def example2():
"""GRU"""
x = tensor.tensor3('x')
dim = 3
fork = Fork(input_dim=dim, output_dims=[dim, dim*2],name='fork',output_names=["linear","gates"], weights_init=initialization.Identity(),biases_init=Constant(0))
gru = GatedRecurrent(dim=dim, weights_init=initialization.Identity(),biases_init=Constant(0))
fork.initialize()
gru.initialize()
linear, gate_inputs = fork.apply(x)
h = gru.apply(linear, gate_inputs)
f = theano.function([x], h)
print(f(np.ones((dim, 1, dim), dtype=theano.config.floatX)))
doubler = Linear(
input_dim=dim, output_dim=dim, weights_init=initialization.Identity(2),
biases_init=initialization.Constant(0))
doubler.initialize()
lin, gate = fork.apply(doubler.apply(x))
h_doubler = gru.apply(lin,gate)
f = theano.function([x], h_doubler)
print(f(np.ones((dim, 1, dim), dtype=theano.config.floatX)))
def example2():
"""GRU"""
x = tensor.tensor3('x')
dim = 3
fork = Fork(input_dim=dim,
output_dims=[dim, dim * 2],
name='fork',
output_names=["linear", "gates"],
weights_init=initialization.Identity(),
biases_init=Constant(0))
gru = GatedRecurrent(dim=dim,
weights_init=initialization.Identity(),
biases_init=Constant(0))
fork.initialize()
gru.initialize()
linear, gate_inputs = fork.apply(x)
h = gru.apply(linear, gate_inputs)
f = theano.function([x], h)
print(f(np.ones((dim, 1, dim), dtype=theano.config.floatX)))
doubler = Linear(input_dim=dim,
output_dim=dim,
weights_init=initialization.Identity(2),
biases_init=initialization.Constant(0))
doubler.initialize()
lin, gate = fork.apply(doubler.apply(x))
h_doubler = gru.apply(lin, gate)
f = theano.function([x], h_doubler)
print(f(np.ones((dim, 1, dim), dtype=theano.config.floatX)))
def build_fork_lookup(vocab_size, args):
x = tensor.lmatrix('features')
virtual_dim = 6
time_length = 5
mini_batch_size = 2
skip_connections = True
layers = 3
# Build the model
output_names = []
output_dims = []
for d in range(layers):
if d > 0:
suffix = '_' + str(d)
else:
suffix = ''
if d == 0 or skip_connections:
output_names.append("inputs" + suffix)
output_dims.append(virtual_dim)
print output_names
print output_dims
lookup = LookupTable(length=vocab_size, dim=virtual_dim)
lookup.weights_init = initialization.IsotropicGaussian(0.1)
lookup.biases_init = initialization.Constant(0)
fork = Fork(output_names=output_names,
input_dim=time_length,
output_dims=output_dims,
prototype=FeedforwardSequence([lookup.apply]))
# Return list of 3D Tensor, one for each layer
# (Batch X Time X embedding_dim)
pre_rnn = fork.apply(x)
fork.initialize()
f = theano.function([x], pre_rnn)
return f
def build_fork_lookup(vocab_size, args):
x = tensor.lmatrix('features')
virtual_dim = 6
time_length = 5
mini_batch_size = 2
skip_connections = True
layers = 3
# Build the model
output_names = []
output_dims = []
for d in range(layers):
if d > 0:
suffix = '_' + str(d)
else:
suffix = ''
if d == 0 or skip_connections:
output_names.append("inputs" + suffix)
output_dims.append(virtual_dim)
print output_names
print output_dims
lookup = LookupTable(length=vocab_size, dim=virtual_dim)
lookup.weights_init = initialization.IsotropicGaussian(0.1)
lookup.biases_init = initialization.Constant(0)
fork = Fork(output_names=output_names, input_dim=time_length,
output_dims=output_dims,
prototype=FeedforwardSequence(
[lookup.apply]))
# Return list of 3D Tensor, one for each layer
# (Batch X Time X embedding_dim)
pre_rnn = fork.apply(x)
fork.initialize()
f = theano.function([x], pre_rnn)
return f
def build_model_hard(vocab_size, args, dtype=floatX):
logger.info('Building model ...')
# Parameters for the model
context = args.context
state_dim = args.state_dim
layers = args.layers
skip_connections = args.skip_connections
# Symbolic variables
# In both cases: Time X Batch
x = tensor.lmatrix('features')
y = tensor.lmatrix('targets')
# Build the model
output_names = []
output_dims = []
for d in range(layers):
if d > 0:
suffix = '_' + str(d)
else:
suffix = ''
if d == 0 or skip_connections:
output_names.append("inputs" + suffix)
output_dims.append(state_dim)
lookup = LookupTable(length=vocab_size, dim=state_dim)
lookup.weights_init = initialization.IsotropicGaussian(0.1)
lookup.biases_init = initialization.Constant(0)
fork = Fork(output_names=output_names,
input_dim=args.mini_batch_size,
output_dims=output_dims,
prototype=FeedforwardSequence([lookup.apply]))
transitions = [SimpleRecurrent(dim=state_dim, activation=Tanh())]
for i in range(layers - 1):
mlp = MLP(activations=[Logistic()],
dims=[2 * state_dim, 1],
weights_init=initialization.IsotropicGaussian(0.1),
biases_init=initialization.Constant(0),
name="mlp_" + str(i))
transitions.append(
HardGatedRecurrent(dim=state_dim, mlp=mlp, activation=Tanh()))
rnn = RecurrentStack(transitions, skip_connections=skip_connections)
# dim = layers * state_dim
output_layer = Linear(input_dim=layers * state_dim,
output_dim=vocab_size,
name="output_layer")
# Return list of 3D Tensor, one for each layer
# (Time X Batch X embedding_dim)
pre_rnn = fork.apply(x)
# Give a name to the input of each layer
if skip_connections:
for t in range(len(pre_rnn)):
pre_rnn[t].name = "pre_rnn_" + str(t)
else:
pre_rnn.name = "pre_rnn"
# Prepare inputs for the RNN
kwargs = OrderedDict()
init_states = {}
for d in range(layers):
if d > 0:
suffix = '_' + str(d)
else:
suffix = ''
if skip_connections:
kwargs['inputs' + suffix] = pre_rnn[d]
elif d == 0:
kwargs['inputs' + suffix] = pre_rnn
init_states[d] = theano.shared(numpy.zeros(
(args.mini_batch_size, state_dim)).astype(floatX),
name='state0_%d' % d)
kwargs['states' + suffix] = init_states[d]
# Apply the RNN to the inputs
h = rnn.apply(low_memory=True, **kwargs)
# Now we have correctly:
# h = [state_1, state_2, state_3 ...]
# Save all the last states
last_states = {}
for d in range(layers):
last_states[d] = h[d][-1, :, :]
# Concatenate all the states
if layers > 1:
h = tensor.concatenate(h, axis=2)
h.name = "hidden_state"
# The updates of the hidden states
updates = []
for d in range(layers):
updates.append((init_states[d], last_states[d]))
presoft = output_layer.apply(h[context:, :, :])
# Define the cost
# Compute the probability distribution
time, batch, feat = presoft.shape
presoft.name = 'presoft'
cross_entropy = Softmax().categorical_cross_entropy(
y[context:, :].flatten(), presoft.reshape((batch * time, feat)))
cross_entropy = cross_entropy / tensor.log(2)
cross_entropy.name = "cross_entropy"
# TODO: add regularisation for the cost
# the log(1) is here in order to differentiate the two variables
# for monitoring
cost = cross_entropy + tensor.log(1)
cost.name = "regularized_cost"
# Initialize the model
logger.info('Initializing...')
fork.initialize()
rnn.weights_init = initialization.Orthogonal()
rnn.biases_init = initialization.Constant(0)
rnn.initialize()
output_layer.weights_init = initialization.IsotropicGaussian(0.1)
output_layer.biases_init = initialization.Constant(0)
output_layer.initialize()
return cost, cross_entropy, updates
def build_model_vanilla(vocab_size, args, dtype=floatX):
logger.info('Building model ...')
# Parameters for the model
context = args.context
state_dim = args.state_dim
layers = args.layers
skip_connections = args.skip_connections
# Symbolic variables
# In both cases: Time X Batch
x = tensor.lmatrix('features')
y = tensor.lmatrix('targets')
# Build the model
output_names = []
output_dims = []
for d in range(layers):
if d > 0:
suffix = '_' + str(d)
else:
suffix = ''
if d == 0 or skip_connections:
output_names.append("inputs" + suffix)
output_dims.append(state_dim)
lookup = LookupTable(length=vocab_size, dim=state_dim)
lookup.weights_init = initialization.IsotropicGaussian(0.1)
lookup.biases_init = initialization.Constant(0)
fork = Fork(output_names=output_names, input_dim=args.mini_batch_size,
output_dims=output_dims,
prototype=FeedforwardSequence(
[lookup.apply]))
transitions = [SimpleRecurrent(dim=state_dim, activation=Tanh())
for _ in range(layers)]
rnn = RecurrentStack(transitions, skip_connections=skip_connections)
# If skip_connections: dim = layers * state_dim
# else: dim = state_dim
output_layer = Linear(
input_dim=skip_connections * layers *
state_dim + (1 - skip_connections) * state_dim,
output_dim=vocab_size, name="output_layer")
# Return list of 3D Tensor, one for each layer
# (Time X Batch X embedding_dim)
pre_rnn = fork.apply(x)
# Give a name to the input of each layer
if skip_connections:
for t in range(len(pre_rnn)):
pre_rnn[t].name = "pre_rnn_" + str(t)
else:
pre_rnn.name = "pre_rnn"
# Prepare inputs for the RNN
kwargs = OrderedDict()
init_states = {}
for d in range(layers):
if d > 0:
suffix = '_' + str(d)
else:
suffix = ''
if skip_connections:
kwargs['inputs' + suffix] = pre_rnn[d]
elif d == 0:
kwargs['inputs'] = pre_rnn
init_states[d] = theano.shared(
numpy.zeros((args.mini_batch_size, state_dim)).astype(floatX),
name='state0_%d' % d)
kwargs['states' + suffix] = init_states[d]
# Apply the RNN to the inputs
h = rnn.apply(low_memory=True, **kwargs)
# We have
# h = [state, state_1, state_2 ...] if layers > 1
# h = state if layers == 1
# If we have skip connections, concatenate all the states
# Else only consider the state of the highest layer
last_states = {}
if layers > 1:
# Save all the last states
for d in range(layers):
last_states[d] = h[d][-1, :, :]
if skip_connections:
h = tensor.concatenate(h, axis=2)
else:
h = h[-1]
else:
last_states[0] = h[-1, :, :]
h.name = "hidden_state"
# The updates of the hidden states
updates = []
for d in range(layers):
updates.append((init_states[d], last_states[d]))
presoft = output_layer.apply(h[context:, :, :])
# Define the cost
# Compute the probability distribution
time, batch, feat = presoft.shape
presoft.name = 'presoft'
cross_entropy = Softmax().categorical_cross_entropy(
y[context:, :].flatten(),
presoft.reshape((batch * time, feat)))
cross_entropy = cross_entropy / tensor.log(2)
cross_entropy.name = "cross_entropy"
# TODO: add regularisation for the cost
# the log(1) is here in order to differentiate the two variables
# for monitoring
cost = cross_entropy + tensor.log(1)
cost.name = "regularized_cost"
# Initialize the model
logger.info('Initializing...')
fork.initialize()
rnn.weights_init = initialization.Orthogonal()
rnn.biases_init = initialization.Constant(0)
rnn.initialize()
output_layer.weights_init = initialization.IsotropicGaussian(0.1)
output_layer.biases_init = initialization.Constant(0)
output_layer.initialize()
return cost, cross_entropy, updates
def get_prernn(args):
# time x batch
x_mask = tensor.fmatrix('mask')
# Compute the state dim
if args.rnn_type == 'lstm':
state_dim = 4 * args.state_dim
else:
state_dim = args.state_dim
# Prepare the arguments for the fork
output_names = []
output_dims = []
for d in range(args.layers):
if d > 0:
suffix = RECURRENTSTACK_SEPARATOR + str(d)
else:
suffix = ''
if d == 0 or args.skip_connections:
output_names.append("inputs" + suffix)
output_dims.append(state_dim)
# Prepare the brick to be forked (LookupTable or Linear)
# Check if the dataset provides indices (in the case of a
# fixed vocabulary, x is 2D tensor) or if it gives raw values
# (x is 3D tensor)
if has_indices(args.dataset):
features = args.mini_batch_size
x = tensor.lmatrix('features')
vocab_size = get_output_size(args.dataset)
lookup = LookupTable(length=vocab_size, dim=state_dim)
lookup.weights_init = initialization.IsotropicGaussian(0.1)
lookup.biases_init = initialization.Constant(0)
forked = FeedforwardSequence([lookup.apply])
if not has_mask(args.dataset):
x_mask = tensor.ones_like(x, dtype=floatX)
else:
x = tensor.tensor3('features', dtype=floatX)
if args.used_inputs is not None:
x = tensor.set_subtensor(x[args.used_inputs:, :, :],
tensor.zeros_like(x[args.used_inputs:,
:, :],
dtype=floatX))
features = get_output_size(args.dataset)
forked = Linear(input_dim=features, output_dim=state_dim)
forked.weights_init = initialization.IsotropicGaussian(0.1)
forked.biases_init = initialization.Constant(0)
if not has_mask(args.dataset):
x_mask = tensor.ones_like(x[:, :, 0], dtype=floatX)
# Define the fork
fork = Fork(output_names=output_names, input_dim=features,
output_dims=output_dims,
prototype=forked)
fork.initialize()
# Apply the fork
prernn = fork.apply(x)
# Give a name to the input of each layer
if args.skip_connections:
for t in range(len(prernn)):
prernn[t].name = "pre_rnn_" + str(t)
else:
prernn.name = "pre_rnn"
return prernn, x_mask
def get_prernn(args):
# time x batch
x_mask = tensor.fmatrix('mask')
# Compute the state dim
if args.rnn_type == 'lstm':
state_dim = 4 * args.state_dim
else:
state_dim = args.state_dim
# Prepare the arguments for the fork
output_names = []
output_dims = []
for d in range(args.layers):
if d > 0:
suffix = RECURRENTSTACK_SEPARATOR + str(d)
else:
suffix = ''
if d == 0 or args.skip_connections:
output_names.append("inputs" + suffix)
output_dims.append(state_dim)
# Prepare the brick to be forked (LookupTable or Linear)
# Check if the dataset provides indices (in the case of a
# fixed vocabulary, x is 2D tensor) or if it gives raw values
# (x is 3D tensor)
if has_indices(args.dataset):
features = args.mini_batch_size
x = tensor.lmatrix('features')
vocab_size = get_output_size(args.dataset)
lookup = LookupTable(length=vocab_size, dim=state_dim)
lookup.weights_init = initialization.IsotropicGaussian(0.1)
lookup.biases_init = initialization.Constant(0)
forked = FeedforwardSequence([lookup.apply])
if not has_mask(args.dataset):
x_mask = tensor.ones_like(x, dtype=floatX)
else:
x = tensor.tensor3('features', dtype=floatX)
if args.used_inputs is not None:
x = tensor.set_subtensor(
x[args.used_inputs:, :, :],
tensor.zeros_like(x[args.used_inputs:, :, :], dtype=floatX))
features = get_output_size(args.dataset)
forked = Linear(input_dim=features, output_dim=state_dim)
forked.weights_init = initialization.IsotropicGaussian(0.1)
forked.biases_init = initialization.Constant(0)
if not has_mask(args.dataset):
x_mask = tensor.ones_like(x[:, :, 0], dtype=floatX)
# Define the fork
fork = Fork(output_names=output_names,
input_dim=features,
output_dims=output_dims,
prototype=forked)
fork.initialize()
# Apply the fork
prernn = fork.apply(x)
# Give a name to the input of each layer
if args.skip_connections:
for t in range(len(prernn)):
prernn[t].name = "pre_rnn_" + str(t)
else:
prernn.name = "pre_rnn"
return prernn, x_mask
def build_fork_lookup(vocab_size, time_length, args):
x = tensor.lmatrix('features')
virtual_dim = 6
state_dim = 6
skip_connections = False
layers = 1
# Build the model
output_names = []
output_dims = []
for d in range(layers):
if d > 0:
suffix = '_' + str(d)
else:
suffix = ''
if d == 0 or skip_connections:
output_names.append("inputs" + suffix)
output_dims.append(virtual_dim)
lookup = LookupTable(length=vocab_size, dim=virtual_dim)
lookup.weights_init = initialization.IsotropicGaussian(0.1)
lookup.biases_init = initialization.Constant(0)
fork = Fork(output_names=output_names, input_dim=time_length,
output_dims=output_dims,
prototype=FeedforwardSequence(
[lookup.apply]))
# Note that this order of the periods makes faster modules flow in slower
# ones with is the opposite of the original paper
transitions = [ClockworkBase(dim=state_dim, activation=Tanh(),
period=2 ** i) for i in range(layers)]
rnn = RecurrentStack(transitions, skip_connections=skip_connections)
# Return list of 3D Tensor, one for each layer
# (Batch X Time X embedding_dim)
pre_rnn = fork.apply(x)
# Give time as the first index for each element in the list:
# (Time X Batch X embedding_dim)
if layers > 1 and skip_connections:
for t in range(len(pre_rnn)):
pre_rnn[t] = pre_rnn[t].dimshuffle(1, 0, 2)
else:
pre_rnn = pre_rnn.dimshuffle(1, 0, 2)
f_pre_rnn = theano.function([x], pre_rnn)
# Prepare inputs for the RNN
kwargs = OrderedDict()
for d in range(layers):
if d > 0:
suffix = '_' + str(d)
else:
suffix = ''
if d == 0 or skip_connections:
if skip_connections:
kwargs['inputs' + suffix] = pre_rnn[d]
else:
kwargs['inputs' + suffix] = pre_rnn
print kwargs
# Apply the RNN to the inputs
h = rnn.apply(low_memory=True, **kwargs)
fork.initialize()
rnn.weights_init = initialization.Orthogonal()
rnn.biases_init = initialization.Constant(0)
rnn.initialize()
f_h = theano.function([x], h)
return f_pre_rnn, f_h
def main(mode, save_path, num_batches, from_dump):
if mode == "train":
# Experiment configuration
dimension = 100
readout_dimension = len(char2code)
# Data processing pipeline
data_stream = DataStreamMapping(
mapping=lambda data: tuple(array.T for array in data),
data_stream=PaddingDataStream(
BatchDataStream(
iteration_scheme=ConstantScheme(10),
data_stream=DataStreamMapping(
mapping=reverse_words,
add_sources=("targets", ),
data_stream=DataStreamFilter(
predicate=lambda data: len(data[0]) <= 100,
data_stream=OneBillionWord(
"training", [99],
char2code,
level="character",
preprocess=str.lower).get_default_stream())))))
# Build the model
chars = tensor.lmatrix("features")
chars_mask = tensor.matrix("features_mask")
targets = tensor.lmatrix("targets")
targets_mask = tensor.matrix("targets_mask")
encoder = Bidirectional(GatedRecurrent(dim=dimension,
activation=Tanh()),
weights_init=Orthogonal())
encoder.initialize()
fork = Fork([
name
for name in encoder.prototype.apply.sequences if name != 'mask'
],
weights_init=IsotropicGaussian(0.1),
biases_init=Constant(0))
fork.input_dim = dimension
fork.fork_dims = {name: dimension for name in fork.fork_names}
fork.initialize()
lookup = LookupTable(readout_dimension,
dimension,
weights_init=IsotropicGaussian(0.1))
lookup.initialize()
transition = Transition(activation=Tanh(),
dim=dimension,
attended_dim=2 * dimension,
name="transition")
attention = SequenceContentAttention(
state_names=transition.apply.states,
match_dim=dimension,
name="attention")
readout = LinearReadout(readout_dim=readout_dimension,
source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedbacker=LookupFeedback(
readout_dimension, dimension),
name="readout")
generator = SequenceGenerator(readout=readout,
transition=transition,
attention=attention,
weights_init=IsotropicGaussian(0.1),
biases_init=Constant(0),
name="generator")
generator.push_initialization_config()
transition.weights_init = Orthogonal()
generator.initialize()
bricks = [encoder, fork, lookup, generator]
# Give an idea of what's going on
params = Selector(bricks).get_params()
logger.info("Parameters:\n" +
pprint.pformat([(key, value.get_value().shape)
for key, value in params.items()],
width=120))
# Build the cost computation graph
batch_cost = generator.cost(
targets,
targets_mask,
attended=encoder.apply(**dict_union(fork.apply(
lookup.lookup(chars), return_dict=True),
mask=chars_mask)),
attended_mask=chars_mask).sum()
batch_size = named_copy(chars.shape[1], "batch_size")
cost = aggregation.mean(batch_cost, batch_size)
cost.name = "sequence_log_likelihood"
logger.info("Cost graph is built")
# Fetch variables useful for debugging
max_length = named_copy(chars.shape[0], "max_length")
cost_per_character = named_copy(
aggregation.mean(batch_cost, batch_size * max_length),
"character_log_likelihood")
cg = ComputationGraph(cost)
energies = unpack(VariableFilter(application=readout.readout,
name="output")(cg.variables),
singleton=True)
min_energy = named_copy(energies.min(), "min_energy")
max_energy = named_copy(energies.max(), "max_energy")
(activations, ) = VariableFilter(
application=generator.transition.apply,
name="states")(cg.variables)
mean_activation = named_copy(activations.mean(), "mean_activation")
# Define the training algorithm.
algorithm = GradientDescent(cost=cost,
step_rule=CompositeRule([
GradientClipping(10.0),
SteepestDescent(0.01)
]))
observables = [
cost, min_energy, max_energy, mean_activation, batch_size,
max_length, cost_per_character, algorithm.total_step_norm,
algorithm.total_gradient_norm
]
for name, param in params.items():
observables.append(named_copy(param.norm(2), name + "_norm"))
observables.append(
named_copy(algorithm.gradients[param].norm(2),
name + "_grad_norm"))
main_loop = MainLoop(
model=bricks,
data_stream=data_stream,
algorithm=algorithm,
extensions=([LoadFromDump(from_dump)] if from_dump else []) + [
Timing(),
TrainingDataMonitoring(observables, after_every_batch=True),
TrainingDataMonitoring(
observables, prefix="average", every_n_batches=10),
FinishAfter(after_n_batches=num_batches).add_condition(
"after_batch", lambda log: math.isnan(
log.current_row.total_gradient_norm)),
Plot(os.path.basename(save_path),
[["average_" + cost.name],
["average_" + cost_per_character.name]],
every_n_batches=10),
SerializeMainLoop(save_path,
every_n_batches=500,
save_separately=["model", "log"]),
Printing(every_n_batches=1)
])
main_loop.run()
elif mode == "test":
with open(save_path, "rb") as source:
encoder, fork, lookup, generator = dill.load(source)
logger.info("Model is loaded")
chars = tensor.lmatrix("features")
generated = generator.generate(
n_steps=3 * chars.shape[0],
batch_size=chars.shape[1],
attended=encoder.apply(**dict_union(
fork.apply(lookup.lookup(chars), return_dict=True))),
attended_mask=tensor.ones(chars.shape))
sample_function = ComputationGraph(generated).get_theano_function()
logging.info("Sampling function is compiled")
while True:
# Python 2-3 compatibility
line = input("Enter a sentence\n")
batch_size = int(input("Enter a number of samples\n"))
encoded_input = [
char2code.get(char, char2code["<UNK>"])
for char in line.lower().strip()
]
encoded_input = ([char2code['<S>']] + encoded_input +
[char2code['</S>']])
print("Encoder input:", encoded_input)
target = reverse_words((encoded_input, ))[0]
print("Target: ", target)
states, samples, glimpses, weights, costs = sample_function(
numpy.repeat(numpy.array(encoded_input)[:, None],
batch_size,
axis=1))
messages = []
for i in range(samples.shape[1]):
sample = list(samples[:, i])
try:
true_length = sample.index(char2code['</S>']) + 1
except ValueError:
true_length = len(sample)
sample = sample[:true_length]
cost = costs[:true_length, i].sum()
message = "({})".format(cost)
message += "".join(code2char[code] for code in sample)
if sample == target:
message += " CORRECT!"
messages.append((cost, message))
messages.sort(key=lambda tuple_: -tuple_[0])
for _, message in messages:
print(message)
def main():
nvis, nhid, nlat, learn_prior = 784, 200, 100, False
theano_rng = MRG_RandomStreams(134663)
# Initialize prior
prior_mu = shared_floatx(numpy.zeros(nlat), name='prior_mu')
prior_log_sigma = shared_floatx(numpy.zeros(nlat), name='prior_log_sigma')
if learn_prior:
add_role(prior_mu, PARAMETER)
add_role(prior_log_sigma, PARAMETER)
# Initialize encoding network
encoding_network = MLP(activations=[Rectifier()],
dims=[nvis, nhid],
weights_init=IsotropicGaussian(std=0.001),
biases_init=Constant(0))
encoding_network.initialize()
encoding_parameter_mapping = Fork(
output_names=['mu_phi', 'log_sigma_phi'], input_dim=nhid,
output_dims=dict(mu_phi=nlat, log_sigma_phi=nlat), prototype=Linear(),
weights_init=IsotropicGaussian(std=0.001), biases_init=Constant(0))
encoding_parameter_mapping.initialize()
# Initialize decoding network
decoding_network = MLP(activations=[Rectifier()],
dims=[nlat, nhid],
weights_init=IsotropicGaussian(std=0.001),
biases_init=Constant(0))
decoding_network.initialize()
decoding_parameter_mapping = Linear(
input_dim=nhid, output_dim=nvis, name='mu_theta',
weights_init=IsotropicGaussian(std=0.001),
biases_init=Constant(0))
decoding_parameter_mapping.initialize()
# Encode / decode
x = tensor.matrix('features')
h_phi = encoding_network.apply(x)
mu_phi, log_sigma_phi = encoding_parameter_mapping.apply(h_phi)
epsilon = theano_rng.normal(size=mu_phi.shape, dtype=mu_phi.dtype)
epsilon.name = 'epsilon'
z = mu_phi + epsilon * tensor.exp(log_sigma_phi)
z.name = 'z'
h_theta = decoding_network.apply(z)
mu_theta = decoding_parameter_mapping.apply(h_theta)
# Compute cost
kl_term = (
prior_log_sigma - log_sigma_phi
+ 0.5 * (
tensor.exp(2 * log_sigma_phi) + (mu_phi - prior_mu) ** 2
) / tensor.exp(2 * prior_log_sigma)
- 0.5
).sum(axis=1)
kl_term.name = 'kl_term'
kl_term_mean = kl_term.mean()
kl_term_mean.name = 'avg_kl_term'
reconstruction_term = - (
x * tensor.nnet.softplus(-mu_theta)
+ (1 - x) * tensor.nnet.softplus(mu_theta)).sum(axis=1)
reconstruction_term.name = 'reconstruction_term'
reconstruction_term_mean = -reconstruction_term.mean()
reconstruction_term_mean.name = 'avg_reconstruction_term'
cost = -(reconstruction_term - kl_term).mean()
cost.name = 'nll_upper_bound'
# Datasets and data streams
mnist_train = MNIST(
'train', start=0, stop=50000, binary=True, sources=('features',))
train_loop_stream = DataStream(
dataset=mnist_train,
iteration_scheme=SequentialScheme(mnist_train.num_examples, 100))
train_monitor_stream = DataStream(
dataset=mnist_train,
iteration_scheme=SequentialScheme(mnist_train.num_examples, 500))
mnist_valid = MNIST(
'train', start=50000, stop=60000, binary=True, sources=('features',))
valid_monitor_stream = DataStream(
dataset=mnist_valid,
iteration_scheme=SequentialScheme(mnist_valid.num_examples, 500))
mnist_test = MNIST('test', binary=True, sources=('features',))
test_monitor_stream = DataStream(
dataset=mnist_test,
iteration_scheme=SequentialScheme(mnist_test.num_examples, 500))
# Get parameters
computation_graph = ComputationGraph([cost])
params = VariableFilter(roles=[PARAMETER])(computation_graph.variables)
# Training loop
step_rule = RMSProp(learning_rate=1e-3, decay_rate=0.95)
algorithm = GradientDescent(cost=cost, params=params, step_rule=step_rule)
monitored_quantities = [cost, reconstruction_term_mean, kl_term_mean]
main_loop = MainLoop(
model=None, data_stream=train_loop_stream, algorithm=algorithm,
extensions=[
Timing(),
FinishAfter(after_n_epochs=200),
DataStreamMonitoring(
monitored_quantities, train_monitor_stream, prefix="train"),
DataStreamMonitoring(
monitored_quantities, valid_monitor_stream, prefix="valid"),
DataStreamMonitoring(
monitored_quantities, test_monitor_stream, prefix="test"),
Printing()])
main_loop.run()
def build_model_soft(vocab_size, args, dtype=floatX):
logger.info('Building model ...')
# Parameters for the model
context = args.context
state_dim = args.state_dim
layers = args.layers
skip_connections = args.skip_connections
# Symbolic variables
# In both cases: Time X Batch
x = tensor.lmatrix('features')
y = tensor.lmatrix('targets')
# Build the model
output_names = []
output_dims = []
for d in range(layers):
if d > 0:
suffix = '_' + str(d)
else:
suffix = ''
if d == 0 or skip_connections:
output_names.append("inputs" + suffix)
output_dims.append(state_dim)
lookup = LookupTable(length=vocab_size, dim=state_dim)
lookup.weights_init = initialization.IsotropicGaussian(0.1)
lookup.biases_init = initialization.Constant(0)
fork = Fork(output_names=output_names, input_dim=args.mini_batch_size,
output_dims=output_dims,
prototype=FeedforwardSequence(
[lookup.apply]))
transitions = [SimpleRecurrent(dim=state_dim, activation=Tanh())]
# Build the MLP
dims = [2 * state_dim]
activations = []
for i in range(args.mlp_layers):
activations.append(Rectifier())
dims.append(state_dim)
# Activation of the last layer of the MLP
if args.mlp_activation == "logistic":
activations.append(Logistic())
elif args.mlp_activation == "rectifier":
activations.append(Rectifier())
elif args.mlp_activation == "hard_logistic":
activations.append(HardLogistic())
else:
assert False
# Output of MLP has dimension 1
dims.append(1)
for i in range(layers - 1):
mlp = MLP(activations=activations, dims=dims,
weights_init=initialization.IsotropicGaussian(0.1),
biases_init=initialization.Constant(0),
name="mlp_" + str(i))
transitions.append(
SoftGatedRecurrent(dim=state_dim,
mlp=mlp,
activation=Tanh()))
rnn = RecurrentStack(transitions, skip_connections=skip_connections)
# dim = layers * state_dim
output_layer = Linear(
input_dim=layers * state_dim,
output_dim=vocab_size, name="output_layer")
# Return list of 3D Tensor, one for each layer
# (Time X Batch X embedding_dim)
pre_rnn = fork.apply(x)
# Give a name to the input of each layer
if skip_connections:
for t in range(len(pre_rnn)):
pre_rnn[t].name = "pre_rnn_" + str(t)
else:
pre_rnn.name = "pre_rnn"
# Prepare inputs for the RNN
kwargs = OrderedDict()
init_states = {}
for d in range(layers):
if d > 0:
suffix = '_' + str(d)
else:
suffix = ''
if skip_connections:
kwargs['inputs' + suffix] = pre_rnn[d]
elif d == 0:
kwargs['inputs' + suffix] = pre_rnn
init_states[d] = theano.shared(
numpy.zeros((args.mini_batch_size, state_dim)).astype(floatX),
name='state0_%d' % d)
kwargs['states' + suffix] = init_states[d]
# Apply the RNN to the inputs
h = rnn.apply(low_memory=True, **kwargs)
# Now we have:
# h = [state, state_1, gate_value_1, state_2, gate_value_2, state_3, ...]
# Extract gate_values
gate_values = h[2::2]
new_h = [h[0]]
new_h.extend(h[1::2])
h = new_h
# Now we have:
# h = [state, state_1, state_2, ...]
# gate_values = [gate_value_1, gate_value_2, gate_value_3]
for i, gate_value in enumerate(gate_values):
gate_value.name = "gate_value_" + str(i)
# Save all the last states
last_states = {}
for d in range(layers):
last_states[d] = h[d][-1, :, :]
# Concatenate all the states
if layers > 1:
h = tensor.concatenate(h, axis=2)
h.name = "hidden_state"
# The updates of the hidden states
updates = []
for d in range(layers):
updates.append((init_states[d], last_states[d]))
presoft = output_layer.apply(h[context:, :, :])
# Define the cost
# Compute the probability distribution
time, batch, feat = presoft.shape
presoft.name = 'presoft'
cross_entropy = Softmax().categorical_cross_entropy(
y[context:, :].flatten(),
presoft.reshape((batch * time, feat)))
cross_entropy = cross_entropy / tensor.log(2)
cross_entropy.name = "cross_entropy"
# TODO: add regularisation for the cost
# the log(1) is here in order to differentiate the two variables
# for monitoring
cost = cross_entropy + tensor.log(1)
cost.name = "regularized_cost"
# Initialize the model
logger.info('Initializing...')
fork.initialize()
rnn.weights_init = initialization.Orthogonal()
rnn.biases_init = initialization.Constant(0)
rnn.initialize()
output_layer.weights_init = initialization.IsotropicGaussian(0.1)
output_layer.biases_init = initialization.Constant(0)
output_layer.initialize()
return cost, cross_entropy, updates, gate_values
def build_model_lstm(vocab_size, args, dtype=floatX):
logger.info('Building model ...')
# Parameters for the model
context = args.context
state_dim = args.state_dim
layers = args.layers
skip_connections = args.skip_connections
virtual_dim = 4 * state_dim
# Symbolic variables
# In both cases: Time X Batch
x = tensor.lmatrix('features')
y = tensor.lmatrix('targets')
# Build the model
output_names = []
output_dims = []
for d in range(layers):
if d > 0:
suffix = '_' + str(d)
else:
suffix = ''
if d == 0 or skip_connections:
output_names.append("inputs" + suffix)
output_dims.append(virtual_dim)
lookup = LookupTable(length=vocab_size, dim=virtual_dim)
lookup.weights_init = initialization.IsotropicGaussian(0.1)
lookup.biases_init = initialization.Constant(0)
# Make sure time_length is what we need
fork = Fork(output_names=output_names,
input_dim=args.mini_batch_size,
output_dims=output_dims,
prototype=FeedforwardSequence([lookup.apply]))
transitions = [
LSTM(dim=state_dim, activation=Tanh()) for _ in range(layers)
]
rnn = RecurrentStack(transitions, skip_connections=skip_connections)
# If skip_connections: dim = layers * state_dim
# else: dim = state_dim
output_layer = Linear(input_dim=skip_connections * layers * state_dim +
(1 - skip_connections) * state_dim,
output_dim=vocab_size,
name="output_layer")
# Return list of 3D Tensor, one for each layer
# (Time X Batch X embedding_dim)
pre_rnn = fork.apply(x)
# Give a name to the input of each layer
if skip_connections:
for t in range(len(pre_rnn)):
pre_rnn[t].name = "pre_rnn_" + str(t)
else:
pre_rnn.name = "pre_rnn"
# Prepare inputs for the RNN
kwargs = OrderedDict()
init_states = {}
init_cells = {}
for d in range(layers):
if d > 0:
suffix = '_' + str(d)
else:
suffix = ''
if skip_connections:
kwargs['inputs' + suffix] = pre_rnn[d]
elif d == 0:
kwargs['inputs'] = pre_rnn
init_states[d] = theano.shared(numpy.zeros(
(args.mini_batch_size, state_dim)).astype(floatX),
name='state0_%d' % d)
init_cells[d] = theano.shared(numpy.zeros(
(args.mini_batch_size, state_dim)).astype(floatX),
name='cell0_%d' % d)
kwargs['states' + suffix] = init_states[d]
kwargs['cells' + suffix] = init_cells[d]
# Apply the RNN to the inputs
h = rnn.apply(low_memory=True, **kwargs)
# h = [state, cell, in, forget, out, state_1,
# cell_1, in_1, forget_1, out_1 ...]
last_states = {}
last_cells = {}
for d in range(layers):
last_states[d] = h[5 * d][-1, :, :]
last_cells[d] = h[5 * d + 1][-1, :, :]
# The updates of the hidden states
updates = []
for d in range(layers):
updates.append((init_states[d], last_states[d]))
updates.append((init_cells[d], last_states[d]))
# h = [state, cell, in, forget, out, state_1,
# cell_1, in_1, forget_1, out_1 ...]
# Extract the values
in_gates = h[2::5]
forget_gates = h[3::5]
out_gates = h[4::5]
gate_values = {
"in_gates": in_gates,
"forget_gates": forget_gates,
"out_gates": out_gates
}
h = h[::5]
# Now we have correctly:
# h = [state, state_1, state_2 ...] if layers > 1
# h = [state] if layers == 1
# If we have skip connections, concatenate all the states
# Else only consider the state of the highest layer
if layers > 1:
if skip_connections:
h = tensor.concatenate(h, axis=2)
else:
h = h[-1]
else:
h = h[0]
h.name = "hidden_state"
presoft = output_layer.apply(h[context:, :, :])
# Define the cost
# Compute the probability distribution
time, batch, feat = presoft.shape
presoft.name = 'presoft'
cross_entropy = Softmax().categorical_cross_entropy(
y[context:, :].flatten(), presoft.reshape((batch * time, feat)))
cross_entropy = cross_entropy / tensor.log(2)
cross_entropy.name = "cross_entropy"
# TODO: add regularisation for the cost
# the log(1) is here in order to differentiate the two variables
# for monitoring
cost = cross_entropy + tensor.log(1)
cost.name = "regularized_cost"
# Initialize the model
logger.info('Initializing...')
fork.initialize()
# Dont initialize as Orthogonal if we are about to load new parameters
if args.load_path is not None:
rnn.weights_init = initialization.Constant(0)
else:
rnn.weights_init = initialization.Orthogonal()
rnn.biases_init = initialization.Constant(0)
rnn.initialize()
output_layer.weights_init = initialization.IsotropicGaussian(0.1)
output_layer.biases_init = initialization.Constant(0)
output_layer.initialize()
return cost, cross_entropy, updates, gate_values
def main():
nvis, nhid, nlat, learn_prior = 784, 200, 100, False
theano_rng = MRG_RandomStreams(134663)
# Initialize prior
prior_mu = shared_floatx(numpy.zeros(nlat), name='prior_mu')
prior_log_sigma = shared_floatx(numpy.zeros(nlat), name='prior_log_sigma')
if learn_prior:
add_role(prior_mu, PARAMETER)
add_role(prior_log_sigma, PARAMETER)
# Initialize encoding network
encoding_network = MLP(activations=[Rectifier()],
dims=[nvis, nhid],
weights_init=IsotropicGaussian(std=0.001),
biases_init=Constant(0))
encoding_network.initialize()
encoding_parameter_mapping = Fork(
output_names=['mu_phi', 'log_sigma_phi'],
input_dim=nhid,
output_dims=dict(mu_phi=nlat, log_sigma_phi=nlat),
prototype=Linear(),
weights_init=IsotropicGaussian(std=0.001),
biases_init=Constant(0))
encoding_parameter_mapping.initialize()
# Initialize decoding network
decoding_network = MLP(activations=[Rectifier()],
dims=[nlat, nhid],
weights_init=IsotropicGaussian(std=0.001),
biases_init=Constant(0))
decoding_network.initialize()
decoding_parameter_mapping = Linear(
input_dim=nhid,
output_dim=nvis,
name='mu_theta',
weights_init=IsotropicGaussian(std=0.001),
biases_init=Constant(0))
decoding_parameter_mapping.initialize()
# Encode / decode
x = tensor.matrix('features')
h_phi = encoding_network.apply(x)
mu_phi, log_sigma_phi = encoding_parameter_mapping.apply(h_phi)
epsilon = theano_rng.normal(size=mu_phi.shape, dtype=mu_phi.dtype)
epsilon.name = 'epsilon'
z = mu_phi + epsilon * tensor.exp(log_sigma_phi)
z.name = 'z'
h_theta = decoding_network.apply(z)
mu_theta = decoding_parameter_mapping.apply(h_theta)
# Compute cost
kl_term = (prior_log_sigma - log_sigma_phi + 0.5 *
(tensor.exp(2 * log_sigma_phi) +
(mu_phi - prior_mu)**2) / tensor.exp(2 * prior_log_sigma) -
0.5).sum(axis=1)
kl_term.name = 'kl_term'
kl_term_mean = kl_term.mean()
kl_term_mean.name = 'avg_kl_term'
reconstruction_term = -(x * tensor.nnet.softplus(-mu_theta) +
(1 - x) * tensor.nnet.softplus(mu_theta)).sum(
axis=1)
reconstruction_term.name = 'reconstruction_term'
reconstruction_term_mean = -reconstruction_term.mean()
reconstruction_term_mean.name = 'avg_reconstruction_term'
cost = -(reconstruction_term - kl_term).mean()
cost.name = 'nll_upper_bound'
# Datasets and data streams
mnist_train = MNIST('train',
start=0,
stop=50000,
binary=True,
sources=('features', ))
train_loop_stream = DataStream(dataset=mnist_train,
iteration_scheme=SequentialScheme(
mnist_train.num_examples, 100))
train_monitor_stream = DataStream(dataset=mnist_train,
iteration_scheme=SequentialScheme(
mnist_train.num_examples, 500))
mnist_valid = MNIST('train',
start=50000,
stop=60000,
binary=True,
sources=('features', ))
valid_monitor_stream = DataStream(dataset=mnist_valid,
iteration_scheme=SequentialScheme(
mnist_valid.num_examples, 500))
mnist_test = MNIST('test', binary=True, sources=('features', ))
test_monitor_stream = DataStream(dataset=mnist_test,
iteration_scheme=SequentialScheme(
mnist_test.num_examples, 500))
# Get parameters
computation_graph = ComputationGraph([cost])
params = VariableFilter(roles=[PARAMETER])(computation_graph.variables)
# Training loop
step_rule = RMSProp(learning_rate=1e-3, decay_rate=0.95)
algorithm = GradientDescent(cost=cost, params=params, step_rule=step_rule)
monitored_quantities = [cost, reconstruction_term_mean, kl_term_mean]
main_loop = MainLoop(model=None,
data_stream=train_loop_stream,
algorithm=algorithm,
extensions=[
Timing(),
FinishAfter(after_n_epochs=200),
DataStreamMonitoring(monitored_quantities,
train_monitor_stream,
prefix="train"),
DataStreamMonitoring(monitored_quantities,
valid_monitor_stream,
prefix="valid"),
DataStreamMonitoring(monitored_quantities,
test_monitor_stream,
prefix="test"),
Printing()
])
main_loop.run()
def main():
x = T.tensor3('features')
m = T.matrix('features_mask')
y = T.imatrix('targets')
x = m.mean() + x #stupid mask not always needed...
#embedding_size = 300
#glove_version = "glove.6B.300d.txt"
embedding_size = 50
glove_version = "vectors.6B.50d.txt"
wstd = 0.02
conv1 = Conv1D(filter_length=5, num_filters=128, input_dim=embedding_size,
weights_init=IsotropicGaussian(std=wstd),
biases_init=Constant(0.0))
conv1.initialize()
o = conv1.apply(x)
o = Rectifier(name="conv1red").apply(o)
o = MaxPooling1D(pooling_length=5
#, step=2
).apply(o)
conv2 = Conv1D(filter_length=5, num_filters=128, input_dim=128,
weights_init=IsotropicGaussian(std=wstd),
biases_init=Constant(0.0),
step=3,
name="conv2")
conv2.initialize()
o = conv2.apply(o)
o = Rectifier(name="conv2rec").apply(o)
conv2 = Conv1D(filter_length=5, num_filters=128, input_dim=128,
weights_init=IsotropicGaussian(std=wstd),
biases_init=Constant(0.0),
step=3,
name="conv3")
conv2.initialize()
o = conv2.apply(o)
o = Rectifier(name="conv3rec").apply(o)
fork = Fork(weights_init=IsotropicGaussian(0.02),
biases_init=Constant(0.),
input_dim=128,
output_dims=[128]*3,
output_names=['inputs', 'reset_inputs', 'update_inputs']
)
fork.initialize()
inputs, reset_inputs, update_inputs = fork.apply(o)
out = o.mean(axis=1)
#gru = GatedRecurrent(dim=128,
#weights_init=IsotropicGaussian(0.02),
#biases_init=IsotropicGaussian(0.0))
#gru.initialize()
#states = gru.apply(inputs=inputs, reset_inputs=reset_inputs, update_inputs=update_inputs)
#out = states[:, -1, :]
hidden = Linear(
input_dim = 128,
output_dim = 128,
weights_init = Uniform(std=0.01),
biases_init = Constant(0.))
hidden.initialize()
o = hidden.apply(out)
o = Rectifier().apply(o)
#hidden = Linear(
#input_dim = 128,
#output_dim = 128,
#weights_init = IsotropicGaussian(std=0.02),
#biases_init = Constant(0.),
#name="hiddenmap2")
#hidden.initialize()
#o = hidden.apply(o)
#o = Rectifier(name="rec2").apply(o)
score_layer = Linear(
input_dim = 128,
output_dim = 1,
weights_init = IsotropicGaussian(std=wstd),
biases_init = Constant(0.),
name="linear2")
score_layer.initialize()
o = score_layer.apply(o)
probs = Sigmoid().apply(o)
cost = - (y * T.log(probs) + (1-y) * T.log(1 - probs)).mean()
cost.name = 'cost'
misclassification = (y * (probs < 0.5) + (1-y) * (probs > 0.5)).mean()
misclassification.name = 'misclassification'
#print (rnn_states * m.dimshuffle(0, 1, 'x')).sum(axis=1).shape.eval(
#{x : np.ones((45, 111, embedding_size), dtype=theano.config.floatX),
#m : np.ones((45, 111), dtype=theano.config.floatX)})
#print (m).sum(axis=1).shape.eval({
#m : np.ones((45, 111), dtype=theano.config.floatX)})
#print (m).shape.eval({
#m : np.ones((45, 111), dtype=theano.config.floatX)})
#raw_input()
# =================
cg = ComputationGraph([cost])
params = cg.parameters
algorithm = GradientDescent(
cost = cost,
params=params,
step_rule = CompositeRule([
StepClipping(threshold=10),
AdaM(),
#AdaDelta(),
])
)
# ========
print "setting up data"
ports = {
'gpu0_train' : 5557,
'gpu0_test' : 5558,
'gpu1_train' : 5559,
'gpu1_test' : 5560,
}
batch_size = 16
def start_server(port, which_set):
fuel.server.logger.setLevel('WARN')
dataset = IMDBText(which_set)
n_train = dataset.num_examples
stream = DataStream(
dataset=dataset,
iteration_scheme=ShuffledScheme(
examples=n_train,
batch_size=batch_size)
)
print "loading glove"
glove = GloveTransformer(glove_version, data_stream=stream)
padded = Padding(
data_stream=glove,
mask_sources=('features',)
)
fuel.server.start_server(padded, port=port, hwm=20)
train_port = ports[theano.config.device + '_train']
train_p = Process(target=start_server, args=(train_port, 'train'))
train_p.start()
test_port = ports[theano.config.device + '_test']
test_p = Process(target=start_server, args=(test_port, 'test'))
test_p.start()
train_stream = ServerDataStream(('features', 'features_mask', 'targets'), port=train_port)
test_stream = ServerDataStream(('features', 'features_mask', 'targets'), port=test_port)
print "setting up model"
#import ipdb
#ipdb.set_trace()
n_examples = 25000
#======
model = Model(cost)
extensions = []
extensions.append(EpochProgress(batch_per_epoch=n_examples // batch_size + 1))
extensions.append(TrainingDataMonitoring(
[cost, misclassification],
prefix='train',
after_epoch=True
))
extensions.append(DataStreamMonitoring(
[cost, misclassification],
data_stream=test_stream,
prefix='test',
after_epoch=True
))
extensions.append(Timing())
extensions.append(Printing())
#extensions.append(Plot("norms", channels=[['train_lstm_norm', 'train_pre_norm']], after_epoch=True))
extensions.append(Plot(theano.config.device+"_result", channels=[['test_misclassification', 'train_misclassification']], after_epoch=True))
main_loop = MainLoop(
model=model,
data_stream=train_stream,
algorithm=algorithm,
extensions=extensions)
main_loop.run()
