labels introspection
p, r, f, s = precision_recall_fscore_support(y_true, y_pred, average=None)
assert_array_almost_equal(p, [0.83, 0.33, 0.42], 2)
assert_array_almost_equal(r, [0.79, 0.09, 0.90], 2)
assert_array_almost_equal(f, [0.81, 0.15, 0.57], 2)
assert_array_equal(s, [24, 31, 20])
# averaging tests
ps = precision_score(y_true, y_pred, pos_label=1, average='micro')
assert_array_almost_equal(ps, 0.53, 2)
rs = recall_score(y_true, y_pred, average='micro')
assert_array_almost_equal(rs, 0.53, 2)
fs = f1_score(y_true, y_pred, average='micro')
assert_array_almost_equal(fs, 0.53, 2)
ps = precision_score(y_true, y_pred, average='macro')
assert_array_almost_equal(ps, 0.53, 2)
rs = recall_score(y_true, y_pred, average='macro')
assert_array_almost_equal(rs, 0.60, 2)
fs = f1_score(y_true, y_pred, average='macro')
assert_array_almost_equal(fs, 0.51, 2)
ps = precision_score(y_true, y_pred, average='weighted')
assert_array_almost_equal(ps, 0.51, 2)
rs = recall_score(y_true, y_pred, average='weighted')
assert_array_almost_equal(rs, 0.53, 2)
fs = f1_score(y_true, y_pred, average='weighted')
assert_array_almost_equal(fs, 0.47, 2)
assert_raises(ValueError, precision_score, y_true, y_pred,
average="samples")
assert_raises(ValueError, recall_score, y_true, y_pred, average="samples")
assert_raises(ValueError, f1_score, y_true, y_pred, average="samples")
assert_raises(ValueError, fbeta_score, y_true, y_pred, average="samples",
beta=0.5)
# same prediction but with and explicit label ordering
p, r, f, s = precision_recall_fscore_support(
y_true, y_pred, labels=[0, 2, 1], average=None)
assert_array_almost_equal(p, [0.83, 0.41, 0.33], 2)
assert_array_almost_equal(r, [0.79, 0.90, 0.10], 2)
assert_array_almost_equal(f, [0.81, 0.57, 0.15], 2)
assert_array_equal(s, [24, 20, 31])
def test_precision_refcall_f1_score_multilabel_unordered_labels():
# test that labels need not be sorted in the multilabel case
y_true = np.array([[1, 1, 0, 0]])
y_pred = np.array([[0, 0, 1, 1]])
for average in ['samples', 'micro', 'macro', 'weighted', None]:
p, r, f, s = precision_recall_fscore_support(
y_true, y_pred, labels=[3, 0, 1, 2], warn_for=[], average=average)
assert_array_equal(p, 0)
assert_array_equal(r, 0)
assert_array_equal(f, 0)
if average is None:
assert_array_equal(s, [0, 1, 1, 0])
def test_precision_recall_f1_score_binary_averaged():
y_true = np.array([0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1])
y_pred = np.array([1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1])
# compute scores with default labels introspection
ps, rs, fs, _ = precision_recall_fscore_support(y_true, y_pred,
average=None)
p, r, f, _ = precision_recall_fscore_support(y_true, y_pred,
average='macro')
assert_equal(p, np.mean(ps))
assert_equal(r, np.mean(rs))
assert_equal(f, np.mean(fs))
p, r, f, _ = precision_recall_fscore_support(y_true, y_pred,
average='weighted')
support = np.bincount(y_true)
assert_equal(p, np.average(ps, weights=support))
assert_equal(r, np.average(rs, weights=support))
assert_equal(f, np.average(fs, weights=support))
def test_zero_precision_recall():
# Check that pathological cases do not bring NaNs
old_error_settings = np.seterr(all='raise')
try:
y_true = np.array([0, 1, 2, 0, 1, 2])
y_pred = np.array([2, 0, 1, 1, 2, 0])
assert_almost_equal(precision_score(y_true, y_pred,
average='macro'), 0.0, 2)
assert_almost_equal(recall_score(y_true, y_pred, average='macro'),
0.0, 2)
assert_almost_equal(f1_score(y_true, y_pred, average='macro'),
0.0, 2)
finally:
np.seterr(**old_error_settings)
def test_confusion_matrix_multiclass():
# Test confusion matrix - multi-class case
y_true, y_pred, _ = make_prediction(binary=False)
def test(y_true, y_pred, string_type=False):
# compute confusion matrix with default labels introspection
cm = confusion_matrix(y_true, y_pred)
assert_array_equal(cm, [[19, 4, 1],
[4, 3, 24],
[0, 2, 18]])
# compute confusion matrix with explicit label ordering
labels = ['0', '2', '1'] if string_type else [0, 2, 1]
cm = confusion_matrix(y_true,
y_pred,
labels=labels)
assert_array_equal(cm, [[19, 1, 4],
[0, 18, 2],
[4, 24, 3]])
test(y_true, y_pred)
test(list(str(y) for y in y_true),
list(str(y) for y in y_pred),
string_type=True)
def test_confusion_matrix_sample_weight():
"""Test confusion matrix - case with sample_weight"""
y_true, y_pred, _ = make_prediction(binary=False)
weights = [.1] * 25 + [.2] * 25 + [.3] * 25
cm = confusion_matrix(y_true, y_pred, sample_weight=weights)
true_cm = (.1 * confusion_matrix(y_true[:25], y_pred[:25]) +
.2 * confusion_matrix(y_true[25:50], y_pred[25:50]) +
.3 * confusion_matrix(y_true[50:], y_pred[50:]))
assert_array_almost_equal(cm, true_cm)
assert_raises(
ValueError, confusion_matrix, y_true, y_pred,
sample_weight=weights[:-1])
def test_confusion_matrix_multiclass_subset_labels():
# Test confusion matrix - multi-class case with subset of labels
y_true, y_pred, _ = make_prediction(binary=False)
# compute confusion matrix with only first two labels considered
cm = confusion_matrix(y_true, y_pred, labels=[0, 1])
assert_array_equal(cm, [[19, 4],
[4, 3]])
# compute confusion matrix with explicit label ordering for only subset
# of labels
cm = confusion_matrix(y_true, y_pred, labels=[2, 1])
assert_array_equal(cm, [[18, 2],
[24, 3]])
# a label not in y_true should result in zeros for that row/column
extra_label = np.max(y_true) + 1
cm = confusion_matrix(y_true, y_pred, labels=[2, extra_label])
assert_array_equal(cm, [[18, 0],
[0, 0]])
# check for exception when none of the specified labels are in y_true
assert_raises(ValueError, confusion_matrix, y_true, y_pred,
labels=[extra_label, extra_label + 1])
def test_confusion_matrix_dtype():
y = [0, 1, 1]
weight = np.ones(len(y))
# confusion_matrix returns int64 by default
cm = confusion_matrix(y, y)
assert_equal(cm.dtype, np.int64)
# The dtype of confusion_matrix is always 64 bit
for dtype in [np.bool_, np.int32, np.uint64]:
cm = confusion_matrix(y, y, sample_weight=weight.astype(dtype))
assert_equal(cm.dtype, np.int64)
for dtype in [np.float32, np.float64, None, object]:
cm = confusion_matrix(y, y, sample_weight=weight.astype(dtype))
assert_equal(cm.dtype, np.float64)
# np.iinfo(np.uint32).max should be accumulated correctly
weight = np.ones(len(y), dtype=np.uint32) * 4294967295
cm = confusion_matrix(y, y, sample_weight=weight)
assert_equal(cm[0, 0], 4294967295)
assert_equal(cm[1, 1], 8589934590)
# np.iinfo(np.int64).max should cause an overflow
weight = np.ones(len(y), dtype=np.int64) * 9223372036854775807
cm = confusion_matrix(y, y, sample_weight=weight)
assert_equal(cm[0, 0], 9223372036854775807)
assert_equal(cm[1, 1], -2)
def test_classification_report_multiclass():
# Test performance report
iris = datasets.load_iris()
y_true, y_pred, _ = make_prediction(dataset=iris, binary=False)
# print classification report with class names
expected_report = """\
precision recall f1-score support
setosa 0.83 0.79 0.81 24
versicolor 0.33 0.10 0.15 31
virginica 0.42 0.90 0.57 20
avg / total 0.51 0.53 0.47 75
"""
report = classification_report(
y_true, y_pred, labels=np.arange(len(iris.target_names)),
target_names=iris.target_names)
assert_equal(report, expected_report)
# print classification report with label detection
expected_report = """\
precision recall f1-score support
0 0.83 0.79 0.81 24
1 0.33 0.10 0.15 31
2 0.42 0.90 0.57 20
avg / total 0.51 0.53 0.47 75
"""
report = classification_report(y_true, y_pred)
assert_equal(report, expected_report)
def test_classification_report_multiclass_with_digits():
# Test performance report with added digits in floating point values
iris = datasets.load_iris()
y_true, y_pred, _ = make_prediction(dataset=iris, binary=False)
# print classification report with class names
expected_report = """\
precision recall f1-score support
setosa 0.82609 0.79167 0.80851 24
versicolor 0.33333 0.09677 0.15000 31
virginica 0.41860 0.90000 0.57143 20
avg / total 0.51375 0.53333 0.47310 75
"""
report = classification_report(
y_true, y_pred, labels=np.arange(len(iris.target_names)),
target_names=iris.target_names, digits=5)
assert_equal(report, expected_report)
# print classification report with label detection
expected_report = """\
precision recall f1-score support
0 0.83 0.79 0.81 24
1 0.33 0.10 0.15 31
2 0.42 0.90 0.57 20
avg / total 0.51 0.53 0.47 75
"""
report = classification_report(y_true, y_pred)
assert_equal(report, expected_report)
def test_classification_report_multiclass_with_string_label():
y_true, y_pred, _ = make_prediction(binary=False)
y_true = np.array(["blue", "green", "red"])[y_true]
y_pred = np.array(["blue", "green", "red"])[y_pred]
expected_report = """\
precision recall f1-score support
blue 0.83 0.79 0.81 24
green 0.33 0.10 0.15 31
red 0.42 0.90 0.57 20
avg / total 0.51 0.53 0.47 75
"""
report = classification_report(y_true, y_pred)
assert_equal(report, expected_report)
expected_report = """\
precision recall f1-score support
a 0.83 0.79 0.81 24
b 0.33 0.10 0.15 31
c 0.42 0.90 0.57 20
avg / total 0.51 0.53 0.47 75
"""
report = classification_report(y_true, y_pred,
target_names=["a", "b", "c"])
assert_equal(report, expected_report)
def test_classification_report_multiclass_with_unicode_label():
y_true, y_pred, _ = make_prediction(binary=False)
labels = np.array([u"blue\xa2", u"green\xa2", u"red\xa2"])
y_true = labels[y_true]
y_pred = labels[y_pred]
expected_report = u"""\
precision recall f1-score support
blue\xa2 0.83 0.79 0.81 24
green\xa2 0.33 0.10 0.15 31
red\xa2 0.42 0.90 0.57 20
avg / total 0.51 0.53 0.47 75
"""
report = classification_report(y_true, y_pred)
assert_equal(report, expected_report)
def test_classification_report_multiclass_with_long_string_label():
y_true, y_pred, _ = make_prediction(binary=False)
labels = np.array(["blue", "green"*5, "red"])
y_true = labels[y_true]
y_pred = labels[y_pred]
expected_report = """\
precision recall f1-score support
blue 0.83 0.79 0.81 24
greengreengreengreengreen 0.33 0.10 0.15 31
red 0.42 0.90 0.57 20
avg / total 0.51 0.53 0.47 75
"""
report = classification_report(y_true, y_pred)
assert_equal(report, expected_report)
def test_classification_report_labels_target_names_unequal_length():
y_true = [0, 0, 2, 0, 0]
y_pred = [0, 2, 2, 0, 0]
target_names = ['class 0', 'class 1', 'class 2']
assert_warns_message(UserWarning,
"labels size, 2, does not "
"match size of target_names, 3",
classification_report,
y_true, y_pred, target_names=target_names)
def test_multilabel_classification_report():
n_classes = 4
n_samples = 50
_, y_true = make_multilabel_classification(n_features=1,
n_samples=n_samples,
n_classes=n_classes,
random_state=0)
_, y_pred = make_multilabel_classification(n_features=1,
n_samples=n_samples,
n_classes=n_classes,
random_state=1)
expected_report = """\
precision recall f1-score support
0 0.50 0.67 0.57 24
1 0.51 0.74 0.61 27
2 0.29 0.08 0.12 26
3 0.52 0.56 0.54 27
avg / total 0.45 0.51 0.46 104
"""
report = classification_report(y_true, y_pred)
assert_equal(report, expected_report)
def test_multilabel_zero_one_loss_subset():
# Dense label indicator matrix format
y1 = np.array([[0, 1, 1], [1, 0, 1]])
y2 = np.array([[0, 0, 1], [1, 0, 1]])
assert_equal(zero_one_loss(y1, y2), 0.5)
assert_equal(zero_one_loss(y1, y1), 0)
assert_equal(zero_one_loss(y2, y2), 0)
assert_equal(zero_one_loss(y2, np.logical_not(y2)), 1)
assert_equal(zero_one_loss(y1, np.logical_not(y1)), 1)
assert_equal(zero_one_loss(y1, np.zeros(y1.shape)), 1)
assert_equal(zero_one_loss(y2, np.zeros(y1.shape)), 1)
def test_multilabel_hamming_loss():
# Dense label indicator matrix format
y1 = np.array([[0, 1, 1], [1, 0, 1]])
y2 = np.array([[0, 0, 1], [1, 0, 1]])
w = np.array([1, 3])
assert_equal(hamming_loss(y1, y2), 1 / 6)
assert_equal(hamming_loss(y1, y1), 0)
assert_equal(hamming_loss(y2, y2), 0)
assert_equal(hamming_loss(y2, 1 - y2), 1)
assert_equal(hamming_loss(y1, 1 - y1), 1)
assert_equal(hamming_loss(y1, np.zeros(y1.shape)), 4 / 6)
assert_equal(hamming_loss(y2, np.zeros(y1.shape)), 0.5)
assert_equal(hamming_loss(y1, y2, sample_weight=w), 1. / 12)
assert_equal(hamming_loss(y1, 1-y2, sample_weight=w), 11. / 12)
assert_equal(hamming_loss(y1, np.zeros_like(y1), sample_weight=w), 2. / 3)
# sp_hamming only works with 1-D arrays
assert_equal(hamming_loss(y1[0], y2[0]), sp_hamming(y1[0], y2[0]))
assert_warns(DeprecationWarning, hamming_loss, y1, y2, classes=[0, 1])
def test_multilabel_jaccard_similarity_score():
# Dense label indicator matrix format
y1 = np.array([[0, 1, 1], [1, 0, 1]])
y2 = np.array([[0, 0, 1], [1, 0, 1]])
# size(y1 \inter y2) = [1, 2]
# size(y1 \union y2) = [2, 2]
assert_equal(jaccard_similarity_score(y1, y2), 0.75)
assert_equal(jaccard_similarity_score(y1, y1), 1)
assert_equal(jaccard_similarity_score(y2, y2), 1)
assert_equal(jaccard_similarity_score(y2, np.logical_not(y2)), 0)
assert_equal(jaccard_similarity_score(y1, np.logical_not(y1)), 0)
assert_equal(jaccard_similarity_score(y1, np.zeros(y1.shape)), 0)
assert_equal(jaccard_similarity_score(y2, np.zeros(y1.shape)), 0)
@ignore_warnings
def test_precision_recall_f1_score_multilabel_1():
# Test precision_recall_f1_score on a crafted multilabel example
# First crafted example
y_true = np.array([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 1]])
y_pred = np.array([[0, 1, 0, 0], [0, 1, 0, 0], [1, 0, 1, 0]])
p, r, f, s = precision_recall_fscore_support(y_true, y_pred, average=None)
# tp = [0, 1, 1, 0]
# fn = [1, 0, 0, 1]
# fp = [1, 1, 0, 0]
# Check per class
assert_array_almost_equal(p, [0.0, 0.5, 1.0, 0.0], 2)
assert_array_almost_equal(r, [0.0, 1.0, 1.0, 0.0], 2)
assert_array_almost_equal(f, [0.0, 1 / 1.5, 1, 0.0], 2)
assert_array_almost_equal(s, [1, 1, 1, 1], 2)
f2 = fbeta_score(y_true, y_pred, beta=2, average=None)
support = s
assert_array_almost_equal(f2, [0, 0.83, 1, 0], 2)
# Check macro
p, r, f, s = precision_recall_fscore_support(y_true, y_pred,
average="macro")
assert_almost_equal(p, 1.5 / 4)
assert_almost_equal(r, 0.5)
assert_almost_equal(f, 2.5 / 1.5 * 0.25)
assert_equal(s, None)
assert_almost_equal(fbeta_score(y_true, y_pred, beta=2, average="macro"),
np.mean(f2))
# Check micro
p, r, f, s = precision_recall_fscore_support(y_true, y_pred,
average="micro")
assert_almost_equal(p, 0.5)
assert_almost_equal(r, 0.5)
assert_almost_equal(f, 0.5)
assert_equal(s, None)
assert_almost_equal(fbeta_score(y_true, y_pred, beta=2,
average="micro"),
(1 + 4) * p * r / (4 * p + r))
# Check weighted
p, r, f, s = precision_recall_fscore_support(y_true, y_pred,
average="weighted")
assert_almost_equal(p, 1.5 / 4)
assert_almost_equal(r, 0.5)
assert_almost_equal(f, 2.5 / 1.5 * 0.25)
assert_equal(s, None)
assert_almost_equal(fbeta_score(y_true, y_pred, beta=2,
average="weighted"),
np.average(f2, weights=support))
# Check samples
# |h(x_i) inter y_i | = [0, 1, 1]
# |y_i| = [1, 1, 2]
# |h(x_i)| = [1, 1, 2]
p, r, f, s = precision_recall_fscore_support(y_true, y_pred,
average="samples")
assert_almost_equal(p, 0.5)
assert_almost_equal(r, 0.5)
assert_almost_equal(f, 0.5)
assert_equal(s, None)
assert_almost_equal(fbeta_score(y_true, y_pred, beta=2, average="samples"),
0.5)
@ignore_warnings
def test_precision_recall_f1_score_multilabel_2():
# Test precision_recall_f1_score on a crafted multilabel example 2
# Second crafted example
y_true = np.array([[1, 0, 0, 0], [0, 1, 0, 0], [0, 1, 1, 0]])
y_pred = np.array([[0, 0, 0, 1], [0, 0, 0, 1], [1, 1, 0, 0]])
# tp = [ 0. 1. 0. 0.]
# fp = [ 1. 0. 0. 2.]
# fn = [ 1. 1. 1. 0.]
p, r, f, s = precision_recall_fscore_support(y_true, y_pred,
average=None)
assert_array_almost_equal(p, [0.0, 1.0, 0.0, 0.0], 2)
assert_array_almost_equal(r, [0.0, 0.5, 0.0, 0.0], 2)
assert_array_almost_equal(f, [0.0, 0.66, 0.0, 0.0], 2)
assert_array_almost_equal(s, [1, 2, 1, 0], 2)
f2 = fbeta_score(y_true, y_pred, beta=2, average=None)
support = s
assert_array_almost_equal(f2, [0, 0.55, 0, 0], 2)
p, r, f, s = precision_recall_fscore_support(y_true, y_pred,
average="micro")
assert_almost_equal(p, 0.25)
assert_almost_equal(r, 0.25)
assert_almost_equal(f, 2 * 0.25 * 0.25 / 0.5)
assert_equal(s, None)
assert_almost_equal(fbeta_score(y_true, y_pred, beta=2,
average="micro"),
(1 + 4) * p * r / (4 * p + r))
p, r, f, s = precision_recall_fscore_support(y_true, y_pred,
average="macro")
assert_almost_equal(p, 0.25)
assert_almost_equal(r, 0.125)
assert_almost_equal(f, 2 / 12)
assert_equal(s, None)
assert_almost_equal(fbeta_score(y_true, y_pred, beta=2,
average="macro"),
np.mean(f2))
p, r, f, s = precision_recall_fscore_support(y_true, y_pred,
average="weighted")
assert_almost_equal(p, 2 / 4)
assert_almost_equal(r, 1 / 4)
assert_almost_equal(f, 2 / 3 * 2 / 4)
assert_equal(s, None)
assert_almost_equal(fbeta_score(y_true, y_pred, beta=2,
average="weighted"),
np.average(f2, weights=support))
p, r, f, s = precision_recall_fscore_support(y_true, y_pred,
average="samples")
# Check samples
# |h(x_i) inter y_i | = [0, 0, 1]
# |y_i| = [1, 1, 2]
# |h(x_i)| = [1, 1, 2]
assert_almost_equal(p, 1 / 6)
assert_almost_equal(r, 1 / 6)
assert_almost_equal(f, 2 / 4 * 1 / 3)
assert_equal(s, None)
assert_almost_equal(fbeta_score(y_true, y_pred, beta=2,
average="samples"),
0.1666, 2)
@ignore_warnings
def test_precision_recall_f1_score_with_an_empty_prediction():
y_true = np.array([[0, 1, 0, 0], [1, 0, 0, 0], [0, 1, 1, 0]])
y_pred = np.array([[0, 0, 0, 0], [0, 0, 0, 1], [0, 1, 1, 0]])
# true_pos = [ 0. 1. 1. 0.]
# false_pos = [ 0. 0. 0. 1.]
# false_neg = [ 1. 1. 0. 0.]
p, r, f, s = precision_recall_fscore_support(y_true, y_pred,
average=None)
assert_array_almost_equal(p, [0.0, 1.0, 1.0, 0.0], 2)
assert_array_almost_equal(r, [0.0, 0.5, 1.0, 0.0], 2)
assert_array_almost_equal(f, [0.0, 1 / 1.5, 1, 0.0], 2)
assert_array_almost_equal(s, [1, 2, 1, 0], 2)
f2 = fbeta_score(y_true, y_pred, beta=2, average=None)
support = s
assert_array_almost_equal(f2, [0, 0.55, 1, 0], 2)
p, r, f, s = precision_recall_fscore_support(y_true, y_pred,
average="macro")
assert_almost_equal(p, 0.5)
assert_almost_equal(r, 1.5 / 4)
assert_almost_equal(f, 2.5 / (4 * 1.5))
assert_equal(s, None)
assert_almost_equal(fbeta_score(y_true, y_pred, beta=2,
average="macro"),
np.mean(f2))
p, r, f, s = precision_recall_fscore_support(y_true, y_pred,
average="micro")
assert_almost_equal(p, 2 / 3)
assert_almost_equal(r, 0.5)
assert_almost_equal(f, 2 / 3 / (2 / 3 + 0.5))
assert_equal(s, None)
assert_almost_equal(fbeta_score(y_true, y_pred, beta=2,
average="micro"),
(1 + 4) * p * r / (4 * p + r))
p, r, f, s = precision_recall_fscore_support(y_true, y_pred,
average="weighted")
assert_almost_equal(p, 3 / 4)
assert_almost_equal(r, 0.5)
assert_almost_equal(f, (2 / 1.5 + 1) / 4)
assert_equal(s, None)
assert_almost_equal(fbeta_score(y_true, y_pred, beta=2,
average="weighted"),
np.average(f2, weights=support))
p, r, f, s = precision_recall_fscore_support(y_true, y_pred,
average="samples")
# |h(x_i) inter y_i | = [0, 0, 2]
# |y_i| = [1, 1, 2]
# |h(x_i)| = [0, 1, 2]
assert_almost_equal(p, 1 / 3)
assert_almost_equal(r, 1 / 3)
assert_almost_equal(f, 1 / 3)
assert_equal(s, None)
assert_almost_equal(fbeta_score(y_true, y_pred, beta=2,
average="samples"),
0.333, 2)
def test_precision_recall_f1_no_labels():
y_true = np.zeros((20, 3))
y_pred = np.zeros_like(y_true)
# tp = [0, 0, 0]
# fn = [0, 0, 0]
# fp = [0, 0, 0]
# support = [0, 0, 0]
# |y_hat_i inter y_i | = [0, 0, 0]
# |y_i| = [0, 0, 0]
# |y_hat_i| = [0, 0, 0]
for beta in [1]:
p, r, f, s = assert_warns(UndefinedMetricWarning,
precision_recall_fscore_support,
y_true, y_pred, average=None, beta=beta)
assert_array_almost_equal(p, [0, 0, 0], 2)
assert_array_almost_equal(r, [0, 0, 0], 2)
assert_array_almost_equal(f, [0, 0, 0], 2)
assert_array_almost_equal(s, [0, 0, 0], 2)
fbeta = assert_warns(UndefinedMetricWarning, fbeta_score,
y_true, y_pred, beta=beta, average=None)
assert_array_almost_equal(fbeta, [0, 0, 0], 2)
for average in ["macro", "micro", "weighted", "samples"]:
p, r, f, s = assert_warns(UndefinedMetricWarning,
precision_recall_fscore_support,
y_true, y_pred, average=average,
beta=beta)
assert_almost_equal(p, 0)
assert_almost_equal(r, 0)
assert_almost_equal(f, 0)
assert_equal(s, None)
fbeta = assert_warns(UndefinedMetricWarning, fbeta_score,
y_true, y_pred,
beta=beta, average=average)
assert_almost_equal(fbeta, 0)
def test_prf_warnings():
# average of per-label scores
f, w = precision_recall_fscore_support, UndefinedMetricWarning
my_assert = assert_warns_message
for average in [None, 'weighted', 'macro']:
msg = ('Precision and F-score are ill-defined and '
'being set to 0.0 in labels with no predicted samples.')
my_assert(w, msg, f, [0, 1, 2], [1, 1, 2], average=average)
msg = ('Recall and F-score are ill-defined and '
'being set to 0.0 in labels with no true samples.')
my_assert(w, msg, f, [1, 1, 2], [0, 1, 2], average=average)
# average of per-sample scores
msg = ('Precision and F-score are ill-defined and '
'being set to 0.0 in samples with no predicted labels.')
my_assert(w, msg, f, np.array([[1, 0], [1, 0]]),
np.array([[1, 0], [0, 0]]), average='samples')
msg = ('Recall and F-score are ill-defined and '
'being set to 0.0 in samples with no true labels.')
my_assert(w, msg, f, np.array([[1, 0], [0, 0]]),
np.array([[1, 0], [1, 0]]),
average='samples')
# single score: micro-average
msg = ('Precision and F-score are ill-defined and '
'being set to 0.0 due to no predicted samples.')
my_assert(w, msg, f, np.array([[1, 1], [1, 1]]),
np.array([[0, 0], [0, 0]]), average='micro')
msg = ('Recall and F-score are ill-defined and '
'being set to 0.0 due to no true samples.')
my_assert(w, msg, f, np.array([[0, 0], [0, 0]]),
np.array([[1, 1], [1, 1]]), average='micro')
# single positive label
msg = ('Precision and F-score are ill-defined and '
'being set to 0.0 due to no predicted samples.')
my_assert(w, msg, f, [1, 1], [-1, -1], average='binary')
msg = ('Recall and F-score are ill-defined and '
'being set to 0.0 due to no true samples.')
my_assert(w, msg, f, [-1, -1], [1, 1], average='binary')
def test_recall_warnings():
assert_no_warnings(recall_score,
np.array([[1, 1], [1, 1]]),
np.array([[0, 0], [0, 0]]),
average='micro')
clean_warning_registry()
with warnings.catch_warnings(record=True) as record:
warnings.simplefilter('always')
recall_score(np.array([[0, 0], [0, 0]]),
np.array([[1, 1], [1, 1]]),
average='micro')
assert_equal(str(record.pop().message),
'Recall is ill-defined and '
'being set to 0.0 due to no true samples.')
def test_precision_warnings():
clean_warning_registry()
with warnings.catch_warnings(record=True) as record:
warnings.simplefilter('always')
precision_score(np.array([[1, 1], [1, 1]]),
np.array([[0, 0], [0, 0]]),
average='micro')
assert_equal(str(record.pop().message),
'Precision is ill-defined and '
'being set to 0.0 due to no predicted samples.')
assert_no_warnings(precision_score,
np.array([[0, 0], [0, 0]]),
np.array([[1, 1], [1, 1]]),
average='micro')
def test_fscore_warnings():
clean_warning_registry()
with warnings.catch_warnings(record=True) as record:
warnings.simplefilter('always')
for score in [f1_score, partial(fbeta_score, beta=2)]:
score(np.array([[1, 1], [1, 1]]),
np.array([[0, 0], [0, 0]]),
average='micro')
assert_equal(str(record.pop().message),
'F-score is ill-defined and '
'being set to 0.0 due to no predicted samples.')
score(np.array([[0, 0], [0, 0]]),
np.array([[1, 1], [1, 1]]),
average='micro')
assert_equal(str(record.pop().message),
'F-score is ill-defined and '
'being set to 0.0 due to no true samples.')
def test_prf_average_binary_data_non_binary():
# Error if user does not explicitly set non-binary average mode
y_true_mc = [1, 2, 3, 3]
y_pred_mc = [1, 2, 3, 1]
y_true_ind = np.array([[0, 1, 1], [1, 0, 0], [0, 0, 1]])
y_pred_ind = np.array([[0, 1, 0], [1, 0, 0], [0, 0, 1]])
for y_true, y_pred, y_type in [
(y_true_mc, y_pred_mc, 'multiclass'),
(y_true_ind, y_pred_ind, 'multilabel-indicator'),
]:
for metric in [precision_score, recall_score, f1_score,
partial(fbeta_score, beta=2)]:
assert_raise_message(ValueError,
"Target is %s but average='binary'. Please "
"choose another average setting." % y_type,
metric, y_true, y_pred)
def test__check_targets():
# Check that _check_targets correctly merges target types, squeezes
# output and fails if input lengths differ.
IND = 'multilabel-indicator'
MC = 'multiclass'
BIN = 'binary'
CNT = 'continuous'
MMC = 'multiclass-multioutput'
MCN = 'continuous-multioutput'
# all of length 3
EXAMPLES = [
(IND, np.array([[0, 1, 1], [1, 0, 0], [0, 0, 1]])),
# must not be considered binary
(IND, np.array([[0, 1], [1, 0], [1, 1]])),
(MC, [2, 3, 1]),
(BIN, [0, 1, 1]),
(CNT, [0., 1.5, 1.]),
(MC, np.array([[2], [3], [1]])),
(BIN, np.array([[0], [1], [1]])),
(CNT, np.array([[0.], [1.5], [1.]])),
(MMC, np.array([[0, 2], [1, 3], [2, 3]])),
(MCN, np.array([[0.5, 2.], [1.1, 3.], [2., 3.]])),
]
# expected type given input types, or None for error
# (types will be tried in either order)
EXPECTED = {
(IND, IND): IND,
(MC, MC): MC,
(BIN, BIN): BIN,
(MC, IND): None,
(BIN, IND): None,
(BIN, MC): MC,
# Disallowed types
(CNT, CNT): None,
(MMC, MMC): None,
(MCN, MCN): None,
(IND, CNT): None,
(MC, CNT): None,
(BIN, CNT): None,
(MMC, CNT): None,
(MCN, CNT): None,
(IND, MMC): None,
(MC, MMC): None,
(BIN, MMC): None,
(MCN, MMC): None,
(IND, MCN): None,
(MC, MCN): None,
(BIN, MCN): None,
}
for (type1, y1), (type2, y2) in product(EXAMPLES, repeat=2):
try:
expected = EXPECTED[type1, type2]
except KeyError:
expected = EXPECTED[type2, type1]
if expected is None:
assert_raises(ValueError, _check_targets, y1, y2)
if type1 != type2:
assert_raise_message(
ValueError,
"Classification metrics can't handle a mix of {0} and {1} "
"targets".format(type1, type2),
_check_targets, y1, y2)
else:
if type1 not in (BIN, MC, IND):
assert_raise_message(ValueError,
"{0} is not supported".format(type1),
_check_targets, y1, y2)
else:
merged_type, y1out, y2out = _check_targets(y1, y2)
assert_equal(merged_type, expected)
if merged_type.startswith('multilabel'):
assert_equal(y1out.format, 'csr')
assert_equal(y2out.format, 'csr')
else:
assert_array_equal(y1out, np.squeeze(y1))
assert_array_equal(y2out, np.squeeze(y2))
assert_raises(ValueError, _check_targets, y1[:-1], y2)
# Make sure seq of seq is not supported
y1 = [(1, 2,), (0, 2, 3)]
y2 = [(2,), (0, 2,)]
msg = ('You appear to be using a legacy multi-label data representation. '
'Sequence of sequences are no longer supported; use a binary array'
' or sparse matrix instead.')
assert_raise_message(ValueError, msg, _check_targets, y1, y2)
def test__check_targets_multiclass_with_both_y_true_and_y_pred_binary():
# https://github.com/scikit-learn/scikit-learn/issues/8098
y_true = [0, 1]
y_pred = [0, -1]
assert_equal(_check_targets(y_true, y_pred)[0], 'multiclass')
def test_hinge_loss_binary():
y_true = np.array([-1, 1, 1, -1])
pred_decision = np.array([-8.5, 0.5, 1.5, -0.3])
assert_equal(hinge_loss(y_true, pred_decision), 1.2 / 4)
y_true = np.array([0, 2, 2, 0])
pred_decision = np.array([-8.5, 0.5, 1.5, -0.3])
assert_equal(hinge_loss(y_true, pred_decision), 1.2 / 4)
def test_hinge_loss_multiclass():
pred_decision = np.array([
[+0.36, -0.17, -0.58, -0.99],
[-0.54, -0.37, -0.48, -0.58],
[-1.45, -0.58, -0.38, -0.17],
[-0.54, -0.38, -0.48, -0.58],
[-2.36, -0.79, -0.27, +0.24],
[-1.45, -0.58, -0.38, -0.17]
])
y_true = np.array([0, 1, 2, 1, 3, 2])
dummy_losses = np.array([
1 - pred_decision[0][0] + pred_decision[0][1],
1 - pred_decision[1][1] + pred_decision[1][2],
1 - pred_decision[2][2] + pred_decision[2][3],
1 - pred_decision[3][1] + pred_decision[3][2],
1 - pred_decision[4][3] + pred_decision[4][2],
1 - pred_decision[5][2] + pred_decision[5][3]
])
dummy_losses[dummy_losses <= 0] = 0
dummy_hinge_loss = np.mean(dummy_losses)
assert_equal(hinge_loss(y_true, pred_decision),
dummy_hinge_loss)
def test_hinge_loss_multiclass_missing_labels_with_labels_none():
y_true = np.array([0, 1, 2, 2])
pred_decision = np.array([
[+1.27, 0.034, -0.68, -1.40],
[-1.45, -0.58, -0.38, -0.17],
[-2.36, -0.79, -0.27, +0.24],
[-2.36, -0.79, -0.27, +0.24]
])
error_message = ("Please include all labels in y_true "
"or pass labels as third argument")
assert_raise_message(ValueError,
error_message,
hinge_loss, y_true, pred_decision)
def test_hinge_loss_multiclass_with_missing_labels():
pred_decision = np.array([
[+0.36, -0.17, -0.58, -0.99],
[-0.55, -0.38, -0.48, -0.58],
[-1.45, -0.58, -0.38, -0.17],
[-0.55, -0.38, -0.48, -0.58],
[-1.45, -0.58, -0.38, -0.17]
])
y_true = np.array([0, 1, 2, 1, 2])
labels = np.array([0, 1, 2, 3])
dummy_losses = np.array([
1 - pred_decision[0][0] + pred_decision[0][1],
1 - pred_decision[1][1] + pred_decision[1][2],
1 - pred_decision[2][2] + pred_decision[2][3],
1 - pred_decision[3][1] + pred_decision[3][2],
1 - pred_decision[4][2] + pred_decision[4][3]
])
dummy_losses[dummy_losses <= 0] = 0
dummy_hinge_loss = np.mean(dummy_losses)
assert_equal(hinge_loss(y_true, pred_decision, labels=labels),
dummy_hinge_loss)
def test_hinge_loss_multiclass_invariance_lists():
# Currently, invariance of string and integer labels cannot be tested
# in common invariance tests because invariance tests for multiclass
# decision functions is not implemented yet.
y_true = ['blue', 'green', 'red',
'green', 'white', 'red']
pred_decision = [
[+0.36, -0.17, -0.58, -0.99],
[-0.55, -0.38, -0.48, -0.58],
[-1.45, -0.58, -0.38, -0.17],
[-0.55, -0.38, -0.48, -0.58],
[-2.36, -0.79, -0.27, +0.24],
[-1.45, -0.58, -0.38, -0.17]]
dummy_losses = np.array([
1 - pred_decision[0][0] + pred_decision[0][1],
1 - pred_decision[1][1] + pred_decision[1][2],
1 - pred_decision[2][2] + pred_decision[2][3],
1 - pred_decision[3][1] + pred_decision[3][2],
1 - pred_decision[4][3] + pred_decision[4][2],
1 - pred_decision[5][2] + pred_decision[5][3]
])
dummy_losses[dummy_losses <= 0] = 0
dummy_hinge_loss = np.mean(dummy_losses)
assert_equal(hinge_loss(y_true, pred_decision),
dummy_hinge_loss)
def test_log_loss():
# binary case with symbolic labels ("no" < "yes")
y_true = ["no", "no", "no", "yes", "yes", "yes"]
y_pred = np.array([[0.5, 0.5], [0.1, 0.9], [0.01, 0.99],
[0.9, 0.1], [0.75, 0.25], [0.001, 0.999]])
loss = log_loss(y_true, y_pred)
assert_almost_equal(loss, 1.8817971)
# multiclass case; adapted from http://bit.ly/RJJHWA
y_true = [1, 0, 2]
y_pred = [[0.2, 0.7, 0.1], [0.6, 0.2, 0.2], [0.6, 0.1, 0.3]]
loss = log_loss(y_true, y_pred, normalize=True)
assert_almost_equal(loss, 0.6904911)
# check that we got all the shapes and axes right
# by doubling the length of y_true and y_pred
y_true *= 2
y_pred *= 2
loss = log_loss(y_true, y_pred, normalize=False)
assert_almost_equal(loss, 0.6904911 * 6, decimal=6)
# check eps and handling of absolute zero and one probabilities
y_pred = np.asarray(y_pred) > .5
loss = log_loss(y_true, y_pred, normalize=True, eps=.1)
assert_almost_equal(loss, log_loss(y_true, np.clip(y_pred, .1, .9)))
# raise error if number of classes are not equal.
y_true = [1, 0, 2]
y_pred = [[0.2, 0.7], [0.6, 0.5], [0.4, 0.1]]
assert_raises(ValueError, log_loss, y_true, y_pred)
# case when y_true is a string array object
y_true = ["ham", "spam", "spam", "ham"]
y_pred = [[0.2, 0.7], [0.6, 0.5], [0.4, 0.1], [0.7, 0.2]]
loss = log_loss(y_true, y_pred)
assert_almost_equal(loss, 1.0383217, decimal=6)
# test labels option
y_true = [2, 2]
y_pred = [[0.2, 0.7], [0.6, 0.5]]
y_score = np.array([[0.1, 0.9], [0.1, 0.9]])
error_str = ('y_true contains only one label (2). Please provide '
'the true labels explicitly through the labels argument.')
assert_raise_message(ValueError, error_str, log_loss, y_true, y_pred)
y_pred = [[0.2, 0.7], [0.6, 0.5], [0.2, 0.3]]
error_str = ('Found input variables with inconsistent numbers of samples: '
'[3, 2]')
assert_raise_message(ValueError, error_str, log_loss, y_true, y_pred)
# works when the labels argument is used
true_log_loss = -np.mean(np.log(y_score[:, 1]))
calculated_log_loss = log_loss(y_true, y_score, labels=[1, 2])
assert_almost_equal(calculated_log_loss, true_log_loss)
# ensure labels work when len(np.unique(y_true)) != y_pred.shape[1]
y_true = [1, 2, 2]
y_score2 = [[0.2, 0.7, 0.3], [0.6, 0.5, 0.3], [0.3, 0.9, 0.1]]
loss = log_loss(y_true, y_score2, labels=[1, 2, 3])
assert_almost_equal(loss, 1.0630345, decimal=6)
def test_log_loss_pandas_input():
# case when input is a pandas series and dataframe gh-5715
y_tr = np.array(["ham", "spam", "spam", "ham"])
y_pr = np.array([[0.2, 0.7], [0.6, 0.5], [0.4, 0.1], [0.7, 0.2]])
types = [(MockDataFrame, MockDataFrame)]
try:
from pandas import Series, DataFrame
types.append((Series, DataFrame))
except ImportError:
pass
for TrueInputType, PredInputType in types:
# y_pred dataframe, y_true series
y_true, y_pred = TrueInputType(y_tr), PredInputType(y_pr)
loss = log_loss(y_true, y_pred)
assert_almost_equal(loss, 1.0383217, decimal=6)
def test_brier_score_loss():
# Check brier_score_loss function
y_true = np.array([0, 1, 1, 0, 1, 1])
y_pred = np.array([0.1, 0.8, 0.9, 0.3, 1., 0.95])
true_score = linalg.norm(y_true - y_pred) ** 2 / len(y_true)
assert_almost_equal(brier_score_loss(y_true, y_true), 0.0)
assert_almost_equal(brier_score_loss(y_true, y_pred), true_score)
assert_almost_equal(brier_score_loss(1. + y_true, y_pred),
true_score)
assert_almost_equal(brier_score_loss(2 * y_true - 1, y_pred),
true_score)
assert_raises(ValueError, brier_score_loss, y_true, y_pred[1:])
assert_raises(ValueError, brier_score_loss, y_true, y_pred + 1.)
assert_raises(ValueError, brier_score_loss, y_true, y_pred - 1.)
# calculate even if only single class in y_true (#6980)
assert_almost_equal(brier_score_loss([0], [0.5]), 0.25)
assert_almost_equal(brier_score_loss([1], [0.5]), 0.25)
| 62,931 | 37.918986 | 89 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/tests/test_score_objects.py | import pickle
import tempfile
import shutil
import os
import numbers
import numpy as np
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_raises_regexp
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import assert_false
from sklearn.utils.testing import ignore_warnings
from sklearn.utils.testing import assert_not_equal
from sklearn.utils.testing import assert_warns_message
from sklearn.base import BaseEstimator
from sklearn.metrics import (f1_score, r2_score, roc_auc_score, fbeta_score,
log_loss, precision_score, recall_score)
from sklearn.metrics import cluster as cluster_module
from sklearn.metrics.scorer import (check_scoring, _PredictScorer,
_passthrough_scorer)
from sklearn.metrics import accuracy_score
from sklearn.metrics.scorer import _check_multimetric_scoring
from sklearn.metrics import make_scorer, get_scorer, SCORERS
from sklearn.svm import LinearSVC
from sklearn.pipeline import make_pipeline
from sklearn.cluster import KMeans
from sklearn.linear_model import Ridge, LogisticRegression
from sklearn.tree import DecisionTreeClassifier, DecisionTreeRegressor
from sklearn.datasets import make_blobs
from sklearn.datasets import make_classification
from sklearn.datasets import make_multilabel_classification
from sklearn.datasets import load_diabetes
from sklearn.model_selection import train_test_split, cross_val_score
from sklearn.model_selection import GridSearchCV
from sklearn.multiclass import OneVsRestClassifier
from sklearn.externals import joblib
REGRESSION_SCORERS = ['explained_variance', 'r2',
'neg_mean_absolute_error', 'neg_mean_squared_error',
'neg_mean_squared_log_error',
'neg_median_absolute_error', 'mean_absolute_error',
'mean_squared_error', 'median_absolute_error']
CLF_SCORERS = ['accuracy', 'f1', 'f1_weighted', 'f1_macro', 'f1_micro',
'roc_auc', 'average_precision', 'precision',
'precision_weighted', 'precision_macro', 'precision_micro',
'recall', 'recall_weighted', 'recall_macro', 'recall_micro',
'neg_log_loss', 'log_loss']
# All supervised cluster scorers (They behave like classification metric)
CLUSTER_SCORERS = ["adjusted_rand_score",
"homogeneity_score",
"completeness_score",
"v_measure_score",
"mutual_info_score",
"adjusted_mutual_info_score",
"normalized_mutual_info_score",
"fowlkes_mallows_score"]
MULTILABEL_ONLY_SCORERS = ['precision_samples', 'recall_samples', 'f1_samples']
def _make_estimators(X_train, y_train, y_ml_train):
# Make estimators that make sense to test various scoring methods
sensible_regr = DecisionTreeRegressor(random_state=0)
sensible_regr.fit(X_train, y_train)
sensible_clf = DecisionTreeClassifier(random_state=0)
sensible_clf.fit(X_train, y_train)
sensible_ml_clf = DecisionTreeClassifier(random_state=0)
sensible_ml_clf.fit(X_train, y_ml_train)
return dict(
[(name, sensible_regr) for name in REGRESSION_SCORERS] +
[(name, sensible_clf) for name in CLF_SCORERS] +
[(name, sensible_clf) for name in CLUSTER_SCORERS] +
[(name, sensible_ml_clf) for name in MULTILABEL_ONLY_SCORERS]
)
X_mm, y_mm, y_ml_mm = None, None, None
ESTIMATORS = None
TEMP_FOLDER = None
def setup_module():
# Create some memory mapped data
global X_mm, y_mm, y_ml_mm, TEMP_FOLDER, ESTIMATORS
TEMP_FOLDER = tempfile.mkdtemp(prefix='sklearn_test_score_objects_')
X, y = make_classification(n_samples=30, n_features=5, random_state=0)
_, y_ml = make_multilabel_classification(n_samples=X.shape[0],
random_state=0)
filename = os.path.join(TEMP_FOLDER, 'test_data.pkl')
joblib.dump((X, y, y_ml), filename)
X_mm, y_mm, y_ml_mm = joblib.load(filename, mmap_mode='r')
ESTIMATORS = _make_estimators(X_mm, y_mm, y_ml_mm)
def teardown_module():
global X_mm, y_mm, y_ml_mm, TEMP_FOLDER, ESTIMATORS
# GC closes the mmap file descriptors
X_mm, y_mm, y_ml_mm, ESTIMATORS = None, None, None, None
shutil.rmtree(TEMP_FOLDER)
class EstimatorWithoutFit(object):
"""Dummy estimator to test scoring validators"""
pass
class EstimatorWithFit(BaseEstimator):
"""Dummy estimator to test scoring validators"""
def fit(self, X, y):
return self
class EstimatorWithFitAndScore(object):
"""Dummy estimator to test scoring validators"""
def fit(self, X, y):
return self
def score(self, X, y):
return 1.0
class EstimatorWithFitAndPredict(object):
"""Dummy estimator to test scoring validators"""
def fit(self, X, y):
self.y = y
return self
def predict(self, X):
return self.y
class DummyScorer(object):
"""Dummy scorer that always returns 1."""
def __call__(self, est, X, y):
return 1
def test_all_scorers_repr():
# Test that all scorers have a working repr
for name, scorer in SCORERS.items():
repr(scorer)
def check_scoring_validator_for_single_metric_usecases(scoring_validator):
# Test all branches of single metric usecases
estimator = EstimatorWithoutFit()
pattern = (r"estimator should be an estimator implementing 'fit' method,"
r" .* was passed")
assert_raises_regexp(TypeError, pattern, scoring_validator, estimator)
estimator = EstimatorWithFitAndScore()
estimator.fit([[1]], [1])
scorer = scoring_validator(estimator)
assert_true(scorer is _passthrough_scorer)
assert_almost_equal(scorer(estimator, [[1]], [1]), 1.0)
estimator = EstimatorWithFitAndPredict()
estimator.fit([[1]], [1])
pattern = (r"If no scoring is specified, the estimator passed should have"
r" a 'score' method\. The estimator .* does not\.")
assert_raises_regexp(TypeError, pattern, scoring_validator, estimator)
scorer = scoring_validator(estimator, "accuracy")
assert_almost_equal(scorer(estimator, [[1]], [1]), 1.0)
estimator = EstimatorWithFit()
scorer = scoring_validator(estimator, "accuracy")
assert_true(isinstance(scorer, _PredictScorer))
# Test the allow_none parameter for check_scoring alone
if scoring_validator is check_scoring:
estimator = EstimatorWithFit()
scorer = scoring_validator(estimator, allow_none=True)
assert_true(scorer is None)
def check_multimetric_scoring_single_metric_wrapper(*args, **kwargs):
# This wraps the _check_multimetric_scoring to take in single metric
# scoring parameter so we can run the tests that we will run for
# check_scoring, for check_multimetric_scoring too for single-metric
# usecases
scorers, is_multi = _check_multimetric_scoring(*args, **kwargs)
# For all single metric use cases, it should register as not multimetric
assert_false(is_multi)
if args[0] is not None:
assert_true(scorers is not None)
names, scorers = zip(*scorers.items())
assert_equal(len(scorers), 1)
assert_equal(names[0], 'score')
scorers = scorers[0]
return scorers
def test_check_scoring_and_check_multimetric_scoring():
check_scoring_validator_for_single_metric_usecases(check_scoring)
# To make sure the check_scoring is correctly applied to the constituent
# scorers
check_scoring_validator_for_single_metric_usecases(
check_multimetric_scoring_single_metric_wrapper)
# For multiple metric use cases
# Make sure it works for the valid cases
for scoring in (('accuracy',), ['precision'],
{'acc': 'accuracy', 'precision': 'precision'},
('accuracy', 'precision'), ['precision', 'accuracy'],
{'accuracy': make_scorer(accuracy_score),
'precision': make_scorer(precision_score)}):
estimator = LinearSVC(random_state=0)
estimator.fit([[1], [2], [3]], [1, 1, 0])
scorers, is_multi = _check_multimetric_scoring(estimator, scoring)
assert_true(is_multi)
assert_true(isinstance(scorers, dict))
assert_equal(sorted(scorers.keys()), sorted(list(scoring)))
assert_true(all([isinstance(scorer, _PredictScorer)
for scorer in list(scorers.values())]))
if 'acc' in scoring:
assert_almost_equal(scorers['acc'](
estimator, [[1], [2], [3]], [1, 0, 0]), 2. / 3.)
if 'accuracy' in scoring:
assert_almost_equal(scorers['accuracy'](
estimator, [[1], [2], [3]], [1, 0, 0]), 2. / 3.)
if 'precision' in scoring:
assert_almost_equal(scorers['precision'](
estimator, [[1], [2], [3]], [1, 0, 0]), 0.5)
estimator = EstimatorWithFitAndPredict()
estimator.fit([[1]], [1])
# Make sure it raises errors when scoring parameter is not valid.
# More weird corner cases are tested at test_validation.py
error_message_regexp = ".*must be unique strings.*"
for scoring in ((make_scorer(precision_score), # Tuple of callables
make_scorer(accuracy_score)), [5],
(make_scorer(precision_score),), (), ('f1', 'f1')):
assert_raises_regexp(ValueError, error_message_regexp,
_check_multimetric_scoring, estimator,
scoring=scoring)
def test_check_scoring_gridsearchcv():
# test that check_scoring works on GridSearchCV and pipeline.
# slightly redundant non-regression test.
grid = GridSearchCV(LinearSVC(), param_grid={'C': [.1, 1]})
scorer = check_scoring(grid, "f1")
assert_true(isinstance(scorer, _PredictScorer))
pipe = make_pipeline(LinearSVC())
scorer = check_scoring(pipe, "f1")
assert_true(isinstance(scorer, _PredictScorer))
# check that cross_val_score definitely calls the scorer
# and doesn't make any assumptions about the estimator apart from having a
# fit.
scores = cross_val_score(EstimatorWithFit(), [[1], [2], [3]], [1, 0, 1],
scoring=DummyScorer())
assert_array_equal(scores, 1)
def test_make_scorer():
# Sanity check on the make_scorer factory function.
f = lambda *args: 0
assert_raises(ValueError, make_scorer, f, needs_threshold=True,
needs_proba=True)
def test_classification_scores():
# Test classification scorers.
X, y = make_blobs(random_state=0, centers=2)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
clf = LinearSVC(random_state=0)
clf.fit(X_train, y_train)
for prefix, metric in [('f1', f1_score), ('precision', precision_score),
('recall', recall_score)]:
score1 = get_scorer('%s_weighted' % prefix)(clf, X_test, y_test)
score2 = metric(y_test, clf.predict(X_test), pos_label=None,
average='weighted')
assert_almost_equal(score1, score2)
score1 = get_scorer('%s_macro' % prefix)(clf, X_test, y_test)
score2 = metric(y_test, clf.predict(X_test), pos_label=None,
average='macro')
assert_almost_equal(score1, score2)
score1 = get_scorer('%s_micro' % prefix)(clf, X_test, y_test)
score2 = metric(y_test, clf.predict(X_test), pos_label=None,
average='micro')
assert_almost_equal(score1, score2)
score1 = get_scorer('%s' % prefix)(clf, X_test, y_test)
score2 = metric(y_test, clf.predict(X_test), pos_label=1)
assert_almost_equal(score1, score2)
# test fbeta score that takes an argument
scorer = make_scorer(fbeta_score, beta=2)
score1 = scorer(clf, X_test, y_test)
score2 = fbeta_score(y_test, clf.predict(X_test), beta=2)
assert_almost_equal(score1, score2)
# test that custom scorer can be pickled
unpickled_scorer = pickle.loads(pickle.dumps(scorer))
score3 = unpickled_scorer(clf, X_test, y_test)
assert_almost_equal(score1, score3)
# smoke test the repr:
repr(fbeta_score)
def test_regression_scorers():
# Test regression scorers.
diabetes = load_diabetes()
X, y = diabetes.data, diabetes.target
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
clf = Ridge()
clf.fit(X_train, y_train)
score1 = get_scorer('r2')(clf, X_test, y_test)
score2 = r2_score(y_test, clf.predict(X_test))
assert_almost_equal(score1, score2)
def test_thresholded_scorers():
# Test scorers that take thresholds.
X, y = make_blobs(random_state=0, centers=2)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
clf = LogisticRegression(random_state=0)
clf.fit(X_train, y_train)
score1 = get_scorer('roc_auc')(clf, X_test, y_test)
score2 = roc_auc_score(y_test, clf.decision_function(X_test))
score3 = roc_auc_score(y_test, clf.predict_proba(X_test)[:, 1])
assert_almost_equal(score1, score2)
assert_almost_equal(score1, score3)
logscore = get_scorer('neg_log_loss')(clf, X_test, y_test)
logloss = log_loss(y_test, clf.predict_proba(X_test))
assert_almost_equal(-logscore, logloss)
# same for an estimator without decision_function
clf = DecisionTreeClassifier()
clf.fit(X_train, y_train)
score1 = get_scorer('roc_auc')(clf, X_test, y_test)
score2 = roc_auc_score(y_test, clf.predict_proba(X_test)[:, 1])
assert_almost_equal(score1, score2)
# test with a regressor (no decision_function)
reg = DecisionTreeRegressor()
reg.fit(X_train, y_train)
score1 = get_scorer('roc_auc')(reg, X_test, y_test)
score2 = roc_auc_score(y_test, reg.predict(X_test))
assert_almost_equal(score1, score2)
# Test that an exception is raised on more than two classes
X, y = make_blobs(random_state=0, centers=3)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
clf.fit(X_train, y_train)
assert_raises(ValueError, get_scorer('roc_auc'), clf, X_test, y_test)
def test_thresholded_scorers_multilabel_indicator_data():
# Test that the scorer work with multilabel-indicator format
# for multilabel and multi-output multi-class classifier
X, y = make_multilabel_classification(allow_unlabeled=False,
random_state=0)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
# Multi-output multi-class predict_proba
clf = DecisionTreeClassifier()
clf.fit(X_train, y_train)
y_proba = clf.predict_proba(X_test)
score1 = get_scorer('roc_auc')(clf, X_test, y_test)
score2 = roc_auc_score(y_test, np.vstack(p[:, -1] for p in y_proba).T)
assert_almost_equal(score1, score2)
# Multi-output multi-class decision_function
# TODO Is there any yet?
clf = DecisionTreeClassifier()
clf.fit(X_train, y_train)
clf._predict_proba = clf.predict_proba
clf.predict_proba = None
clf.decision_function = lambda X: [p[:, 1] for p in clf._predict_proba(X)]
y_proba = clf.decision_function(X_test)
score1 = get_scorer('roc_auc')(clf, X_test, y_test)
score2 = roc_auc_score(y_test, np.vstack(p for p in y_proba).T)
assert_almost_equal(score1, score2)
# Multilabel predict_proba
clf = OneVsRestClassifier(DecisionTreeClassifier())
clf.fit(X_train, y_train)
score1 = get_scorer('roc_auc')(clf, X_test, y_test)
score2 = roc_auc_score(y_test, clf.predict_proba(X_test))
assert_almost_equal(score1, score2)
# Multilabel decision function
clf = OneVsRestClassifier(LinearSVC(random_state=0))
clf.fit(X_train, y_train)
score1 = get_scorer('roc_auc')(clf, X_test, y_test)
score2 = roc_auc_score(y_test, clf.decision_function(X_test))
assert_almost_equal(score1, score2)
def test_supervised_cluster_scorers():
# Test clustering scorers against gold standard labeling.
X, y = make_blobs(random_state=0, centers=2)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
km = KMeans(n_clusters=3)
km.fit(X_train)
for name in CLUSTER_SCORERS:
score1 = get_scorer(name)(km, X_test, y_test)
score2 = getattr(cluster_module, name)(y_test, km.predict(X_test))
assert_almost_equal(score1, score2)
@ignore_warnings
def test_raises_on_score_list():
# Test that when a list of scores is returned, we raise proper errors.
X, y = make_blobs(random_state=0)
f1_scorer_no_average = make_scorer(f1_score, average=None)
clf = DecisionTreeClassifier()
assert_raises(ValueError, cross_val_score, clf, X, y,
scoring=f1_scorer_no_average)
grid_search = GridSearchCV(clf, scoring=f1_scorer_no_average,
param_grid={'max_depth': [1, 2]})
assert_raises(ValueError, grid_search.fit, X, y)
@ignore_warnings
def test_scorer_sample_weight():
# Test that scorers support sample_weight or raise sensible errors
# Unlike the metrics invariance test, in the scorer case it's harder
# to ensure that, on the classifier output, weighted and unweighted
# scores really should be unequal.
X, y = make_classification(random_state=0)
_, y_ml = make_multilabel_classification(n_samples=X.shape[0],
random_state=0)
split = train_test_split(X, y, y_ml, random_state=0)
X_train, X_test, y_train, y_test, y_ml_train, y_ml_test = split
sample_weight = np.ones_like(y_test)
sample_weight[:10] = 0
# get sensible estimators for each metric
estimator = _make_estimators(X_train, y_train, y_ml_train)
for name, scorer in SCORERS.items():
if name in MULTILABEL_ONLY_SCORERS:
target = y_ml_test
else:
target = y_test
try:
weighted = scorer(estimator[name], X_test, target,
sample_weight=sample_weight)
ignored = scorer(estimator[name], X_test[10:], target[10:])
unweighted = scorer(estimator[name], X_test, target)
assert_not_equal(weighted, unweighted,
msg="scorer {0} behaves identically when "
"called with sample weights: {1} vs "
"{2}".format(name, weighted, unweighted))
assert_almost_equal(weighted, ignored,
err_msg="scorer {0} behaves differently when "
"ignoring samples and setting sample_weight to"
" 0: {1} vs {2}".format(name, weighted,
ignored))
except TypeError as e:
assert_true("sample_weight" in str(e),
"scorer {0} raises unhelpful exception when called "
"with sample weights: {1}".format(name, str(e)))
@ignore_warnings # UndefinedMetricWarning for P / R scores
def check_scorer_memmap(scorer_name):
scorer, estimator = SCORERS[scorer_name], ESTIMATORS[scorer_name]
if scorer_name in MULTILABEL_ONLY_SCORERS:
score = scorer(estimator, X_mm, y_ml_mm)
else:
score = scorer(estimator, X_mm, y_mm)
assert isinstance(score, numbers.Number), scorer_name
def test_scorer_memmap_input():
# Non-regression test for #6147: some score functions would
# return singleton memmap when computed on memmap data instead of scalar
# float values.
for name in SCORERS.keys():
yield check_scorer_memmap, name
def test_deprecated_names():
X, y = make_blobs(random_state=0, centers=2)
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0)
clf = LogisticRegression(random_state=0)
clf.fit(X_train, y_train)
for name in ('mean_absolute_error', 'mean_squared_error',
'median_absolute_error', 'log_loss'):
warning_msg = "Scoring method %s was renamed to" % name
for scorer in (get_scorer(name), SCORERS[name]):
assert_warns_message(DeprecationWarning,
warning_msg,
scorer, clf, X, y)
assert_warns_message(DeprecationWarning,
warning_msg,
cross_val_score, clf, X, y, scoring=name)
def test_scoring_is_not_metric():
assert_raises_regexp(ValueError, 'make_scorer', check_scoring,
LogisticRegression(), f1_score)
assert_raises_regexp(ValueError, 'make_scorer', check_scoring,
LogisticRegression(), roc_auc_score)
assert_raises_regexp(ValueError, 'make_scorer', check_scoring,
Ridge(), r2_score)
assert_raises_regexp(ValueError, 'make_scorer', check_scoring,
KMeans(), cluster_module.adjusted_rand_score)
| 21,280 | 39.228733 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/tests/__init__.py | 0 | 0 | 0 | py |
|
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/tests/test_pairwise.py | import numpy as np
from numpy import linalg
from scipy.sparse import dok_matrix, csr_matrix, issparse
from scipy.spatial.distance import cosine, cityblock, minkowski, wminkowski
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_array_equal
from sklearn.utils.testing import assert_raises
from sklearn.utils.testing import assert_raises_regexp
from sklearn.utils.testing import assert_true
from sklearn.utils.testing import assert_warns
from sklearn.utils.testing import ignore_warnings
from sklearn.externals.six import iteritems
from sklearn.metrics.pairwise import euclidean_distances
from sklearn.metrics.pairwise import manhattan_distances
from sklearn.metrics.pairwise import linear_kernel
from sklearn.metrics.pairwise import chi2_kernel, additive_chi2_kernel
from sklearn.metrics.pairwise import polynomial_kernel
from sklearn.metrics.pairwise import rbf_kernel
from sklearn.metrics.pairwise import laplacian_kernel
from sklearn.metrics.pairwise import sigmoid_kernel
from sklearn.metrics.pairwise import cosine_similarity
from sklearn.metrics.pairwise import cosine_distances
from sklearn.metrics.pairwise import pairwise_distances
from sklearn.metrics.pairwise import pairwise_distances_argmin_min
from sklearn.metrics.pairwise import pairwise_distances_argmin
from sklearn.metrics.pairwise import pairwise_kernels
from sklearn.metrics.pairwise import PAIRWISE_KERNEL_FUNCTIONS
from sklearn.metrics.pairwise import PAIRWISE_DISTANCE_FUNCTIONS
from sklearn.metrics.pairwise import PAIRWISE_BOOLEAN_FUNCTIONS
from sklearn.metrics.pairwise import PAIRED_DISTANCES
from sklearn.metrics.pairwise import check_pairwise_arrays
from sklearn.metrics.pairwise import check_paired_arrays
from sklearn.metrics.pairwise import paired_distances
from sklearn.metrics.pairwise import paired_euclidean_distances
from sklearn.metrics.pairwise import paired_manhattan_distances
from sklearn.preprocessing import normalize
from sklearn.exceptions import DataConversionWarning
def test_pairwise_distances():
# Test the pairwise_distance helper function.
rng = np.random.RandomState(0)
# Euclidean distance should be equivalent to calling the function.
X = rng.random_sample((5, 4))
S = pairwise_distances(X, metric="euclidean")
S2 = euclidean_distances(X)
assert_array_almost_equal(S, S2)
# Euclidean distance, with Y != X.
Y = rng.random_sample((2, 4))
S = pairwise_distances(X, Y, metric="euclidean")
S2 = euclidean_distances(X, Y)
assert_array_almost_equal(S, S2)
# Test with tuples as X and Y
X_tuples = tuple([tuple([v for v in row]) for row in X])
Y_tuples = tuple([tuple([v for v in row]) for row in Y])
S2 = pairwise_distances(X_tuples, Y_tuples, metric="euclidean")
assert_array_almost_equal(S, S2)
# "cityblock" uses scikit-learn metric, cityblock (function) is
# scipy.spatial.
S = pairwise_distances(X, metric="cityblock")
S2 = pairwise_distances(X, metric=cityblock)
assert_equal(S.shape[0], S.shape[1])
assert_equal(S.shape[0], X.shape[0])
assert_array_almost_equal(S, S2)
# The manhattan metric should be equivalent to cityblock.
S = pairwise_distances(X, Y, metric="manhattan")
S2 = pairwise_distances(X, Y, metric=cityblock)
assert_equal(S.shape[0], X.shape[0])
assert_equal(S.shape[1], Y.shape[0])
assert_array_almost_equal(S, S2)
# Using size_threshold argument should raise
# a deprecation warning
assert_warns(DeprecationWarning,
manhattan_distances, X, Y, size_threshold=10)
# Test cosine as a string metric versus cosine callable
# The string "cosine" uses sklearn.metric,
# while the function cosine is scipy.spatial
S = pairwise_distances(X, Y, metric="cosine")
S2 = pairwise_distances(X, Y, metric=cosine)
assert_equal(S.shape[0], X.shape[0])
assert_equal(S.shape[1], Y.shape[0])
assert_array_almost_equal(S, S2)
# Test with sparse X and Y,
# currently only supported for Euclidean, L1 and cosine.
X_sparse = csr_matrix(X)
Y_sparse = csr_matrix(Y)
S = pairwise_distances(X_sparse, Y_sparse, metric="euclidean")
S2 = euclidean_distances(X_sparse, Y_sparse)
assert_array_almost_equal(S, S2)
S = pairwise_distances(X_sparse, Y_sparse, metric="cosine")
S2 = cosine_distances(X_sparse, Y_sparse)
assert_array_almost_equal(S, S2)
S = pairwise_distances(X_sparse, Y_sparse.tocsc(), metric="manhattan")
S2 = manhattan_distances(X_sparse.tobsr(), Y_sparse.tocoo())
assert_array_almost_equal(S, S2)
S2 = manhattan_distances(X, Y)
assert_array_almost_equal(S, S2)
# Test with scipy.spatial.distance metric, with a kwd
kwds = {"p": 2.0}
S = pairwise_distances(X, Y, metric="minkowski", **kwds)
S2 = pairwise_distances(X, Y, metric=minkowski, **kwds)
assert_array_almost_equal(S, S2)
# same with Y = None
kwds = {"p": 2.0}
S = pairwise_distances(X, metric="minkowski", **kwds)
S2 = pairwise_distances(X, metric=minkowski, **kwds)
assert_array_almost_equal(S, S2)
# Test that scipy distance metrics throw an error if sparse matrix given
assert_raises(TypeError, pairwise_distances, X_sparse, metric="minkowski")
assert_raises(TypeError, pairwise_distances, X, Y_sparse,
metric="minkowski")
# Test that a value error is raised if the metric is unknown
assert_raises(ValueError, pairwise_distances, X, Y, metric="blah")
# ignore conversion to boolean in pairwise_distances
@ignore_warnings(category=DataConversionWarning)
def test_pairwise_boolean_distance():
# test that we convert to boolean arrays for boolean distances
rng = np.random.RandomState(0)
X = rng.randn(5, 4)
Y = X.copy()
Y[0, 0] = 1 - Y[0, 0]
for metric in PAIRWISE_BOOLEAN_FUNCTIONS:
for Z in [Y, None]:
res = pairwise_distances(X, Z, metric=metric)
res[np.isnan(res)] = 0
assert_true(np.sum(res != 0) == 0)
def test_pairwise_precomputed():
for func in [pairwise_distances, pairwise_kernels]:
# Test correct shape
assert_raises_regexp(ValueError, '.* shape .*',
func, np.zeros((5, 3)), metric='precomputed')
# with two args
assert_raises_regexp(ValueError, '.* shape .*',
func, np.zeros((5, 3)), np.zeros((4, 4)),
metric='precomputed')
# even if shape[1] agrees (although thus second arg is spurious)
assert_raises_regexp(ValueError, '.* shape .*',
func, np.zeros((5, 3)), np.zeros((4, 3)),
metric='precomputed')
# Test not copied (if appropriate dtype)
S = np.zeros((5, 5))
S2 = func(S, metric="precomputed")
assert_true(S is S2)
# with two args
S = np.zeros((5, 3))
S2 = func(S, np.zeros((3, 3)), metric="precomputed")
assert_true(S is S2)
# Test always returns float dtype
S = func(np.array([[1]], dtype='int'), metric='precomputed')
assert_equal('f', S.dtype.kind)
# Test converts list to array-like
S = func([[1.]], metric='precomputed')
assert_true(isinstance(S, np.ndarray))
def check_pairwise_parallel(func, metric, kwds):
rng = np.random.RandomState(0)
for make_data in (np.array, csr_matrix):
X = make_data(rng.random_sample((5, 4)))
Y = make_data(rng.random_sample((3, 4)))
try:
S = func(X, metric=metric, n_jobs=1, **kwds)
except (TypeError, ValueError) as exc:
# Not all metrics support sparse input
# ValueError may be triggered by bad callable
if make_data is csr_matrix:
assert_raises(type(exc), func, X, metric=metric,
n_jobs=2, **kwds)
continue
else:
raise
S2 = func(X, metric=metric, n_jobs=2, **kwds)
assert_array_almost_equal(S, S2)
S = func(X, Y, metric=metric, n_jobs=1, **kwds)
S2 = func(X, Y, metric=metric, n_jobs=2, **kwds)
assert_array_almost_equal(S, S2)
def test_pairwise_parallel():
wminkowski_kwds = {'w': np.arange(1, 5).astype('double'), 'p': 1}
metrics = [(pairwise_distances, 'euclidean', {}),
(pairwise_distances, wminkowski, wminkowski_kwds),
(pairwise_distances, 'wminkowski', wminkowski_kwds),
(pairwise_kernels, 'polynomial', {'degree': 1}),
(pairwise_kernels, callable_rbf_kernel, {'gamma': .1}),
]
for func, metric, kwds in metrics:
yield check_pairwise_parallel, func, metric, kwds
def test_pairwise_callable_nonstrict_metric():
# paired_distances should allow callable metric where metric(x, x) != 0
# Knowing that the callable is a strict metric would allow the diagonal to
# be left uncalculated and set to 0.
assert_equal(pairwise_distances([[1.]], metric=lambda x, y: 5)[0, 0], 5)
def callable_rbf_kernel(x, y, **kwds):
# Callable version of pairwise.rbf_kernel.
K = rbf_kernel(np.atleast_2d(x), np.atleast_2d(y), **kwds)
return K
def test_pairwise_kernels(): # Test the pairwise_kernels helper function.
rng = np.random.RandomState(0)
X = rng.random_sample((5, 4))
Y = rng.random_sample((2, 4))
# Test with all metrics that should be in PAIRWISE_KERNEL_FUNCTIONS.
test_metrics = ["rbf", "laplacian", "sigmoid", "polynomial", "linear",
"chi2", "additive_chi2"]
for metric in test_metrics:
function = PAIRWISE_KERNEL_FUNCTIONS[metric]
# Test with Y=None
K1 = pairwise_kernels(X, metric=metric)
K2 = function(X)
assert_array_almost_equal(K1, K2)
# Test with Y=Y
K1 = pairwise_kernels(X, Y=Y, metric=metric)
K2 = function(X, Y=Y)
assert_array_almost_equal(K1, K2)
# Test with tuples as X and Y
X_tuples = tuple([tuple([v for v in row]) for row in X])
Y_tuples = tuple([tuple([v for v in row]) for row in Y])
K2 = pairwise_kernels(X_tuples, Y_tuples, metric=metric)
assert_array_almost_equal(K1, K2)
# Test with sparse X and Y
X_sparse = csr_matrix(X)
Y_sparse = csr_matrix(Y)
if metric in ["chi2", "additive_chi2"]:
# these don't support sparse matrices yet
assert_raises(ValueError, pairwise_kernels,
X_sparse, Y=Y_sparse, metric=metric)
continue
K1 = pairwise_kernels(X_sparse, Y=Y_sparse, metric=metric)
assert_array_almost_equal(K1, K2)
# Test with a callable function, with given keywords.
metric = callable_rbf_kernel
kwds = {'gamma': 0.1}
K1 = pairwise_kernels(X, Y=Y, metric=metric, **kwds)
K2 = rbf_kernel(X, Y=Y, **kwds)
assert_array_almost_equal(K1, K2)
# callable function, X=Y
K1 = pairwise_kernels(X, Y=X, metric=metric, **kwds)
K2 = rbf_kernel(X, Y=X, **kwds)
assert_array_almost_equal(K1, K2)
def test_pairwise_kernels_filter_param():
rng = np.random.RandomState(0)
X = rng.random_sample((5, 4))
Y = rng.random_sample((2, 4))
K = rbf_kernel(X, Y, gamma=0.1)
params = {"gamma": 0.1, "blabla": ":)"}
K2 = pairwise_kernels(X, Y, metric="rbf", filter_params=True, **params)
assert_array_almost_equal(K, K2)
assert_raises(TypeError, pairwise_kernels, X, Y, "rbf", **params)
def test_paired_distances():
# Test the pairwise_distance helper function.
rng = np.random.RandomState(0)
# Euclidean distance should be equivalent to calling the function.
X = rng.random_sample((5, 4))
# Euclidean distance, with Y != X.
Y = rng.random_sample((5, 4))
for metric, func in iteritems(PAIRED_DISTANCES):
S = paired_distances(X, Y, metric=metric)
S2 = func(X, Y)
assert_array_almost_equal(S, S2)
S3 = func(csr_matrix(X), csr_matrix(Y))
assert_array_almost_equal(S, S3)
if metric in PAIRWISE_DISTANCE_FUNCTIONS:
# Check the pairwise_distances implementation
# gives the same value
distances = PAIRWISE_DISTANCE_FUNCTIONS[metric](X, Y)
distances = np.diag(distances)
assert_array_almost_equal(distances, S)
# Check the callable implementation
S = paired_distances(X, Y, metric='manhattan')
S2 = paired_distances(X, Y, metric=lambda x, y: np.abs(x - y).sum(axis=0))
assert_array_almost_equal(S, S2)
# Test that a value error is raised when the lengths of X and Y should not
# differ
Y = rng.random_sample((3, 4))
assert_raises(ValueError, paired_distances, X, Y)
def test_pairwise_distances_argmin_min():
# Check pairwise minimum distances computation for any metric
X = [[0], [1]]
Y = [[-1], [2]]
Xsp = dok_matrix(X)
Ysp = csr_matrix(Y, dtype=np.float32)
# euclidean metric
D, E = pairwise_distances_argmin_min(X, Y, metric="euclidean")
D2 = pairwise_distances_argmin(X, Y, metric="euclidean")
assert_array_almost_equal(D, [0, 1])
assert_array_almost_equal(D2, [0, 1])
assert_array_almost_equal(D, [0, 1])
assert_array_almost_equal(E, [1., 1.])
# sparse matrix case
Dsp, Esp = pairwise_distances_argmin_min(Xsp, Ysp, metric="euclidean")
assert_array_equal(Dsp, D)
assert_array_equal(Esp, E)
# We don't want np.matrix here
assert_equal(type(Dsp), np.ndarray)
assert_equal(type(Esp), np.ndarray)
# Non-euclidean scikit-learn metric
D, E = pairwise_distances_argmin_min(X, Y, metric="manhattan")
D2 = pairwise_distances_argmin(X, Y, metric="manhattan")
assert_array_almost_equal(D, [0, 1])
assert_array_almost_equal(D2, [0, 1])
assert_array_almost_equal(E, [1., 1.])
D, E = pairwise_distances_argmin_min(Xsp, Ysp, metric="manhattan")
D2 = pairwise_distances_argmin(Xsp, Ysp, metric="manhattan")
assert_array_almost_equal(D, [0, 1])
assert_array_almost_equal(E, [1., 1.])
# Non-euclidean Scipy distance (callable)
D, E = pairwise_distances_argmin_min(X, Y, metric=minkowski,
metric_kwargs={"p": 2})
assert_array_almost_equal(D, [0, 1])
assert_array_almost_equal(E, [1., 1.])
# Non-euclidean Scipy distance (string)
D, E = pairwise_distances_argmin_min(X, Y, metric="minkowski",
metric_kwargs={"p": 2})
assert_array_almost_equal(D, [0, 1])
assert_array_almost_equal(E, [1., 1.])
# Compare with naive implementation
rng = np.random.RandomState(0)
X = rng.randn(97, 149)
Y = rng.randn(111, 149)
dist = pairwise_distances(X, Y, metric="manhattan")
dist_orig_ind = dist.argmin(axis=0)
dist_orig_val = dist[dist_orig_ind, range(len(dist_orig_ind))]
dist_chunked_ind, dist_chunked_val = pairwise_distances_argmin_min(
X, Y, axis=0, metric="manhattan", batch_size=50)
np.testing.assert_almost_equal(dist_orig_ind, dist_chunked_ind, decimal=7)
np.testing.assert_almost_equal(dist_orig_val, dist_chunked_val, decimal=7)
def test_euclidean_distances():
# Check the pairwise Euclidean distances computation
X = [[0]]
Y = [[1], [2]]
D = euclidean_distances(X, Y)
assert_array_almost_equal(D, [[1., 2.]])
X = csr_matrix(X)
Y = csr_matrix(Y)
D = euclidean_distances(X, Y)
assert_array_almost_equal(D, [[1., 2.]])
rng = np.random.RandomState(0)
X = rng.random_sample((10, 4))
Y = rng.random_sample((20, 4))
X_norm_sq = (X ** 2).sum(axis=1).reshape(1, -1)
Y_norm_sq = (Y ** 2).sum(axis=1).reshape(1, -1)
# check that we still get the right answers with {X,Y}_norm_squared
D1 = euclidean_distances(X, Y)
D2 = euclidean_distances(X, Y, X_norm_squared=X_norm_sq)
D3 = euclidean_distances(X, Y, Y_norm_squared=Y_norm_sq)
D4 = euclidean_distances(X, Y, X_norm_squared=X_norm_sq,
Y_norm_squared=Y_norm_sq)
assert_array_almost_equal(D2, D1)
assert_array_almost_equal(D3, D1)
assert_array_almost_equal(D4, D1)
# check we get the wrong answer with wrong {X,Y}_norm_squared
X_norm_sq *= 0.5
Y_norm_sq *= 0.5
wrong_D = euclidean_distances(X, Y,
X_norm_squared=np.zeros_like(X_norm_sq),
Y_norm_squared=np.zeros_like(Y_norm_sq))
assert_greater(np.max(np.abs(wrong_D - D1)), .01)
def test_cosine_distances():
# Check the pairwise Cosine distances computation
rng = np.random.RandomState(1337)
x = np.abs(rng.rand(910))
XA = np.vstack([x, x])
D = cosine_distances(XA)
assert_array_almost_equal(D, [[0., 0.], [0., 0.]])
# check that all elements are in [0, 2]
assert_true(np.all(D >= 0.))
assert_true(np.all(D <= 2.))
# check that diagonal elements are equal to 0
assert_array_almost_equal(D[np.diag_indices_from(D)], [0., 0.])
XB = np.vstack([x, -x])
D2 = cosine_distances(XB)
# check that all elements are in [0, 2]
assert_true(np.all(D2 >= 0.))
assert_true(np.all(D2 <= 2.))
# check that diagonal elements are equal to 0 and non diagonal to 2
assert_array_almost_equal(D2, [[0., 2.], [2., 0.]])
# check large random matrix
X = np.abs(rng.rand(1000, 5000))
D = cosine_distances(X)
# check that diagonal elements are equal to 0
assert_array_almost_equal(D[np.diag_indices_from(D)], [0.] * D.shape[0])
assert_true(np.all(D >= 0.))
assert_true(np.all(D <= 2.))
# Paired distances
def test_paired_euclidean_distances():
# Check the paired Euclidean distances computation
X = [[0], [0]]
Y = [[1], [2]]
D = paired_euclidean_distances(X, Y)
assert_array_almost_equal(D, [1., 2.])
def test_paired_manhattan_distances():
# Check the paired manhattan distances computation
X = [[0], [0]]
Y = [[1], [2]]
D = paired_manhattan_distances(X, Y)
assert_array_almost_equal(D, [1., 2.])
def test_chi_square_kernel():
rng = np.random.RandomState(0)
X = rng.random_sample((5, 4))
Y = rng.random_sample((10, 4))
K_add = additive_chi2_kernel(X, Y)
gamma = 0.1
K = chi2_kernel(X, Y, gamma=gamma)
assert_equal(K.dtype, np.float)
for i, x in enumerate(X):
for j, y in enumerate(Y):
chi2 = -np.sum((x - y) ** 2 / (x + y))
chi2_exp = np.exp(gamma * chi2)
assert_almost_equal(K_add[i, j], chi2)
assert_almost_equal(K[i, j], chi2_exp)
# check diagonal is ones for data with itself
K = chi2_kernel(Y)
assert_array_equal(np.diag(K), 1)
# check off-diagonal is < 1 but > 0:
assert_true(np.all(K > 0))
assert_true(np.all(K - np.diag(np.diag(K)) < 1))
# check that float32 is preserved
X = rng.random_sample((5, 4)).astype(np.float32)
Y = rng.random_sample((10, 4)).astype(np.float32)
K = chi2_kernel(X, Y)
assert_equal(K.dtype, np.float32)
# check integer type gets converted,
# check that zeros are handled
X = rng.random_sample((10, 4)).astype(np.int32)
K = chi2_kernel(X, X)
assert_true(np.isfinite(K).all())
assert_equal(K.dtype, np.float)
# check that kernel of similar things is greater than dissimilar ones
X = [[.3, .7], [1., 0]]
Y = [[0, 1], [.9, .1]]
K = chi2_kernel(X, Y)
assert_greater(K[0, 0], K[0, 1])
assert_greater(K[1, 1], K[1, 0])
# test negative input
assert_raises(ValueError, chi2_kernel, [[0, -1]])
assert_raises(ValueError, chi2_kernel, [[0, -1]], [[-1, -1]])
assert_raises(ValueError, chi2_kernel, [[0, 1]], [[-1, -1]])
# different n_features in X and Y
assert_raises(ValueError, chi2_kernel, [[0, 1]], [[.2, .2, .6]])
# sparse matrices
assert_raises(ValueError, chi2_kernel, csr_matrix(X), csr_matrix(Y))
assert_raises(ValueError, additive_chi2_kernel,
csr_matrix(X), csr_matrix(Y))
def test_kernel_symmetry():
# Valid kernels should be symmetric
rng = np.random.RandomState(0)
X = rng.random_sample((5, 4))
for kernel in (linear_kernel, polynomial_kernel, rbf_kernel,
laplacian_kernel, sigmoid_kernel, cosine_similarity):
K = kernel(X, X)
assert_array_almost_equal(K, K.T, 15)
def test_kernel_sparse():
rng = np.random.RandomState(0)
X = rng.random_sample((5, 4))
X_sparse = csr_matrix(X)
for kernel in (linear_kernel, polynomial_kernel, rbf_kernel,
laplacian_kernel, sigmoid_kernel, cosine_similarity):
K = kernel(X, X)
K2 = kernel(X_sparse, X_sparse)
assert_array_almost_equal(K, K2)
def test_linear_kernel():
rng = np.random.RandomState(0)
X = rng.random_sample((5, 4))
K = linear_kernel(X, X)
# the diagonal elements of a linear kernel are their squared norm
assert_array_almost_equal(K.flat[::6], [linalg.norm(x) ** 2 for x in X])
def test_rbf_kernel():
rng = np.random.RandomState(0)
X = rng.random_sample((5, 4))
K = rbf_kernel(X, X)
# the diagonal elements of a rbf kernel are 1
assert_array_almost_equal(K.flat[::6], np.ones(5))
def test_laplacian_kernel():
rng = np.random.RandomState(0)
X = rng.random_sample((5, 4))
K = laplacian_kernel(X, X)
# the diagonal elements of a laplacian kernel are 1
assert_array_almost_equal(np.diag(K), np.ones(5))
# off-diagonal elements are < 1 but > 0:
assert_true(np.all(K > 0))
assert_true(np.all(K - np.diag(np.diag(K)) < 1))
def test_cosine_similarity_sparse_output():
# Test if cosine_similarity correctly produces sparse output.
rng = np.random.RandomState(0)
X = rng.random_sample((5, 4))
Y = rng.random_sample((3, 4))
Xcsr = csr_matrix(X)
Ycsr = csr_matrix(Y)
K1 = cosine_similarity(Xcsr, Ycsr, dense_output=False)
assert_true(issparse(K1))
K2 = pairwise_kernels(Xcsr, Y=Ycsr, metric="cosine")
assert_array_almost_equal(K1.todense(), K2)
def test_cosine_similarity():
# Test the cosine_similarity.
rng = np.random.RandomState(0)
X = rng.random_sample((5, 4))
Y = rng.random_sample((3, 4))
Xcsr = csr_matrix(X)
Ycsr = csr_matrix(Y)
for X_, Y_ in ((X, None), (X, Y),
(Xcsr, None), (Xcsr, Ycsr)):
# Test that the cosine is kernel is equal to a linear kernel when data
# has been previously normalized by L2-norm.
K1 = pairwise_kernels(X_, Y=Y_, metric="cosine")
X_ = normalize(X_)
if Y_ is not None:
Y_ = normalize(Y_)
K2 = pairwise_kernels(X_, Y=Y_, metric="linear")
assert_array_almost_equal(K1, K2)
def test_check_dense_matrices():
# Ensure that pairwise array check works for dense matrices.
# Check that if XB is None, XB is returned as reference to XA
XA = np.resize(np.arange(40), (5, 8))
XA_checked, XB_checked = check_pairwise_arrays(XA, None)
assert_true(XA_checked is XB_checked)
assert_array_equal(XA, XA_checked)
def test_check_XB_returned():
# Ensure that if XA and XB are given correctly, they return as equal.
# Check that if XB is not None, it is returned equal.
# Note that the second dimension of XB is the same as XA.
XA = np.resize(np.arange(40), (5, 8))
XB = np.resize(np.arange(32), (4, 8))
XA_checked, XB_checked = check_pairwise_arrays(XA, XB)
assert_array_equal(XA, XA_checked)
assert_array_equal(XB, XB_checked)
XB = np.resize(np.arange(40), (5, 8))
XA_checked, XB_checked = check_paired_arrays(XA, XB)
assert_array_equal(XA, XA_checked)
assert_array_equal(XB, XB_checked)
def test_check_different_dimensions():
# Ensure an error is raised if the dimensions are different.
XA = np.resize(np.arange(45), (5, 9))
XB = np.resize(np.arange(32), (4, 8))
assert_raises(ValueError, check_pairwise_arrays, XA, XB)
XB = np.resize(np.arange(4 * 9), (4, 9))
assert_raises(ValueError, check_paired_arrays, XA, XB)
def test_check_invalid_dimensions():
# Ensure an error is raised on 1D input arrays.
# The modified tests are not 1D. In the old test, the array was internally
# converted to 2D anyways
XA = np.arange(45).reshape(9, 5)
XB = np.arange(32).reshape(4, 8)
assert_raises(ValueError, check_pairwise_arrays, XA, XB)
XA = np.arange(45).reshape(9, 5)
XB = np.arange(32).reshape(4, 8)
assert_raises(ValueError, check_pairwise_arrays, XA, XB)
def test_check_sparse_arrays():
# Ensures that checks return valid sparse matrices.
rng = np.random.RandomState(0)
XA = rng.random_sample((5, 4))
XA_sparse = csr_matrix(XA)
XB = rng.random_sample((5, 4))
XB_sparse = csr_matrix(XB)
XA_checked, XB_checked = check_pairwise_arrays(XA_sparse, XB_sparse)
# compare their difference because testing csr matrices for
# equality with '==' does not work as expected.
assert_true(issparse(XA_checked))
assert_equal(abs(XA_sparse - XA_checked).sum(), 0)
assert_true(issparse(XB_checked))
assert_equal(abs(XB_sparse - XB_checked).sum(), 0)
XA_checked, XA_2_checked = check_pairwise_arrays(XA_sparse, XA_sparse)
assert_true(issparse(XA_checked))
assert_equal(abs(XA_sparse - XA_checked).sum(), 0)
assert_true(issparse(XA_2_checked))
assert_equal(abs(XA_2_checked - XA_checked).sum(), 0)
def tuplify(X):
# Turns a numpy matrix (any n-dimensional array) into tuples.
s = X.shape
if len(s) > 1:
# Tuplify each sub-array in the input.
return tuple(tuplify(row) for row in X)
else:
# Single dimension input, just return tuple of contents.
return tuple(r for r in X)
def test_check_tuple_input():
# Ensures that checks return valid tuples.
rng = np.random.RandomState(0)
XA = rng.random_sample((5, 4))
XA_tuples = tuplify(XA)
XB = rng.random_sample((5, 4))
XB_tuples = tuplify(XB)
XA_checked, XB_checked = check_pairwise_arrays(XA_tuples, XB_tuples)
assert_array_equal(XA_tuples, XA_checked)
assert_array_equal(XB_tuples, XB_checked)
def test_check_preserve_type():
# Ensures that type float32 is preserved.
XA = np.resize(np.arange(40), (5, 8)).astype(np.float32)
XB = np.resize(np.arange(40), (5, 8)).astype(np.float32)
XA_checked, XB_checked = check_pairwise_arrays(XA, None)
assert_equal(XA_checked.dtype, np.float32)
# both float32
XA_checked, XB_checked = check_pairwise_arrays(XA, XB)
assert_equal(XA_checked.dtype, np.float32)
assert_equal(XB_checked.dtype, np.float32)
# mismatched A
XA_checked, XB_checked = check_pairwise_arrays(XA.astype(np.float),
XB)
assert_equal(XA_checked.dtype, np.float)
assert_equal(XB_checked.dtype, np.float)
# mismatched B
XA_checked, XB_checked = check_pairwise_arrays(XA,
XB.astype(np.float))
assert_equal(XA_checked.dtype, np.float)
assert_equal(XB_checked.dtype, np.float)
| 27,335 | 37.178771 | 78 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/cluster/bicluster.py | from __future__ import division
import numpy as np
from sklearn.utils.linear_assignment_ import linear_assignment
from sklearn.utils.validation import check_consistent_length, check_array
__all__ = ["consensus_score"]
def _check_rows_and_columns(a, b):
"""Unpacks the row and column arrays and checks their shape."""
check_consistent_length(*a)
check_consistent_length(*b)
checks = lambda x: check_array(x, ensure_2d=False)
a_rows, a_cols = map(checks, a)
b_rows, b_cols = map(checks, b)
return a_rows, a_cols, b_rows, b_cols
def _jaccard(a_rows, a_cols, b_rows, b_cols):
"""Jaccard coefficient on the elements of the two biclusters."""
intersection = ((a_rows * b_rows).sum() *
(a_cols * b_cols).sum())
a_size = a_rows.sum() * a_cols.sum()
b_size = b_rows.sum() * b_cols.sum()
return intersection / (a_size + b_size - intersection)
def _pairwise_similarity(a, b, similarity):
"""Computes pairwise similarity matrix.
result[i, j] is the Jaccard coefficient of a's bicluster i and b's
bicluster j.
"""
a_rows, a_cols, b_rows, b_cols = _check_rows_and_columns(a, b)
n_a = a_rows.shape[0]
n_b = b_rows.shape[0]
result = np.array(list(list(similarity(a_rows[i], a_cols[i],
b_rows[j], b_cols[j])
for j in range(n_b))
for i in range(n_a)))
return result
def consensus_score(a, b, similarity="jaccard"):
"""The similarity of two sets of biclusters.
Similarity between individual biclusters is computed. Then the
best matching between sets is found using the Hungarian algorithm.
The final score is the sum of similarities divided by the size of
the larger set.
Read more in the :ref:`User Guide <biclustering>`.
Parameters
----------
a : (rows, columns)
Tuple of row and column indicators for a set of biclusters.
b : (rows, columns)
Another set of biclusters like ``a``.
similarity : string or function, optional, default: "jaccard"
May be the string "jaccard" to use the Jaccard coefficient, or
any function that takes four arguments, each of which is a 1d
indicator vector: (a_rows, a_columns, b_rows, b_columns).
References
----------
* Hochreiter, Bodenhofer, et. al., 2010. `FABIA: factor analysis
for bicluster acquisition
<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2881408/>`__.
"""
if similarity == "jaccard":
similarity = _jaccard
matrix = _pairwise_similarity(a, b, similarity)
indices = linear_assignment(1. - matrix)
n_a = len(a[0])
n_b = len(b[0])
return matrix[indices[:, 0], indices[:, 1]].sum() / max(n_a, n_b)
| 2,797 | 31.16092 | 73 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/cluster/setup.py | import os
import numpy
from numpy.distutils.misc_util import Configuration
def configuration(parent_package="", top_path=None):
config = Configuration("metrics/cluster", parent_package, top_path)
libraries = []
if os.name == 'posix':
libraries.append('m')
config.add_extension("expected_mutual_info_fast",
sources=["expected_mutual_info_fast.pyx"],
include_dirs=[numpy.get_include()],
libraries=libraries)
config.add_subpackage("tests")
return config
if __name__ == "__main__":
from numpy.distutils.core import setup
setup(**configuration().todict())
| 672 | 27.041667 | 71 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/cluster/supervised.py | """Utilities to evaluate the clustering performance of models.
Functions named as *_score return a scalar value to maximize: the higher the
better.
"""
# Authors: Olivier Grisel <[email protected]>
# Wei LI <[email protected]>
# Diego Molla <[email protected]>
# Arnaud Fouchet <[email protected]>
# Thierry Guillemot <[email protected]>
# Gregory Stupp <[email protected]>
# Joel Nothman <[email protected]>
# License: BSD 3 clause
from __future__ import division
from math import log
import numpy as np
from scipy import sparse as sp
from .expected_mutual_info_fast import expected_mutual_information
from ...utils.validation import check_array
from ...utils.fixes import comb
def comb2(n):
# the exact version is faster for k == 2: use it by default globally in
# this module instead of the float approximate variant
return comb(n, 2, exact=1)
def check_clusterings(labels_true, labels_pred):
"""Check that the two clusterings matching 1D integer arrays."""
labels_true = np.asarray(labels_true)
labels_pred = np.asarray(labels_pred)
# input checks
if labels_true.ndim != 1:
raise ValueError(
"labels_true must be 1D: shape is %r" % (labels_true.shape,))
if labels_pred.ndim != 1:
raise ValueError(
"labels_pred must be 1D: shape is %r" % (labels_pred.shape,))
if labels_true.shape != labels_pred.shape:
raise ValueError(
"labels_true and labels_pred must have same size, got %d and %d"
% (labels_true.shape[0], labels_pred.shape[0]))
return labels_true, labels_pred
def contingency_matrix(labels_true, labels_pred, eps=None, sparse=False):
"""Build a contingency matrix describing the relationship between labels.
Parameters
----------
labels_true : int array, shape = [n_samples]
Ground truth class labels to be used as a reference
labels_pred : array, shape = [n_samples]
Cluster labels to evaluate
eps : None or float, optional.
If a float, that value is added to all values in the contingency
matrix. This helps to stop NaN propagation.
If ``None``, nothing is adjusted.
sparse : boolean, optional.
If True, return a sparse CSR continency matrix. If ``eps is not None``,
and ``sparse is True``, will throw ValueError.
.. versionadded:: 0.18
Returns
-------
contingency : {array-like, sparse}, shape=[n_classes_true, n_classes_pred]
Matrix :math:`C` such that :math:`C_{i, j}` is the number of samples in
true class :math:`i` and in predicted class :math:`j`. If
``eps is None``, the dtype of this array will be integer. If ``eps`` is
given, the dtype will be float.
Will be a ``scipy.sparse.csr_matrix`` if ``sparse=True``.
"""
if eps is not None and sparse:
raise ValueError("Cannot set 'eps' when sparse=True")
classes, class_idx = np.unique(labels_true, return_inverse=True)
clusters, cluster_idx = np.unique(labels_pred, return_inverse=True)
n_classes = classes.shape[0]
n_clusters = clusters.shape[0]
# Using coo_matrix to accelerate simple histogram calculation,
# i.e. bins are consecutive integers
# Currently, coo_matrix is faster than histogram2d for simple cases
contingency = sp.coo_matrix((np.ones(class_idx.shape[0]),
(class_idx, cluster_idx)),
shape=(n_classes, n_clusters),
dtype=np.int)
if sparse:
contingency = contingency.tocsr()
contingency.sum_duplicates()
else:
contingency = contingency.toarray()
if eps is not None:
# don't use += as contingency is integer
contingency = contingency + eps
return contingency
# clustering measures
def adjusted_rand_score(labels_true, labels_pred):
"""Rand index adjusted for chance.
The Rand Index computes a similarity measure between two clusterings
by considering all pairs of samples and counting pairs that are
assigned in the same or different clusters in the predicted and
true clusterings.
The raw RI score is then "adjusted for chance" into the ARI score
using the following scheme::
ARI = (RI - Expected_RI) / (max(RI) - Expected_RI)
The adjusted Rand index is thus ensured to have a value close to
0.0 for random labeling independently of the number of clusters and
samples and exactly 1.0 when the clusterings are identical (up to
a permutation).
ARI is a symmetric measure::
adjusted_rand_score(a, b) == adjusted_rand_score(b, a)
Read more in the :ref:`User Guide <adjusted_rand_score>`.
Parameters
----------
labels_true : int array, shape = [n_samples]
Ground truth class labels to be used as a reference
labels_pred : array, shape = [n_samples]
Cluster labels to evaluate
Returns
-------
ari : float
Similarity score between -1.0 and 1.0. Random labelings have an ARI
close to 0.0. 1.0 stands for perfect match.
Examples
--------
Perfectly matching labelings have a score of 1 even
>>> from sklearn.metrics.cluster import adjusted_rand_score
>>> adjusted_rand_score([0, 0, 1, 1], [0, 0, 1, 1])
1.0
>>> adjusted_rand_score([0, 0, 1, 1], [1, 1, 0, 0])
1.0
Labelings that assign all classes members to the same clusters
are complete be not always pure, hence penalized::
>>> adjusted_rand_score([0, 0, 1, 2], [0, 0, 1, 1]) # doctest: +ELLIPSIS
0.57...
ARI is symmetric, so labelings that have pure clusters with members
coming from the same classes but unnecessary splits are penalized::
>>> adjusted_rand_score([0, 0, 1, 1], [0, 0, 1, 2]) # doctest: +ELLIPSIS
0.57...
If classes members are completely split across different clusters, the
assignment is totally incomplete, hence the ARI is very low::
>>> adjusted_rand_score([0, 0, 0, 0], [0, 1, 2, 3])
0.0
References
----------
.. [Hubert1985] `L. Hubert and P. Arabie, Comparing Partitions,
Journal of Classification 1985`
http://link.springer.com/article/10.1007%2FBF01908075
.. [wk] https://en.wikipedia.org/wiki/Rand_index#Adjusted_Rand_index
See also
--------
adjusted_mutual_info_score: Adjusted Mutual Information
"""
labels_true, labels_pred = check_clusterings(labels_true, labels_pred)
n_samples = labels_true.shape[0]
n_classes = np.unique(labels_true).shape[0]
n_clusters = np.unique(labels_pred).shape[0]
# Special limit cases: no clustering since the data is not split;
# or trivial clustering where each document is assigned a unique cluster.
# These are perfect matches hence return 1.0.
if (n_classes == n_clusters == 1 or
n_classes == n_clusters == 0 or
n_classes == n_clusters == n_samples):
return 1.0
# Compute the ARI using the contingency data
contingency = contingency_matrix(labels_true, labels_pred, sparse=True)
sum_comb_c = sum(comb2(n_c) for n_c in np.ravel(contingency.sum(axis=1)))
sum_comb_k = sum(comb2(n_k) for n_k in np.ravel(contingency.sum(axis=0)))
sum_comb = sum(comb2(n_ij) for n_ij in contingency.data)
prod_comb = (sum_comb_c * sum_comb_k) / comb(n_samples, 2)
mean_comb = (sum_comb_k + sum_comb_c) / 2.
return (sum_comb - prod_comb) / (mean_comb - prod_comb)
def homogeneity_completeness_v_measure(labels_true, labels_pred):
"""Compute the homogeneity and completeness and V-Measure scores at once.
Those metrics are based on normalized conditional entropy measures of
the clustering labeling to evaluate given the knowledge of a Ground
Truth class labels of the same samples.
A clustering result satisfies homogeneity if all of its clusters
contain only data points which are members of a single class.
A clustering result satisfies completeness if all the data points
that are members of a given class are elements of the same cluster.
Both scores have positive values between 0.0 and 1.0, larger values
being desirable.
Those 3 metrics are independent of the absolute values of the labels:
a permutation of the class or cluster label values won't change the
score values in any way.
V-Measure is furthermore symmetric: swapping ``labels_true`` and
``label_pred`` will give the same score. This does not hold for
homogeneity and completeness.
Read more in the :ref:`User Guide <homogeneity_completeness>`.
Parameters
----------
labels_true : int array, shape = [n_samples]
ground truth class labels to be used as a reference
labels_pred : array, shape = [n_samples]
cluster labels to evaluate
Returns
-------
homogeneity : float
score between 0.0 and 1.0. 1.0 stands for perfectly homogeneous labeling
completeness : float
score between 0.0 and 1.0. 1.0 stands for perfectly complete labeling
v_measure : float
harmonic mean of the first two
See also
--------
homogeneity_score
completeness_score
v_measure_score
"""
labels_true, labels_pred = check_clusterings(labels_true, labels_pred)
if len(labels_true) == 0:
return 1.0, 1.0, 1.0
entropy_C = entropy(labels_true)
entropy_K = entropy(labels_pred)
contingency = contingency_matrix(labels_true, labels_pred, sparse=True)
MI = mutual_info_score(None, None, contingency=contingency)
homogeneity = MI / (entropy_C) if entropy_C else 1.0
completeness = MI / (entropy_K) if entropy_K else 1.0
if homogeneity + completeness == 0.0:
v_measure_score = 0.0
else:
v_measure_score = (2.0 * homogeneity * completeness /
(homogeneity + completeness))
return homogeneity, completeness, v_measure_score
def homogeneity_score(labels_true, labels_pred):
"""Homogeneity metric of a cluster labeling given a ground truth.
A clustering result satisfies homogeneity if all of its clusters
contain only data points which are members of a single class.
This metric is independent of the absolute values of the labels:
a permutation of the class or cluster label values won't change the
score value in any way.
This metric is not symmetric: switching ``label_true`` with ``label_pred``
will return the :func:`completeness_score` which will be different in
general.
Read more in the :ref:`User Guide <homogeneity_completeness>`.
Parameters
----------
labels_true : int array, shape = [n_samples]
ground truth class labels to be used as a reference
labels_pred : array, shape = [n_samples]
cluster labels to evaluate
Returns
-------
homogeneity : float
score between 0.0 and 1.0. 1.0 stands for perfectly homogeneous labeling
References
----------
.. [1] `Andrew Rosenberg and Julia Hirschberg, 2007. V-Measure: A
conditional entropy-based external cluster evaluation measure
<http://aclweb.org/anthology/D/D07/D07-1043.pdf>`_
See also
--------
completeness_score
v_measure_score
Examples
--------
Perfect labelings are homogeneous::
>>> from sklearn.metrics.cluster import homogeneity_score
>>> homogeneity_score([0, 0, 1, 1], [1, 1, 0, 0])
1.0
Non-perfect labelings that further split classes into more clusters can be
perfectly homogeneous::
>>> print("%.6f" % homogeneity_score([0, 0, 1, 1], [0, 0, 1, 2]))
... # doctest: +ELLIPSIS
1.0...
>>> print("%.6f" % homogeneity_score([0, 0, 1, 1], [0, 1, 2, 3]))
... # doctest: +ELLIPSIS
1.0...
Clusters that include samples from different classes do not make for an
homogeneous labeling::
>>> print("%.6f" % homogeneity_score([0, 0, 1, 1], [0, 1, 0, 1]))
... # doctest: +ELLIPSIS
0.0...
>>> print("%.6f" % homogeneity_score([0, 0, 1, 1], [0, 0, 0, 0]))
... # doctest: +ELLIPSIS
0.0...
"""
return homogeneity_completeness_v_measure(labels_true, labels_pred)[0]
def completeness_score(labels_true, labels_pred):
"""Completeness metric of a cluster labeling given a ground truth.
A clustering result satisfies completeness if all the data points
that are members of a given class are elements of the same cluster.
This metric is independent of the absolute values of the labels:
a permutation of the class or cluster label values won't change the
score value in any way.
This metric is not symmetric: switching ``label_true`` with ``label_pred``
will return the :func:`homogeneity_score` which will be different in
general.
Read more in the :ref:`User Guide <homogeneity_completeness>`.
Parameters
----------
labels_true : int array, shape = [n_samples]
ground truth class labels to be used as a reference
labels_pred : array, shape = [n_samples]
cluster labels to evaluate
Returns
-------
completeness : float
score between 0.0 and 1.0. 1.0 stands for perfectly complete labeling
References
----------
.. [1] `Andrew Rosenberg and Julia Hirschberg, 2007. V-Measure: A
conditional entropy-based external cluster evaluation measure
<http://aclweb.org/anthology/D/D07/D07-1043.pdf>`_
See also
--------
homogeneity_score
v_measure_score
Examples
--------
Perfect labelings are complete::
>>> from sklearn.metrics.cluster import completeness_score
>>> completeness_score([0, 0, 1, 1], [1, 1, 0, 0])
1.0
Non-perfect labelings that assign all classes members to the same clusters
are still complete::
>>> print(completeness_score([0, 0, 1, 1], [0, 0, 0, 0]))
1.0
>>> print(completeness_score([0, 1, 2, 3], [0, 0, 1, 1]))
1.0
If classes members are split across different clusters, the
assignment cannot be complete::
>>> print(completeness_score([0, 0, 1, 1], [0, 1, 0, 1]))
0.0
>>> print(completeness_score([0, 0, 0, 0], [0, 1, 2, 3]))
0.0
"""
return homogeneity_completeness_v_measure(labels_true, labels_pred)[1]
def v_measure_score(labels_true, labels_pred):
"""V-measure cluster labeling given a ground truth.
This score is identical to :func:`normalized_mutual_info_score`.
The V-measure is the harmonic mean between homogeneity and completeness::
v = 2 * (homogeneity * completeness) / (homogeneity + completeness)
This metric is independent of the absolute values of the labels:
a permutation of the class or cluster label values won't change the
score value in any way.
This metric is furthermore symmetric: switching ``label_true`` with
``label_pred`` will return the same score value. This can be useful to
measure the agreement of two independent label assignments strategies
on the same dataset when the real ground truth is not known.
Read more in the :ref:`User Guide <homogeneity_completeness>`.
Parameters
----------
labels_true : int array, shape = [n_samples]
ground truth class labels to be used as a reference
labels_pred : array, shape = [n_samples]
cluster labels to evaluate
Returns
-------
v_measure : float
score between 0.0 and 1.0. 1.0 stands for perfectly complete labeling
References
----------
.. [1] `Andrew Rosenberg and Julia Hirschberg, 2007. V-Measure: A
conditional entropy-based external cluster evaluation measure
<http://aclweb.org/anthology/D/D07/D07-1043.pdf>`_
See also
--------
homogeneity_score
completeness_score
Examples
--------
Perfect labelings are both homogeneous and complete, hence have score 1.0::
>>> from sklearn.metrics.cluster import v_measure_score
>>> v_measure_score([0, 0, 1, 1], [0, 0, 1, 1])
1.0
>>> v_measure_score([0, 0, 1, 1], [1, 1, 0, 0])
1.0
Labelings that assign all classes members to the same clusters
are complete be not homogeneous, hence penalized::
>>> print("%.6f" % v_measure_score([0, 0, 1, 2], [0, 0, 1, 1]))
... # doctest: +ELLIPSIS
0.8...
>>> print("%.6f" % v_measure_score([0, 1, 2, 3], [0, 0, 1, 1]))
... # doctest: +ELLIPSIS
0.66...
Labelings that have pure clusters with members coming from the same
classes are homogeneous but un-necessary splits harms completeness
and thus penalize V-measure as well::
>>> print("%.6f" % v_measure_score([0, 0, 1, 1], [0, 0, 1, 2]))
... # doctest: +ELLIPSIS
0.8...
>>> print("%.6f" % v_measure_score([0, 0, 1, 1], [0, 1, 2, 3]))
... # doctest: +ELLIPSIS
0.66...
If classes members are completely split across different clusters,
the assignment is totally incomplete, hence the V-Measure is null::
>>> print("%.6f" % v_measure_score([0, 0, 0, 0], [0, 1, 2, 3]))
... # doctest: +ELLIPSIS
0.0...
Clusters that include samples from totally different classes totally
destroy the homogeneity of the labeling, hence::
>>> print("%.6f" % v_measure_score([0, 0, 1, 1], [0, 0, 0, 0]))
... # doctest: +ELLIPSIS
0.0...
"""
return homogeneity_completeness_v_measure(labels_true, labels_pred)[2]
def mutual_info_score(labels_true, labels_pred, contingency=None):
"""Mutual Information between two clusterings.
The Mutual Information is a measure of the similarity between two labels of
the same data. Where :math:`|U_i|` is the number of the samples
in cluster :math:`U_i` and :math:`|V_j|` is the number of the
samples in cluster :math:`V_j`, the Mutual Information
between clusterings :math:`U` and :math:`V` is given as:
.. math::
MI(U,V)=\sum_{i=1}^|U| \sum_{j=1}^|V| \\frac{|U_i\cap V_j|}{N}
\log\\frac{N|U_i \cap V_j|}{|U_i||V_j|}
This metric is independent of the absolute values of the labels:
a permutation of the class or cluster label values won't change the
score value in any way.
This metric is furthermore symmetric: switching ``label_true`` with
``label_pred`` will return the same score value. This can be useful to
measure the agreement of two independent label assignments strategies
on the same dataset when the real ground truth is not known.
Read more in the :ref:`User Guide <mutual_info_score>`.
Parameters
----------
labels_true : int array, shape = [n_samples]
A clustering of the data into disjoint subsets.
labels_pred : array, shape = [n_samples]
A clustering of the data into disjoint subsets.
contingency : {None, array, sparse matrix},
shape = [n_classes_true, n_classes_pred]
A contingency matrix given by the :func:`contingency_matrix` function.
If value is ``None``, it will be computed, otherwise the given value is
used, with ``labels_true`` and ``labels_pred`` ignored.
Returns
-------
mi : float
Mutual information, a non-negative value
See also
--------
adjusted_mutual_info_score: Adjusted against chance Mutual Information
normalized_mutual_info_score: Normalized Mutual Information
"""
if contingency is None:
labels_true, labels_pred = check_clusterings(labels_true, labels_pred)
contingency = contingency_matrix(labels_true, labels_pred, sparse=True)
else:
contingency = check_array(contingency,
accept_sparse=['csr', 'csc', 'coo'],
dtype=[int, np.int32, np.int64])
if isinstance(contingency, np.ndarray):
# For an array
nzx, nzy = np.nonzero(contingency)
nz_val = contingency[nzx, nzy]
elif sp.issparse(contingency):
# For a sparse matrix
nzx, nzy, nz_val = sp.find(contingency)
else:
raise ValueError("Unsupported type for 'contingency': %s" %
type(contingency))
contingency_sum = contingency.sum()
pi = np.ravel(contingency.sum(axis=1))
pj = np.ravel(contingency.sum(axis=0))
log_contingency_nm = np.log(nz_val)
contingency_nm = nz_val / contingency_sum
# Don't need to calculate the full outer product, just for non-zeroes
outer = pi.take(nzx) * pj.take(nzy)
log_outer = -np.log(outer) + log(pi.sum()) + log(pj.sum())
mi = (contingency_nm * (log_contingency_nm - log(contingency_sum)) +
contingency_nm * log_outer)
return mi.sum()
def adjusted_mutual_info_score(labels_true, labels_pred):
"""Adjusted Mutual Information between two clusterings.
Adjusted Mutual Information (AMI) is an adjustment of the Mutual
Information (MI) score to account for chance. It accounts for the fact that
the MI is generally higher for two clusterings with a larger number of
clusters, regardless of whether there is actually more information shared.
For two clusterings :math:`U` and :math:`V`, the AMI is given as::
AMI(U, V) = [MI(U, V) - E(MI(U, V))] / [max(H(U), H(V)) - E(MI(U, V))]
This metric is independent of the absolute values of the labels:
a permutation of the class or cluster label values won't change the
score value in any way.
This metric is furthermore symmetric: switching ``label_true`` with
``label_pred`` will return the same score value. This can be useful to
measure the agreement of two independent label assignments strategies
on the same dataset when the real ground truth is not known.
Be mindful that this function is an order of magnitude slower than other
metrics, such as the Adjusted Rand Index.
Read more in the :ref:`User Guide <mutual_info_score>`.
Parameters
----------
labels_true : int array, shape = [n_samples]
A clustering of the data into disjoint subsets.
labels_pred : array, shape = [n_samples]
A clustering of the data into disjoint subsets.
Returns
-------
ami: float(upperlimited by 1.0)
The AMI returns a value of 1 when the two partitions are identical
(ie perfectly matched). Random partitions (independent labellings) have
an expected AMI around 0 on average hence can be negative.
See also
--------
adjusted_rand_score: Adjusted Rand Index
mutual_information_score: Mutual Information (not adjusted for chance)
Examples
--------
Perfect labelings are both homogeneous and complete, hence have
score 1.0::
>>> from sklearn.metrics.cluster import adjusted_mutual_info_score
>>> adjusted_mutual_info_score([0, 0, 1, 1], [0, 0, 1, 1])
1.0
>>> adjusted_mutual_info_score([0, 0, 1, 1], [1, 1, 0, 0])
1.0
If classes members are completely split across different clusters,
the assignment is totally in-complete, hence the AMI is null::
>>> adjusted_mutual_info_score([0, 0, 0, 0], [0, 1, 2, 3])
0.0
References
----------
.. [1] `Vinh, Epps, and Bailey, (2010). Information Theoretic Measures for
Clusterings Comparison: Variants, Properties, Normalization and
Correction for Chance, JMLR
<http://jmlr.csail.mit.edu/papers/volume11/vinh10a/vinh10a.pdf>`_
.. [2] `Wikipedia entry for the Adjusted Mutual Information
<https://en.wikipedia.org/wiki/Adjusted_Mutual_Information>`_
"""
labels_true, labels_pred = check_clusterings(labels_true, labels_pred)
n_samples = labels_true.shape[0]
classes = np.unique(labels_true)
clusters = np.unique(labels_pred)
# Special limit cases: no clustering since the data is not split.
# This is a perfect match hence return 1.0.
if (classes.shape[0] == clusters.shape[0] == 1 or
classes.shape[0] == clusters.shape[0] == 0):
return 1.0
contingency = contingency_matrix(labels_true, labels_pred, sparse=True)
contingency = contingency.astype(np.float64)
# Calculate the MI for the two clusterings
mi = mutual_info_score(labels_true, labels_pred,
contingency=contingency)
# Calculate the expected value for the mutual information
emi = expected_mutual_information(contingency, n_samples)
# Calculate entropy for each labeling
h_true, h_pred = entropy(labels_true), entropy(labels_pred)
ami = (mi - emi) / (max(h_true, h_pred) - emi)
return ami
def normalized_mutual_info_score(labels_true, labels_pred):
"""Normalized Mutual Information between two clusterings.
Normalized Mutual Information (NMI) is an normalization of the Mutual
Information (MI) score to scale the results between 0 (no mutual
information) and 1 (perfect correlation). In this function, mutual
information is normalized by ``sqrt(H(labels_true) * H(labels_pred))``
This measure is not adjusted for chance. Therefore
:func:`adjusted_mustual_info_score` might be preferred.
This metric is independent of the absolute values of the labels:
a permutation of the class or cluster label values won't change the
score value in any way.
This metric is furthermore symmetric: switching ``label_true`` with
``label_pred`` will return the same score value. This can be useful to
measure the agreement of two independent label assignments strategies
on the same dataset when the real ground truth is not known.
Read more in the :ref:`User Guide <mutual_info_score>`.
Parameters
----------
labels_true : int array, shape = [n_samples]
A clustering of the data into disjoint subsets.
labels_pred : array, shape = [n_samples]
A clustering of the data into disjoint subsets.
Returns
-------
nmi : float
score between 0.0 and 1.0. 1.0 stands for perfectly complete labeling
See also
--------
adjusted_rand_score: Adjusted Rand Index
adjusted_mutual_info_score: Adjusted Mutual Information (adjusted
against chance)
Examples
--------
Perfect labelings are both homogeneous and complete, hence have
score 1.0::
>>> from sklearn.metrics.cluster import normalized_mutual_info_score
>>> normalized_mutual_info_score([0, 0, 1, 1], [0, 0, 1, 1])
1.0
>>> normalized_mutual_info_score([0, 0, 1, 1], [1, 1, 0, 0])
1.0
If classes members are completely split across different clusters,
the assignment is totally in-complete, hence the NMI is null::
>>> normalized_mutual_info_score([0, 0, 0, 0], [0, 1, 2, 3])
0.0
"""
labels_true, labels_pred = check_clusterings(labels_true, labels_pred)
classes = np.unique(labels_true)
clusters = np.unique(labels_pred)
# Special limit cases: no clustering since the data is not split.
# This is a perfect match hence return 1.0.
if (classes.shape[0] == clusters.shape[0] == 1 or
classes.shape[0] == clusters.shape[0] == 0):
return 1.0
contingency = contingency_matrix(labels_true, labels_pred, sparse=True)
contingency = contingency.astype(np.float64)
# Calculate the MI for the two clusterings
mi = mutual_info_score(labels_true, labels_pred,
contingency=contingency)
# Calculate the expected value for the mutual information
# Calculate entropy for each labeling
h_true, h_pred = entropy(labels_true), entropy(labels_pred)
nmi = mi / max(np.sqrt(h_true * h_pred), 1e-10)
return nmi
def fowlkes_mallows_score(labels_true, labels_pred, sparse=False):
"""Measure the similarity of two clusterings of a set of points.
The Fowlkes-Mallows index (FMI) is defined as the geometric mean between of
the precision and recall::
FMI = TP / sqrt((TP + FP) * (TP + FN))
Where ``TP`` is the number of **True Positive** (i.e. the number of pair of
points that belongs in the same clusters in both ``labels_true`` and
``labels_pred``), ``FP`` is the number of **False Positive** (i.e. the
number of pair of points that belongs in the same clusters in
``labels_true`` and not in ``labels_pred``) and ``FN`` is the number of
**False Negative** (i.e the number of pair of points that belongs in the
same clusters in ``labels_pred`` and not in ``labels_True``).
The score ranges from 0 to 1. A high value indicates a good similarity
between two clusters.
Read more in the :ref:`User Guide <fowlkes_mallows_scores>`.
Parameters
----------
labels_true : int array, shape = (``n_samples``,)
A clustering of the data into disjoint subsets.
labels_pred : array, shape = (``n_samples``, )
A clustering of the data into disjoint subsets.
sparse : bool
Compute contingency matrix internally with sparse matrix.
Returns
-------
score : float
The resulting Fowlkes-Mallows score.
Examples
--------
Perfect labelings are both homogeneous and complete, hence have
score 1.0::
>>> from sklearn.metrics.cluster import fowlkes_mallows_score
>>> fowlkes_mallows_score([0, 0, 1, 1], [0, 0, 1, 1])
1.0
>>> fowlkes_mallows_score([0, 0, 1, 1], [1, 1, 0, 0])
1.0
If classes members are completely split across different clusters,
the assignment is totally random, hence the FMI is null::
>>> fowlkes_mallows_score([0, 0, 0, 0], [0, 1, 2, 3])
0.0
References
----------
.. [1] `E. B. Fowkles and C. L. Mallows, 1983. "A method for comparing two
hierarchical clusterings". Journal of the American Statistical
Association
<http://wildfire.stat.ucla.edu/pdflibrary/fowlkes.pdf>`_
.. [2] `Wikipedia entry for the Fowlkes-Mallows Index
<https://en.wikipedia.org/wiki/Fowlkes-Mallows_index>`_
"""
labels_true, labels_pred = check_clusterings(labels_true, labels_pred)
n_samples, = labels_true.shape
c = contingency_matrix(labels_true, labels_pred, sparse=True)
tk = np.dot(c.data, c.data) - n_samples
pk = np.sum(np.asarray(c.sum(axis=0)).ravel() ** 2) - n_samples
qk = np.sum(np.asarray(c.sum(axis=1)).ravel() ** 2) - n_samples
return tk / np.sqrt(pk * qk) if tk != 0. else 0.
def entropy(labels):
"""Calculates the entropy for a labeling."""
if len(labels) == 0:
return 1.0
label_idx = np.unique(labels, return_inverse=True)[1]
pi = np.bincount(label_idx).astype(np.float64)
pi = pi[pi > 0]
pi_sum = np.sum(pi)
# log(a / b) should be calculated as log(a) - log(b) for
# possible loss of precision
return -np.sum((pi / pi_sum) * (np.log(pi) - log(pi_sum)))
| 31,406 | 34.975945 | 79 | py |
cba-pipeline-public | cba-pipeline-public-master/containernet/ndn-containers/ndn_headless-player/bandits/venv/lib/python3.6/site-packages/sklearn/metrics/cluster/unsupervised.py | """Unsupervised evaluation metrics."""
# Authors: Robert Layton <[email protected]>
# Arnaud Fouchet <[email protected]>
# Thierry Guillemot <[email protected]>
# License: BSD 3 clause
import numpy as np
from ...utils import check_random_state
from ...utils import check_X_y
from ..pairwise import pairwise_distances
from ...preprocessing import LabelEncoder
def check_number_of_labels(n_labels, n_samples):
if not 1 < n_labels < n_samples:
raise ValueError("Number of labels is %d. Valid values are 2 "
"to n_samples - 1 (inclusive)" % n_labels)
def silhouette_score(X, labels, metric='euclidean', sample_size=None,
random_state=None, **kwds):
"""Compute the mean Silhouette Coefficient of all samples.
The Silhouette Coefficient is calculated using the mean intra-cluster
distance (``a``) and the mean nearest-cluster distance (``b``) for each
sample. The Silhouette Coefficient for a sample is ``(b - a) / max(a,
b)``. To clarify, ``b`` is the distance between a sample and the nearest
cluster that the sample is not a part of.
Note that Silhouette Coefficient is only defined if number of labels
is 2 <= n_labels <= n_samples - 1.
This function returns the mean Silhouette Coefficient over all samples.
To obtain the values for each sample, use :func:`silhouette_samples`.
The best value is 1 and the worst value is -1. Values near 0 indicate
overlapping clusters. Negative values generally indicate that a sample has
been assigned to the wrong cluster, as a different cluster is more similar.
Read more in the :ref:`User Guide <silhouette_coefficient>`.
Parameters
----------
X : array [n_samples_a, n_samples_a] if metric == "precomputed", or, \
[n_samples_a, n_features] otherwise
Array of pairwise distances between samples, or a feature array.
labels : array, shape = [n_samples]
Predicted labels for each sample.
metric : string, or callable
The metric to use when calculating distance between instances in a
feature array. If metric is a string, it must be one of the options
allowed by :func:`metrics.pairwise.pairwise_distances
<sklearn.metrics.pairwise.pairwise_distances>`. If X is the distance
array itself, use ``metric="precomputed"``.
sample_size : int or None
The size of the sample to use when computing the Silhouette Coefficient
on a random subset of the data.
If ``sample_size is None``, no sampling is used.
random_state : int, RandomState instance or None, optional (default=None)
The generator used to randomly select a subset of samples. If int,
random_state is the seed used by the random number generator; If
RandomState instance, random_state is the random number generator; If
None, the random number generator is the RandomState instance used by
`np.random`. Used when ``sample_size is not None``.
**kwds : optional keyword parameters
Any further parameters are passed directly to the distance function.
If using a scipy.spatial.distance metric, the parameters are still
metric dependent. See the scipy docs for usage examples.
Returns
-------
silhouette : float
Mean Silhouette Coefficient for all samples.
References
----------
.. [1] `Peter J. Rousseeuw (1987). "Silhouettes: a Graphical Aid to the
Interpretation and Validation of Cluster Analysis". Computational
and Applied Mathematics 20: 53-65.
<http://www.sciencedirect.com/science/article/pii/0377042787901257>`_
.. [2] `Wikipedia entry on the Silhouette Coefficient
<https://en.wikipedia.org/wiki/Silhouette_(clustering)>`_
"""
if sample_size is not None:
X, labels = check_X_y(X, labels, accept_sparse=['csc', 'csr'])
random_state = check_random_state(random_state)
indices = random_state.permutation(X.shape[0])[:sample_size]
if metric == "precomputed":
X, labels = X[indices].T[indices].T, labels[indices]
else:
X, labels = X[indices], labels[indices]
return np.mean(silhouette_samples(X, labels, metric=metric, **kwds))
def silhouette_samples(X, labels, metric='euclidean', **kwds):
"""Compute the Silhouette Coefficient for each sample.
The Silhouette Coefficient is a measure of how well samples are clustered
with samples that are similar to themselves. Clustering models with a high
Silhouette Coefficient are said to be dense, where samples in the same
cluster are similar to each other, and well separated, where samples in
different clusters are not very similar to each other.
The Silhouette Coefficient is calculated using the mean intra-cluster
distance (``a``) and the mean nearest-cluster distance (``b``) for each
sample. The Silhouette Coefficient for a sample is ``(b - a) / max(a,
b)``.
Note that Silhouette Coefficient is only defined if number of labels
is 2 <= n_labels <= n_samples - 1.
This function returns the Silhouette Coefficient for each sample.
The best value is 1 and the worst value is -1. Values near 0 indicate
overlapping clusters.
Read more in the :ref:`User Guide <silhouette_coefficient>`.
Parameters
----------
X : array [n_samples_a, n_samples_a] if metric == "precomputed", or, \
[n_samples_a, n_features] otherwise
Array of pairwise distances between samples, or a feature array.
labels : array, shape = [n_samples]
label values for each sample
metric : string, or callable
The metric to use when calculating distance between instances in a
feature array. If metric is a string, it must be one of the options
allowed by :func:`sklearn.metrics.pairwise.pairwise_distances`. If X is
the distance array itself, use "precomputed" as the metric.
**kwds : optional keyword parameters
Any further parameters are passed directly to the distance function.
If using a ``scipy.spatial.distance`` metric, the parameters are still
metric dependent. See the scipy docs for usage examples.
Returns
-------
silhouette : array, shape = [n_samples]
Silhouette Coefficient for each samples.
References
----------
.. [1] `Peter J. Rousseeuw (1987). "Silhouettes: a Graphical Aid to the
Interpretation and Validation of Cluster Analysis". Computational
and Applied Mathematics 20: 53-65.
<http://www.sciencedirect.com/science/article/pii/0377042787901257>`_
.. [2] `Wikipedia entry on the Silhouette Coefficient
<https://en.wikipedia.org/wiki/Silhouette_(clustering)>`_
"""
X, labels = check_X_y(X, labels, accept_sparse=['csc', 'csr'])
le = LabelEncoder()
labels = le.fit_transform(labels)
check_number_of_labels(len(le.classes_), X.shape[0])
distances = pairwise_distances(X, metric=metric, **kwds)
unique_labels = le.classes_
n_samples_per_label = np.bincount(labels, minlength=len(unique_labels))
# For sample i, store the mean distance of the cluster to which
# it belongs in intra_clust_dists[i]
intra_clust_dists = np.zeros(distances.shape[0], dtype=distances.dtype)
# For sample i, store the mean distance of the second closest
# cluster in inter_clust_dists[i]
inter_clust_dists = np.inf + intra_clust_dists
for curr_label in range(len(unique_labels)):
# Find inter_clust_dist for all samples belonging to the same
# label.
mask = labels == curr_label
current_distances = distances[mask]
# Leave out current sample.
n_samples_curr_lab = n_samples_per_label[curr_label] - 1
if n_samples_curr_lab != 0:
intra_clust_dists[mask] = np.sum(
current_distances[:, mask], axis=1) / n_samples_curr_lab
# Now iterate over all other labels, finding the mean
# cluster distance that is closest to every sample.
for other_label in range(len(unique_labels)):
if other_label != curr_label:
other_mask = labels == other_label
other_distances = np.mean(
current_distances[:, other_mask], axis=1)
inter_clust_dists[mask] = np.minimum(
inter_clust_dists[mask], other_distances)
sil_samples = inter_clust_dists - intra_clust_dists
sil_samples /= np.maximum(intra_clust_dists, inter_clust_dists)
# score 0 for clusters of size 1, according to the paper
sil_samples[n_samples_per_label.take(labels) == 1] = 0
return sil_samples
def calinski_harabaz_score(X, labels):
"""Compute the Calinski and Harabaz score.
The score is defined as ratio between the within-cluster dispersion and
the between-cluster dispersion.
Read more in the :ref:`User Guide <calinski_harabaz_index>`.
Parameters
----------
X : array-like, shape (``n_samples``, ``n_features``)
List of ``n_features``-dimensional data points. Each row corresponds
to a single data point.
labels : array-like, shape (``n_samples``,)
Predicted labels for each sample.
Returns
-------
score : float
The resulting Calinski-Harabaz score.
References
----------
.. [1] `T. Calinski and J. Harabasz, 1974. "A dendrite method for cluster
analysis". Communications in Statistics
<http://www.tandfonline.com/doi/abs/10.1080/03610927408827101>`_
"""
X, labels = check_X_y(X, labels)
le = LabelEncoder()
labels = le.fit_transform(labels)
n_samples, _ = X.shape
n_labels = len(le.classes_)
check_number_of_labels(n_labels, n_samples)
extra_disp, intra_disp = 0., 0.
mean = np.mean(X, axis=0)
for k in range(n_labels):
cluster_k = X[labels == k]
mean_k = np.mean(cluster_k, axis=0)
extra_disp += len(cluster_k) * np.sum((mean_k - mean) ** 2)
intra_disp += np.sum((cluster_k - mean_k) ** 2)
return (1. if intra_disp == 0. else
extra_disp * (n_samples - n_labels) /
(intra_disp * (n_labels - 1.)))
| 10,322 | 38.857143 | 79 | py |
Subsets and Splits