Mercurial > ift6266
diff deep/stacked_dae/old/sgd_optimization.py @ 275:7b4507295eba
merge
author | Xavier Glorot <glorotxa@iro.umontreal.ca> |
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date | Mon, 22 Mar 2010 10:20:10 -0400 |
parents | c8fe09a65039 |
children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/deep/stacked_dae/old/sgd_optimization.py Mon Mar 22 10:20:10 2010 -0400 @@ -0,0 +1,234 @@ +#!/usr/bin/python +# coding: utf-8 + +# Generic SdA optimization loop, adapted from the deeplearning.net tutorial + +import numpy +import theano +import time +import datetime +import theano.tensor as T +import sys + +from jobman import DD +import jobman, jobman.sql + +from stacked_dae import SdA + +def shared_dataset(data_xy): + data_x, data_y = data_xy + #shared_x = theano.shared(numpy.asarray(data_x, dtype=theano.config.floatX)) + #shared_y = theano.shared(numpy.asarray(data_y, dtype=theano.config.floatX)) + #shared_y = T.cast(shared_y, 'int32') + shared_x = theano.shared(data_x) + shared_y = theano.shared(data_y) + return shared_x, shared_y + +class DummyMux(): + def append(self, param1, param2): + pass + +class SdaSgdOptimizer: + def __init__(self, dataset, hyperparameters, n_ins, n_outs, input_divider=1.0, series_mux=None): + self.dataset = dataset + self.hp = hyperparameters + self.n_ins = n_ins + self.n_outs = n_outs + self.input_divider = input_divider + + if not series_mux: + series_mux = DummyMux() + print "No series multiplexer set" + self.series_mux = series_mux + + self.rng = numpy.random.RandomState(1234) + + self.init_datasets() + self.init_classifier() + + sys.stdout.flush() + + def init_datasets(self): + print "init_datasets" + sys.stdout.flush() + + train_set, valid_set, test_set = self.dataset + self.test_set_x, self.test_set_y = shared_dataset(test_set) + self.valid_set_x, self.valid_set_y = shared_dataset(valid_set) + self.train_set_x, self.train_set_y = shared_dataset(train_set) + + # compute number of minibatches for training, validation and testing + self.n_train_batches = self.train_set_x.value.shape[0] / self.hp.minibatch_size + self.n_valid_batches = self.valid_set_x.value.shape[0] / self.hp.minibatch_size + # remove last batch in case it's incomplete + self.n_test_batches = (self.test_set_x.value.shape[0] / self.hp.minibatch_size) - 1 + + def init_classifier(self): + print "Constructing classifier" + + # we don't want to save arrays in DD objects, so + # we recreate those arrays here + nhl = self.hp.num_hidden_layers + layers_sizes = [self.hp.hidden_layers_sizes] * nhl + corruption_levels = [self.hp.corruption_levels] * nhl + + # construct the stacked denoising autoencoder class + self.classifier = SdA( \ + train_set_x= self.train_set_x, \ + train_set_y = self.train_set_y,\ + batch_size = self.hp.minibatch_size, \ + n_ins= self.n_ins, \ + hidden_layers_sizes = layers_sizes, \ + n_outs = self.n_outs, \ + corruption_levels = corruption_levels,\ + rng = self.rng,\ + pretrain_lr = self.hp.pretraining_lr, \ + finetune_lr = self.hp.finetuning_lr,\ + input_divider = self.input_divider ) + + #theano.printing.pydotprint(self.classifier.pretrain_functions[0], "function.graph") + + sys.stdout.flush() + + def train(self): + self.pretrain() + self.finetune() + + def pretrain(self): + print "STARTING PRETRAINING, time = ", datetime.datetime.now() + sys.stdout.flush() + + #time_acc_func = 0.0 + #time_acc_total = 0.0 + + start_time = time.clock() + ## Pre-train layer-wise + for i in xrange(self.classifier.n_layers): + # go through pretraining epochs + for epoch in xrange(self.hp.pretraining_epochs_per_layer): + # go through the training set + for batch_index in xrange(self.n_train_batches): + #t1 = time.clock() + c = self.classifier.pretrain_functions[i](batch_index) + #t2 = time.clock() + + #time_acc_func += t2 - t1 + + #if batch_index % 500 == 0: + # print "acc / total", time_acc_func / (t2 - start_time), time_acc_func + + self.series_mux.append("reconstruction_error", c) + + print 'Pre-training layer %i, epoch %d, cost '%(i,epoch),c + sys.stdout.flush() + + self.series_mux.append("params", self.classifier.all_params) + + end_time = time.clock() + + print ('Pretraining took %f minutes' %((end_time-start_time)/60.)) + self.hp.update({'pretraining_time': end_time-start_time}) + + sys.stdout.flush() + + def finetune(self): + print "STARTING FINETUNING, time = ", datetime.datetime.now() + + index = T.lscalar() # index to a [mini]batch + minibatch_size = self.hp.minibatch_size + + # create a function to compute the mistakes that are made by the model + # on the validation set, or testing set + shared_divider = theano.shared(numpy.asarray(self.input_divider, dtype=theano.config.floatX)) + test_model = theano.function([index], self.classifier.errors, + givens = { + self.classifier.x: self.test_set_x[index*minibatch_size:(index+1)*minibatch_size] / shared_divider, + self.classifier.y: self.test_set_y[index*minibatch_size:(index+1)*minibatch_size]}) + + validate_model = theano.function([index], self.classifier.errors, + givens = { + self.classifier.x: self.valid_set_x[index*minibatch_size:(index+1)*minibatch_size] / shared_divider, + self.classifier.y: self.valid_set_y[index*minibatch_size:(index+1)*minibatch_size]}) + + + # early-stopping parameters + patience = 10000 # look as this many examples regardless + patience_increase = 2. # wait this much longer when a new best is + # found + improvement_threshold = 0.995 # a relative improvement of this much is + # considered significant + validation_frequency = min(self.n_train_batches, patience/2) + # go through this many + # minibatche before checking the network + # on the validation set; in this case we + # check every epoch + + best_params = None + best_validation_loss = float('inf') + test_score = 0. + start_time = time.clock() + + done_looping = False + epoch = 0 + + while (epoch < self.hp.max_finetuning_epochs) and (not done_looping): + epoch = epoch + 1 + for minibatch_index in xrange(self.n_train_batches): + + cost_ij = self.classifier.finetune(minibatch_index) + iter = epoch * self.n_train_batches + minibatch_index + + self.series_mux.append("training_error", cost_ij) + + if (iter+1) % validation_frequency == 0: + + validation_losses = [validate_model(i) for i in xrange(self.n_valid_batches)] + this_validation_loss = numpy.mean(validation_losses) + self.series_mux.append("validation_error", this_validation_loss) + print('epoch %i, minibatch %i/%i, validation error %f %%' % \ + (epoch, minibatch_index+1, self.n_train_batches, \ + this_validation_loss*100.)) + + + # if we got the best validation score until now + if this_validation_loss < best_validation_loss: + + #improve patience if loss improvement is good enough + if this_validation_loss < best_validation_loss * \ + improvement_threshold : + patience = max(patience, iter * patience_increase) + + # save best validation score and iteration number + best_validation_loss = this_validation_loss + best_iter = iter + + # test it on the test set + test_losses = [test_model(i) for i in xrange(self.n_test_batches)] + test_score = numpy.mean(test_losses) + self.series_mux.append("test_error", test_score) + print((' epoch %i, minibatch %i/%i, test error of best ' + 'model %f %%') % + (epoch, minibatch_index+1, self.n_train_batches, + test_score*100.)) + + sys.stdout.flush() + + self.series_mux.append("params", self.classifier.all_params) + + if patience <= iter : + done_looping = True + break + + end_time = time.clock() + self.hp.update({'finetuning_time':end_time-start_time,\ + 'best_validation_error':best_validation_loss,\ + 'test_score':test_score, + 'num_finetuning_epochs':epoch}) + + print(('Optimization complete with best validation score of %f %%,' + 'with test performance %f %%') % + (best_validation_loss * 100., test_score*100.)) + print ('The finetuning ran for %f minutes' % ((end_time-start_time)/60.)) + + +