def init_classifier(self):
print "Constructing classifier"
n_ins, convlayers = get_conv_shape(
self.hp.kernels, self.hp.imgshp, self.hp.minibatch_size, self.hp.max_pool_layers
)
self.classifier = CSdA(
n_ins_mlp=n_ins,
batch_size=self.hp.minibatch_size,
conv_hidden_layers_sizes=convlayers,
mlp_hidden_layers_sizes=self.hp.mlp_size,
corruption_levels=self.hp.corruption_levels,
rng=self.rng,
n_out=self.n_outs,
pretrain_lr=self.hp.pretraining_lr,
finetune_lr=self.hp.finetuning_lr,
)
# theano.printing.pydotprint(self.classifier.pretrain_functions[0], "function.graph")
sys.stdout.flush()
class CSdASgdOptimizer:
def __init__(
self, dataset, hyperparameters, n_ins, n_outs, examples_per_epoch, series=default_series, max_minibatches=None
):
self.dataset = dataset
self.hp = hyperparameters
self.n_ins = n_ins
self.n_outs = n_outs
self.parameters_pre = []
self.max_minibatches = max_minibatches
print "CSdASgdOptimizer, max_minibatches =", max_minibatches
self.ex_per_epoch = examples_per_epoch
self.mb_per_epoch = examples_per_epoch / self.hp.minibatch_size
self.series = series
self.rng = numpy.random.RandomState(1234)
self.init_classifier()
sys.stdout.flush()
def init_classifier(self):
print "Constructing classifier"
n_ins, convlayers = get_conv_shape(
self.hp.kernels, self.hp.imgshp, self.hp.minibatch_size, self.hp.max_pool_layers
)
self.classifier = CSdA(
n_ins_mlp=n_ins,
batch_size=self.hp.minibatch_size,
conv_hidden_layers_sizes=convlayers,
mlp_hidden_layers_sizes=self.hp.mlp_size,
corruption_levels=self.hp.corruption_levels,
rng=self.rng,
n_out=self.n_outs,
pretrain_lr=self.hp.pretraining_lr,
finetune_lr=self.hp.finetuning_lr,
)
# theano.printing.pydotprint(self.classifier.pretrain_functions[0], "function.graph")
sys.stdout.flush()
def train(self):
self.pretrain(self.dataset)
self.finetune(self.dataset)
def pretrain(self, dataset):
print "STARTING PRETRAINING, time = ", datetime.datetime.now()
sys.stdout.flush()
un_fichier = int(819200.0 / self.hp.minibatch_size) # Number of batches in a P07 file
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
batch_index = 0
count = 0
num_files = 0
for x, y in dataset.train(self.hp.minibatch_size):
if x.shape[0] != self.hp.minibatch_size:
continue
c = self.classifier.pretrain_functions[i](x)
count += 1
self.series["reconstruction_error"].append((epoch, batch_index), c)
batch_index += 1
# if batch_index % 100 == 0:
# print "100 batches"
# useful when doing tests
if self.max_minibatches and batch_index >= self.max_minibatches:
break
# When we pass through the data only once (the case with P07)
# There is approximately 800*1024=819200 examples per file (1k per example and files are 800M)
if self.hp.pretraining_epochs_per_layer == 1 and count % un_fichier == 0:
print "Pre-training layer %i, epoch %d, cost " % (i, num_files), c
num_files += 1
sys.stdout.flush()
self.series["params"].append((num_files,), self.classifier.all_params)
# When NIST is used
if self.hp.pretraining_epochs_per_layer > 1:
print "Pre-training layer %i, epoch %d, cost " % (i, epoch), c
sys.stdout.flush()
self.series["params"].append((epoch,), self.classifier.all_params)
end_time = time.clock()
print ("Pretraining took %f minutes" % ((end_time - start_time) / 60.0))
self.hp.update({"pretraining_time": end_time - start_time})
sys.stdout.flush()
# To be able to load them later for tests on finetune
self.parameters_pre = [copy(x.value) for x in self.classifier.params]
f = open("params_pretrain.txt", "w")
pickle.dump(self.parameters_pre, f)
f.close()
def finetune(self, dataset, dataset_test, num_finetune, ind_test, special=0, decrease=0):
if special != 0 and special != 1:
sys.exit("Bad value for variable special. Must be in {0,1}")
print "STARTING FINETUNING, time = ", datetime.datetime.now()
minibatch_size = self.hp.minibatch_size
if ind_test == 0 or ind_test == 20:
nom_test = "NIST"
nom_train = "P07"
else:
nom_test = "P07"
nom_train = "NIST"
# create a function to compute the mistakes that are made by the model
# on the validation set, or testing set
test_model = theano.function([self.classifier.x, self.classifier.y], self.classifier.errors)
# givens = {
# self.classifier.x: ensemble_x,
# self.classifier.y: ensemble_y]})
validate_model = theano.function([self.classifier.x, self.classifier.y], self.classifier.errors)
# givens = {
# self.classifier.x: ,
# self.classifier.y: ]})
# early-stopping parameters
patience = 10000 # look as this many examples regardless
patience_increase = 2.0 # 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.mb_per_epoch, patience / 2)
# go through this many
# minibatche before checking the network
# on the validation set; in this case we
# check every epoch
if self.max_minibatches and validation_frequency > self.max_minibatches:
validation_frequency = self.max_minibatches / 2
best_params = None
best_validation_loss = float("inf")
test_score = 0.0
start_time = time.clock()
done_looping = False
epoch = 0
total_mb_index = 0
minibatch_index = 0
parameters_finetune = []
learning_rate = self.hp.finetuning_lr
while (epoch < num_finetune) and (not done_looping):
epoch = epoch + 1
for x, y in dataset.train(minibatch_size, bufsize=buffersize):
minibatch_index += 1
if x.shape[0] != self.hp.minibatch_size:
print "bim"
continue
cost_ij = self.classifier.finetune(x, y) # ,learning_rate)
total_mb_index += 1
self.series["training_error"].append((epoch, minibatch_index), cost_ij)
if (total_mb_index + 1) % validation_frequency == 0:
# minibatch_index += 1
# The validation set is always NIST (we want the model to be good on NIST)
iter = dataset_test.valid(minibatch_size, bufsize=buffersize)
if self.max_minibatches:
iter = itermax(iter, self.max_minibatches)
validation_losses = []
for x, y in iter:
if x.shape[0] != self.hp.minibatch_size:
print "bim"
continue
validation_losses.append(validate_model(x, y))
this_validation_loss = numpy.mean(validation_losses)
self.series["validation_error"].append((epoch, minibatch_index), this_validation_loss * 100.0)
print (
"epoch %i, minibatch %i, validation error on NIST : %f %%"
% (epoch, minibatch_index + 1, this_validation_loss * 100.0)
)
# 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, total_mb_index * patience_increase)
# save best validation score, iteration number and parameters
best_validation_loss = this_validation_loss
best_iter = total_mb_index
parameters_finetune = [copy(x.value) for x in self.classifier.params]
# test it on the test set
iter = dataset.test(minibatch_size, bufsize=buffersize)
if self.max_minibatches:
iter = itermax(iter, self.max_minibatches)
test_losses = []
test_losses2 = []
for x, y in iter:
if x.shape[0] != self.hp.minibatch_size:
print "bim"
continue
test_losses.append(test_model(x, y))
test_score = numpy.mean(test_losses)
# test it on the second test set
iter2 = dataset_test.test(minibatch_size, bufsize=buffersize)
if self.max_minibatches:
iter2 = itermax(iter2, self.max_minibatches)
for x, y in iter2:
if x.shape[0] != self.hp.minibatch_size:
continue
test_losses2.append(test_model(x, y))
test_score2 = numpy.mean(test_losses2)
self.series["test_error"].append((epoch, minibatch_index), test_score * 100.0)
print (
(
" epoch %i, minibatch %i, test error on dataset %s (train data) of best "
"model %f %%"
)
% (epoch, minibatch_index + 1, nom_train, test_score * 100.0)
)
print (
(" epoch %i, minibatch %i, test error on dataset %s of best " "model %f %%")
% (epoch, minibatch_index + 1, nom_test, test_score2 * 100.0)
)
if patience <= total_mb_index:
done_looping = True
break # to exit the FOR loop
sys.stdout.flush()
# useful when doing tests
if self.max_minibatches and minibatch_index >= self.max_minibatches:
break
if decrease == 1:
learning_rate /= 2 # divide the learning rate by 2 for each new epoch
self.series["params"].append((epoch,), self.classifier.all_params)
if done_looping == True: # To exit completly the fine-tuning
break # to exit the WHILE loop
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 (
(
"\nOptimization complete with best validation score of %f %%,"
"with test performance %f %% on dataset %s "
)
% (best_validation_loss * 100.0, test_score * 100.0, nom_train)
)
print (("The test score on the %s dataset is %f") % (nom_test, test_score2 * 100.0))
print ("The finetuning ran for %f minutes" % ((end_time - start_time) / 60.0))
sys.stdout.flush()
# Save a copy of the parameters in a file to be able to get them in the future
if special == 1: # To keep a track of the value of the parameters
f = open("params_finetune_stanford.txt", "w")
pickle.dump(parameters_finetune, f)
f.close()
elif ind_test == 0 | ind_test == 20: # To keep a track of the value of the parameters
f = open("params_finetune_P07.txt", "w")
pickle.dump(parameters_finetune, f)
f.close()
elif ind_test == 1: # For the run with 2 finetunes. It will be faster.
f = open("params_finetune_NIST.txt", "w")
pickle.dump(parameters_finetune, f)
f.close()
elif ind_test == 21: # To keep a track of the value of the parameters
f = open("params_finetune_P07_then_NIST.txt", "w")
pickle.dump(parameters_finetune, f)
f.close()
# Set parameters like they where right after pre-train or finetune
def reload_parameters(self, which):
# self.parameters_pre=pickle.load('params_pretrain.txt')
f = open(which)
self.parameters_pre = pickle.load(f)
f.close()
for idx, x in enumerate(self.parameters_pre):
if x.dtype == "float64":
self.classifier.params[idx].value = theano._asarray(copy(x), dtype=theano.config.floatX)
else:
self.classifier.params[idx].value = copy(x)
def training_error(self, dataset):
# create a function to compute the mistakes that are made by the model
# on the validation set, or testing set
test_model = theano.function([self.classifier.x, self.classifier.y], self.classifier.errors)
iter2 = dataset.train(self.hp.minibatch_size, bufsize=buffersize)
train_losses2 = [test_model(x, y) for x, y in iter2]
train_score2 = numpy.mean(train_losses2)
print "Training error is: " + str(train_score2)
