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, 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, path, nn_char_map, no_transition_cost=1e12, **kwargs): # Since we currently support only type, it is ignored. # if type_ != 'fst': # raise ValueError("Supports only FST's so far.") fst = FST(path) fst_char_map = dict(fst.fst.isyms.items()) del fst_char_map['<eps>'] if not len(fst_char_map) == len(nn_char_map): raise ValueError() remap_table = { nn_char_map[character]: fst_code for character, fst_code in fst_char_map.items() } transition = FSTTransition(fst, remap_table, no_transition_cost) # This SequenceGenerator will be used only in a very limited way. # That's why it is sufficient to equip it with a completely # fake readout. dummy_readout = Readout(source_names=['add'], readout_dim=len(remap_table), merge=Merge(input_names=['costs'], prototype=Identity()), post_merge=Identity(), emitter=SoftmaxEmitter()) super(LanguageModel, self).__init__(transition=transition, fork=Fork(output_names=[ name for name in transition.apply.sequences if name != 'mask' ], prototype=Identity()), readout=dummy_readout, **kwargs)
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 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 __init__(self, vocab_size, embedding_dim, state_dim, representation_dim,topical_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 #self.topical_dim=topical_dim; # 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") self.topical_attention=SequenceContentAttention( state_names=self.transition.apply.states, attended_dim=topical_dim, match_dim=state_dim, name="topical_attention")#not sure whether the match dim would be correct. # 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]],#check! 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, topical_attention=self.topical_attention, topical_name='topical_embeddingq', content_name='content_embedding', 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 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 __init__(self, vocab_size, embedding_dim, dgru_state_dim, igru_state_dim, state_dim, representation_dim, transition_depth, trg_igru_depth, trg_dgru_depth, trg_space_idx, trg_bos, theano_seed=None, **kwargs): super(Decoder, self).__init__(**kwargs) self.vocab_size = vocab_size self.embedding_dim = embedding_dim self.dgru_state_dim = dgru_state_dim self.igru_state_dim = igru_state_dim self.state_dim = state_dim self.trg_space_idx = trg_space_idx self.representation_dim = representation_dim self.theano_seed = theano_seed # Initialize gru with special initial state self.transition = RecurrentStack([ GRUInitialState(attended_dim=state_dim, dim=state_dim, activation=Tanh(), name='decoder_gru_withinit') ] + [ GatedRecurrent( dim=state_dim, activation=Tanh(), name='decoder_gru' + str(i)) for i in range(1, transition_depth) ], skip_connections=False) # Initialize the attention mechanism self.attention = SequenceContentAttention( state_names=self.transition.apply.states, attended_dim=representation_dim, match_dim=state_dim, name="attention") self.interpolator = Interpolator( vocab_size=vocab_size, embedding_dim=embedding_dim, igru_state_dim=igru_state_dim, igru_depth=trg_igru_depth, trg_dgru_depth=trg_dgru_depth, source_names=[ 'states', 'feedback', self.attention.take_glimpses.outputs[0] ], readout_dim=self.vocab_size, emitter=SoftmaxEmitter(initial_output=trg_bos, theano_seed=theano_seed), feedback_brick=TargetWordEncoder(vocab_size, embedding_dim, self.dgru_state_dim, trg_dgru_depth)) # Build sequence generator accordingly self.sequence_generator = SequenceGeneratorDCNMT( trg_space_idx=self.trg_space_idx, readout=self.interpolator, transition=self.transition, attention=self.attention, transition_depth=transition_depth, igru_depth=trg_igru_depth, trg_dgru_depth=trg_dgru_depth, 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, topicWord_size, embedding_dim, state_dim, topical_dim, representation_dim, match_function='SumMacthFunction', use_doubly_stochastic=False, lambda_ds=0.001, use_local_attention=False, window_size=10, use_step_decay_cost=False, use_concentration_cost=False, lambda_ct=10, use_stablilizer=False, lambda_st=50, theano_seed=None, **kwargs): super(Decoder, self).__init__(**kwargs) self.vocab_size = vocab_size self.topicWord_size = topicWord_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 = GRU(attended_dim=state_dim, dim=state_dim, activation=Tanh(), name='decoder') self.energy_computer = globals()[match_function](name='energy_comp') # Initialize the attention mechanism self.attention = SequenceContentAttention( state_names=self.transition.apply.states, attended_dim=representation_dim, match_dim=state_dim, energy_computer=self.energy_computer, use_local_attention=use_local_attention, window_size=window_size, name="attention") self.topical_attention = SequenceContentAttention( state_names=self.transition.apply.states, attended_dim=topical_dim, match_dim=state_dim, energy_computer=self.energy_computer, use_local_attention=use_local_attention, window_size=window_size, name="topical_attention" ) #not sure whether the match dim would be correct. # 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, name='readout') # calculate the readout of topic word, # no specific feedback brick, use the trival feedback break # no post_merge and merge, use Bias and Linear topicWordReadout = Readout(source_names=[ 'states', 'feedback', self.attention.take_glimpses.outputs[0] ], readout_dim=self.topicWord_size, emitter=SoftmaxEmitter( initial_output=-1, theano_seed=theano_seed), name='twReadout') # Build sequence generator accordingly self.sequence_generator = SequenceGenerator( readout=readout, topicWordReadout=topicWordReadout, topic_vector_names=['topicSumVector'], transition=self.transition, attention=self.attention, topical_attention=self.topical_attention, q_dim=self.state_dim, #q_name='topic_embedding', topical_name='topic_embedding', content_name='content_embedding', use_step_decay_cost=use_step_decay_cost, use_doubly_stochastic=use_doubly_stochastic, lambda_ds=lambda_ds, use_concentration_cost=use_concentration_cost, lambda_ct=lambda_ct, use_stablilizer=use_stablilizer, lambda_st=lambda_st, fork=Fork([ name for name in self.transition.apply.sequences if name != 'mask' ], prototype=Linear())) self.children = [self.sequence_generator]
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
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)
eos_token=None, unk_token='<UNK>', level='character') alphabet_size = 4 lstm_dim = 2 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()
def __init__(self, initial_output='\n'): self.theano_rng = MRG_RandomStreams(seed=random.randint(0,100000)) SoftmaxEmitter.__init__(self, initial_output=initial_output)
def __init__( self, input_dims, input_num_chars, eos_label, num_phonemes, dim_dec, dims_bidir, enc_transition, dec_transition, use_states_for_readout, attention_type, criterion, bottom, lm=None, character_map=None, bidir=True, subsample=None, dims_top=None, prior=None, conv_n=None, post_merge_activation=None, post_merge_dims=None, dim_matcher=None, embed_outputs=True, dim_output_embedding=None, dec_stack=1, conv_num_filters=1, data_prepend_eos=True, # softmax is the default set in SequenceContentAndConvAttention energy_normalizer=None, # for speech this is the approximate phoneme duration in frames max_decoded_length_scale=1, **kwargs): if post_merge_activation is None: post_merge_activation = Tanh() super(SpeechRecognizer, self).__init__(**kwargs) 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 self.criterion = criterion self.max_decoded_length_scale = max_decoded_length_scale post_merge_activation = post_merge_activation if dim_matcher is None: dim_matcher = dim_dec # The bottom part, before BiRNN bottom_class = bottom.pop('bottom_class') bottom = bottom_class(input_dims=input_dims, input_num_chars=input_num_chars, name='bottom', **bottom) # BiRNN if not subsample: subsample = [1] * len(dims_bidir) encoder = Encoder(self.enc_transition, dims_bidir, bottom.get_dim(bottom.apply.outputs[0]), subsample, bidir=bidir) dim_encoded = encoder.get_dim(encoder.apply.outputs[0]) generators = [None, None] for i in range(2): # The top part, on top of BiRNN but before the attention if dims_top: top = MLP([Tanh()], [dim_encoded] + dims_top + [dim_encoded], name="top{}".format(i)) else: top = Identity(name='top{}'.format(i)) if dec_stack == 1: transition = self.dec_transition(dim=dim_dec, activation=Tanh(), name="transition{}".format(i)) else: transitions = [ self.dec_transition(dim=dim_dec, activation=Tanh(), name="transition_{}_{}".format( i, 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=dim_encoded, match_dim=dim_matcher, name="cont_att" + i) 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=dim_encoded, match_dim=dim_matcher, prior=prior, energy_normalizer=energy_normalizer, name="conv_att{}".format(i)) else: raise ValueError( "Unknown attention type {}".format(attention_type)) if embed_outputs: feedback = LookupFeedback( num_phonemes + 1, dim_dec if dim_output_embedding is None else dim_output_embedding) else: feedback = OneOfNFeedback(num_phonemes + 1) if criterion['name'] == 'log_likelihood': emitter = SoftmaxEmitter(initial_output=num_phonemes, name="emitter{}".format(i)) if lm: # In case we use LM it is Readout that is responsible # for normalization. emitter = LMEmitter() elif criterion['name'].startswith('mse'): emitter = RewardRegressionEmitter(criterion['name'], eos_label, num_phonemes, criterion.get( 'min_reward', -1.0), name="emitter") else: raise ValueError("Unknown criterion {}".format( criterion['name'])) 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{}".format(i)) 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{}'.format(i)) readout = Readout(**readout_config) language_model = None if lm and lm.get('path'): 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) generators[i] = SequenceGenerator(readout=readout, transition=transition, attention=attention, language_model=language_model, name="generator{}".format(i)) self.generator = generators[0] self.forward_to_backward = Linear(dim_dec, dim_dec) # Remember child bricks self.encoder = encoder self.bottom = bottom self.top = top self.generators = generators self.children = [self.forward_to_backward, encoder, top, bottom ] + generators # Create input variables self.inputs = self.bottom.batch_inputs self.inputs_mask = self.bottom.mask self.labels = tensor.lmatrix('labels') self.labels_mask = tensor.matrix("labels_mask") self.single_inputs = self.bottom.single_inputs self.single_labels = tensor.lvector('labels') self.n_steps = tensor.lscalar('n_steps')
def test_sequence_generator_with_lm(): floatX = theano.config.floatX 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()) language_model = SequenceGenerator(Readout( readout_dim=readout_dim, source_names=["states"], emitter=SoftmaxEmitter(theano_seed=1234), feedback_brick=LookupFeedback(readout_dim, dim, name='feedback')), SimpleRecurrent(dim, Tanh()), name='language_model') generator = SequenceGenerator(Readout( readout_dim=readout_dim, source_names=["states", "lm_states"], emitter=SoftmaxEmitter(theano_seed=1234), feedback_brick=LookupFeedback(readout_dim, feedback_dim)), transition, language_model=language_model, weights_init=IsotropicGaussian(0.1), biases_init=Constant(0), seed=1234) generator.initialize() # Test 'cost_matrix' method y = tensor.lmatrix('y') y.tag.test_value = numpy.zeros((15, batch_size), dtype='int64') mask = tensor.matrix('mask') mask.tag.test_value = numpy.ones((15, batch_size)) 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(), 483.153, 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, 16.105, 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, 1.61051, rtol=1e-5) # Test generate states, outputs, lm_states, 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(), -4.88367, rtol=1e-5) assert_allclose(costs_val.sum(), 486.681, rtol=1e-5) assert outputs_val.sum() == 627 # 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)
def main(config): vocab_src, _ = text_to_dict([config['train_src'], config['dev_src'], config['test_src']]) vocab_tgt, cabvo = text_to_dict([config['train_tgt'], config['dev_tgt']]) # Create Theano variables logger.info('Creating theano variables') source_sentence = tensor.lmatrix('source') source_sentence_mask = tensor.matrix('source_mask') target_sentence = tensor.lmatrix('target') target_sentence_mask = tensor.matrix('target_mask') source_sentence.tag.test_value = [[13, 20, 0, 20, 0, 20, 0], [1, 4, 8, 4, 8, 4, 8],] source_sentence_mask.tag.test_value = [[0, 1, 0, 1, 0, 1, 0], [1, 0, 1, 0, 1, 0, 1],] target_sentence.tag.test_value = [[0,1,1,5], [2,0,1,0],] target_sentence_mask.tag.test_value = [[0,1,1,0], [1,1,1,0],] logger.info('Building RNN encoder-decoder') ### Building Encoder embedder = LookupTable( length=len(vocab_src), dim=config['embed_src'], weights_init=IsotropicGaussian(), biases_init=Constant(0.0), name='embedder') transformer = Linear( config['embed_src'], config['hidden_src']*4, weights_init=IsotropicGaussian(), biases_init=Constant(0.0), name='transformer') lstminit = np.asarray([0.0,]*config['hidden_src']+[0.0,]*config['hidden_src']+[1.0,]*config['hidden_src']+[0.0,]*config['hidden_src']) encoder = Bidirectional( LSTM( dim=config['hidden_src'], weights_init=IsotropicGaussian(0.01), biases_init=Constant(lstminit)), name='encoderBiLSTM' ) encoder.prototype.weights_init = Orthogonal() ### Building Decoder lstminit = np.asarray([0.0,]*config['hidden_tgt']+[0.0,]*config['hidden_tgt']+[1.0,]*config['hidden_tgt']+[0.0,]*config['hidden_tgt']) transition = LSTM2GO( attended_dim=config['hidden_tgt'], dim=config['hidden_tgt'], weights_init=IsotropicGaussian(0.01), biases_init=Constant(lstminit), name='decoderLSTM') attention = SequenceContentAttention( state_names=transition.apply.states, # default activation is Tanh state_dims=[config['hidden_tgt']], attended_dim=config['hidden_src']*2, match_dim=config['hidden_tgt'], name="attention") readout = Readout( source_names=['states', 'feedback', attention.take_glimpses.outputs[0]], readout_dim=len(vocab_tgt), emitter = SoftmaxEmitter( name='emitter'), feedback_brick = LookupFeedback( num_outputs=len(vocab_tgt), feedback_dim=config['embed_tgt'], name='feedback'), post_merge=InitializableFeedforwardSequence([ Bias(dim=config['hidden_tgt'], name='softmax_bias').apply, Linear(input_dim=config['hidden_tgt'], output_dim=config['embed_tgt'], use_bias=False, name='softmax0').apply, Linear(input_dim=config['embed_tgt'], name='softmax1').apply]), merged_dim=config['hidden_tgt']) decoder = SequenceGenerator( readout=readout, transition=transition, attention=attention, weights_init=IsotropicGaussian(0.01), biases_init=Constant(0), name="generator", fork=Fork( [name for name in transition.apply.sequences if name != 'mask'], prototype=Linear()), add_contexts=True) decoder.transition.weights_init = Orthogonal() #printchildren(encoder, 1) # Initialize model logger.info('Initializing model') embedder.initialize() transformer.initialize() encoder.initialize() decoder.initialize() # Apply model embedded = embedder.apply(source_sentence) tansformed = transformer.apply(embedded) encoded = encoder.apply(tansformed)[0] generated = decoder.generate( n_steps=2*source_sentence.shape[1], batch_size=source_sentence.shape[0], attended = encoded.dimshuffle(1,0,2), attended_mask=tensor.ones(source_sentence.shape).T ) print 'Generated: ', generated # generator_generate_outputs #samples = generated[1] # For GRU samples = generated[2] # For LSTM samples.name = 'samples' #samples_cost = generated[4] # For GRU samples_cost = generated[5] # For LSTM samples_cost = 'sampling_cost' cost = decoder.cost( mask = target_sentence_mask.T, outputs = target_sentence.T, attended = encoded.dimshuffle(1,0,2), attended_mask = source_sentence_mask.T) cost.name = 'target_cost' cost.tag.aggregation_scheme = TakeLast(cost) model = Model(cost) logger.info('Creating computational graph') cg = ComputationGraph(cost) # apply dropout for regularization if config['dropout'] < 1.0: # dropout is applied to the output of maxout in ghog logger.info('Applying dropout') dropout_inputs = [x for x in cg.intermediary_variables if x.name == 'maxout_apply_output'] cg = apply_dropout(cg, dropout_inputs, config['dropout']) ######## # Print shapes shapes = [param.get_value().shape for param in cg.parameters] logger.info("Parameter shapes: ") for shape, count in Counter(shapes).most_common(): logger.info(' {:15}: {}'.format(shape, count)) logger.info("Total number of parameters: {}".format(len(shapes))) printchildren(embedder, 1) printchildren(transformer, 1) printchildren(encoder, 1) printchildren(decoder, 1) # Print parameter names # enc_dec_param_dict = merge(Selector(embedder).get_parameters(), Selector(encoder).get_parameters(), Selector(decoder).get_parameters()) # enc_dec_param_dict = merge(Selector(decoder).get_parameters()) # logger.info("Parameter names: ") # for name, value in enc_dec_param_dict.items(): # logger.info(' {:15}: {}'.format(value.get_value().shape, name)) # logger.info("Total number of parameters: {}".format(len(enc_dec_param_dict))) ########## # Training data train_stream = get_train_stream(config, [config['train_src'],], [config['train_tgt'],], vocab_src, vocab_tgt) dev_stream = get_dev_stream( [config['dev_src'],], [config['dev_tgt'],], vocab_src, vocab_tgt) test_stream = get_test_stream([config['test_src'],], vocab_src) # Set extensions logger.info("Initializing extensions") extensions = [ FinishAfter(after_n_batches=config['finish_after']), ProgressBar(), TrainingDataMonitoring([cost], prefix="tra", after_batch=True), DataStreamMonitoring(variables=[cost], data_stream=dev_stream, prefix="dev", after_batch=True), Sampler( model=Model(samples), data_stream=dev_stream, vocab=cabvo, saveto=config['saveto']+'dev', every_n_batches=config['save_freq']), Sampler( model=Model(samples), data_stream=test_stream, vocab=cabvo, saveto=config['saveto']+'test', after_n_batches=1, on_resumption=True, before_training=True), Plotter(saveto=config['saveto'], after_batch=True), Printing(after_batch=True), Checkpoint( path=config['saveto'], parameters = cg.parameters, save_main_loop=False, every_n_batches=config['save_freq'])] if BOKEH_AVAILABLE: Plot('Training cost', channels=[['target_cost']], after_batch=True) if config['reload']: extensions.append(Load(path=config['saveto'], load_iteration_state=False, load_log=False)) else: with open(config['saveto']+'.txt', 'w') as f: pass # Set up training algorithm logger.info("Initializing training algorithm") algorithm = GradientDescent(cost=cost, parameters=cg.parameters, step_rule=CompositeRule([StepClipping(config['step_clipping']), eval(config['step_rule'])()]) ) # Initialize main loop logger.info("Initializing main loop") main_loop = MainLoop( model=model, algorithm=algorithm, data_stream=train_stream, extensions=extensions) main_loop.run()
def __init__(self): SoftmaxEmitter.__init__(self) self.theano_rng = MRG_RandomStreams(seed=random.randint(0, 100000))
def __init__(self): SoftmaxEmitter.__init__(self) self.theano_rng = MRG_RandomStreams(seed=random.randint(0,100000))
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(floatX) freqs /= freqs.sum() print("Frequencies:\n {} vs {}".format(freqs, MarkovChainDataset.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, MarkovChainDataset.trans_prob)) 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 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)
def test_softmax_emitter_initial_outputs(): emitter = SoftmaxEmitter(3) emitter.readout_dim = 0 assert_equal(emitter.initial_outputs(2).eval(), 3 * numpy.ones((2,), dtype='int64'))
def main(mode, save_path, steps, time_budget, reset): num_states = ChainDataset.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", 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.push_initialization_config() transition.weights_init = Orthogonal() generator.initialize() 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( ChainDataset.entropy)) logger.info("Expected min error: {}".format( -ChainDataset.entropy * seq_len * batch_size)) if os.path.isfile(save_path) and not reset: model = Pylearn2Model.load(save_path) else: model = Pylearn2Model(generator) # Build the cost computation graph. # Note: would be probably nicer to make cost part of the model. x = tensor.ltensor3('x') cost = Pylearn2Cost(model.brick.cost(x[:, :, 0]).sum()) dataset = ChainDataset(rng, seq_len) sgd = SGD(learning_rate=0.0001, cost=cost, batch_size=batch_size, batches_per_iter=10, monitoring_dataset=dataset, monitoring_batch_size=batch_size, monitoring_batches=1, learning_rule=Pylearn2LearningRule( SGDLearningRule(), dict(training_objective=cost.cost))) train = Pylearn2Train(dataset, model, algorithm=sgd, save_path=save_path, save_freq=10) train.main_loop(time_budget=time_budget) elif mode == "sample": model = Pylearn2Model.load(save_path) generator = model.brick sample = ComputationGraph(generator.generate( n_steps=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, ChainDataset.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, ChainDataset.trans_prob)) else: assert False
def __init__(self, vocab_size, embedding_dim, state_dim, representation_dim, context_dim, target_transition, theano_seed=None, loss_function='cross_entropy', **kwargs): super(InitialContextDecoder, 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 = target_transition(attended_dim=state_dim, context_dim=context_dim, dim=state_dim, activation=Tanh(), name='decoder') # self.transition = GRUInitialStateWithInitialStateConcatContext( # attended_dim=state_dim, context_dim=context_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', # Chris: it's key that we're taking the first output of self.attention.take_glimpses.outputs # Chris: the first output is the weighted avgs, the second is the weights in (batch, time) 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 if loss_function == 'cross_entropy': self.sequence_generator = InitialContextSequenceGenerator( readout=readout, transition=self.transition, attention=self.attention, fork=Fork([ name for name in self.transition.apply.sequences if name != 'mask' ], prototype=Linear())) elif loss_function == 'min_risk': self.sequence_generator = MinRiskInitialContextSequenceGenerator( readout=readout, transition=self.transition, attention=self.attention, fork=Fork([ name for name in self.transition.apply.sequences if name != 'mask' ], prototype=Linear())) # the name is important, because it lets us match the brick hierarchy names for the vanilla SequenceGenerator # to load pretrained models # TODO: quick hack to fix bug self.sequence_generator.name = 'initialcontextsequencegenerator' else: raise ValueError( 'The decoder does not support the loss function: {}'.format( loss_function)) # TODO: uncomment this!! # self.sequence_generator.name = 'sequencegenerator' self.children = [self.sequence_generator]
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)
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]
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