def test_sequence_generator():
# Disclaimer: here we only check shapes, not values.
output_dim = 1
dim = 20
batch_size = 30
n_steps = 10
transition = GatedRecurrent(
name="transition", activation=Tanh(), dim=dim,
weights_init=Orthogonal())
generator = SequenceGenerator(
LinearReadout(readout_dim=output_dim, source_names=["states"],
emitter=TestEmitter(name="emitter"), name="readout"),
transition,
weights_init=IsotropicGaussian(0.01), biases_init=Constant(0),
name="generator")
generator.initialize()
y = tensor.tensor3('y')
mask = tensor.matrix('mask')
costs = generator.cost(y, mask)
assert costs.ndim == 2
costs_val = theano.function([y, mask], [costs])(
numpy.zeros((n_steps, batch_size, output_dim), dtype=floatX),
numpy.ones((n_steps, batch_size), dtype=floatX))[0]
assert costs_val.shape == (n_steps, batch_size)
states, outputs, costs = [variable.eval() for variable in
generator.generate(
iterate=True, batch_size=batch_size,
n_steps=n_steps)]
assert states.shape == (n_steps, batch_size, dim)
assert outputs.shape == (n_steps, batch_size, output_dim)
assert costs.shape == (n_steps, batch_size)
def __init__(self, vocab_size, embedding_dim, state_dim,
representation_dim, **kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
self.transition = GRUInitialState(attended_dim=state_dim,
dim=state_dim,
activation=Tanh(),
name='decoder')
self.attention = SequenceContentAttention(
state_names=self.transition.apply.states,
attended_dim=representation_dim,
match_dim=state_dim,
name="attention")
readout = Readout(source_names=[
'states', 'feedback', self.attention.take_glimpses.outputs[0]
],
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(initial_output=-1),
feedback_brick=LookupFeedbackWMT15(
vocab_size, embedding_dim),
post_merge=InitializableFeedforwardSequence([
Bias(dim=state_dim, name='maxout_bias').apply,
Maxout(num_pieces=2, name='maxout').apply,
Linear(input_dim=state_dim / 2,
output_dim=embedding_dim,
use_bias=False,
name='softmax0').apply,
Linear(input_dim=embedding_dim,
name='softmax1').apply
]),
merged_dim=state_dim,
merge_prototype=Linear(use_bias=True))
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([
name
for name in self.transition.apply.sequences if name != 'mask'
],
prototype=Linear()))
self.children = [self.sequence_generator]
def __init__(self, dimen, vocab_size): #{
# No idea what this is doing, but otherwise "allocated" is not set
super(MorphGen, self).__init__(self)
# The encoder
encoder = Bidirectional(SimpleRecurrent(dim=dimen, activation=Tanh()))
# What is this doing ?
fork = Fork([name for name in encoder.prototype.apply.sequences if name != 'mask'])
fork.input_dim = dimen
fork.output_dims = [encoder.prototype.get_dim(name) for name in fork.input_names]
lookup = LookupTable(vocab_size, dimen)
transition = SimpleRecurrent(dim=dimen, activation=Tanh(), name="transition")
atten = SequenceContentAttention(state_names=transition.apply.states,attended_dim=2*dimen, match_dim=dimen, name="attention")
readout = Readout(
readout_dim=vocab_size,
source_names=[transition.apply.states[0],
atten.take_glimpses.outputs[0]],
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(vocab_size, dimen),
name="readout");
generator = SequenceGenerator(readout=readout, transition=transition, attention=atten,name="generator")
self.lookup = lookup
self.fork = fork
self.encoder = encoder
self.generator = generator
self.children = [lookup, fork, encoder, generator]
def __init__(self, dimension, alphabet_size, **kwargs):
super(WordReverser, self).__init__(**kwargs)
encoder = Bidirectional(
SimpleRecurrent(dim=dimension, activation=Tanh()))
fork = Fork([name for name in encoder.prototype.apply.sequences
if name != 'mask'])
fork.input_dim = dimension
fork.output_dims = [dimension for name in fork.input_names]
lookup = LookupTable(alphabet_size, dimension)
transition = SimpleRecurrent(
activation=Tanh(),
dim=dimension, name="transition")
attention = SequenceContentAttention(
state_names=transition.apply.states,
attended_dim=2 * dimension, match_dim=dimension, name="attention")
readout = Readout(
readout_dim=alphabet_size,
source_names=[transition.apply.states[0],
attention.take_glimpses.outputs[0]],
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(alphabet_size, dimension),
name="readout")
generator = SequenceGenerator(
readout=readout, transition=transition, attention=attention,
name="generator")
self.lookup = lookup
self.fork = fork
self.encoder = encoder
self.generator = generator
self.children = [lookup, fork, encoder, generator]
def __init__(self,hidden_size_recurrent, k, **kwargs):
super(Scribe, self).__init__(**kwargs)
readout_size =6*k+1
transition = [GatedRecurrent(dim=hidden_size_recurrent,
name = "gru_{}".format(i) ) for i in range(3)]
transition = RecurrentStack( transition,
name="transition", skip_connections = True)
emitter = BivariateGMMEmitter(k = k)
source_names = [name for name in transition.apply.states
if 'states' in name]
readout = Readout(
readout_dim = readout_size,
source_names =source_names,
emitter=emitter,
name="readout")
self.generator = SequenceGenerator(readout=readout,
transition=transition,
name = "generator")
self.children = [self.generator]
def __init__(self, dimension, alphabet_size, **kwargs):
super(SimpleGenerator, self).__init__(**kwargs)
lookup = LookupTable(alphabet_size, dimension)
transition = SimpleRecurrent(activation=Tanh(),
dim=dimension,
name="transition")
attention = SequenceContentAttention(
state_names=transition.apply.states,
attended_dim=dimension,
match_dim=dimension,
name="attention")
readout = Readout(readout_dim=alphabet_size,
source_names=[
transition.apply.states[0],
attention.take_glimpses.outputs[0]
],
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(
alphabet_size, dimension),
name="readout")
generator = SequenceGenerator(readout=readout,
transition=transition,
attention=attention,
name="generator")
self.lookup = lookup
self.generator = generator
self.children = [lookup, generator]
def __init__(self, vocab_size, embedding_dim, state_dim,
representation_dim, theano_seed=None, **kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
self.theano_seed = theano_seed
# Initialize gru with special initial state
self.transition = GRUInitialState(
attended_dim=state_dim, dim=state_dim,
activation=Tanh(), name='decoder')
# Initialize the attention mechanism
self.attention = SequenceContentAttention(
state_names=self.transition.apply.states,
attended_dim=representation_dim,
match_dim=state_dim, name="attention")
# Initialize the readout, note that SoftmaxEmitter emits -1 for
# initial outputs which is used by LookupFeedBackWMT15
readout = Readout(
source_names=['states', 'feedback',
self.attention.take_glimpses.outputs[0]],
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(initial_output=-1, theano_seed=theano_seed),
feedback_brick=LookupFeedbackWMT15(vocab_size, embedding_dim),
post_merge=InitializableFeedforwardSequence(
[Bias(dim=state_dim, name='maxout_bias').apply,
Maxout(num_pieces=2, name='maxout').apply,
Linear(input_dim=state_dim / 2, output_dim=embedding_dim,
use_bias=False, name='softmax0').apply,
Linear(input_dim=embedding_dim, name='softmax1').apply]),
merged_dim=state_dim)
# Build sequence generator accordingly
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([name for name in self.transition.apply.sequences
if name != 'mask'], prototype=Linear())
)
self.children = [self.sequence_generator]
def __init__(self, vocab_size, embedding_dim, state_dim,
representation_dim, **kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
readout = Readout(
source_names=['states', 'feedback', 'readout_context'],
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(),
feedback_brick=LookupFeedback(vocab_size, embedding_dim),
post_merge=InitializableFeedforwardSequence([
Bias(dim=1000).apply,
Maxout(num_pieces=2).apply,
Linear(input_dim=state_dim / 2, output_dim=100,
use_bias=False).apply,
Linear(input_dim=100).apply
]),
merged_dim=1000)
self.transition = GatedRecurrentWithContext(Tanh(),
dim=state_dim,
name='decoder')
# Readout will apply the linear transformation to 'readout_context'
# with a Merge brick, so no need to fork it here
self.fork = Fork([
name for name in self.transition.apply.contexts +
self.transition.apply.states if name != 'readout_context'
],
prototype=Linear())
self.tanh = Tanh()
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
fork_inputs=[
name for name in self.transition.apply.sequences
if name != 'mask'
],
)
self.children = [self.fork, self.sequence_generator, self.tanh]
def getRnnGenerator(vocab_size,hidden_dim,input_dim=512):
"""
"Apply" the RNN to the input x
For initializing the network, the vocab size needs to be known
Default of the hidden layer is set tot 512 like Karpathy
"""
generator = SequenceGenerator(
Readout(readout_dim = vocab_size,
source_names = ["states"], # transition.apply.states ???
emitter = SoftmaxEmitter(name="emitter"),
feedback_brick = LookupFeedback(
vocab_size,
input_dim,
name = 'feedback'
),
name = "readout"
),
MySimpleRecurrent(
name = "transition",
activation = Tanh(),
dim = hidden_dim
),
weights_init = IsotropicGaussian(0.01),
biases_init = Constant(0),
name = "generator"
)
generator.push_initialization_config()
generator.transition.weights_init = IsotropicGaussian(0.01)
generator.initialize()
return generator
def test_integer_sequence_generator():
# Disclaimer: here we only check shapes, not values.
readout_dim = 5
feedback_dim = 3
dim = 20
batch_size = 30
n_steps = 10
transition = GatedRecurrent(
name="transition", activation=Tanh(), dim=dim,
weights_init=Orthogonal())
generator = SequenceGenerator(
LinearReadout(readout_dim=readout_dim, source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedbacker=LookupFeedback(readout_dim, feedback_dim),
name="readout"),
transition,
weights_init=IsotropicGaussian(0.01), biases_init=Constant(0),
name="generator")
generator.initialize()
y = tensor.lmatrix('y')
mask = tensor.matrix('mask')
costs = generator.cost(y, mask)
assert costs.ndim == 2
costs_val = theano.function([y, mask], [costs])(
numpy.zeros((n_steps, batch_size), dtype='int64'),
numpy.ones((n_steps, batch_size), dtype=floatX))[0]
assert costs_val.shape == (n_steps, batch_size)
states, outputs, costs = generator.generate(
iterate=True, batch_size=batch_size, n_steps=n_steps)
states_val, outputs_val, costs_val = theano.function(
[], [states, outputs, costs],
updates=costs.owner.inputs[0].owner.tag.updates)()
assert states_val.shape == (n_steps, batch_size, dim)
assert outputs_val.shape == (n_steps, batch_size)
assert outputs_val.dtype == 'int64'
assert costs_val.shape == (n_steps, batch_size)
def test_sequence_generator():
# Disclaimer: here we only check shapes, not values.
output_dim = 1
dim = 20
batch_size = 30
n_steps = 10
transition = GatedRecurrent(
name="transition", activation=Tanh(), dim=dim,
weights_init=Orthogonal())
generator = SequenceGenerator(
LinearReadout(readout_dim=output_dim, source_names=["states"],
emitter=TestEmitter(name="emitter"), name="readout"),
transition,
weights_init=IsotropicGaussian(0.01), biases_init=Constant(0),
name="generator")
generator.initialize()
y = tensor.tensor3('y')
mask = tensor.matrix('mask')
costs = generator.cost(y, mask)
assert costs.ndim == 2
costs_val = theano.function([y, mask], [costs])(
numpy.zeros((n_steps, batch_size, output_dim), dtype=floatX),
numpy.ones((n_steps, batch_size), dtype=floatX))[0]
assert costs_val.shape == (n_steps, batch_size)
states, outputs, costs = [variable.eval() for variable in
generator.generate(
iterate=True, batch_size=batch_size,
n_steps=n_steps)]
assert states.shape == (n_steps, batch_size, dim)
assert outputs.shape == (n_steps, batch_size, output_dim)
assert costs.shape == (n_steps, batch_size)
def test_recurrentstack_sequence_generator():
"""Test RecurrentStack behaviour inside a SequenceGenerator.
"""
floatX = theano.config.floatX
rng = numpy.random.RandomState(1234)
output_dim = 1
dim = 20
batch_size = 30
n_steps = 10
depth=2
transitions = [LSTM(dim=dim) for _ in range(depth)]
transition = RecurrentStack(transitions,fast=True,
weights_init=Constant(2),
biases_init=Constant(0))
generator = SequenceGenerator(
Readout(readout_dim=output_dim, source_names=["states_%d"%(depth-1)],
emitter=TestEmitter()),
transition,
weights_init=IsotropicGaussian(0.1), biases_init=Constant(0.0),
seed=1234)
generator.initialize()
y = tensor.tensor3('y')
cost = generator.cost(y)
# Check that all states can be accessed and not just the state connected
# to readout.
cg = ComputationGraph(cost)
from blocks.roles import INPUT, OUTPUT
dropout_target = VariableFilter(roles=[INNER_OUTPUT],
# bricks=transitions,
# name_regex='*'
)(cg.variables)
assert_equal(len(dropout_target), depth)
def __init__(self, vocab_size, embedding_dim, state_dim,
representation_dim, theano_seed=None, **kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
self.theano_seed = theano_seed
# Initialize gru with special initial state
self.transition = GRUInitialState(
attended_dim=state_dim, dim=state_dim,
activation=Tanh(), name='decoder')
# Initialize the attention mechanism
self.attention = SequenceContentAttention(
state_names=self.transition.apply.states,
attended_dim=representation_dim,
match_dim=state_dim, name="attention")
# Initialize the readout, note that SoftmaxEmitter emits -1 for
# initial outputs which is used by LookupFeedBackWMT15
readout = Readout(
source_names=['states', 'feedback',
self.attention.take_glimpses.outputs[0]],
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(initial_output=-1, theano_seed=theano_seed),
feedback_brick=LookupFeedbackWMT15(vocab_size, embedding_dim),
post_merge=InitializableFeedforwardSequence(
[Bias(dim=state_dim, name='maxout_bias').apply,
Maxout(num_pieces=2, name='maxout').apply,
Linear(input_dim=state_dim / 2, output_dim=embedding_dim,
use_bias=False, name='softmax0').apply,
Linear(input_dim=embedding_dim, name='softmax1').apply]),
merged_dim=state_dim)
# Build sequence generator accordingly
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([name for name in self.transition.apply.sequences
if name != 'mask'], prototype=Linear())
)
self.children = [self.sequence_generator]
def __init__(self, vocab_size, embedding_dim, state_dim,
representation_dim, **kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
self.transition = GRUInitialState(
attended_dim=state_dim, dim=state_dim,
activation=Tanh(), name='decoder')
self.attention = SequenceContentAttention(
state_names=self.transition.apply.states,
attended_dim=representation_dim,
match_dim=state_dim, name="attention")
readout = Readout(
source_names=['states', 'feedback', self.attention.take_glimpses.outputs[0]],
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(initial_output=-1),
feedback_brick=LookupFeedbackWMT15(vocab_size, embedding_dim),
post_merge=InitializableFeedforwardSequence(
[Bias(dim=state_dim, name='maxout_bias').apply,
Maxout(num_pieces=2, name='maxout').apply,
Linear(input_dim=state_dim / 2, output_dim=embedding_dim,
use_bias=False, name='softmax0').apply,
Linear(input_dim=embedding_dim, name='softmax1').apply]),
merged_dim=state_dim,
merge_prototype=Linear(use_bias=True))
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([name for name in self.transition.apply.sequences
if name != 'mask'], prototype=Linear())
)
self.children = [self.sequence_generator]
def __init__(self, vocab_size, embedding_dim,
state_dim, theano_seed=None, **kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.theano_seed = theano_seed
self.transition = GatedRecurrent(dim=state_dim,
activation=Tanh(), name='decoder')
readout = Readout(
source_names=['states'],
readout_dim=self.vocab_size,
merged_dim=state_dim)
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
fork=Fork([name for name in self.transition.apply.sequences
if name != 'mask'], prototype=Linear()))
self.children = [self.sequence_generator]
def test_integer_sequence_generator():
# Disclaimer: here we only check shapes, not values.
readout_dim = 5
feedback_dim = 3
dim = 20
batch_size = 30
n_steps = 10
transition = GatedRecurrent(name="transition",
activation=Tanh(),
dim=dim,
weights_init=Orthogonal())
generator = SequenceGenerator(LinearReadout(
readout_dim=readout_dim,
source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedbacker=LookupFeedback(readout_dim, feedback_dim),
name="readout"),
transition,
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(0),
name="generator")
generator.initialize()
y = tensor.lmatrix('y')
mask = tensor.matrix('mask')
costs = generator.cost(y, mask)
assert costs.ndim == 2
costs_val = theano.function([y, mask],
[costs])(numpy.zeros((n_steps, batch_size),
dtype='int64'),
numpy.ones((n_steps, batch_size),
dtype=floatX))[0]
assert costs_val.shape == (n_steps, batch_size)
states, outputs, costs = generator.generate(iterate=True,
batch_size=batch_size,
n_steps=n_steps)
states_val, outputs_val, costs_val = theano.function(
[], [states, outputs, costs],
updates=costs.owner.inputs[0].owner.tag.updates)()
assert states_val.shape == (n_steps, batch_size, dim)
assert outputs_val.shape == (n_steps, batch_size)
assert outputs_val.dtype == 'int64'
assert costs_val.shape == (n_steps, batch_size)
def __init__(self, vocab_size, embedding_dim, state_dim,
representation_dim, **kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
readout = Readout(
source_names=['states', 'feedback', 'readout_context'],
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(),
feedback_brick=LookupFeedback(vocab_size, embedding_dim),
post_merge=InitializableFeedforwardSequence(
[Bias(dim=1000).apply,
Maxout(num_pieces=2).apply,
Linear(input_dim=state_dim / 2, output_dim=100,
use_bias=False).apply,
Linear(input_dim=100).apply]),
merged_dim=1000)
self.transition = GatedRecurrentWithContext(Tanh(), dim=state_dim,
name='decoder')
# Readout will apply the linear transformation to 'readout_context'
# with a Merge brick, so no need to fork it here
self.fork = Fork([name for name in
self.transition.apply.contexts +
self.transition.apply.states
if name != 'readout_context'], prototype=Linear())
self.tanh = Tanh()
self.sequence_generator = SequenceGenerator(
readout=readout, transition=self.transition,
fork_inputs=[name for name in self.transition.apply.sequences
if name != 'mask'],
)
self.children = [self.fork, self.sequence_generator, self.tanh]
def build_model(alphabet_size, config):
layers = config['lstm_layers']
dimensions = [config['lstm_dim_' + str(i)] for i in range(layers)]
uniform_width = config['lstm_init_width']
stack = []
for dim in dimensions:
stack.append(LSTM(dim=dim, use_bias=True,
weights_init = Uniform(width=uniform_width),
forget_init=Constant(1.)))
recurrent_stack = RecurrentStack(stack, name='transition')
readout = Readout(readout_dim=alphabet_size,
source_names=['states#' + str(layers - 1)],
emitter=SoftmaxEmitter(name='emitter'),
feedback_brick=LookupFeedback(alphabet_size,
feedback_dim=alphabet_size,
name='feedback'),
name='readout')
generator = SequenceGenerator(readout=readout,
transition=recurrent_stack,
weights_init=Uniform(width=uniform_width),
biases_init=Constant(0),
name='generator')
generator.push_initialization_config()
generator.initialize()
x = tensor.lmatrix('features')
mask = tensor.fmatrix('features_mask')
cost_matrix = generator.cost_matrix(x, mask=mask)
log2e = math.log(math.e, 2)
if 'batch_length' in config:
length = config['batch_length'] - config['batch_overlap']
cost = log2e * aggregation.mean(cost_matrix[:,-length:].sum(),
mask[:,-length:].sum())
else:
cost = log2e * aggregation.mean(cost_matrix[:,:].sum(),
mask[:,:].sum())
cost.name = 'bits_per_character'
return generator, cost
class Decoder(Initializable):
def __init__(self, vocab_size, embedding_dim,
state_dim, theano_seed=None, **kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.theano_seed = theano_seed
self.transition = GatedRecurrent(dim=state_dim,
activation=Tanh(), name='decoder')
readout = Readout(
source_names=['states'],
readout_dim=self.vocab_size,
merged_dim=state_dim)
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
fork=Fork([name for name in self.transition.apply.sequences
if name != 'mask'], prototype=Linear()))
self.children = [self.sequence_generator]
@application(inputs=['representation', 'source_sentence_mask',
'target_sentence_mask', 'target_sentence'],
outputs=['cost'])
def cost(self, representation, source_sentence_mask,
target_sentence, target_sentence_mask):
source_sentence_mask = source_sentence_mask.T
target_sentence = target_sentence.T
target_sentence_mask = target_sentence_mask.T
cost = self.sequence_generator.cost_matrix(**{
'mask': target_sentence_mask,
'outputs': target_sentence})
class Decoder(Initializable):
"""Decoder of RNNsearch model which uses a full softmax output
layer and embedding matrices for feedback.
"""
def __init__(self,
vocab_size,
embedding_dim,
state_dim,
att_dim,
maxout_dim,
representation_dim,
attention_strategy='content',
attention_sources='s',
readout_sources='sfa',
memory='none',
memory_size=500,
seq_len=50,
init_strategy='last',
make_prunable=False,
theano_seed=None,
**kwargs):
"""Creates a new decoder brick.
Args:
vocab_size (int): Target language vocabulary size
embedding_dim (int): Size of feedback embedding layer
state_dim (int): Number of hidden units
att_dim (int): Size of attention match vector
maxout_dim (int): Size of maxout layer
representation_dim (int): Dimension of source annotations
attention_strategy (string): Which attention should be used
cf. ``_initialize_attention``
attention_sources (string): Defines the sources used by the
attention model 's' for decoder
states, 'f' for feedback
readout_sources (string): Defines the sources used in the
readout network. 's' for decoder
states, 'f' for feedback, 'a' for
attention (context vector)
memory (string): Which external memory should be used
(cf. ``_initialize_attention``)
memory_size (int): Size of the external memory structure
seq_len (int): Maximum sentence length
init_strategy (string): How to initialize the RNN state
(cf. ``GRUInitialState``)
theano_seed: Random seed
"""
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
self.theano_seed = theano_seed
# Initialize gru with special initial state
self.transition = GRUInitialState(attended_dim=representation_dim / 2,
init_strategy=init_strategy,
dim=state_dim,
activation=Tanh(),
name='decoder')
# Initialize the attention mechanism
att_dim = att_dim if att_dim > 0 else state_dim
self.attention, src_names = _initialize_attention(
attention_strategy, seq_len, self.transition, representation_dim,
att_dim, attention_sources, readout_sources, memory, memory_size)
# Initialize the readout, note that SoftmaxEmitter emits -1 for
# initial outputs which is used by LookupFeedBackWMT15
maxout_dim = maxout_dim if maxout_dim > 0 else state_dim
post_layers = [
Bias(dim=maxout_dim, name='maxout_bias').apply,
Maxout(num_pieces=2, name='maxout').apply,
Linear(input_dim=maxout_dim / 2,
output_dim=embedding_dim,
use_bias=False,
name='softmax0').apply,
Linear(input_dim=embedding_dim, name='softmax1').apply
]
if make_prunable:
post_merge = PrunableInitializableFeedforwardSequence(post_layers)
else:
post_merge = InitializableFeedforwardSequence(post_layers)
readout = Readout(source_names=src_names,
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(initial_output=-1,
theano_seed=theano_seed),
feedback_brick=LookupFeedbackWMT15(
vocab_size, embedding_dim),
post_merge=post_merge,
merged_dim=maxout_dim)
# Build sequence generator accordingly
if make_prunable:
self.sequence_generator = PrunableSequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([
name for name in self.transition.apply.sequences
if name != 'mask'
],
prototype=Linear()))
else:
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([
name for name in self.transition.apply.sequences
if name != 'mask'
],
prototype=Linear()))
self.children = [self.sequence_generator]
@application(inputs=[
'representation', 'source_sentence_mask', 'target_sentence_mask',
'target_sentence'
],
outputs=['cost'])
def cost(self, representation, source_sentence_mask, target_sentence,
target_sentence_mask):
target_sentence = target_sentence.T
target_sentence_mask = target_sentence_mask.T
# Get the cost matrix
cost = self.sequence_generator.cost_matrix(
**{
'mask': target_sentence_mask,
'outputs': target_sentence,
'attended': representation,
'attended_mask': source_sentence_mask
})
return (cost * target_sentence_mask).sum() / \
target_sentence_mask.shape[1]
@application
def generate(self, source_shape, representation, **kwargs):
return self.sequence_generator.generate(
n_steps=2 * source_shape[1],
batch_size=source_shape[0],
attended=representation,
attended_mask=tensor.ones(source_shape).T,
**kwargs)
class Decoder(Initializable):
"""Decoder of RNNsearch model."""
def __init__(self,
vocab_size,
embedding_dim,
state_dim,
representation_dim,
theano_seed=None,
**kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
self.theano_seed = theano_seed
# Initialize gru with special initial state
self.transition = GRUInitialState(attended_dim=state_dim,
dim=state_dim,
activation=Tanh(),
name='decoder')
# Initialize the attention mechanism
self.attention = SequenceContentAttention(
state_names=self.transition.apply.states,
attended_dim=representation_dim,
match_dim=state_dim,
name="attention")
# Initialize the readout, note that SoftmaxEmitter emits -1 for
# initial outputs which is used by LookupFeedBackWMT15
readout = Readout(source_names=[
'states', 'feedback', self.attention.take_glimpses.outputs[0]
],
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(initial_output=-1,
theano_seed=theano_seed),
feedback_brick=LookupFeedbackWMT15(
vocab_size, embedding_dim),
post_merge=InitializableFeedforwardSequence([
Bias(dim=state_dim, name='maxout_bias').apply,
Maxout(num_pieces=2, name='maxout').apply,
Linear(input_dim=state_dim / 2,
output_dim=embedding_dim,
use_bias=False,
name='softmax0').apply,
Linear(input_dim=embedding_dim,
name='softmax1').apply
]),
merged_dim=state_dim)
# Build sequence generator accordingly
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([
name
for name in self.transition.apply.sequences if name != 'mask'
],
prototype=Linear()))
self.children = [self.sequence_generator]
@application(inputs=[
'representation', 'source_sentence_mask', 'target_sentence_mask',
'target_sentence'
],
outputs=['cost'])
def cost(self, representation, source_sentence_mask, target_sentence,
target_sentence_mask):
source_sentence_mask = source_sentence_mask.T
target_sentence = target_sentence.T
target_sentence_mask = target_sentence_mask.T
# Get the cost matrix
cost = self.sequence_generator.cost_matrix(
**{
'mask': target_sentence_mask,
'outputs': target_sentence,
'attended': representation,
'attended_mask': source_sentence_mask
})
return (cost * target_sentence_mask).sum() / \
target_sentence_mask.shape[1]
@application
def generate(self, source_sentence, representation, **kwargs):
return self.sequence_generator.generate(
n_steps=2 * source_sentence.shape[1],
batch_size=source_sentence.shape[0],
attended=representation,
attended_mask=tensor.ones(source_sentence.shape).T,
**kwargs)
name = "gru_{}".format(i) ) for i in range(3)]
transition = RecurrentStack( transition,
name="transition", skip_connections = True)
emitter = BivariateGMMEmitter(k = k)
source_names = [name for name in transition.apply.states if 'states' in name]
readout = Readout(
readout_dim = readout_size,
source_names =source_names,
emitter=emitter,
name="readout")
generator = SequenceGenerator(readout=readout,
transition=transition,
name = "generator")
generator.weights_init = IsotropicGaussian(0.01)
generator.biases_init = Constant(0.001)
generator.push_initialization_config()
#generator.transition.weights_init = initialization.Identity(0.98)
#generator.transition.biases_init = IsotropicGaussian(0.01,0.9)
generator.transition.push_initialization_config()
generator.initialize()
cost_matrix = generator.cost_matrix(x, x_mask)
cost = cost_matrix.sum(axis = 0).mean()
cost.name = "nll"
def __init__(self, config, vocab_size):
context = tensor.imatrix('context')
context_mask = tensor.imatrix('context_mask')
answer = tensor.imatrix('answer')
answer_mask = tensor.imatrix('answer_mask')
bricks = []
context = context.dimshuffle(1, 0)
context_mask = context_mask.dimshuffle(1, 0)
answer = answer.dimshuffle(1, 0)
answer_mask = answer_mask.dimshuffle(1, 0)
context_bag = to_bag(context, vocab_size)
# Embed questions and context
embed = LookupTable(vocab_size, config.embed_size, name='embed')
embed.weights_init = IsotropicGaussian(0.01)
#embeddings_initial_value = init_embedding_table(filename='embeddings/vocab_embeddings.txt')
#embed.weights_init = Constant(embeddings_initial_value)
# Calculate context encoding (concatenate layer1)
cembed = embed.apply(context)
clstms, chidden_list = make_bidir_lstm_stack(
cembed, config.embed_size,
context_mask.astype(theano.config.floatX), config.ctx_lstm_size,
config.ctx_skip_connections, 'ctx')
bricks = bricks + clstms
if config.ctx_skip_connections:
cenc_dim = 2 * sum(config.ctx_lstm_size) #2 : fw & bw
cenc = tensor.concatenate(chidden_list, axis=2)
else:
cenc_dim = 2 * config.ctx_lstm_size[-1]
cenc = tensor.concatenate(chidden_list[-2:], axis=2)
cenc.name = 'cenc'
# Build the encoder bricks
transition = GatedRecurrent(activation=Tanh(),
dim=config.generator_lstm_size,
name="transition")
attention = SequenceContentAttention(
state_names=transition.apply.states,
attended_dim=cenc_dim,
match_dim=config.generator_lstm_size,
name="attention")
readout = Readout(readout_dim=vocab_size,
source_names=[
transition.apply.states[0],
attention.take_glimpses.outputs[0]
],
emitter=MaskedSoftmaxEmitter(context_bag=context_bag,
name='emitter'),
feedback_brick=LookupFeedback(
vocab_size, config.feedback_size),
name="readout")
generator = SequenceGenerator(readout=readout,
transition=transition,
attention=attention,
name="generator")
cost = generator.cost(answer,
answer_mask.astype(theano.config.floatX),
attended=cenc,
attended_mask=context_mask.astype(
theano.config.floatX),
name="cost")
self.predictions = generator.generate(
n_steps=7,
batch_size=config.batch_size,
attended=cenc,
attended_mask=context_mask.astype(theano.config.floatX),
iterate=True)[1]
# Apply dropout
cg = ComputationGraph([cost])
if config.w_noise > 0:
noise_vars = VariableFilter(roles=[WEIGHT])(cg)
cg = apply_noise(cg, noise_vars, config.w_noise)
if config.dropout > 0:
cg = apply_dropout(cg, chidden_list, config.dropout)
[cost_reg] = cg.outputs
# Other stuff
cost.name = 'cost'
cost_reg.name = 'cost_reg'
self.sgd_cost = cost_reg
self.monitor_vars = [[cost_reg]]
self.monitor_vars_valid = [[cost_reg]]
# initialize new stuff manually (change!)
generator.weights_init = IsotropicGaussian(0.01)
generator.biases_init = Constant(0)
generator.push_allocation_config()
generator.push_initialization_config()
transition.weights_init = Orthogonal()
generator.initialize()
# Initialize bricks
embed.initialize()
for brick in bricks:
brick.weights_init = config.weights_init
brick.biases_init = config.biases_init
brick.initialize()
def test_sequence_generator():
"""Test a sequence generator with no contexts and continuous outputs.
Such sequence generators can be used to model e.g. dynamical systems.
"""
rng = numpy.random.RandomState(1234)
output_dim = 1
dim = 20
batch_size = 30
n_steps = 10
transition = SimpleRecurrent(activation=Tanh(), dim=dim,
weights_init=Orthogonal())
generator = SequenceGenerator(
Readout(readout_dim=output_dim, source_names=["states"],
emitter=TestEmitter()),
transition,
weights_init=IsotropicGaussian(0.1), biases_init=Constant(0.0),
seed=1234)
generator.initialize()
# Test 'cost_matrix' method
y = tensor.tensor3('y')
mask = tensor.matrix('mask')
costs = generator.cost_matrix(y, mask)
assert costs.ndim == 2
y_test = rng.uniform(size=(n_steps, batch_size, output_dim)).astype(floatX)
m_test = numpy.ones((n_steps, batch_size), dtype=floatX)
costs_val = theano.function([y, mask], [costs])(y_test, m_test)[0]
assert costs_val.shape == (n_steps, batch_size)
assert_allclose(costs_val.sum(), 115.593, rtol=1e-5)
# Test 'cost' method
cost = generator.cost(y, mask)
assert cost.ndim == 0
cost_val = theano.function([y, mask], [cost])(y_test, m_test)
assert_allclose(cost_val, 3.8531, rtol=1e-5)
# Test 'AUXILIARY' variable 'per_sequence_element' in 'cost' method
cg = ComputationGraph([cost])
var_filter = VariableFilter(roles=[AUXILIARY])
aux_var_name = '_'.join([generator.name, generator.cost.name,
'per_sequence_element'])
cost_per_el = [el for el in var_filter(cg.variables)
if el.name == aux_var_name][0]
assert cost_per_el.ndim == 0
cost_per_el_val = theano.function([y, mask], [cost_per_el])(y_test, m_test)
assert_allclose(cost_per_el_val, 0.38531, rtol=1e-5)
# Test 'generate' method
states, outputs, costs = [variable.eval() for variable in
generator.generate(
states=rng.uniform(
size=(batch_size, dim)).astype(floatX),
iterate=True, batch_size=batch_size,
n_steps=n_steps)]
assert states.shape == (n_steps, batch_size, dim)
assert outputs.shape == (n_steps, batch_size, output_dim)
assert costs.shape == (n_steps, batch_size)
assert_allclose(outputs.sum(), -0.33683, rtol=1e-5)
assert_allclose(states.sum(), 15.7909, rtol=1e-5)
# There is no generation cost in this case, since generation is
# deterministic
assert_allclose(costs.sum(), 0.0)
class NoLookupDecoder(Initializable):
"""This is the decoder implementation without embedding layer or
softmax. The target sentence is represented as a sequence of #
vectors as defined by the sparse feature map.
"""
def __init__(self,
vocab_size,
embedding_dim,
state_dim,
representation_dim,
attention_strategy='content',
attention_sources='s',
readout_sources='sfa',
memory='none',
memory_size=500,
seq_len=50,
init_strategy='last',
theano_seed=None,
**kwargs):
"""Creates a new decoder brick without embedding.
Args:
vocab_size (int): Target language vocabulary size
embedding_dim (int): Size of feedback embedding layer
state_dim (int): Number of hidden units
representation_dim (int): Dimension of source annotations
attention_strategy (string): Which attention should be used
cf. ``_initialize_attention``
attention_sources (string): Defines the sources used by the
attention model 's' for decoder
states, 'f' for feedback
readout_sources (string): Defines the sources used in the
readout network. 's' for decoder
states, 'f' for feedback, 'a' for
attention (context vector)
memory (string): Which external memory should be used
(cf. ``_initialize_attention``)
memory_size (int): Size of the external memory structure
seq_len (int): Maximum sentence length
init_strategy (string): How to initialize the RNN state
(cf. ``GRUInitialState``)
theano_seed: Random seed
"""
super(NoLookupDecoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
self.theano_seed = theano_seed
# Initialize gru with special initial state
self.transition = GRUInitialState(attended_dim=state_dim,
init_strategy=init_strategy,
dim=state_dim,
activation=Tanh(),
name='decoder')
# Initialize the attention mechanism
self.attention, src_names = _initialize_attention(
attention_strategy, seq_len, self.transition, representation_dim,
state_dim, attention_sources, readout_sources, memory, memory_size)
# Initialize the readout, note that SoftmaxEmitter emits -1 for
# initial outputs which is used by LookupFeedBackWMT15
readout = Readout(
source_names=src_names,
readout_dim=embedding_dim,
emitter=NoLookupEmitter(initial_output=-1,
readout_dim=embedding_dim,
cost_brick=SquaredError()),
# cost_brick=CategoricalCrossEntropy()),
feedback_brick=TrivialFeedback(output_dim=embedding_dim),
post_merge=InitializableFeedforwardSequence([
Bias(dim=state_dim, name='maxout_bias').apply,
Maxout(num_pieces=2, name='maxout').apply,
Linear(input_dim=state_dim / 2,
output_dim=embedding_dim,
use_bias=False,
name='softmax0').apply,
Logistic(name='softmax1').apply
]),
merged_dim=state_dim)
# Build sequence generator accordingly
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([
name
for name in self.transition.apply.sequences if name != 'mask'
],
prototype=Linear()))
self.children = [self.sequence_generator]
@application(inputs=[
'representation', 'representation_mask', 'target_sentence_mask',
'target_sentence'
],
outputs=['cost'])
def cost(self, representation, representation_mask, target_sentence,
target_sentence_mask):
target_sentence = target_sentence.T
target_sentence_mask = target_sentence_mask.T
# Get the cost matrix
cost = self.sequence_generator.cost_matrix(
**{
'mask': target_sentence_mask,
'outputs': target_sentence,
'attended': representation,
'attended_mask': representation_mask
})
return (cost * target_sentence_mask).sum() / \
target_sentence_mask.shape[1]
@application
def generate(self, source_shape, representation, **kwargs):
return self.sequence_generator.generate(
n_steps=2 * source_shape[1],
batch_size=source_shape[0],
attended=representation,
attended_mask=tensor.ones(source_shape).T,
**kwargs)
def main(mode, save_path, steps, num_batches):
num_states = MarkovChainDataset.num_states
if mode == "train":
# Experiment configuration
rng = numpy.random.RandomState(1)
batch_size = 50
seq_len = 100
dim = 10
feedback_dim = 8
# Build the bricks and initialize them
transition = GatedRecurrent(name="transition", dim=dim,
activation=Tanh())
generator = SequenceGenerator(
Readout(readout_dim=num_states, source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(
num_states, feedback_dim, name='feedback'),
name="readout"),
transition,
weights_init=IsotropicGaussian(0.01), biases_init=Constant(0),
name="generator")
generator.push_initialization_config()
transition.weights_init = Orthogonal()
generator.initialize()
# Give an idea of what's going on.
logger.info("Parameters:\n" +
pprint.pformat(
[(key, value.get_value().shape) for key, value
in Selector(generator).get_params().items()],
width=120))
logger.info("Markov chain entropy: {}".format(
MarkovChainDataset.entropy))
logger.info("Expected min error: {}".format(
-MarkovChainDataset.entropy * seq_len))
# Build the cost computation graph.
x = tensor.lmatrix('data')
cost = aggregation.mean(generator.cost_matrix(x[:, :]).sum(),
x.shape[1])
cost.name = "sequence_log_likelihood"
algorithm = GradientDescent(
cost=cost, params=list(Selector(generator).get_params().values()),
step_rule=Scale(0.001))
main_loop = MainLoop(
algorithm=algorithm,
data_stream=DataStream(
MarkovChainDataset(rng, seq_len),
iteration_scheme=ConstantScheme(batch_size)),
model=Model(cost),
extensions=[FinishAfter(after_n_batches=num_batches),
TrainingDataMonitoring([cost], prefix="this_step",
after_batch=True),
TrainingDataMonitoring([cost], prefix="average",
every_n_batches=100),
Checkpoint(save_path, every_n_batches=500),
Printing(every_n_batches=100)])
main_loop.run()
elif mode == "sample":
main_loop = cPickle.load(open(save_path, "rb"))
generator = main_loop.model
sample = ComputationGraph(generator.generate(
n_steps=steps, batch_size=1, iterate=True)).get_theano_function()
states, outputs, costs = [data[:, 0] for data in sample()]
numpy.set_printoptions(precision=3, suppress=True)
print("Generation cost:\n{}".format(costs.sum()))
freqs = numpy.bincount(outputs).astype(theano.config.floatX)
freqs /= freqs.sum()
print("Frequencies:\n {} vs {}".format(freqs,
MarkovChainDataset.equilibrium))
trans_freqs = numpy.zeros((num_states, num_states),
dtype=theano.config.floatX)
for a, b in zip(outputs, outputs[1:]):
trans_freqs[a, b] += 1
trans_freqs /= trans_freqs.sum(axis=1)[:, None]
print("Transition frequencies:\n{}\nvs\n{}".format(
trans_freqs, MarkovChainDataset.trans_prob))
else:
assert False
weights_init=Orthogonal())
rnn = RecurrentStack([lstm1, lstm2, lstm3],
name="transition")
readout = Readout(readout_dim = alphabet_size,
source_names=["states#2"],
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(alphabet_size,
feedback_dim=alphabet_size,
name="feedback"),
name="readout")
seq_gen = SequenceGenerator(readout=readout,
transition=rnn,
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(0),
name="generator")
seq_gen.push_initialization_config()
rnn.weights_init = Orthogonal()
seq_gen.initialize()
# z markov_tutorial
x = tensor.lvector('features')
x = x.reshape( (x.shape[0], 1) )
cost = aggregation.mean(seq_gen.cost_matrix(x[:,:]).sum(), x.shape[1])
cost.name = "sequence_log_likelihood"
cost_cg = ComputationGraph(cost)
# theano.printing.pydotprint(cost, outfile="./pics/symbolic_graph_unopt.png", var_with_name_simple=True)
repeat=20)
if args.mode == "train":
seq_len = 100
dim = 100
feedback_dim = 100
# Build the bricks and initialize them
transition = GatedRecurrent(name="transition", dim=dim, activation=Tanh())
generator = SequenceGenerator(
Readout(
readout_dim=vocab_size,
source_names=["states"], # transition.apply.states ???
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(vocab_size,
feedback_dim,
name='feedback'),
name="readout"),
transition,
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(0),
name="generator")
generator.push_initialization_config()
transition.weights_init = Orthogonal()
generator.initialize()
# Build the cost computation graph.
x = tensor.lmatrix('inchar')
cost = generator.cost(outputs=x)
cost.name = "sequence_cost"
def main():
logging.basicConfig(
level=logging.DEBUG,
format="%(asctime)s: %(name)s: %(levelname)s: %(message)s")
parser = argparse.ArgumentParser(
"Case study of generating a Markov chain with RNN.",
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument(
"mode",
choices=["train", "sample"],
help="The mode to run. Use `train` to train a new model"
" and `sample` to sample a sequence generated by an"
" existing one.")
parser.add_argument("prefix",
default="sine",
help="The prefix for model, timing and state files")
parser.add_argument("--steps",
type=int,
default=100,
help="Number of steps to plot")
args = parser.parse_args()
dim = 10
num_states = ChainIterator.num_states
feedback_dim = 8
transition = GatedRecurrent(name="transition", activation=Tanh(), dim=dim)
generator = SequenceGenerator(LinearReadout(
readout_dim=num_states,
source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedbacker=LookupFeedback(num_states, feedback_dim, name='feedback'),
name="readout"),
transition,
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(0),
name="generator")
generator.allocate()
logger.debug("Parameters:\n" + pprint.pformat(
[(key, value.get_value().shape)
for key, value in Selector(generator).get_params().items()],
width=120))
if args.mode == "train":
rng = numpy.random.RandomState(1)
batch_size = 50
generator.push_initialization_config()
transition.weights_init = Orthogonal()
generator.initialize()
logger.debug("transition.weights_init={}".format(
transition.weights_init))
cost = generator.cost(tensor.lmatrix('x')).sum()
gh_model = GroundhogModel(generator, cost)
state = GroundhogState(args.prefix, batch_size,
learning_rate=0.0001).as_dict()
data = ChainIterator(rng, 100, batch_size)
trainer = SGD(gh_model, state, data)
main_loop = MainLoop(data, None, None, gh_model, trainer, state, None)
main_loop.main()
elif args.mode == "sample":
load_params(generator, args.prefix + "model.npz")
sample = ComputationGraph(
generator.generate(n_steps=args.steps, batch_size=1,
iterate=True)).function()
states, outputs, costs = [data[:, 0] for data in sample()]
numpy.set_printoptions(precision=3, suppress=True)
print("Generation cost:\n{}".format(costs.sum()))
freqs = numpy.bincount(outputs).astype(floatX)
freqs /= freqs.sum()
print("Frequencies:\n {} vs {}".format(freqs,
ChainIterator.equilibrium))
trans_freqs = numpy.zeros((num_states, num_states), dtype=floatX)
for a, b in zip(outputs, outputs[1:]):
trans_freqs[a, b] += 1
trans_freqs /= trans_freqs.sum(axis=1)[:, None]
print("Transition frequencies:\n{}\nvs\n{}".format(
trans_freqs, ChainIterator.trans_prob))
else:
assert False
def __init__(
self,
recordings_source,
labels_source,
eos_label,
num_features,
num_phonemes,
dim_dec,
dims_bidir,
dims_bottom,
enc_transition,
dec_transition,
use_states_for_readout,
attention_type,
lm=None,
character_map=None,
subsample=None,
dims_top=None,
prior=None,
conv_n=None,
bottom_activation=None,
post_merge_activation=None,
post_merge_dims=None,
dim_matcher=None,
embed_outputs=True,
dec_stack=1,
conv_num_filters=1,
data_prepend_eos=True,
energy_normalizer=None, # softmax is th edefault set in SequenceContentAndConvAttention
**kwargs):
if bottom_activation is None:
bottom_activation = Tanh()
if post_merge_activation is None:
post_merge_activation = Tanh()
super(SpeechRecognizer, self).__init__(**kwargs)
self.recordings_source = recordings_source
self.labels_source = labels_source
self.eos_label = eos_label
self.data_prepend_eos = data_prepend_eos
self.rec_weights_init = None
self.initial_states_init = None
self.enc_transition = enc_transition
self.dec_transition = dec_transition
self.dec_stack = dec_stack
bottom_activation = bottom_activation
post_merge_activation = post_merge_activation
if dim_matcher is None:
dim_matcher = dim_dec
# The bottom part, before BiRNN
if dims_bottom:
bottom = MLP([bottom_activation] * len(dims_bottom),
[num_features] + dims_bottom,
name="bottom")
else:
bottom = Identity(name='bottom')
# BiRNN
if not subsample:
subsample = [1] * len(dims_bidir)
encoder = Encoder(
self.enc_transition, dims_bidir,
dims_bottom[-1] if len(dims_bottom) else num_features, subsample)
# The top part, on top of BiRNN but before the attention
if dims_top:
top = MLP([Tanh()],
[2 * dims_bidir[-1]] + dims_top + [2 * dims_bidir[-1]],
name="top")
else:
top = Identity(name='top')
if dec_stack == 1:
transition = self.dec_transition(dim=dim_dec,
activation=Tanh(),
name="transition")
else:
transitions = [
self.dec_transition(dim=dim_dec,
activation=Tanh(),
name="transition_{}".format(trans_level))
for trans_level in xrange(dec_stack)
]
transition = RecurrentStack(transitions=transitions,
skip_connections=True)
# Choose attention mechanism according to the configuration
if attention_type == "content":
attention = SequenceContentAttention(
state_names=transition.apply.states,
attended_dim=2 * dims_bidir[-1],
match_dim=dim_matcher,
name="cont_att")
elif attention_type == "content_and_conv":
attention = SequenceContentAndConvAttention(
state_names=transition.apply.states,
conv_n=conv_n,
conv_num_filters=conv_num_filters,
attended_dim=2 * dims_bidir[-1],
match_dim=dim_matcher,
prior=prior,
energy_normalizer=energy_normalizer,
name="conv_att")
else:
raise ValueError(
"Unknown attention type {}".format(attention_type))
if embed_outputs:
feedback = LookupFeedback(num_phonemes + 1, dim_dec)
else:
feedback = OneOfNFeedback(num_phonemes + 1)
if lm:
# In case we use LM it is Readout that is responsible
# for normalization.
emitter = LMEmitter()
else:
emitter = SoftmaxEmitter(initial_output=num_phonemes,
name="emitter")
readout_config = dict(readout_dim=num_phonemes,
source_names=(transition.apply.states if
use_states_for_readout else []) +
[attention.take_glimpses.outputs[0]],
emitter=emitter,
feedback_brick=feedback,
name="readout")
if post_merge_dims:
readout_config['merged_dim'] = post_merge_dims[0]
readout_config['post_merge'] = InitializableSequence(
[
Bias(post_merge_dims[0]).apply,
post_merge_activation.apply,
MLP(
[post_merge_activation] *
(len(post_merge_dims) - 1) + [Identity()],
# MLP was designed to support Maxout is activation
# (because Maxout in a way is not one). However
# a single layer Maxout network works with the trick below.
# For deeper Maxout network one has to use the
# Sequence brick.
[
d //
getattr(post_merge_activation, 'num_pieces', 1)
for d in post_merge_dims
] + [num_phonemes]).apply,
],
name='post_merge')
readout = Readout(**readout_config)
language_model = None
if lm:
lm_weight = lm.pop('weight', 0.0)
normalize_am_weights = lm.pop('normalize_am_weights', True)
normalize_lm_weights = lm.pop('normalize_lm_weights', False)
normalize_tot_weights = lm.pop('normalize_tot_weights', False)
am_beta = lm.pop('am_beta', 1.0)
if normalize_am_weights + normalize_lm_weights + normalize_tot_weights < 1:
logger.warn(
"Beam search is prone to fail with no log-prob normalization"
)
language_model = LanguageModel(nn_char_map=character_map, **lm)
readout = ShallowFusionReadout(
lm_costs_name='lm_add',
lm_weight=lm_weight,
normalize_am_weights=normalize_am_weights,
normalize_lm_weights=normalize_lm_weights,
normalize_tot_weights=normalize_tot_weights,
am_beta=am_beta,
**readout_config)
generator = SequenceGenerator(readout=readout,
transition=transition,
attention=attention,
language_model=language_model,
name="generator")
# Remember child bricks
self.encoder = encoder
self.bottom = bottom
self.top = top
self.generator = generator
self.children = [encoder, top, bottom, generator]
# Create input variables
self.recordings = tensor.tensor3(self.recordings_source)
self.recordings_mask = tensor.matrix(self.recordings_source + "_mask")
self.labels = tensor.lmatrix(self.labels_source)
self.labels_mask = tensor.matrix(self.labels_source + "_mask")
self.batch_inputs = [
self.recordings, self.recordings_source, self.labels,
self.labels_mask
]
self.single_recording = tensor.matrix(self.recordings_source)
self.single_transcription = tensor.lvector(self.labels_source)
class Decoder(Initializable):
def __init__(self, vocab_size, embedding_dim, state_dim,
representation_dim, **kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
self.transition = GRUInitialState(
attended_dim=state_dim, dim=state_dim,
activation=Tanh(), name='decoder')
self.attention = SequenceContentAttention(
state_names=self.transition.apply.states,
attended_dim=representation_dim,
match_dim=state_dim, name="attention")
readout = Readout(
source_names=['states', 'feedback', self.attention.take_glimpses.outputs[0]],
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(initial_output=-1),
feedback_brick=LookupFeedbackWMT15(vocab_size, embedding_dim),
post_merge=InitializableFeedforwardSequence(
[Bias(dim=state_dim, name='maxout_bias').apply,
Maxout(num_pieces=2, name='maxout').apply,
Linear(input_dim=state_dim / 2, output_dim=embedding_dim,
use_bias=False, name='softmax0').apply,
Linear(input_dim=embedding_dim, name='softmax1').apply]),
merged_dim=state_dim)
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([name for name in self.transition.apply.sequences
if name != 'mask'], prototype=Linear())
)
self.children = [self.sequence_generator]
@application(inputs=['representation', 'source_sentence_mask',
'target_sentence_mask', 'target_sentence'],
outputs=['cost'])
def cost(self, representation, source_sentence_mask,
target_sentence, target_sentence_mask):
source_sentence_mask = source_sentence_mask.T
target_sentence = target_sentence.T
target_sentence_mask = target_sentence_mask.T
# Get the cost matrix
cost = self.sequence_generator.cost_matrix(
**{'mask': target_sentence_mask,
'outputs': target_sentence,
'attended': representation,
'attended_mask': source_sentence_mask}
)
return (cost * target_sentence_mask).sum() / target_sentence_mask.shape[1]
@application
def generate(self, source_sentence, representation):
return self.sequence_generator.generate(
n_steps=2 * source_sentence.shape[1],
batch_size=source_sentence.shape[0],
attended=representation,
attended_mask=tensor.ones(source_sentence.shape).T)
state_names = source_names,
state_dims = [hidden_size_recurrent],
attended_dim = context_size,
name = "attention")
#ipdb.set_trace()
# Verify source names
readout = Readout(
readout_dim = hidden_size_recurrent,
source_names =source_names + ['feedback'] + ['glimpses'],
emitter=gmm_emitter,
feedback_brick = feedback,
name="readout")
generator = SequenceGenerator(readout=readout,
transition=transition,
attention = attention,
name = "generator")
mlp_context = MLP(activations = activations_context,
dims = dims_context)
bricks = [mlp_context]
for brick in bricks:
brick.weights_init = IsotropicGaussian(0.01)
brick.biases_init = Constant(0.)
brick.initialize()
generator.weights_init = IsotropicGaussian(0.01)
generator.biases_init = Constant(0.)
generator.push_initialization_config()
def main(name, epochs, batch_size, learning_rate,
dim, mix_dim, old_model_name, max_length, bokeh, GRU, dropout,
depth, max_grad, step_method, epsilon, sample, skip, uniform, top):
#----------------------------------------------------------------------
datasource = name
def shnum(x):
""" Convert a positive float into a short tag-usable string
E.g.: 0 -> 0, 0.005 -> 53, 100 -> 1-2
"""
return '0' if x <= 0 else '%s%d' % (("%e"%x)[0], -np.floor(np.log10(x)))
jobname = "%s-%dX%dm%dd%dr%sb%de%s" % (datasource, depth, dim, mix_dim,
int(dropout*10),
shnum(learning_rate), batch_size,
shnum(epsilon))
if max_length != 600:
jobname += '-L%d'%max_length
if GRU:
jobname += 'g'
if max_grad != 5.:
jobname += 'G%g'%max_grad
if step_method != 'adam':
jobname += step_method
if skip:
jobname += 'D'
assert depth > 1
if top:
jobname += 'T'
assert depth > 1
if uniform > 0.:
jobname += 'u%d'%int(uniform*100)
if debug:
jobname += ".debug"
if sample:
print("Sampling")
else:
print("\nRunning experiment %s" % jobname)
if old_model_name:
print("starting from model %s"%old_model_name)
#----------------------------------------------------------------------
transitions = [GatedRecurrent(dim=dim) if GRU else LSTM(dim=dim)
for _ in range(depth)]
if depth > 1:
transition = RecurrentStack(transitions, name="transition",
fast=True, skip_connections=skip or top)
if skip:
source_names=['states'] + ['states_%d'%d for d in range(1,depth)]
else:
source_names=['states_%d'%(depth-1)]
else:
transition = transitions[0]
transition.name = "transition"
source_names=['states']
emitter = SketchEmitter(mix_dim=mix_dim,
epsilon=epsilon,
name="emitter")
readout = Readout(
readout_dim=emitter.get_dim('inputs'),
source_names=source_names,
emitter=emitter,
name="readout")
normal_inputs = [name for name in transition.apply.sequences
if 'mask' not in name]
fork = Fork(normal_inputs, prototype=Linear(use_bias=True))
generator = SequenceGenerator(readout=readout, transition=transition,
fork=fork)
# Initialization settings
if uniform > 0.:
generator.weights_init = Uniform(width=uniform*2.)
else:
generator.weights_init = OrthogonalGlorot()
generator.biases_init = Constant(0)
# Build the cost computation graph [steps, batch_size, 3]
x = T.tensor3('features', dtype=floatX)
if debug:
x.tag.test_value = np.ones((max_length,batch_size,3)).astype(floatX)
x = x[:max_length,:,:] # has to be after setting test_value
cost = generator.cost(x)
cost.name = "sequence_log_likelihood"
# Give an idea of what's going on
model = Model(cost)
params = model.get_params()
logger.info("Parameters:\n" +
pprint.pformat(
[(key, value.get_value().shape) for key, value
in params.items()],
width=120))
model_size = 0
for v in params.itervalues():
s = v.get_value().shape
model_size += s[0] * (s[1] if len(s) > 1 else 1)
logger.info("Total number of parameters %d"%model_size)
#------------------------------------------------------------
extensions = []
if old_model_name == 'continue':
extensions.append(LoadFromDump(jobname))
elif old_model_name:
# or you can just load the weights without state using:
old_params = LoadFromDump(old_model_name).manager.load_parameters()
model.set_param_values(old_params)
else:
# Initialize parameters
for brick in model.get_top_bricks():
brick.initialize()
if sample:
assert old_model_name and old_model_name != 'continue'
Sample(generator, steps=max_length, path=old_model_name).do(None)
exit(0)
#------------------------------------------------------------
# Define the training algorithm.
cg = ComputationGraph(cost)
if dropout > 0.:
from blocks.roles import INPUT, OUTPUT
dropout_target = VariableFilter(roles=[OUTPUT],
bricks=transitions,
name_regex='states')(cg.variables)
print('# dropout %d' % len(dropout_target))
cg = apply_dropout(cg, dropout_target, dropout)
opt_cost = cg.outputs[0]
else:
opt_cost = cost
if step_method == 'adam':
step_rule = Adam(learning_rate)
elif step_method == 'rmsprop':
step_rule = RMSProp(learning_rate, decay_rate=0.95)
elif step_method == 'adagrad':
step_rule = AdaGrad(learning_rate)
elif step_method == 'adadelta':
step_rule = AdaDelta()
elif step_method == 'scale':
step_rule = Scale(learning_rate)
else:
raise Exception('Unknown sttep method %s'%step_method)
step_rule = CompositeRule([StepClipping(max_grad), step_rule])
algorithm = GradientDescent(
cost=opt_cost, params=cg.parameters,
step_rule=step_rule)
#------------------------------------------------------------
observables = [cost]
# Fetch variables useful for debugging
(energies,) = VariableFilter(
applications=[generator.readout.readout],
name_regex="output")(cg.variables)
min_energy = named_copy(energies.min(), "min_energy")
max_energy = named_copy(energies.max(), "max_energy")
observables += [min_energy, max_energy]
# (activations,) = VariableFilter(
# applications=[generator.transition.apply],
# name=generator.transition.apply.states[0])(cg.variables)
# mean_activation = named_copy(abs(activations).mean(),
# "mean_activation")
# observables.append(mean_activation)
observables += [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"))
#------------------------------------------------------------
datasource_fname = os.path.join(fuel.config.data_path, datasource,
datasource+'.hdf5')
train_ds = H5PYDataset(datasource_fname, #max_length=max_length,
which_set='train', sources=('features',),
load_in_memory=True)
train_stream = DataStream(train_ds,
iteration_scheme=ShuffledScheme(
train_ds.num_examples, batch_size))
test_ds = H5PYDataset(datasource_fname, #max_length=max_length,
which_set='test', sources=('features',),
load_in_memory=True)
test_stream = DataStream(test_ds,
iteration_scheme=SequentialScheme(
test_ds.num_examples, batch_size))
train_stream = Mapping(train_stream, _transpose)
test_stream = Mapping(test_stream, _transpose)
def stream_stats(ds, label):
itr = ds.get_epoch_iterator(as_dict=True)
batch_count = 0
examples_count = 0
for batch in itr:
batch_count += 1
examples_count += batch['features'].shape[1]
print('%s #batch %d #examples %d' %
(label, batch_count, examples_count))
stream_stats(train_stream, 'train')
stream_stats(test_stream, 'test')
extensions += [Timing(every_n_batches=10),
TrainingDataMonitoring(
observables, prefix="train",
every_n_batches=10),
DataStreamMonitoring(
[cost], # without dropout
test_stream,
prefix="test",
on_resumption=True,
after_epoch=False, # by default this is True
every_n_batches=100),
# all monitored data is ready so print it...
# (next steps may take more time and we want to see the
# results as soon as possible so print as soon as you can)
Printing(every_n_batches=10),
# perform multiple dumps at different intervals
# so if one of them breaks (has nan) we can hopefully
# find a model from few batches ago in the other
Dump(jobname, every_n_batches=11),
Dump(jobname+'.test', every_n_batches=100),
Sample(generator, steps=max_length,
path=jobname+'.test',
every_n_batches=100),
ProgressBar(),
FinishAfter(after_n_epochs=epochs)
# This shows a way to handle NaN emerging during
# training: simply finish it.
.add_condition("after_batch", _is_nan),
]
if bokeh:
from blocks.extensions.plot import Plot
extensions.append(Plot(
'sketch',
channels=[
['cost'],]))
# Construct the main loop and start training!
main_loop = MainLoop(
model=model,
data_stream=train_stream,
algorithm=algorithm,
extensions=extensions
)
main_loop.run()
def main(mode, save_path, steps, num_batches, load_params):
chars = (list(string.ascii_uppercase) + list(range(10)) +
[' ', '.', ',', '\'', '"', '!', '?', '<UNK>'])
char_to_ind = {char: i for i, char in enumerate(chars)}
ind_to_char = {v: k for k, v in char_to_ind.iteritems()}
train_dataset = TextFile(['/Tmp/serdyuk/data/wsj_text_train'],
char_to_ind, bos_token=None, eos_token=None,
level='character')
valid_dataset = TextFile(['/Tmp/serdyuk/data/wsj_text_valid'],
char_to_ind, bos_token=None, eos_token=None,
level='character')
vocab_size = len(char_to_ind)
logger.info('Dictionary size: {}'.format(vocab_size))
if mode == 'continue':
continue_training(save_path)
return
elif mode == "sample":
main_loop = load(open(save_path, "rb"))
generator = main_loop.model.get_top_bricks()[-1]
sample = ComputationGraph(generator.generate(
n_steps=steps, batch_size=1, iterate=True)).get_theano_function()
states, outputs, costs = [data[:, 0] for data in sample()]
print("".join([ind_to_char[s] for s in outputs]))
numpy.set_printoptions(precision=3, suppress=True)
print("Generation cost:\n{}".format(costs.sum()))
freqs = numpy.bincount(outputs).astype(floatX)
freqs /= freqs.sum()
trans_freqs = numpy.zeros((vocab_size, vocab_size), dtype=floatX)
for a, b in zip(outputs, outputs[1:]):
trans_freqs[a, b] += 1
trans_freqs /= trans_freqs.sum(axis=1)[:, None]
return
# Experiment configuration
batch_size = 20
dim = 650
feedback_dim = 650
valid_stream = valid_dataset.get_example_stream()
valid_stream = Batch(valid_stream,
iteration_scheme=ConstantScheme(batch_size))
valid_stream = Padding(valid_stream)
valid_stream = Mapping(valid_stream, _transpose)
# Build the bricks and initialize them
transition = GatedRecurrent(name="transition", dim=dim,
activation=Tanh())
generator = SequenceGenerator(
Readout(readout_dim=vocab_size, source_names=transition.apply.states,
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(
vocab_size, feedback_dim, name='feedback'),
name="readout"),
transition,
weights_init=Uniform(std=0.04), biases_init=Constant(0),
name="generator")
generator.push_initialization_config()
transition.weights_init = Orthogonal()
transition.push_initialization_config()
generator.initialize()
# Build the cost computation graph.
features = tensor.lmatrix('features')
features_mask = tensor.matrix('features_mask')
cost_matrix = generator.cost_matrix(
features, mask=features_mask)
batch_cost = cost_matrix.sum()
cost = aggregation.mean(
batch_cost,
features.shape[1])
cost.name = "sequence_log_likelihood"
char_cost = aggregation.mean(
batch_cost, features_mask.sum())
char_cost.name = 'character_log_likelihood'
ppl = 2 ** (cost / numpy.log(2))
ppl.name = 'ppl'
bits_per_char = char_cost / tensor.log(2)
bits_per_char.name = 'bits_per_char'
length = features.shape[0]
length.name = 'length'
model = Model(batch_cost)
if load_params:
params = load_parameter_values(save_path)
model.set_parameter_values(params)
if mode == "train":
# Give an idea of what's going on.
logger.info("Parameters:\n" +
pprint.pformat(
[(key, value.get_value().shape) for key, value
in Selector(generator).get_parameters().items()],
width=120))
train_stream = train_dataset.get_example_stream()
train_stream = Mapping(train_stream, _truncate)
train_stream = Batch(train_stream,
iteration_scheme=ConstantScheme(batch_size))
train_stream = Padding(train_stream)
train_stream = Mapping(train_stream, _transpose)
parameters = model.get_parameter_dict()
maxnorm_subjects = VariableFilter(roles=[WEIGHT])(parameters.values())
algorithm = GradientDescent(
cost=batch_cost,
parameters=parameters.values(),
step_rule=CompositeRule([StepClipping(1000.),
AdaDelta(epsilon=1e-8) #, Restrict(VariableClipping(1.0, axis=0), maxnorm_subjects)
]))
ft = features[:6, 0]
ft.name = 'feature_example'
observables = [cost, ppl, char_cost, length, bits_per_char]
for name, param in parameters.items():
num_elements = numpy.product(param.get_value().shape)
norm = param.norm(2) / num_elements ** 0.5
grad_norm = algorithm.gradients[param].norm(2) / num_elements ** 0.5
step_norm = algorithm.steps[param].norm(2) / num_elements ** 0.5
stats = tensor.stack(norm, grad_norm, step_norm, step_norm / grad_norm)
stats.name = name + '_stats'
observables.append(stats)
track_the_best_bpc = TrackTheBest('valid_bits_per_char')
root_path, extension = os.path.splitext(save_path)
this_step_monitoring = TrainingDataMonitoring(
observables + [ft], prefix="this_step", after_batch=True)
average_monitoring = TrainingDataMonitoring(
observables + [algorithm.total_step_norm,
algorithm.total_gradient_norm],
prefix="average",
every_n_batches=10)
valid_monitoring = DataStreamMonitoring(
observables, prefix="valid",
every_n_batches=1500, before_training=False,
data_stream=valid_stream)
main_loop = MainLoop(
algorithm=algorithm,
data_stream=train_stream,
model=model,
extensions=[
this_step_monitoring,
average_monitoring,
valid_monitoring,
track_the_best_bpc,
Checkpoint(save_path, ),
Checkpoint(save_path,
every_n_batches=500,
save_separately=["model", "log"],
use_cpickle=True)
.add_condition(
['after_epoch'],
OnLogRecord(track_the_best_bpc.notification_name),
(root_path + "_best" + extension,)),
Timing(after_batch=True),
Printing(every_n_batches=10),
Plot(root_path,
[[average_monitoring.record_name(cost),
valid_monitoring.record_name(cost)],
[average_monitoring.record_name(algorithm.total_step_norm)],
[average_monitoring.record_name(algorithm.total_gradient_norm)],
[average_monitoring.record_name(ppl),
valid_monitoring.record_name(ppl)],
[average_monitoring.record_name(char_cost),
valid_monitoring.record_name(char_cost)],
[average_monitoring.record_name(bits_per_char),
valid_monitoring.record_name(bits_per_char)]],
every_n_batches=10)
])
main_loop.run()
elif mode == 'evaluate':
with open('/data/lisatmp3/serdyuk/wsj_lms/lms/wsj_trigram_with_initial_eos/lexicon.txt') as f:
raw_words = [line.split()[1:-1] for line in f.readlines()]
words = [[char_to_ind[c] if c in char_to_ind else char_to_ind['<UNK>'] for c in w]
for w in raw_words]
max_word_length = max([len(w) for w in words])
initial_states = tensor.matrix('init_states')
cost_matrix_step = generator.cost_matrix(features, mask=features_mask,
states=initial_states)
cg = ComputationGraph(cost_matrix_step)
states = cg.auxiliary_variables[-2]
compute_cost = theano.function([features, features_mask, initial_states],
[cost_matrix_step.sum(axis=0), states])
cost_matrix = generator.cost_matrix(features, mask=features_mask)
initial_cg = ComputationGraph(cost_matrix)
initial_states = initial_cg.auxiliary_variables[-2]
total_word_cost = 0
num_words = 0
examples = numpy.zeros((max_word_length + 1, len(words)),
dtype='int64')
all_masks = numpy.zeros((max_word_length + 1, len(words)),
dtype=floatX)
for i, word in enumerate(words):
examples[:len(word), i] = word
all_masks[:len(word), i] = 1.
single_space = numpy.array([char_to_ind[' ']])[:, None]
for batch in valid_stream.get_epoch_iterator():
for example, mask in equizip(batch[0].T, batch[1].T):
example = example[:(mask.sum())]
spc_inds = list(numpy.where(example == char_to_ind[" "])[0])
state = generator.transition.transition.initial_states_.get_value()[None, :]
for i, j in equizip([-1] + spc_inds, spc_inds + [-1]):
word = example[(i+1):j, None]
word_cost, states = compute_cost(
word, numpy.ones_like(word, dtype=floatX), state)
state = states[-1]
costs = numpy.exp(-compute_cost(
examples, all_masks, numpy.tile(state, [examples.shape[1], 1]))[0])
_, space_states = compute_cost(
single_space, numpy.ones_like(single_space, dtype=floatX), state)
state = space_states[-1]
word_prob = numpy.exp(-word_cost)
total_word_cost += word_cost + numpy.log(numpy.sum(costs))
num_words += 1
print(word_prob)
print(numpy.sum(costs))
print("Average cost", total_word_cost / num_words)
print("PPL", numpy.exp(total_word_cost / num_words))
print("Word-level perplexity")
print(total_word_cost / num_words)
else:
assert False
def __init__(self, config, vocab_size):
question = tensor.imatrix('question')
question_mask = tensor.imatrix('question_mask')
context = tensor.imatrix('context')
context_mask = tensor.imatrix('context_mask')
answer = tensor.ivector('answer')
candidates = tensor.imatrix('candidates')
candidates_mask = tensor.imatrix('candidates_mask')
bricks = []
question = question.dimshuffle(1, 0)
question_mask = question_mask.dimshuffle(1, 0)
context = context.dimshuffle(1, 0)
context_mask = context_mask.dimshuffle(1, 0)
# Embed questions and cntext
embed = LookupTable(vocab_size, config.embed_size, name='question_embed')
bricks.append(embed)
qembed = embed.apply(question)
cembed = embed.apply(context)
qlstms, qhidden_list = make_bidir_lstm_stack(qembed, config.embed_size, question_mask.astype(theano.config.floatX),
config.question_lstm_size, config.question_skip_connections, 'q')
clstms, chidden_list = make_bidir_lstm_stack(cembed, config.embed_size, context_mask.astype(theano.config.floatX),
config.ctx_lstm_size, config.ctx_skip_connections, 'ctx')
bricks = bricks + qlstms + clstms
# Calculate question encoding (concatenate layer1)
if config.question_skip_connections:
qenc_dim = 2*sum(config.question_lstm_size)
qenc = tensor.concatenate([h[-1,:,:] for h in qhidden_list], axis=1)
else:
qenc_dim = 2*config.question_lstm_size[-1]
qenc = tensor.concatenate([h[-1,:,:] for h in qhidden_list[-2:]], axis=1)
qenc.name = 'qenc'
# Calculate context encoding (concatenate layer1)
if config.ctx_skip_connections: #default yes
cenc_dim = 2*sum(config.ctx_lstm_size) #2 : fw & bw
cenc = tensor.concatenate(chidden_list, axis=2)
else:
cenc_dim = 2*config.ctx_lstm_size[-1]
cenc = tensor.concatenate(chidden_list[-2:], axis=2)
cenc.name = 'cenc'
# Attention mechanism MLP activation: Tanh, identity
attention_mlp = MLP(dims=config.attention_mlp_hidden + [1],
activations=config.attention_mlp_activations[1:] + [Identity()],
name='attention_mlp')
attention_qlinear = Linear(input_dim=qenc_dim, output_dim=config.attention_mlp_hidden[0], name='attq') #Wum
attention_clinear = Linear(input_dim=cenc_dim, output_dim=config.attention_mlp_hidden[0], use_bias=False, name='attc') # Wym
bricks += [attention_mlp, attention_qlinear, attention_clinear]
layer1 = Tanh().apply(attention_clinear.apply(cenc.reshape((cenc.shape[0]*cenc.shape[1], cenc.shape[2])))
.reshape((cenc.shape[0],cenc.shape[1],config.attention_mlp_hidden[0]))
+ attention_qlinear.apply(qenc)[None, :, :])
layer1.name = 'layer1'
att_weights = attention_mlp.apply(layer1.reshape((layer1.shape[0]*layer1.shape[1], layer1.shape[2])))
att_weights.name = 'att_weights_0'
att_weights = att_weights.reshape((layer1.shape[0], layer1.shape[1]))
att_weights.name = 'att_weights'
attended = tensor.sum(cenc * tensor.nnet.softmax(att_weights.T).T[:, :, None], axis=0)
attended.name = 'attended'
print("attended shape: %d" %attended.shape)
dimension = qenc_dim + cenc_dim
transition = SimpleRecurrent(activation=Tanh(),dim=dimension, name="transition")
readout = Readout(
readout_dim=vocab_size,
source_names=[transition.apply.states[0]],
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(vocab_size, dimension),
name="readout")
generator = SequenceGenerator(
readout=readout, transition=transition,
name="generator")
self.generator = generator
bricks += [generator]
cost = self.generator.cost()
# Now we can calculate our output
out_mlp = MLP(dims=[cenc_dim + qenc_dim] + config.out_mlp_hidden + [config.n_entities],
activations=config.out_mlp_activations + [Identity()],
name='out_mlp')
bricks += [out_mlp]
probs = out_mlp.apply(tensor.concatenate([attended, qenc], axis=1))
probs.name = 'probs'
is_candidate = tensor.eq(tensor.arange(config.n_entities, dtype='int32')[None, None, :],
tensor.switch(candidates_mask, candidates, -tensor.ones_like(candidates))[:, :, None]).sum(axis=1)
probs = tensor.switch(is_candidate, probs, -1000 * tensor.ones_like(probs))
# Calculate prediction, cost and error rate
pred = probs.argmax(axis=1)
cost = Softmax().categorical_cross_entropy(answer, probs).mean()
error_rate = tensor.neq(answer, pred).mean()
# Apply dropout
cg = ComputationGraph([cost, error_rate])
if config.w_noise > 0:
noise_vars = VariableFilter(roles=[WEIGHT])(cg)
cg = apply_noise(cg, noise_vars, config.w_noise)
if config.dropout > 0:
cg = apply_dropout(cg, qhidden_list + chidden_list, config.dropout)
[cost_reg, error_rate_reg] = cg.outputs
# Other stuff
cost_reg.name = cost.name = 'cost'
error_rate_reg.name = error_rate.name = 'error_rate'
self.sgd_cost = cost_reg
self.monitor_vars = [[cost_reg], [error_rate_reg]]
self.monitor_vars_valid = [[cost], [error_rate]]
# Initialize bricks
for brick in bricks:
brick.weights_init = config.weights_init
brick.biases_init = config.biases_init
brick.initialize()
def main():
logging.basicConfig(
level=logging.DEBUG,
format="%(asctime)s: %(name)s: %(levelname)s: %(message)s")
parser = argparse.ArgumentParser(
"Case study of generating a Markov chain with RNN.",
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument(
"mode", choices=["train", "sample"],
help="The mode to run. Use `train` to train a new model"
" and `sample` to sample a sequence generated by an"
" existing one.")
parser.add_argument(
"prefix", default="sine",
help="The prefix for model, timing and state files")
parser.add_argument(
"--steps", type=int, default=100,
help="Number of steps to plot")
args = parser.parse_args()
dim = 10
num_states = ChainIterator.num_states
feedback_dim = 8
transition = GatedRecurrent(name="transition", activation=Tanh(), dim=dim)
generator = SequenceGenerator(
LinearReadout(readout_dim=num_states, source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedbacker=LookupFeedback(
num_states, feedback_dim, name='feedback'),
name="readout"),
transition,
weights_init=IsotropicGaussian(0.01), biases_init=Constant(0),
name="generator")
generator.allocate()
logger.debug("Parameters:\n" +
pprint.pformat(
[(key, value.get_value().shape) for key, value
in Selector(generator).get_params().items()],
width=120))
if args.mode == "train":
rng = numpy.random.RandomState(1)
batch_size = 50
generator.push_initialization_config()
transition.weights_init = Orthogonal()
generator.initialize()
logger.debug("transition.weights_init={}".format(
transition.weights_init))
cost = generator.cost(tensor.lmatrix('x')).sum()
gh_model = GroundhogModel(generator, cost)
state = GroundhogState(args.prefix, batch_size,
learning_rate=0.0001).as_dict()
data = ChainIterator(rng, 100, batch_size)
trainer = SGD(gh_model, state, data)
main_loop = MainLoop(data, None, None, gh_model, trainer, state, None)
main_loop.main()
elif args.mode == "sample":
load_params(generator, args.prefix + "model.npz")
sample = ComputationGraph(generator.generate(
n_steps=args.steps, batch_size=1, iterate=True)).function()
states, outputs, costs = [data[:, 0] for data in sample()]
numpy.set_printoptions(precision=3, suppress=True)
print("Generation cost:\n{}".format(costs.sum()))
freqs = numpy.bincount(outputs).astype(floatX)
freqs /= freqs.sum()
print("Frequencies:\n {} vs {}".format(freqs,
ChainIterator.equilibrium))
trans_freqs = numpy.zeros((num_states, num_states), dtype=floatX)
for a, b in zip(outputs, outputs[1:]):
trans_freqs[a, b] += 1
trans_freqs /= trans_freqs.sum(axis=1)[:, None]
print("Transition frequencies:\n{}\nvs\n{}".format(
trans_freqs, ChainIterator.trans_prob))
else:
assert False
source_names=['states']
readout = Readout(
readout_dim = hidden_size_recurrent,
source_names =source_names,
emitter=emitter,
feedback_brick = feedback,
name="readout")
attention = SimpleSequenceAttention(
state_names = source_names,
state_dims = [hidden_size_recurrent],
attended_dim = context_size)
generator = SequenceGenerator(readout=readout,
transition=transition,
attention = attention,
name = "generator")
generator.weights_init = IsotropicGaussian(0.01)
generator.biases_init = Constant(0.)
generator.initialize()
mlp_context.weights_init = IsotropicGaussian(0.01)
mlp_context.biases_init = Constant(0.)
mlp_context.initialize()
#ipdb.set_trace()
cost_matrix = generator.cost_matrix(x, x_mask,
attended = mlp_context.apply(context))
cost = cost_matrix.sum()/x_mask.sum()
cost.name = "sequence_log_likelihood"
def main():
logging.basicConfig(
level=logging.DEBUG,
format="%(asctime)s: %(name)s: %(levelname)s: %(message)s")
parser = argparse.ArgumentParser(
"Case study of language modeling with RNN",
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument(
"mode", choices=["train", "sample"],
help="The mode to run. Use `train` to train a new model"
" and `sample` to sample a sequence generated by an"
" existing one.")
parser.add_argument(
"prefix", default="sine",
help="The prefix for model, timing and state files")
parser.add_argument(
"state", nargs="?", default="",
help="Changes to Groundhog state")
parser.add_argument("--path", help="Path to a language dataset")
parser.add_argument("--dict", help="Path to the dataset dictionary")
parser.add_argument("--restart", help="Start anew")
parser.add_argument(
"--reset", action="store_true", default=False,
help="Reset the hidden state between batches")
parser.add_argument(
"--steps", type=int, default=100,
help="Number of steps to plot for the 'sample' mode"
" OR training sequence length for the 'train' mode.")
args = parser.parse_args()
logger.debug("Args:\n" + str(args))
dim = 200
num_chars = 50
transition = GatedRecurrent(
name="transition", activation=Tanh(), dim=dim,
weights_init=Orthogonal())
generator = SequenceGenerator(
LinearReadout(readout_dim=num_chars, source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedbacker=LookupFeedback(
num_chars, dim, name='feedback'),
name="readout"),
transition,
weights_init=IsotropicGaussian(0.01), biases_init=Constant(0),
name="generator")
generator.allocate()
logger.debug("Parameters:\n" +
pprint.pformat(
[(key, value.get_value().shape) for key, value
in Selector(generator).get_params().items()],
width=120))
if args.mode == "train":
batch_size = 1
seq_len = args.steps
generator.initialize()
# Build cost computation graph that uses the saved hidden states.
# An issue: for Groundhog this is completely transparent, that's
# why it does not carry the hidden state over the period when
# validation in done. We should find a way to fix in the future.
x = tensor.lmatrix('x')
init_states = shared_floatx_zeros((batch_size, dim),
name='init_states')
reset = tensor.scalar('reset')
cost = ComputationGraph(
generator.cost(x, states=init_states * reset).sum())
# TODO: better search routine
states = [v for v in cost.variables
if hasattr(v.tag, 'application_call')
and v.tag.application_call.brick == generator.transition
and (v.tag.application_call.application ==
generator.transition.apply)
and v.tag.role == VariableRole.OUTPUT
and v.tag.name == 'states']
assert len(states) == 1
states = states[0]
gh_model = GroundhogModel(generator, cost)
gh_model.properties.append(
('bpc', cost.outputs[0] * numpy.log(2) / seq_len))
gh_model.properties.append(('mean_init_state', init_states.mean()))
gh_model.properties.append(('reset', reset))
if not args.reset:
gh_model.updates.append((init_states, states[-1]))
state = GroundhogState(args.prefix, batch_size,
learning_rate=0.0001).as_dict()
changes = eval("dict({})".format(args.state))
state.update(changes)
def output_format(x, y, reset):
return dict(x=x[:, None], reset=reset)
train, valid, test = [
LMIterator(batch_size=batch_size,
use_infinite_loop=mode == 'train',
path=args.path,
seq_len=seq_len,
mode=mode,
chunks='chars',
output_format=output_format,
can_fit=True)
for mode in ['train', 'valid', 'test']]
trainer = SGD(gh_model, state, train)
state['on_nan'] = 'warn'
state['cutoff'] = 1.
main_loop = MainLoop(train, valid, None, gh_model,
trainer, state, None)
if not args.restart:
main_loop.load()
main_loop.main()
elif args.mode == "sample":
load_params(generator, args.prefix + "model.npz")
chars = numpy.load(args.dict)['unique_chars']
sample = ComputationGraph(generator.generate(
n_steps=args.steps, batch_size=10, iterate=True)).function()
states, outputs, costs = sample()
for i in range(10):
print("Generation cost: {}".format(costs[:, i].sum()))
print("".join([chars[o] for o in outputs[:, i]]))
else:
assert False
from play.bricks.recurrent import SimpleSequenceAttention
attention = SimpleSequenceAttention(
state_names=source_names, state_dims=[hidden_size_recurrent], attended_dim=context_size, name="attention"
)
readout = Readout(
readout_dim=hidden_size_recurrent,
source_names=source_names + ["feedback"] + ["glimpses"],
emitter=emitter,
feedback_brick=feedback,
name="readout",
)
generator = SequenceGenerator(readout=readout, transition=transition, attention=attention, name="generator")
generator.weights_init = IsotropicGaussian(0.01)
generator.biases_init = Constant(0.0)
generator.push_initialization_config()
generator.transition.biases_init = IsotropicGaussian(0.01, 1)
generator.transition.push_initialization_config()
generator.initialize()
lookup.weights_init = IsotropicGaussian(0.001)
lookup.biases_init = Constant(0.0)
lookup.initialize()
# states = {}
def test_with_attention():
"""Test a sequence generator with continuous outputs and attention."""
rng = numpy.random.RandomState(1234)
inp_dim = 2
inp_len = 10
attended_dim = 3
attended_len = 11
batch_size = 4
n_steps = 30
# For values
def rand(size):
return rng.uniform(size=size).astype(floatX)
# For masks
def generate_mask(length, batch_size):
mask = numpy.ones((length, batch_size), dtype=floatX)
# To make it look like read data
for i in range(batch_size):
mask[1 + rng.randint(0, length - 1):, i] = 0.0
return mask
output_vals = rand((inp_len, batch_size, inp_dim))
output_mask_vals = generate_mask(inp_len, batch_size)
attended_vals = rand((attended_len, batch_size, attended_dim))
attended_mask_vals = generate_mask(attended_len, batch_size)
transition = TestTransition(
dim=inp_dim, attended_dim=attended_dim, activation=Identity())
attention = SequenceContentAttention(
state_names=transition.apply.states, match_dim=inp_dim)
generator = SequenceGenerator(
Readout(
readout_dim=inp_dim,
source_names=[transition.apply.states[0],
attention.take_glimpses.outputs[0]],
emitter=TestEmitter()),
transition=transition,
attention=attention,
weights_init=IsotropicGaussian(0.1), biases_init=Constant(0),
add_contexts=False, seed=1234)
generator.initialize()
# Test 'cost_matrix' method
attended = tensor.tensor3("attended")
attended_mask = tensor.matrix("attended_mask")
outputs = tensor.tensor3('outputs')
mask = tensor.matrix('mask')
costs = generator.cost_matrix(outputs, mask,
attended=attended,
attended_mask=attended_mask)
costs_vals = costs.eval({outputs: output_vals,
mask: output_mask_vals,
attended: attended_vals,
attended_mask: attended_mask_vals})
assert costs_vals.shape == (inp_len, batch_size)
assert_allclose(costs_vals.sum(), 13.5042, rtol=1e-5)
# Test `generate` method
results = (
generator.generate(n_steps=n_steps, batch_size=attended.shape[1],
attended=attended, attended_mask=attended_mask))
assert len(results) == 5
states_vals, outputs_vals, glimpses_vals, weights_vals, costs_vals = (
theano.function([attended, attended_mask], results)
(attended_vals, attended_mask_vals))
assert states_vals.shape == (n_steps, batch_size, inp_dim)
assert states_vals.shape == outputs_vals.shape
assert glimpses_vals.shape == (n_steps, batch_size, attended_dim)
assert weights_vals.shape == (n_steps, batch_size, attended_len)
assert costs_vals.shape == (n_steps, batch_size)
assert_allclose(states_vals.sum(), 23.4172, rtol=1e-5)
# There is no generation cost in this case, since generation is
# deterministic
assert_allclose(costs_vals.sum(), 0.0, rtol=1e-5)
assert_allclose(weights_vals.sum(), 120.0, rtol=1e-5)
assert_allclose(glimpses_vals.sum(), 199.2402, rtol=1e-5)
assert_allclose(outputs_vals.sum(), -11.6008, rtol=1e-5)
class Decoder(Initializable):
def __init__(self, vocab_size, embedding_dim, state_dim,
representation_dim, **kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
readout = Readout(
source_names=['states', 'feedback', 'readout_context'],
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(),
feedback_brick=LookupFeedback(vocab_size, embedding_dim),
post_merge=InitializableFeedforwardSequence(
[Bias(dim=1000).apply,
Maxout(num_pieces=2).apply,
Linear(input_dim=state_dim / 2, output_dim=100,
use_bias=False).apply,
Linear(input_dim=100).apply]),
merged_dim=1000)
self.transition = GatedRecurrentWithContext(Tanh(), dim=state_dim,
name='decoder')
# Readout will apply the linear transformation to 'readout_context'
# with a Merge brick, so no need to fork it here
self.fork = Fork([name for name in
self.transition.apply.contexts +
self.transition.apply.states
if name != 'readout_context'], prototype=Linear())
self.tanh = Tanh()
self.sequence_generator = SequenceGenerator(
readout=readout, transition=self.transition,
fork_inputs=[name for name in self.transition.apply.sequences
if name != 'mask'],
)
self.children = [self.fork, self.sequence_generator, self.tanh]
def _push_allocation_config(self):
self.fork.input_dim = self.representation_dim
self.fork.output_dims = [self.state_dim
for _ in self.fork.output_names]
@application(inputs=['representation', 'target_sentence_mask',
'target_sentence'], outputs=['cost'])
def cost(self, representation, target_sentence, target_sentence_mask):
target_sentence = target_sentence.dimshuffle(1, 0)
target_sentence_mask = target_sentence_mask.T
# The initial state and contexts, all functions of the representation
contexts = {key: value.dimshuffle('x', 0, 1)
if key not in self.transition.apply.states else value
for key, value
in self.fork.apply(representation, as_dict=True).items()}
contexts['states'] = self.tanh.apply(contexts['states'])
cost = self.sequence_generator.cost(**merge(
contexts, {'mask': target_sentence_mask,
'outputs': target_sentence,
'readout_context': representation.dimshuffle('x', 0, 1)}
))
return (cost * target_sentence_mask).sum() / target_sentence_mask.shape[1]
def test_integer_sequence_generator():
"""Test a sequence generator with integer outputs.
Such sequence generators can be used to e.g. model language.
"""
rng = numpy.random.RandomState(1234)
readout_dim = 5
feedback_dim = 3
dim = 20
batch_size = 30
n_steps = 10
transition = GatedRecurrent(dim=dim, activation=Tanh(),
weights_init=Orthogonal())
generator = SequenceGenerator(
Readout(readout_dim=readout_dim, source_names=["states"],
emitter=SoftmaxEmitter(theano_seed=1234),
feedback_brick=LookupFeedback(readout_dim,
feedback_dim)),
transition,
weights_init=IsotropicGaussian(0.1), biases_init=Constant(0),
seed=1234)
generator.initialize()
# Test 'cost_matrix' method
y = tensor.lmatrix('y')
mask = tensor.matrix('mask')
costs = generator.cost_matrix(y, mask)
assert costs.ndim == 2
costs_fun = theano.function([y, mask], [costs])
y_test = rng.randint(readout_dim, size=(n_steps, batch_size))
m_test = numpy.ones((n_steps, batch_size), dtype=floatX)
costs_val = costs_fun(y_test, m_test)[0]
assert costs_val.shape == (n_steps, batch_size)
assert_allclose(costs_val.sum(), 482.827, rtol=1e-5)
# Test 'cost' method
cost = generator.cost(y, mask)
assert cost.ndim == 0
cost_val = theano.function([y, mask], [cost])(y_test, m_test)
assert_allclose(cost_val, 16.0942, rtol=1e-5)
# Test 'AUXILIARY' variable 'per_sequence_element' in 'cost' method
cg = ComputationGraph([cost])
var_filter = VariableFilter(roles=[AUXILIARY])
aux_var_name = '_'.join([generator.name, generator.cost.name,
'per_sequence_element'])
cost_per_el = [el for el in var_filter(cg.variables)
if el.name == aux_var_name][0]
assert cost_per_el.ndim == 0
cost_per_el_val = theano.function([y, mask], [cost_per_el])(y_test, m_test)
assert_allclose(cost_per_el_val, 1.60942, rtol=1e-5)
# Test generate
states, outputs, costs = generator.generate(
iterate=True, batch_size=batch_size, n_steps=n_steps)
cg = ComputationGraph(states + outputs + costs)
states_val, outputs_val, costs_val = theano.function(
[], [states, outputs, costs],
updates=cg.updates)()
assert states_val.shape == (n_steps, batch_size, dim)
assert outputs_val.shape == (n_steps, batch_size)
assert outputs_val.dtype == 'int64'
assert costs_val.shape == (n_steps, batch_size)
assert_allclose(states_val.sum(), -17.91811, rtol=1e-5)
assert_allclose(costs_val.sum(), 482.863, rtol=1e-5)
assert outputs_val.sum() == 630
# Test masks agnostic results of cost
cost1 = costs_fun([[1], [2]], [[1], [1]])[0]
cost2 = costs_fun([[3, 1], [4, 2], [2, 0]],
[[1, 1], [1, 1], [1, 0]])[0]
assert_allclose(cost1.sum(), cost2[:, 1].sum(), rtol=1e-5)
lstm1 = LSTM(dim=lstm_dim, use_bias=False, weights_init=Orthogonal())
lstm2 = LSTM(dim=lstm_dim, use_bias=False, weights_init=Orthogonal())
rnn = RecurrentStack([lstm1, lstm2], name="transition")
readout = Readout(readout_dim=alphabet_size,
source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(alphabet_size,
feedback_dim=alphabet_size,
name="feedback"),
name="readout")
seq_gen = SequenceGenerator(readout=readout,
transition=rnn,
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(0),
name="generator")
seq_gen.push_initialization_config()
rnn.weights_init = Orthogonal()
seq_gen.initialize()
# z markov_tutorial
x = tensor.lvector('features')
x = x.reshape((x.shape[0], 1))
cost = aggregation.mean(seq_gen.cost_matrix(x[:, :]).sum(), x.shape[1])
cost.name = "negative log-likelihood"
cost_cg = ComputationGraph(cost)
print VariableFilter(roles=[WEIGHT])(cost_cg.variables)
def test_attention_transition():
inp_dim = 2
inp_len = 10
attended_dim = 3
attended_len = 11
batch_size = 4
n_steps = 30
transition = TestTransition(dim=inp_dim,
attended_dim=attended_dim,
name="transition")
attention = SequenceContentAttention(transition.apply.states,
match_dim=inp_dim,
name="attention")
mixer = Mixer(
[name for name in transition.apply.sequences if name != 'mask'],
attention.take_look.outputs[0],
name="mixer")
att_trans = AttentionTransition(transition,
attention,
mixer,
name="att_trans")
att_trans.weights_init = IsotropicGaussian(0.01)
att_trans.biases_init = Constant(0)
att_trans.initialize()
attended = tensor.tensor3("attended")
attended_mask = tensor.matrix("attended_mask")
inputs = tensor.tensor3("inputs")
inputs_mask = tensor.matrix("inputs_mask")
states, glimpses, weights = att_trans.apply(input_=inputs,
mask=inputs_mask,
attended=attended,
attended_mask=attended_mask)
assert states.ndim == 3
assert glimpses.ndim == 3
assert weights.ndim == 3
input_vals = numpy.zeros((inp_len, batch_size, inp_dim), dtype=floatX)
input_mask_vals = numpy.ones((inp_len, batch_size), dtype=floatX)
attended_vals = numpy.zeros((attended_len, batch_size, attended_dim),
dtype=floatX)
attended_mask_vals = numpy.ones((attended_len, batch_size), dtype=floatX)
func = theano.function([inputs, inputs_mask, attended, attended_mask],
[states, glimpses, weights])
states_vals, glimpses_vals, weight_vals = func(input_vals, input_mask_vals,
attended_vals,
attended_mask_vals)
assert states_vals.shape == input_vals.shape
assert glimpses_vals.shape == (inp_len, batch_size, attended_dim)
assert weight_vals.shape == (inp_len, batch_size, attended_len)
# Test SequenceGenerator using AttentionTransition
generator = SequenceGenerator(LinearReadout(
readout_dim=inp_dim,
source_names=["state"],
emitter=TestEmitter(name="emitter"),
name="readout"),
transition=transition,
attention=attention,
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(0),
name="generator")
outputs = tensor.tensor3('outputs')
costs = generator.cost(outputs,
attended=attended,
attended_mask=attended_mask)
costs_vals = costs.eval({
outputs: input_vals,
attended: attended_vals,
attended_mask: attended_mask_vals
})
assert costs_vals.shape == (inp_len, batch_size)
results = (generator.generate(n_steps=n_steps,
batch_size=attended.shape[1],
attended=attended,
attended_mask=attended_mask))
assert len(results) == 5
states_vals, outputs_vals, glimpses_vals, weights_vals, costs_vals = (
theano.function([attended, attended_mask],
results)(attended_vals, attended_mask_vals))
assert states_vals.shape == (n_steps, batch_size, inp_dim)
assert states_vals.shape == outputs_vals.shape
assert glimpses_vals.shape == (n_steps, batch_size, attended_dim)
assert weights_vals.shape == (n_steps, batch_size, attended_len)
assert costs_vals.shape == (n_steps, batch_size)
class PyramidLayer(Initializable):
"""Basic unit for the pyramid model.
"""
def __init__(self,
batch_size,
frame_size,
k,
depth,
size,
**kwargs):
super(PyramidLayer, self).__init__(**kwargs)
target_size = frame_size * k
depth_x = depth
hidden_size_mlp_x = 32*size
depth_transition = depth-1
depth_theta = depth
hidden_size_mlp_theta = 32*size
hidden_size_recurrent = 32*size*3
depth_context = depth
hidden_size_mlp_context = 32*size
context_size = 32*size
activations_x = [Rectifier()]*depth_x
dims_x = [frame_size] + [hidden_size_mlp_x]*(depth_x-1) + \
[4*hidden_size_recurrent]
activations_theta = [Rectifier()]*depth_theta
dims_theta = [hidden_size_recurrent] + \
[hidden_size_mlp_theta]*depth_theta
activations_context = [Rectifier()]*depth_context
dims_context = [frame_size] + [hidden_size_mlp_context]*(depth_context-1) + \
[context_size]
mlp_x = MLP(activations = activations_x,
dims = dims_x,
name = "mlp_x")
feedback = DeepTransitionFeedback(mlp = mlp_x)
transition = [GatedRecurrent(dim=hidden_size_recurrent,
use_bias = True,
name = "gru_{}".format(i) ) for i in range(depth_transition)]
transition = RecurrentStack( transition,
name="transition", skip_connections = True)
self.transition = transition
mlp_theta = MLP( activations = activations_theta,
dims = dims_theta,
name = "mlp_theta")
mlp_gmm = GMMMLP(mlp = mlp_theta,
dim = target_size,
k = k,
const = 0.00001,
name = "gmm_wrap")
gmm_emitter = GMMEmitter(gmmmlp = mlp_gmm,
output_size = frame_size, k = k)
source_names = [name for name in transition.apply.states if 'states' in name]
attention = SimpleSequenceAttention(
state_names = source_names,
state_dims = [hidden_size_recurrent],
attended_dim = context_size,
name = "attention")
#ipdb.set_trace()
# Verify source names
readout = Readout(
readout_dim = hidden_size_recurrent,
source_names =source_names + ['feedback'] + ['glimpses'],
emitter=gmm_emitter,
feedback_brick = feedback,
name="readout")
self.generator = SequenceGenerator(readout=readout,
transition=transition,
attention = attention,
name = "generator")
self.mlp_context = MLP(activations = activations_context,
dims = dims_context)
self.children = [self.generator, self.mlp_context]
self.final_states = []
def monitoring_vars(self, cg):
readout = self.generator.readout
readouts = VariableFilter( applications = [readout.readout],
name_regex = "output")(cg.variables)[0]
mu, sigma, coeff = readout.emitter.components(readouts)
min_sigma = sigma.min().copy(name="sigma_min")
mean_sigma = sigma.mean().copy(name="sigma_mean")
max_sigma = sigma.max().copy(name="sigma_max")
min_mu = mu.min().copy(name="mu_min")
mean_mu = mu.mean().copy(name="mu_mean")
max_mu = mu.max().copy(name="mu_max")
monitoring_vars = [mean_sigma, min_sigma,
min_mu, max_mu, mean_mu, max_sigma]
return monitoring_vars
@application
def cost(self, x, context, **kwargs):
cost_matrix = self.generator.cost_matrix(
x, attended=self.mlp_context.apply(context),
**kwargs)
return cost_matrix.mean()
@application
def generate(context):
return self.generator.generate(
attended = self.mlp_context.apply(context),
n_steps = context.shape[0],
batch_size = context.shape[1],
iterate = True)
mlp_gmm = GMMMLP(mlp=mlp_theta, dim=target_size, k=k, const=0.00001)
emitter = GMMEmitter(gmmmlp=mlp_gmm,
output_size=frame_size,
k=k,
name="emitter")
source_names = [name for name in transition.apply.states if 'states' in name]
readout = Readout(readout_dim=hidden_size_recurrent,
source_names=source_names,
emitter=emitter,
feedback_brick=feedback,
name="readout")
generator = SequenceGenerator(readout=readout,
transition=transition,
name="generator")
generator.weights_init = IsotropicGaussian(0.01)
generator.biases_init = Constant(0.)
generator.push_initialization_config()
generator.transition.biases_init = IsotropicGaussian(0.01, 1)
generator.transition.push_initialization_config()
generator.initialize()
states = {}
states = generator.transition.apply.outputs
states = {
def __init__(self,
batch_size,
frame_size,
k,
depth,
size,
**kwargs):
super(PyramidLayer, self).__init__(**kwargs)
target_size = frame_size * k
depth_x = depth
hidden_size_mlp_x = 32*size
depth_transition = depth-1
depth_theta = depth
hidden_size_mlp_theta = 32*size
hidden_size_recurrent = 32*size*3
depth_context = depth
hidden_size_mlp_context = 32*size
context_size = 32*size
activations_x = [Rectifier()]*depth_x
dims_x = [frame_size] + [hidden_size_mlp_x]*(depth_x-1) + \
[4*hidden_size_recurrent]
activations_theta = [Rectifier()]*depth_theta
dims_theta = [hidden_size_recurrent] + \
[hidden_size_mlp_theta]*depth_theta
activations_context = [Rectifier()]*depth_context
dims_context = [frame_size] + [hidden_size_mlp_context]*(depth_context-1) + \
[context_size]
mlp_x = MLP(activations = activations_x,
dims = dims_x,
name = "mlp_x")
feedback = DeepTransitionFeedback(mlp = mlp_x)
transition = [GatedRecurrent(dim=hidden_size_recurrent,
use_bias = True,
name = "gru_{}".format(i) ) for i in range(depth_transition)]
transition = RecurrentStack( transition,
name="transition", skip_connections = True)
self.transition = transition
mlp_theta = MLP( activations = activations_theta,
dims = dims_theta,
name = "mlp_theta")
mlp_gmm = GMMMLP(mlp = mlp_theta,
dim = target_size,
k = k,
const = 0.00001,
name = "gmm_wrap")
gmm_emitter = GMMEmitter(gmmmlp = mlp_gmm,
output_size = frame_size, k = k)
source_names = [name for name in transition.apply.states if 'states' in name]
attention = SimpleSequenceAttention(
state_names = source_names,
state_dims = [hidden_size_recurrent],
attended_dim = context_size,
name = "attention")
#ipdb.set_trace()
# Verify source names
readout = Readout(
readout_dim = hidden_size_recurrent,
source_names =source_names + ['feedback'] + ['glimpses'],
emitter=gmm_emitter,
feedback_brick = feedback,
name="readout")
self.generator = SequenceGenerator(readout=readout,
transition=transition,
attention = attention,
name = "generator")
self.mlp_context = MLP(activations = activations_context,
dims = dims_context)
self.children = [self.generator, self.mlp_context]
self.final_states = []
def __init__(self,
vocab_size,
embedding_dim,
state_dim,
att_dim,
maxout_dim,
representation_dim,
attention_strategy='content',
attention_sources='s',
readout_sources='sfa',
memory='none',
memory_size=500,
seq_len=50,
init_strategy='last',
theano_seed=None,
**kwargs):
"""Creates a new decoder brick without embedding.
Args:
vocab_size (int): Target language vocabulary size
embedding_dim (int): Size of feedback embedding layer
state_dim (int): Number of hidden units
att_dim (int): Size of attention match vector
maxout_dim (int): Size of maxout layer
representation_dim (int): Dimension of source annotations
attention_strategy (string): Which attention should be used
cf. ``_initialize_attention``
attention_sources (string): Defines the sources used by the
attention model 's' for decoder
states, 'f' for feedback
readout_sources (string): Defines the sources used in the
readout network. 's' for decoder
states, 'f' for feedback, 'a' for
attention (context vector)
memory (string): Which external memory should be used
(cf. ``_initialize_attention``)
memory_size (int): Size of the external memory structure
seq_len (int): Maximum sentence length
init_strategy (string): How to initialize the RNN state
(cf. ``GRUInitialState``)
theano_seed: Random seed
"""
super(NoLookupDecoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
self.theano_seed = theano_seed
# Initialize gru with special initial state
self.transition = GRUInitialState(attended_dim=state_dim,
init_strategy=init_strategy,
dim=state_dim,
activation=Tanh(),
name='decoder')
# Initialize the attention mechanism
att_dim = att_dim if att_dim > 0 else state_dim
self.attention, src_names = _initialize_attention(
attention_strategy, seq_len, self.transition, representation_dim,
att_dim, attention_sources, readout_sources, memory, memory_size)
# Initialize the readout, note that SoftmaxEmitter emits -1 for
# initial outputs which is used by LookupFeedBackWMT15
maxout_dim = maxout_dim if maxout_dim > 0 else state_dim
readout = Readout(
source_names=src_names,
readout_dim=embedding_dim,
emitter=NoLookupEmitter(initial_output=-1,
readout_dim=embedding_dim,
cost_brick=SquaredError()),
# cost_brick=CategoricalCrossEntropy()),
feedback_brick=TrivialFeedback(output_dim=embedding_dim),
post_merge=InitializableFeedforwardSequence([
Bias(dim=maxout_dim, name='maxout_bias').apply,
Maxout(num_pieces=2, name='maxout').apply,
Linear(input_dim=maxout_dim / 2,
output_dim=embedding_dim,
use_bias=False,
name='softmax0').apply,
Logistic(name='softmax1').apply
]),
merged_dim=maxout_dim)
# Build sequence generator accordingly
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([
name
for name in self.transition.apply.sequences if name != 'mask'
],
prototype=Linear()))
self.children = [self.sequence_generator]
emitter = GMMEmitter(gmmmlp = mlp_gmm,
output_size = frame_size,
k = k,
name = "emitter")
source_names = [name for name in transition.apply.states if 'states' in name]
readout = Readout(
readout_dim = hidden_size_recurrent,
source_names =source_names,
emitter=emitter,
feedback_brick = feedback,
name="readout")
generator = SequenceGenerator(readout=readout,
transition=transition,
name = "generator")
generator.weights_init = IsotropicGaussian(0.01)
generator.biases_init = Constant(0.)
generator.push_initialization_config()
generator.transition.biases_init = IsotropicGaussian(0.01,1)
generator.transition.push_initialization_config()
generator.initialize()
cost_matrix = generator.cost_matrix(x)
cost = cost_matrix.mean()
cost.name = "sequence_log_likelihood"
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)
mlp_theta = MLP( activations = activations_theta,
dims = dims_theta)
emitter = SPF0Emitter(mlp = mlp_theta,
name = "emitter")
source_names = [name for name in transition.apply.states if 'states' in name]
readout = Readout(
readout_dim = hidden_size_recurrent,
source_names =source_names,
emitter=emitter,
#feedback_brick = feedback,
name="readout")
generator = SequenceGenerator(readout=readout,
transition=transition,
name = "generator")
#######################################
steps = 2048
n_samples = 10
from blocks.utils import shared_floatx_zeros, shared_floatx
states = generator.transition.apply.outputs
states = {name: shared_floatx_zeros((batch_size, hidden_size_recurrent)) for name in states}
from theano import tensor, function
f0 = tensor.matrix('f0')
voiced = tensor.matrix('voiced')
k=k,
name="emitter")
source_names = ['states']
readout = Readout(readout_dim=hidden_size_recurrent,
source_names=source_names,
emitter=emitter,
feedback_brick=feedback,
name="readout")
attention = SimpleSequenceAttention(state_names=source_names,
state_dims=[hidden_size_recurrent],
attended_dim=context_size)
generator = SequenceGenerator(readout=readout,
transition=transition,
attention=attention,
name="generator")
generator.weights_init = IsotropicGaussian(0.01)
generator.biases_init = Constant(0.)
generator.initialize()
mlp_context.weights_init = IsotropicGaussian(0.01)
mlp_context.biases_init = Constant(0.)
mlp_context.initialize()
#ipdb.set_trace()
cost_matrix = generator.cost_matrix(x,
x_mask,
attended=mlp_context.apply(context))
cost = cost_matrix.sum() / x_mask.sum()
def train():
if os.path.isfile('trainingdata.tar'):
with open('trainingdata.tar', 'rb') as f:
main = load(f)
else:
hidden_size = 512
filename = 'warpeace.hdf5'
encoder = HDF5CharEncoder('warpeace_input.txt', 1000)
encoder.write(filename)
alphabet_len = encoder.length
x = theano.tensor.lmatrix('x')
readout = Readout(
readout_dim=alphabet_len,
feedback_brick=LookupFeedback(alphabet_len, hidden_size, name='feedback'),
source_names=['states'],
emitter=RandomSoftmaxEmitter(),
name='readout'
)
transition = GatedRecurrent(
activation=Tanh(),
dim=hidden_size)
transition.weights_init = IsotropicGaussian(0.01)
gen = SequenceGenerator(readout=readout,
transition=transition,
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(0),
name='sequencegenerator')
gen.push_initialization_config()
gen.initialize()
cost = gen.cost(outputs=x)
cost.name = 'cost'
cg = ComputationGraph(cost)
algorithm = GradientDescent(cost=cost,
parameters=cg.parameters,
step_rule=Scale(0.5))
train_set = encoder.get_dataset()
train_stream = DataStream.default_stream(
train_set, iteration_scheme=SequentialScheme(
train_set.num_examples, batch_size=128))
main = MainLoop(
model=Model(cost),
data_stream=train_stream,
algorithm=algorithm,
extensions=[
FinishAfter(),
Printing(),
Checkpoint('trainingdata.tar', every_n_epochs=10),
ShowOutput(every_n_epochs=10)
])
main.run()
