def pdf(self, X):
"""
Evaluate the pdf of data to belong to the mixture
:param data: (npArray) data to evaluate
:return: proba (npArray)
"""
proba = None
for i in range(self.K):
w = self.w[i]
probaToAdd = GMM.gaussianPdf(X, self.mean[i], self.cov[i]) * w
if proba is None:
proba = probaToAdd
else:
proba += probaToAdd
return proba
