Mercurial > pylearn

annotate cost.py @ 429:2bde0bed1919

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
simple example of theano
author Thierry Bertin-Mahieux <bertinmt@iro.umontreal.ca>
date Fri, 25 Jul 2008 17:02:28 -0400
parents 319bf28c2dd5
children 0f366ecb11ee
rev   line source
413
f63dfb0ac7dc Added cost functions
Joseph Turian <turian@iro.umontreal.ca>
parents:
diff changeset
1 """
f63dfb0ac7dc Added cost functions
Joseph Turian <turian@iro.umontreal.ca>
parents:
diff changeset
2 Cost functions.
f63dfb0ac7dc Added cost functions
Joseph Turian <turian@iro.umontreal.ca>
parents:
diff changeset
3 """
f63dfb0ac7dc Added cost functions
Joseph Turian <turian@iro.umontreal.ca>
parents:
diff changeset
4
415
319bf28c2dd5 Small bugfix
Joseph Turian <turian@iro.umontreal.ca>
parents: 413
diff changeset
5 import theano.tensor as T
319bf28c2dd5 Small bugfix
Joseph Turian <turian@iro.umontreal.ca>
parents: 413
diff changeset
6
413
f63dfb0ac7dc Added cost functions
Joseph Turian <turian@iro.umontreal.ca>
parents:
diff changeset
7 def quadratic(target, output, axis=1):
f63dfb0ac7dc Added cost functions
Joseph Turian <turian@iro.umontreal.ca>
parents:
diff changeset
8 return T.mean(T.sqr(target - output), axis)
f63dfb0ac7dc Added cost functions
Joseph Turian <turian@iro.umontreal.ca>
parents:
diff changeset
9
f63dfb0ac7dc Added cost functions
Joseph Turian <turian@iro.umontreal.ca>
parents:
diff changeset
10 def cross_entropy(target, output, axis=1):
f63dfb0ac7dc Added cost functions
Joseph Turian <turian@iro.umontreal.ca>
parents:
diff changeset
11 return -T.mean(target * T.log2(output) + (1 - target) * T.log2(1 - output), axis=axis)