Mercurial > pylearn
diff simple_autoassociator.py/model.py @ 386:a474341861fa
Added a simple AA
author | Joseph Turian <turian@gmail.com> |
---|---|
date | Tue, 08 Jul 2008 02:27:00 -0400 |
parents | sparse_random_autoassociator/model.py@42cc94cf6c12 |
children | 98ca97cc9910 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/simple_autoassociator.py/model.py Tue Jul 08 02:27:00 2008 -0400 @@ -0,0 +1,46 @@ +""" +The model for an autoassociator for sparse inputs, using Ronan Collobert + Jason +Weston's sampling trick (2008). +""" + +from graph import trainfn +import parameters + +import globals +from globals import LR + +import numpy +import random +random.seed(globals.SEED) + +class Model: + def __init__(self): + self.parameters = parameters.Parameters(randomly_initialize=True) + + def update(self, instance): + """ + Update the L{Model} using one training instance. + @param instance: A dict from feature index to (non-zero) value. + @todo: Should assert that nonzero_indices and zero_indices + are correct (i.e. are truly nonzero/zero). + """ + x = numpy.zeros(globals.INPUT_DIMENSION) + for idx in instance.keys(): + x[idx] = instance[idx] + + (y, loss, gw1, gb1, gw2, gb2) = trainfn(x, self.parameters.w1, self.parameters.b1, self.parameters.w2, self.parameters.b2) + print + print "instance:", instance + print "OLD y:", y + print "OLD total loss:", loss + + # SGD update + self.parameters.w1 -= LR * gw1 + self.parameters.b1 -= LR * gb1 + self.parameters.w2 -= LR * gw2 + self.parameters.b2 -= LR * gb2 + + # Recompute the loss, to make sure it's descreasing + (y, loss, gw1, gb1, gw2, gb2) = trainfn(x, self.parameters.w1, self.parameters.b1, self.parameters.w2, self.parameters.b2) + print "NEW y:", y + print "NEW total loss:", loss