erasmopurif's picture
First commit
d2a8669
import numpy as np
from aif360.algorithms.inprocessing.celisMeta.General import General
class StatisticalRate(General):
def getExpectedGrad(self, dist, a, b, params, samples, mu, z_prior):
l_1, l_2 = params
t, c_1, c_2 = self.getValueForX(dist, a, b, params, z_prior, samples,
return_cs=True)
t1 = t * c_1/np.sqrt(t**2 + mu**2)
t2 = t * c_2/np.sqrt(t**2 + mu**2)
exp1 = np.mean(t1)
exp2 = np.mean(t2)
dl1 = exp1 - b + (b-a)/2 + (b-a)*l_1 / (2*np.sqrt(l_1**2 + mu**2))
dl2 = exp2 - b + (b-a)/2 + (b-a)*l_2 / (2*np.sqrt(l_2**2 + mu**2))
return dl1, dl2
def getValueForX(self, dist, a, b, params, z_prior, x, return_cs=False):
l_1, l_2 = params
z_0, z_1 = 1-z_prior, z_prior
pos = np.ones(len(x))
prob_1_1 = self.prob(dist, np.c_[x, pos, pos])
prob_m1_1 = self.prob(dist, np.c_[x, -pos, pos])
prob_1_0 = self.prob(dist, np.c_[x, pos, np.zeros(len(x))])
prob_m1_0 = self.prob(dist, np.c_[x, -pos, np.zeros(len(x))])
total = prob_1_1 + prob_1_0 + prob_m1_0 + prob_m1_1
# if total == 0:
# return 0
prob_y_1 = (prob_1_1 + prob_1_0) / total
prob_z_0 = (prob_m1_0 + prob_1_0) / total
prob_z_1 = (prob_m1_1 + prob_1_1) / total
c_0 = prob_y_1 - 0.5
c_1 = prob_z_0 / z_0
c_2 = prob_z_1 / z_1
t = c_0 + c_1*l_1 + c_2*l_2
if return_cs:
return t, c_1, c_2
else:
return t
def getFuncValue(self, dist, a, b, params, samples, z_prior):
l_1, l_2 = params
exp = np.mean(np.abs(self.getValueForX(dist, a, b, params, z_prior,
samples)))
result = exp - b*l_1 - b*l_2
if l_1 > 0:
result += (b-a)*l_1
if l_2 > 0:
result += (b-a)*l_2
return result
@property
def num_params(self):
return 2
def init_params(self, i):
return [i-5] * self.num_params
def gamma(self, y_true, y_pred, sens):
pos_0 = np.mean(y_pred[sens == 0] == 1)
pos_1 = np.mean(y_pred[sens == 1] == 1)
if pos_0 == 0 or pos_1 == 0:
return 0
return min(pos_0/pos_1, pos_1/pos_0)