view cost.py @ 421:e01f17be270a

Kernel regression learning algorithm
author Yoshua Bengio <bengioy@iro.umontreal.ca>
date Sat, 19 Jul 2008 10:11:22 -0400
parents 319bf28c2dd5
children 0f366ecb11ee
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"""
Cost functions.
"""

import theano.tensor as T

def quadratic(target, output, axis=1):
    return T.mean(T.sqr(target - output), axis)

def cross_entropy(target, output, axis=1):
    return -T.mean(target * T.log2(output) + (1 - target) * T.log2(1 - output), axis=axis)