# HG changeset patch
# User Joseph Turian <turian@iro.umontreal.ca>
# Date 1233351482 18000
# Node ID 88603b2ac8f906e19697d37cc876e8ffa85606f4
# Parent  ac6e7ce28f7061eeaa966b5d3c3b35db5d31b770
Bugfix in cost.py to correctly use theano.tensor.xlogx

diff -r ac6e7ce28f70 -r 88603b2ac8f9 pylearn/algorithms/cost.py
--- a/pylearn/algorithms/cost.py	Sat Jan 24 17:25:41 2009 -0500
+++ b/pylearn/algorithms/cost.py	Fri Jan 30 16:38:02 2009 -0500
@@ -10,6 +10,7 @@
 """
 
 import theano.tensor as T
+from theano.tensor.xlogx import xlogx
 
 def quadratic(target, output, axis=1):
     return T.mean(T.sqr(target - output), axis=axis)
@@ -28,5 +29,5 @@
     different shapes then the result will be garbled.
     """
     return -(target * T.log(output) + (1 - target) * T.log(1 - output)) \
-            + (T.xlogx(target) + T.xlogx(1 - target))
+            + (xlogx(target) + xlogx(1 - target))
 #    return cross_entropy(target, output, axis) - cross_entropy(target, target, axis)