File size: 4,783 Bytes
a79cd47
 
 
 
484451a
 
 
 
 
 
a79cd47
 
 
 
 
 
 
 
 
 
 
 
484451a
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2df0d19
 
 
 
484451a
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
c972581
 
2df0d19
 
c972581
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
484451a
a79cd47
 
 
 
 
2df0d19
 
 
 
 
 
 
 
 
c972581
 
 
2df0d19
 
a79cd47
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
import gradio as gr
import numpy as np
import matplotlib.pyplot as plt
from sklearn.model_selection import train_test_split

import matplotlib.cm as cm
from sklearn.utils import shuffle
from sklearn.utils import check_random_state
from sklearn.cluster import MiniBatchKMeans
from sklearn.cluster import KMeans

theme = gr.themes.Monochrome(
    primary_hue="indigo",
    secondary_hue="blue",
    neutral_hue="slate",
)

description = f"""
## Description
This demo can be used to evaluate the ability of k-means initializations strategies to make the algorithm convergence robust
"""

# k-means models can do several random inits so as to be able to trade
# CPU time for convergence robustness
n_init_range = np.array([1, 5, 10, 15, 20])

# Datasets generation parameters
scale = 0.1

def make_data(random_state, n_samples_per_center, grid_size, scale):
    random_state = check_random_state(random_state)
    centers = np.array([[i, j] for i in range(grid_size) for j in range(grid_size)])
    n_clusters_true, n_features = centers.shape

    noise = random_state.normal(
        scale=scale, size=(n_samples_per_center, centers.shape[1])
    )

    X = np.concatenate([c + noise for c in centers])
    y = np.concatenate([[i] * n_samples_per_center for i in range(n_clusters_true)])
    return shuffle(X, y, random_state=random_state)

def quant_evaluation(n_runs, n_samples_per_center, grid_size):
    
    n_clusters = grid_size**2

    plt.figure()
    plots = []
    legends = []
    
    cases = [
        (KMeans, "k-means++", {}, "^-"),
        (KMeans, "random", {}, "o-"),
        (MiniBatchKMeans, "k-means++", {"max_no_improvement": 3}, "x-"),
        (MiniBatchKMeans, "random", {"max_no_improvement": 3, "init_size": 500}, "d-"),
    ]
    
    for factory, init, params, format in cases:
        print("Evaluation of %s with %s init" % (factory.__name__, init))
        inertia = np.empty((len(n_init_range), n_runs))
    
        for run_id in range(n_runs):
            X, y = make_data(run_id, n_samples_per_center, grid_size, scale)
            for i, n_init in enumerate(n_init_range):
                km = factory(
                    n_clusters=n_clusters,
                    init=init,
                    random_state=run_id,
                    n_init=n_init,
                    **params,
                ).fit(X)
                inertia[i, run_id] = km.inertia_
        p = plt.errorbar(
            n_init_range, inertia.mean(axis=1), inertia.std(axis=1), fmt=format
        )
        plots.append(p[0])
        legends.append("%s with %s init" % (factory.__name__, init))
    
    plt.xlabel("n_init")
    plt.ylabel("inertia")
    plt.legend(plots, legends)
    plt.title("Mean inertia for various k-means init across %d runs" % n_runs)
    return plt

def qual_evaluation(random_state, n_samples_per_center, grid_size):
    n_clusters = grid_size**2
    X, y = make_data(random_state, n_samples_per_center, grid_size, scale)
    km = MiniBatchKMeans(
    n_clusters=n_clusters, init="random", n_init=1, random_state=random_state
    ).fit(X)

    plt.figure()
    for k in range(n_clusters):
        my_members = km.labels_ == k
        color = cm.nipy_spectral(float(k) / n_clusters, 1)
        plt.plot(X[my_members, 0], X[my_members, 1], ".", c=color)
        cluster_center = km.cluster_centers_[k]
        plt.plot(
            cluster_center[0],
            cluster_center[1],
            "o",
            markerfacecolor=color,
            markeredgecolor="k",
            markersize=6,
        )
        plt.title(
            "Example cluster allocation with a single random init\nwith MiniBatchKMeans"
        )
    return plt

with gr.Blocks(theme=theme) as demo:
    gr.Markdown('''
            <h1 style='text-align: center'>Empirical evaluation of the impact of k-means initialization 📊</h1>
        ''')
    gr.Markdown(description)
    with gr.Row():
        n_runs = gr.Slider(minimum=1, maximum=10, step=1, value=5, label="Number of Evaluation Runs")
        random_state = gr.Slider(minimum=0, maximum=2000, step=5, value=0, label="Random state")
        n_samples_per_center = gr.Slider(minimum=50, maximum=200, step=10, value=100, label="Number of Samples per Center")
        grid_size = gr.Slider(minimum=1, maximum=8, step=1, value=3, label="Grid Size") 

    with gr.Row():
        run_button = gr.Button('Evaluate Inertia')
        run_button_qual = gr.Button('Generate Cluster Allocations')
    with gr.Row():
        plot_inertia = gr.Plot()
        plot_vis = gr.Plot()
    run_button.click(fn=quant_evaluation, inputs=[n_runs, n_samples_per_center, grid_size], outputs=plot_inertia)
    run_button_qual.click(fn=qual_evaluation, inputs=[random_state, n_samples_per_center, grid_size], outputs=plot_vis)

demo.launch()