transform = theano.function([minibatch], cae(minibatch))
print "Transformed data:"
print numpy.histogram(transform(data))
# We'll now create a stacked denoising autoencoder. First, we change
# the number of hidden units to be a list. This tells the build_stacked_AE
# method how many layers to make.
stack_conf = conf.copy()
stack_conf['nhids'] = [20, 20, 10]
#choose which layer is a regular da and which one is a cae
stack_conf['contracting']=[True,False,True]
stack_conf['anneal_start'] = None # Don't anneal these learning rates
scae = build_stacked_ae(nvis=stack_conf['nvis'],
nhids=stack_conf['nhids'],
act_enc=stack_conf['act_enc'],
act_dec=stack_conf['act_dec'],
contracting=stack_conf['contracting'])
# To pretrain it, we'll use a different SGDOptimizer for each layer.
optimizers = []
thislayer_input = [minibatch]
for layer in scae.layers():
cost = SquaredError(layer)(thislayer_input[0],
layer.reconstruct(thislayer_input[0])
).mean()
if isinstance(layer,ContractiveAutoencoder):
cost+=layer.contraction_penalty(thislayer_input[0]).mean()
opt = SGDOptimizer( layer.params(),
stack_conf['base_lr'],
stack_conf['anneal_start']
# Add to cost function a regularization term for each layer :
# - Layer1 : l1_penalty with sparse_penalty = 0.01
# - Layer2 : sqr_penalty with sparsity_target = 0.2
# and sparsity_target_penalty = 0.01
# - Layer3 : l1_penalty with sparse_penalty = 0.1
sda_conf['solution'] = ['l1_penalty','sqr_penalty','l1_penalty']
sda_conf['sparse_penalty'] = [0.02, 0, 0.1]
sda_conf['sparsity_target'] = [0, 0.3, 0]
sda_conf['sparsity_target_penalty'] = [0, 0.001, 0]
sda_conf['anneal_start'] = None # Don't anneal these learning rates
sda = build_stacked_ae(sda_conf['nvis'], sda_conf['nhid'],
sda_conf['act_enc'], sda_conf['act_dec'],
corruptor=corruptor, contracting=False,
solution=sda_conf['solution'],
sparse_penalty=sda_conf['sparse_penalty'],
sparsity_target=sda_conf['sparsity_target'],
sparsity_target_penalty=sda_conf['sparsity_target_penalty'])
# To pretrain it, we'll use a different SGDOptimizer for each layer.
optimizers = []
thislayer_input = [minibatch]
for layer in sda.layers():
cost = SquaredError(layer)(thislayer_input[0],
layer.reconstruct(thislayer_input[0])).mean()
opt = SGDOptimizer(layer.params(), sda_conf['base_lr'],
sda_conf['anneal_start'])
optimizers.append((opt, cost))
# Retrieve a Theano function for training this layer.
transform = theano.function([minibatch], cae(minibatch))
print "Transformed data:"
print numpy.histogram(transform(data))
# We'll now create a stacked denoising autoencoder. First, we change
# the number of hidden units to be a list. This tells the build_stacked_AE
# method how many layers to make.
stack_conf = conf.copy()
stack_conf['nhids'] = [20, 20, 10]
#choose which layer is a regular da and which one is a cae
stack_conf['contracting'] = [True, False, True]
stack_conf['anneal_start'] = None # Don't anneal these learning rates
scae = build_stacked_ae(nvis=stack_conf['nvis'],
nhids=stack_conf['nhids'],
act_enc=stack_conf['act_enc'],
act_dec=stack_conf['act_dec'],
contracting=stack_conf['contracting'])
# To pretrain it, we'll use a different SGDOptimizer for each layer.
optimizers = []
thislayer_input = [minibatch]
for layer in scae.layers():
cost = SquaredError(layer)(thislayer_input[0],
layer.reconstruct(
thislayer_input[0])).mean()
if isinstance(layer, ContractiveAutoencoder):
cost += layer.contraction_penalty(thislayer_input[0]).mean()
opt = SGDOptimizer(layer.params(), stack_conf['base_lr'],
stack_conf['anneal_start'])
optimizers.append((opt, cost))
# - Layer2 : sqr_penalty with sparsity_target = 0.2
# and sparsity_target_penalty = 0.01
# - Layer3 : l1_penalty with sparse_penalty = 0.1
sda_conf['solution'] = ['l1_penalty', 'sqr_penalty', 'l1_penalty']
sda_conf['sparse_penalty'] = [0.02, 0, 0.1]
sda_conf['sparsity_target'] = [0, 0.3, 0]
sda_conf['sparsity_target_penalty'] = [0, 0.001, 0]
sda_conf['anneal_start'] = None # Don't anneal these learning rates
sda = build_stacked_ae(
sda_conf['nvis'],
sda_conf['nhid'],
sda_conf['act_enc'],
sda_conf['act_dec'],
corruptor=corruptor,
contracting=False,
solution=sda_conf['solution'],
sparse_penalty=sda_conf['sparse_penalty'],
sparsity_target=sda_conf['sparsity_target'],
sparsity_target_penalty=sda_conf['sparsity_target_penalty'])
# To pretrain it, we'll use a different SGDOptimizer for each layer.
optimizers = []
thislayer_input = [minibatch]
for layer in sda.layers():
cost = SquaredError(layer)(thislayer_input[0],
layer.reconstruct(
thislayer_input[0])).mean()
opt = SGDOptimizer(layer.params(), sda_conf['base_lr'],