def test_dA(learning_rate=0.1, training_epochs=50,
dataset='../data/train',
batch_size=100, output_folder='dA_plots'):
#datasets = load_data(dataset)
#train_set_x, train_set_y = datasets[0]
dr = data_reader(dataset,batch_size=2501,patch=256)
train_set_x = dr.next_batch()
print train_set_x.get_value(borrow=True).shape
# compute number of minibatches for training, validation and testing
n_train_batches = train_set_x.get_value(borrow=True).shape[0] / batch_size
# start-snippet-2
# allocate symbolic variables for the data
index = T.lscalar() # index to a [mini]batch
x = T.matrix('x') # the data is presented as rasterized images
# end-snippet-2
if not os.path.isdir(output_folder):
os.makedirs(output_folder)
os.chdir(output_folder)
# start-snippet-3
#####################################
# BUILDING THE MODEL CORRUPTION 30% #
#####################################
rng = numpy.random.RandomState(123)
theano_rng = RandomStreams(rng.randint(2 ** 30))
da = dA(
numpy_rng=rng,
theano_rng=theano_rng,
input=x,
n_visible=256 * 256,
n_hidden=6000
)
cost, updates = da.get_cost_updates(
corruption_level=0.3,
learning_rate=learning_rate
)
train_da = theano.function(
[index],
cost,
updates=updates,
givens={
x: train_set_x[index * batch_size: (index + 1) * batch_size]
}
)
start_time = timeit.default_timer()
############
# TRAINING #
############
# go through training epochs
for epoch in xrange(training_epochs):
# go through trainng set
c = []
for batch_index in xrange(n_train_batches):
c.append(train_da(batch_index))
print 'Training epoch %d, cost ' % epoch, numpy.mean(c)
end_time = timeit.default_timer()
training_time = (end_time - start_time)
print >> sys.stderr, ('The 30% corruption code for file ' +
os.path.split(__file__)[1] +
' ran for %.2fm' % (training_time / 60.))
# end-snippet-3
# start-snippet-4
image = Image.fromarray(tile_raster_images(
X=da.W.get_value(borrow=True).T,
img_shape=(256, 256), tile_shape=(10, 10),
tile_spacing=(1, 1)))
image.save('filters_corruption_30_256.png')
# end-snippet-4
os.chdir('../')
def test_dA(learning_rate=0.1,
training_epochs=50,
dataset='../data/train',
batch_size=100,
output_folder='dA_plots'):
#datasets = load_data(dataset)
#train_set_x, train_set_y = datasets[0]
dr = data_reader(dataset, batch_size=2501, patch=256)
train_set_x = dr.next_batch()
print train_set_x.get_value(borrow=True).shape
# compute number of minibatches for training, validation and testing
n_train_batches = train_set_x.get_value(borrow=True).shape[0] / batch_size
# start-snippet-2
# allocate symbolic variables for the data
index = T.lscalar() # index to a [mini]batch
x = T.matrix('x') # the data is presented as rasterized images
# end-snippet-2
if not os.path.isdir(output_folder):
os.makedirs(output_folder)
os.chdir(output_folder)
# start-snippet-3
#####################################
# BUILDING THE MODEL CORRUPTION 30% #
#####################################
rng = numpy.random.RandomState(123)
theano_rng = RandomStreams(rng.randint(2**30))
da = dA(numpy_rng=rng,
theano_rng=theano_rng,
input=x,
n_visible=256 * 256,
n_hidden=6000)
cost, updates = da.get_cost_updates(corruption_level=0.3,
learning_rate=learning_rate)
train_da = theano.function(
[index],
cost,
updates=updates,
givens={x: train_set_x[index * batch_size:(index + 1) * batch_size]})
start_time = timeit.default_timer()
############
# TRAINING #
############
# go through training epochs
for epoch in xrange(training_epochs):
# go through trainng set
c = []
for batch_index in xrange(n_train_batches):
c.append(train_da(batch_index))
print 'Training epoch %d, cost ' % epoch, numpy.mean(c)
end_time = timeit.default_timer()
training_time = (end_time - start_time)
print >> sys.stderr, ('The 30% corruption code for file ' +
os.path.split(__file__)[1] + ' ran for %.2fm' %
(training_time / 60.))
# end-snippet-3
# start-snippet-4
image = Image.fromarray(
tile_raster_images(X=da.W.get_value(borrow=True).T,
img_shape=(256, 256),
tile_shape=(10, 10),
tile_spacing=(1, 1)))
image.save('filters_corruption_30_256.png')
# end-snippet-4
os.chdir('../')
def test_SdA(finetune_lr=0.1, pretraining_epochs=100,
pretrain_lr=0.1, training_epochs=1000,
dataset='mnist.pkl.gz', batch_size=100):
"""
Demonstrates how to train and test a stochastic denoising autoencoder.
This is demonstrated on MNIST.
:type learning_rate: float
:param learning_rate: learning rate used in the finetune stage
(factor for the stochastic gradient)
:type pretraining_epochs: int
:param pretraining_epochs: number of epoch to do pretraining
:type pretrain_lr: float
:param pretrain_lr: learning rate to be used during pre-training
:type n_iter: int
:param n_iter: maximal number of iterations ot run the optimizer
:type dataset: string
:param dataset: path the the pickled dataset
"""
#datasets = load_data(dataset)
train_path = "../data/train"
train_label_path = "../train_label"
test_path = "../data/test"
test_label_path = "../data/test_label"
val_path = "../data/val"
val_label_path = "../data/val_label"
dr_train = data_reader(train_path,train_label_path,2501,patch=256)
dr_test = data_reader(test_path,test_label_path,4952,patch=256)
dr_val = data_reader(val_path,val_label_path,2509,patch=256)
train_set_x, train_set_y = dr_train.next_batch()
valid_set_x, valid_set_y = dr_val.next_batch()
test_set_x, test_set_y = dr_test.next_batch()
datasets = [(train_set_x, train_set_y), (valid_set_x, valid_set_y),(test_set_x, test_set_y)]
print train_set_x.get_value(borrow=True).shape
print test_set_x.get_value(borrow=True).shape
print valid_set_x.get_value(borrow=True).shape
# compute number of minibatches for training, validation and testing
n_train_batches = train_set_x.get_value(borrow=True).shape[0]
n_train_batches /= batch_size
# numpy random generator
# start-snippet-3
numpy_rng = numpy.random.RandomState(89677)
print '... building the model'
# construct the stacked denoising autoencoder class
sda = SdA(
numpy_rng=numpy_rng,
n_ins=256*256,
hidden_layers_sizes=[3000, 500],
n_outs=20
)
# end-snippet-3 start-snippet-4
#########################
# PRETRAINING THE MODEL #
#########################
print '... getting the pretraining functions'
pretraining_fns = sda.pretraining_functions(train_set_x=train_set_x,
batch_size=batch_size)
print '... pre-training the model'
start_time = timeit.default_timer()
## Pre-train layer-wise
corruption_levels = [.1, .2]
for i in xrange(sda.n_layers):
# go through pretraining epochs
for epoch in xrange(pretraining_epochs):
# go through the training set
c = []
for batch_index in xrange(n_train_batches):
c.append(pretraining_fns[i](index=batch_index,
corruption=corruption_levels[i],
lr=pretrain_lr))
print 'Pre-training layer %i, epoch %d, cost ' % (i, epoch),
print numpy.mean(c)
end_time = timeit.default_timer()
print >> sys.stderr, ('The pretraining code for file ' +
os.path.split(__file__)[1] +
' ran for %.2fm' % ((end_time - start_time) / 60.))
# end-snippet-4
########################
# FINETUNING THE MODEL #
########################
# get the training, validation and testing function for the model
print '... getting the finetuning functions'
train_fn, validate_model, test_model = sda.build_finetune_functions(
datasets=datasets,
batch_size=batch_size,
learning_rate=finetune_lr
)
print '... finetunning the model'
# early-stopping parameters
patience = 10 * n_train_batches # 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(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_validation_loss = numpy.inf
test_score = 0.
start_time = timeit.default_timer()
done_looping = False
epoch = 0
while (epoch < training_epochs) and (not done_looping):
epoch = epoch + 1
for minibatch_index in xrange(n_train_batches):
minibatch_avg_cost = train_fn(minibatch_index)
iter = (epoch - 1) * n_train_batches + minibatch_index
if (iter + 1) % validation_frequency == 0:
validation_losses = validate_model()
this_validation_loss = numpy.mean(validation_losses)
print('epoch %i, minibatch %i/%i, validation error %f %%' %
(epoch, minibatch_index + 1, 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()
test_score = numpy.mean(test_losses)
print((' epoch %i, minibatch %i/%i, test error of '
'best model %f %%') %
(epoch, minibatch_index + 1, n_train_batches,
test_score * 100.))
if patience <= iter:
done_looping = True
break
end_time = timeit.default_timer()
print(
(
'Optimization complete with best validation score of %f %%, '
'on iteration %i, '
'with test performance %f %%'
)
% (best_validation_loss * 100., best_iter + 1, test_score * 100.)
)
print >> sys.stderr, ('The training code for file ' +
os.path.split(__file__)[1] +
' ran for %.2fm' % ((end_time - start_time) / 60.))
