def test_cache():
dataset = ContainerDataset(range(100))
stream = DataStream(dataset)
batched_stream = BatchDataStream(stream, ConstantScheme(11))
cached_stream = CachedDataStream(batched_stream, ConstantScheme(7))
epoch = cached_stream.get_epoch_iterator()
# Make sure that cache is filled as expected
for (features,), cache_size in zip(epoch, [4, 8, 1, 5, 9, 2,
6, 10, 3, 7, 0, 4]):
assert len(cached_stream.cache[0]) == cache_size
# Make sure that the epoch finishes correctly
for (features,) in cached_stream.get_epoch_iterator():
pass
assert len(features) == 100 % 7
assert not cached_stream.cache[0]
# Ensure that the epoch transition is correct
cached_stream = CachedDataStream(batched_stream,
ConstantScheme(7, times=3))
for _, epoch in zip(range(2), cached_stream.iterate_epochs()):
cache_sizes = [4, 8, 1]
for i, (features,) in enumerate(epoch):
assert len(cached_stream.cache[0]) == cache_sizes[i]
assert len(features) == 7
assert numpy.all(range(100)[i * 7:(i + 1) * 7] == features)
assert i == 2
def get_data_stream(iterable):
dataset = ContainerDataset({'numbers': iterable})
data_stream = DataStreamMapping(dataset.get_default_stream(),
lambda data: (math.sqrt(data[0]), ),
add_sources=('roots', ))
data_stream = DataStreamMapping(
data_stream, lambda data: tuple(
(numpy.asarray(d, dtype=floatX) for d in data)))
return BatchDataStream(data_stream, ConstantScheme(20))
def test_batch_data_stream():
stream = ContainerDataset([1, 2, 3, 4, 5]).get_default_stream()
batches = list(BatchDataStream(stream, ConstantScheme(2))
.get_epoch_iterator())
expected = [(numpy.array([1, 2]),),
(numpy.array([3, 4]),),
(numpy.array([5]),)]
assert len(batches) == len(expected)
for b, e in zip(batches, expected):
assert (b[0] == e[0]).all()
# Check the `strict` flag
def try_strict():
list(BatchDataStream(stream, ConstantScheme(2), strict=True)
.get_epoch_iterator())
assert_raises(ValueError, try_strict)
stream2 = ContainerDataset([1, 2, 3, 4, 5, 6]).get_default_stream()
assert len(list(BatchDataStream(stream2, ConstantScheme(2), strict=True)
.get_epoch_iterator())) == 3
def test_padding_data_stream():
# 1-D sequences
stream = BatchDataStream(
ContainerDataset([[1], [2, 3], [], [4, 5, 6], [7]])
.get_default_stream(),
ConstantScheme(2))
mask_stream = PaddingDataStream(stream)
assert mask_stream.sources == ("data", "data_mask")
it = mask_stream.get_epoch_iterator()
data, mask = next(it)
assert (data == numpy.array([[1, 0], [2, 3]])).all()
assert (mask == numpy.array([[1, 0], [1, 1]])).all()
data, mask = next(it)
assert (data == numpy.array([[0, 0, 0], [4, 5, 6]])).all()
assert (mask == numpy.array([[0, 0, 0], [1, 1, 1]])).all()
data, mask = next(it)
assert (data == numpy.array([[7]])).all()
assert (mask == numpy.array([[1]])).all()
# 2D sequences
stream2 = BatchDataStream(
ContainerDataset([numpy.ones((3, 4)), 2 * numpy.ones((2, 4))])
.get_default_stream(),
ConstantScheme(2))
it = PaddingDataStream(stream2).get_epoch_iterator()
data, mask = next(it)
assert data.shape == (2, 3, 4)
assert (data[0, :, :] == 1).all()
assert (data[1, :2, :] == 2).all()
assert (mask == numpy.array([[1, 1, 1], [1, 1, 0]])).all()
# 2 sources
stream3 = PaddingDataStream(BatchDataStream(
ContainerDataset(dict(features=[[1], [2, 3], []],
targets=[[4, 5, 6], [7]]))
.get_default_stream(),
ConstantScheme(2)))
assert len(next(stream3.get_epoch_iterator())) == 4
def main(mode, save_path, num_batches, from_dump):
if mode == "train":
# Experiment configuration
dimension = 100
readout_dimension = len(char2code)
# Data processing pipeline
data_stream = DataStreamMapping(
mapping=lambda data: tuple(array.T for array in data),
data_stream=PaddingDataStream(
BatchDataStream(
iteration_scheme=ConstantScheme(10),
data_stream=DataStreamMapping(
mapping=reverse_words,
add_sources=("targets", ),
data_stream=DataStreamFilter(
predicate=lambda data: len(data[0]) <= 100,
data_stream=OneBillionWord(
"training", [99],
char2code,
level="character",
preprocess=str.lower).get_default_stream())))))
# Build the model
chars = tensor.lmatrix("features")
chars_mask = tensor.matrix("features_mask")
targets = tensor.lmatrix("targets")
targets_mask = tensor.matrix("targets_mask")
encoder = Bidirectional(GatedRecurrent(dim=dimension,
activation=Tanh()),
weights_init=Orthogonal())
encoder.initialize()
fork = Fork([
name
for name in encoder.prototype.apply.sequences if name != 'mask'
],
weights_init=IsotropicGaussian(0.1),
biases_init=Constant(0))
fork.input_dim = dimension
fork.fork_dims = {name: dimension for name in fork.fork_names}
fork.initialize()
lookup = LookupTable(readout_dimension,
dimension,
weights_init=IsotropicGaussian(0.1))
lookup.initialize()
transition = Transition(activation=Tanh(),
dim=dimension,
attended_dim=2 * dimension,
name="transition")
attention = SequenceContentAttention(
state_names=transition.apply.states,
match_dim=dimension,
name="attention")
readout = LinearReadout(readout_dim=readout_dimension,
source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedbacker=LookupFeedback(
readout_dimension, dimension),
name="readout")
generator = SequenceGenerator(readout=readout,
transition=transition,
attention=attention,
weights_init=IsotropicGaussian(0.1),
biases_init=Constant(0),
name="generator")
generator.push_initialization_config()
transition.weights_init = Orthogonal()
generator.initialize()
bricks = [encoder, fork, lookup, generator]
# Give an idea of what's going on
params = Selector(bricks).get_params()
logger.info("Parameters:\n" +
pprint.pformat([(key, value.get_value().shape)
for key, value in params.items()],
width=120))
# Build the cost computation graph
batch_cost = generator.cost(
targets,
targets_mask,
attended=encoder.apply(**dict_union(fork.apply(
lookup.lookup(chars), return_dict=True),
mask=chars_mask)),
attended_mask=chars_mask).sum()
batch_size = named_copy(chars.shape[1], "batch_size")
cost = aggregation.mean(batch_cost, batch_size)
cost.name = "sequence_log_likelihood"
logger.info("Cost graph is built")
# Fetch variables useful for debugging
max_length = named_copy(chars.shape[0], "max_length")
cost_per_character = named_copy(
aggregation.mean(batch_cost, batch_size * max_length),
"character_log_likelihood")
cg = ComputationGraph(cost)
energies = unpack(VariableFilter(application=readout.readout,
name="output")(cg.variables),
singleton=True)
min_energy = named_copy(energies.min(), "min_energy")
max_energy = named_copy(energies.max(), "max_energy")
(activations, ) = VariableFilter(
application=generator.transition.apply,
name="states")(cg.variables)
mean_activation = named_copy(activations.mean(), "mean_activation")
# Define the training algorithm.
algorithm = GradientDescent(cost=cost,
step_rule=CompositeRule([
GradientClipping(10.0),
SteepestDescent(0.01)
]))
observables = [
cost, min_energy, max_energy, mean_activation, batch_size,
max_length, cost_per_character, algorithm.total_step_norm,
algorithm.total_gradient_norm
]
for name, param in params.items():
observables.append(named_copy(param.norm(2), name + "_norm"))
observables.append(
named_copy(algorithm.gradients[param].norm(2),
name + "_grad_norm"))
main_loop = MainLoop(
model=bricks,
data_stream=data_stream,
algorithm=algorithm,
extensions=([LoadFromDump(from_dump)] if from_dump else []) + [
Timing(),
TrainingDataMonitoring(observables, after_every_batch=True),
TrainingDataMonitoring(
observables, prefix="average", every_n_batches=10),
FinishAfter(after_n_batches=num_batches).add_condition(
"after_batch", lambda log: math.isnan(
log.current_row.total_gradient_norm)),
Plot(os.path.basename(save_path),
[["average_" + cost.name],
["average_" + cost_per_character.name]],
every_n_batches=10),
SerializeMainLoop(save_path,
every_n_batches=500,
save_separately=["model", "log"]),
Printing(every_n_batches=1)
])
main_loop.run()
elif mode == "test":
with open(save_path, "rb") as source:
encoder, fork, lookup, generator = dill.load(source)
logger.info("Model is loaded")
chars = tensor.lmatrix("features")
generated = generator.generate(
n_steps=3 * chars.shape[0],
batch_size=chars.shape[1],
attended=encoder.apply(**dict_union(
fork.apply(lookup.lookup(chars), return_dict=True))),
attended_mask=tensor.ones(chars.shape))
sample_function = ComputationGraph(generated).get_theano_function()
logging.info("Sampling function is compiled")
while True:
# Python 2-3 compatibility
line = input("Enter a sentence\n")
batch_size = int(input("Enter a number of samples\n"))
encoded_input = [
char2code.get(char, char2code["<UNK>"])
for char in line.lower().strip()
]
encoded_input = ([char2code['<S>']] + encoded_input +
[char2code['</S>']])
print("Encoder input:", encoded_input)
target = reverse_words((encoded_input, ))[0]
print("Target: ", target)
states, samples, glimpses, weights, costs = sample_function(
numpy.repeat(numpy.array(encoded_input)[:, None],
batch_size,
axis=1))
messages = []
for i in range(samples.shape[1]):
sample = list(samples[:, i])
try:
true_length = sample.index(char2code['</S>']) + 1
except ValueError:
true_length = len(sample)
sample = sample[:true_length]
cost = costs[:true_length, i].sum()
message = "({})".format(cost)
message += "".join(code2char[code] for code in sample)
if sample == target:
message += " CORRECT!"
messages.append((cost, message))
messages.sort(key=lambda tuple_: -tuple_[0])
for _, message in messages:
print(message)
def try_strict():
list(BatchDataStream(stream, ConstantScheme(2), strict=True)
.get_epoch_iterator())
def try_strict(strictness):
return list(
BatchDataStream(stream, ConstantScheme(2), strictness=strictness)
.get_epoch_iterator())