交叉熵cross_entropy的python实现

代码实现

import math
# Write a function that takes as input two lists Y, P,
# and returns the float corresponding to their cross-entropy.
def cross_entropy(Y, P):
    sum=0.0
    for x in map(lambda y,p:(1-y)*math.log(1-p)+y*math.log(p),Y,P):
        sum+=x
    return -sum/len(Y)
if __name__ ==