Mercurial > pylearn
annotate cost.py @ 439:45879c1ecde7
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author | Joseph Turian <turian@iro.umontreal.ca> |
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date | Tue, 19 Aug 2008 18:41:39 -0400 |
parents | 0f366ecb11ee |
children | 0961d4b56ec5 |
rev | line source |
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413 | 1 """ |
2 Cost functions. | |
439 | 3 |
4 @note: All of these functions return one cost per example. So it is your | |
5 job to perform a tensor.sum over the individual example losses. | |
413 | 6 """ |
7 | |
415 | 8 import theano.tensor as T |
9 | |
413 | 10 def quadratic(target, output, axis=1): |
11 return T.mean(T.sqr(target - output), axis) | |
12 | |
13 def cross_entropy(target, output, axis=1): | |
434
0f366ecb11ee
log2->log in cost
Olivier Breuleux <breuleuo@iro.umontreal.ca>
parents:
415
diff
changeset
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14 return -T.mean(target * T.log(output) + (1 - target) * T.log(1 - output), axis=axis) |