Esempio n. 1
0
def main(config,
         tr_stream,
         dev_stream,
         source_vocab,
         target_vocab,
         use_bokeh=False):

    # 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')
    initial_context = tensor.matrix('initial_context')

    # Construct model
    logger.info('Building RNN encoder-decoder')
    encoder = BidirectionalEncoder(config['src_vocab_size'],
                                   config['enc_embed'], config['enc_nhids'])

    # let user specify the target transition class name in config,
    # eval it and pass to decoder
    target_transition_name = config.get(
        'target_transition', 'GRUInitialStateWithInitialStateSumContext')
    target_transition = eval(target_transition_name)

    logger.info('Using target transition: {}'.format(target_transition_name))
    decoder = InitialContextDecoder(config['trg_vocab_size'],
                                    config['dec_embed'], config['dec_nhids'],
                                    config['enc_nhids'] * 2,
                                    config['context_dim'], target_transition)

    cost = decoder.cost(encoder.apply(source_sentence, source_sentence_mask),
                        source_sentence_mask, target_sentence,
                        target_sentence_mask, initial_context)

    cost.name = 'decoder_cost'

    # Initialize model
    logger.info('Initializing model')
    encoder.weights_init = decoder.weights_init = IsotropicGaussian(
        config['weight_scale'])
    encoder.biases_init = decoder.biases_init = Constant(0)
    encoder.push_initialization_config()
    decoder.push_initialization_config()
    encoder.bidir.prototype.weights_init = Orthogonal()
    decoder.transition.weights_init = Orthogonal()
    encoder.initialize()
    decoder.initialize()

    logger.info('Creating computational graph')
    cg = ComputationGraph(cost)

    # GRAPH TRANSFORMATIONS FOR BETTER TRAINING
    # TODO: validate performance with/without regularization
    if config.get('l2_regularization', False) is True:
        l2_reg_alpha = config['l2_regularization_alpha']
        logger.info(
            'Applying l2 regularization with alpha={}'.format(l2_reg_alpha))
        model_weights = VariableFilter(roles=[WEIGHT])(cg.variables)

        for W in model_weights:
            cost = cost + (l2_reg_alpha * (W**2).sum())

        # why do we need to name the cost variable? Where did the original name come from?
        cost.name = 'decoder_cost_cost'

    cg = ComputationGraph(cost)

    # apply dropout for regularization
    if config['dropout'] < 1.0:
        # dropout is applied to the output of maxout in ghog
        # this is the probability of dropping out, so you probably want to make it <=0.5
        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)))

    # Print parameter names
    enc_dec_param_dict = merge(
        Selector(encoder).get_parameters(),
        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)))

    # Set up training model
    logger.info("Building model")
    training_model = Model(cost)

    # create the training directory, and copy this config there if directory doesn't exist
    if not os.path.isdir(config['saveto']):
        os.makedirs(config['saveto'])
        shutil.copy(config['config_file'], config['saveto'])

    # Set extensions

    # TODO: add checking for existing model and loading
    logger.info("Initializing extensions")
    extensions = [
        FinishAfter(after_n_batches=config['finish_after']),
        TrainingDataMonitoring([cost], after_batch=True),
        Printing(after_batch=True),
        CheckpointNMT(config['saveto'], every_n_batches=config['save_freq'])
    ]

    # Create the theano variables that we need for the sampling graph
    sampling_input = tensor.lmatrix('input')
    sampling_context = tensor.matrix('context_input')

    # Set up beam search and sampling computation graphs if necessary
    if config['hook_samples'] >= 1 or config.get('bleu_script',
                                                 None) is not None:
        logger.info("Building sampling model")
        sampling_representation = encoder.apply(
            sampling_input, tensor.ones(sampling_input.shape))

        generated = decoder.generate(sampling_input, sampling_representation,
                                     sampling_context)
        search_model = Model(generated)
        _, samples = VariableFilter(
            bricks=[decoder.sequence_generator], name="outputs")(
                ComputationGraph(generated[1]))  # generated[1] is next_outputs

    # Add sampling
    if config['hook_samples'] >= 1:
        logger.info("Building sampler")
        extensions.append(
            Sampler(
                model=search_model,
                data_stream=tr_stream,
                hook_samples=config['hook_samples'],
                every_n_batches=config['sampling_freq'],
                src_vocab=source_vocab,
                trg_vocab=target_vocab,
                src_vocab_size=config['src_vocab_size'],
            ))

    # Add early stopping based on bleu
    if config.get('bleu_script', None) is not None:
        logger.info("Building bleu validator")
        extensions.append(
            BleuValidator(sampling_input,
                          sampling_context,
                          samples=samples,
                          config=config,
                          model=search_model,
                          data_stream=dev_stream,
                          src_vocab=source_vocab,
                          trg_vocab=target_vocab,
                          normalize=config['normalized_bleu'],
                          every_n_batches=config['bleu_val_freq']))

    # Add early stopping based on Meteor
    if config.get('meteor_directory', None) is not None:
        logger.info("Building meteor validator")
        extensions.append(
            MeteorValidator(sampling_input,
                            sampling_context,
                            samples=samples,
                            config=config,
                            model=search_model,
                            data_stream=dev_stream,
                            src_vocab=source_vocab,
                            trg_vocab=target_vocab,
                            normalize=config['normalized_bleu'],
                            every_n_batches=config['bleu_val_freq']))

    # Reload model if necessary
    if config['reload']:
        extensions.append(LoadNMT(config['saveto']))

    # Plot cost in bokeh if necessary
    if use_bokeh and BOKEH_AVAILABLE:
        extensions.append(
            Plot(config['model_save_directory'],
                 channels=[[
                     'decoder_cost', 'validation_set_bleu_score',
                     'validation_set_meteor_score'
                 ]],
                 every_n_batches=10))

    # Set up training algorithm
    logger.info("Initializing training algorithm")
    # if there is dropout or random noise, we need to use the output of the modified graph
    if config['dropout'] < 1.0 or config['weight_noise_ff'] > 0.0:
        algorithm = GradientDescent(cost=cg.outputs[0],
                                    parameters=cg.parameters,
                                    step_rule=CompositeRule([
                                        StepClipping(config['step_clipping']),
                                        eval(config['step_rule'])()
                                    ]))
    else:
        algorithm = GradientDescent(cost=cost,
                                    parameters=cg.parameters,
                                    step_rule=CompositeRule([
                                        StepClipping(config['step_clipping']),
                                        eval(config['step_rule'])()
                                    ]))

    # enrich the logged information
    extensions.append(Timing(every_n_batches=100))

    # Initialize main loop
    logger.info("Initializing main loop")
    main_loop = MainLoop(model=training_model,
                         algorithm=algorithm,
                         data_stream=tr_stream,
                         extensions=extensions)

    # Train!
    main_loop.run()
def main(config, tr_stream, dev_stream, use_bokeh=False):

    # 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')
    sampling_input = tensor.lmatrix('input')

    # Construct model
    logger.info('Building RNN encoder-decoder')
    encoder = BidirectionalEncoder(config['src_vocab_size'],
                                   config['enc_embed'], config['enc_nhids'])
    decoder = Decoder(config['trg_vocab_size'], config['dec_embed'],
                      config['dec_nhids'], config['enc_nhids'] * 2)
    cost = decoder.cost(encoder.apply(source_sentence, source_sentence_mask),
                        source_sentence_mask, target_sentence,
                        target_sentence_mask)

    logger.info('Creating computational graph')
    cg = ComputationGraph(cost)

    # Initialize model
    logger.info('Initializing model')
    encoder.weights_init = decoder.weights_init = IsotropicGaussian(
        config['weight_scale'])
    encoder.biases_init = decoder.biases_init = Constant(0)
    encoder.push_initialization_config()
    decoder.push_initialization_config()
    encoder.bidir.prototype.weights_init = Orthogonal()
    decoder.transition.weights_init = Orthogonal()
    encoder.initialize()
    decoder.initialize()

    # 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'])

    # Apply weight noise for regularization
    if config['weight_noise_ff'] > 0.0:
        logger.info('Applying weight noise to ff layers')
        enc_params = Selector(encoder.lookup).get_params().values()
        enc_params += Selector(encoder.fwd_fork).get_params().values()
        enc_params += Selector(encoder.back_fork).get_params().values()
        dec_params = Selector(
            decoder.sequence_generator.readout).get_params().values()
        dec_params += Selector(
            decoder.sequence_generator.fork).get_params().values()
        dec_params += Selector(decoder.state_init).get_params().values()
        cg = apply_noise(cg, enc_params + dec_params,
                         config['weight_noise_ff'])

    # 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)))

    # Print parameter names
    enc_dec_param_dict = merge(
        Selector(encoder).get_parameters(),
        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)))

    # Set up training model
    logger.info("Building model")
    training_model = Model(cost)

    # Set extensions
    logger.info("Initializing extensions")
    extensions = [
        FinishAfter(after_n_batches=config['finish_after']),
        TrainingDataMonitoring([cost], after_batch=True),
        Printing(after_batch=True),
        CheckpointNMT(config['saveto'], every_n_batches=config['save_freq'])
    ]

    # Set up beam search and sampling computation graphs if necessary
    if config['hook_samples'] >= 1 or config['bleu_script'] is not None:
        logger.info("Building sampling model")
        sampling_representation = encoder.apply(
            sampling_input, tensor.ones(sampling_input.shape))
        generated = decoder.generate(sampling_input, sampling_representation)
        search_model = Model(generated)
        _, samples = VariableFilter(
            bricks=[decoder.sequence_generator], name="outputs")(
                ComputationGraph(generated[1]))  # generated[1] is next_outputs

    # Add sampling
    if config['hook_samples'] >= 1:
        logger.info("Building sampler")
        extensions.append(
            Sampler(model=search_model,
                    data_stream=tr_stream,
                    hook_samples=config['hook_samples'],
                    every_n_batches=config['sampling_freq'],
                    src_vocab_size=config['src_vocab_size']))

    # Add early stopping based on bleu
    if config['bleu_script'] is not None:
        logger.info("Building bleu validator")
        extensions.append(
            BleuValidator(sampling_input,
                          samples=samples,
                          config=config,
                          model=search_model,
                          data_stream=dev_stream,
                          normalize=config['normalized_bleu'],
                          every_n_batches=config['bleu_val_freq']))

    # Reload model if necessary
    if config['reload']:
        extensions.append(LoadNMT(config['saveto']))

    # Plot cost in bokeh if necessary
    if use_bokeh and BOKEH_AVAILABLE:
        extensions.append(
            Plot('Cs-En', channels=[['decoder_cost_cost']], after_batch=True))

    # 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=training_model,
                         algorithm=algorithm,
                         data_stream=tr_stream,
                         extensions=extensions)

    # Train!
    main_loop.run()
Esempio n. 3
0
def main(exp_config, source_vocab, target_vocab, dev_stream, use_bokeh=True):

    # def setup_model_and_stream(exp_config, source_vocab, target_vocab):
    # def setup_model_and_stream(exp_config, source_vocab, target_vocab):
    train_encoder, train_decoder, theano_sampling_source_input, theano_sampling_context_input, generated, masked_stream = setup_model_and_stream(
        exp_config, source_vocab, target_vocab)
    cost = create_model(train_encoder, train_decoder,
                        exp_config.get('imt_smoothing_constant', 0.005))

    # Set up training model
    logger.info("Building model")
    train_model = Model(cost)

    # Set the parameters from a trained models (.npz file)
    logger.info("Loading parameters from model: {}".format(
        exp_config['saved_parameters']))
    # Note the brick delimeter='-' is here for legacy reasons because blocks changed the serialization API
    param_values = LoadNMT.load_parameter_values(
        exp_config['saved_parameters'],
        brick_delimiter=exp_config.get('brick_delimiter', None))
    LoadNMT.set_model_parameters(train_model, param_values)

    logger.info('Creating computational graph')
    cg = ComputationGraph(cost)

    # GRAPH TRANSFORMATIONS FOR BETTER TRAINING
    if exp_config.get('l2_regularization', False) is True:
        l2_reg_alpha = exp_config['l2_regularization_alpha']
        logger.info(
            'Applying l2 regularization with alpha={}'.format(l2_reg_alpha))
        model_weights = VariableFilter(roles=[WEIGHT])(cg.variables)

        for W in model_weights:
            cost = cost + (l2_reg_alpha * (W**2).sum())

        # why do we need to rename the cost variable? Where did the original name come from?
        cost.name = 'decoder_cost_cost'

    cg = ComputationGraph(cost)

    # apply dropout for regularization
    # Note dropout variables are hard-coded here
    if exp_config['dropout'] < 1.0:
        # dropout is applied to the output of maxout in ghog
        # this is the probability of dropping out, so you probably want to make it <=0.5
        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, exp_config['dropout'])

    # create the training directory, and copy this config there if directory doesn't exist
    if not os.path.isdir(exp_config['saveto']):
        os.makedirs(exp_config['saveto'])
        # TODO: mv the actual config file once we switch to .yaml for min-risk
        shutil.copy(exp_config['config_file'], exp_config['saveto'])

    # Set extensions
    logger.info("Initializing extensions")
    extensions = [
        FinishAfter(after_n_batches=exp_config['finish_after']),
        TrainingDataMonitoring([cost], after_batch=True),
        Printing(after_batch=True),
        CheckpointNMT(exp_config['saveto'],
                      every_n_batches=exp_config['save_freq'])
    ]

    # Set up beam search and sampling computation graphs if necessary
    # TODO: change the if statement here
    if exp_config['hook_samples'] >= 1 or exp_config['bleu_script'] is not None:
        logger.info("Building sampling model")
        search_model = Model(generated)
        _, samples = VariableFilter(
            bricks=[train_decoder.sequence_generator], name="outputs")(
                ComputationGraph(generated[1]))  # generated[1] is next_outputs

    # Add sampling -- TODO: sampling is broken for min-risk
    #if config['hook_samples'] >= 1:
    #    logger.info("Building sampler")
    #    extensions.append(
    #        Sampler(model=search_model, data_stream=tr_stream,
    #                hook_samples=config['hook_samples'],
    #                every_n_batches=config['sampling_freq'],
    #                src_vocab_size=config['src_vocab_size']))

    # Add early stopping based on bleu
    # TODO: use multimodal meteor and BLEU validator
    # TODO: add 'validator' key to IMT config
    # Add early stopping based on bleu
    if exp_config.get('bleu_script', None) is not None:
        logger.info("Building bleu validator")
        extensions.append(
            BleuValidator(theano_sampling_source_input,
                          theano_sampling_context_input,
                          samples=samples,
                          config=exp_config,
                          model=search_model,
                          data_stream=dev_stream,
                          src_vocab=source_vocab,
                          trg_vocab=target_vocab,
                          normalize=exp_config['normalized_bleu'],
                          every_n_batches=exp_config['bleu_val_freq']))

    if exp_config.get('imt_f1_validation', False) is not False:
        logger.info("Building imt F1 validator")
        extensions.append(
            IMT_F1_Validator(theano_sampling_source_input,
                             theano_sampling_context_input,
                             samples=samples,
                             config=exp_config,
                             model=search_model,
                             data_stream=dev_stream,
                             src_vocab=source_vocab,
                             trg_vocab=target_vocab,
                             normalize=exp_config['normalized_bleu'],
                             every_n_batches=exp_config['bleu_val_freq']))

    # Add early stopping based on Meteor
    # if exp_config.get('meteor_directory', None) is not None:
    #     logger.info("Building meteor validator")
    #     extensions.append(
    #         MeteorValidator(theano_sampling_source_input, theano_sampling_context_input,
    #                         samples=samples,
    #                         config=config,
    #                         model=search_model, data_stream=dev_stream,
    #                         src_vocab=src_vocab,
    #                         trg_vocab=trg_vocab,
    #                         normalize=config['normalized_bleu'],
    #                         every_n_batches=config['bleu_val_freq']))

    # Reload model if necessary
    if exp_config['reload']:
        extensions.append(LoadNMT(exp_config['saveto']))

    # Plot cost in bokeh if necessary
    if use_bokeh and BOKEH_AVAILABLE:
        extensions.append(
            Plot(exp_config['model_save_directory'],
                 channels=[[
                     'decoder_cost_cost', 'validation_set_imt_f1_score',
                     'validation_set_bleu_score', 'validation_set_meteor_score'
                 ]],
                 every_n_batches=10))

    # Set up training algorithm
    logger.info("Initializing training algorithm")

    # if there is l2_regularization, dropout or random noise, we need to use the output of the modified graph
    # WORKING: try to catch and fix nan
    if exp_config['dropout'] < 1.0:
        if exp_config.get('nan_guard', False):
            from theano.compile.nanguardmode import NanGuardMode
            algorithm = GradientDescent(cost=cg.outputs[0],
                                        parameters=cg.parameters,
                                        step_rule=CompositeRule([
                                            StepClipping(
                                                exp_config['step_clipping']),
                                            eval(exp_config['step_rule'])()
                                        ]),
                                        on_unused_sources='warn',
                                        theano_func_kwargs={
                                            'mode':
                                            NanGuardMode(nan_is_error=True,
                                                         inf_is_error=True)
                                        })
        else:
            algorithm = GradientDescent(cost=cg.outputs[0],
                                        parameters=cg.parameters,
                                        step_rule=CompositeRule([
                                            StepClipping(
                                                exp_config['step_clipping']),
                                            eval(exp_config['step_rule'])()
                                        ]),
                                        on_unused_sources='warn')
    else:
        algorithm = GradientDescent(cost=cost,
                                    parameters=cg.parameters,
                                    step_rule=CompositeRule([
                                        StepClipping(
                                            exp_config['step_clipping']),
                                        eval(exp_config['step_rule'])()
                                    ]),
                                    on_unused_sources='warn')

    # enrich the logged information
    extensions.append(Timing(every_n_batches=100))

    # Initialize main loop
    logger.info("Initializing main loop")
    main_loop = MainLoop(model=train_model,
                         algorithm=algorithm,
                         data_stream=masked_stream,
                         extensions=extensions)

    # Train!
    main_loop.run()
Esempio n. 4
0
def main(config,
         tr_stream,
         dev_stream,
         source_vocab,
         target_vocab,
         use_bokeh=False):

    # Create Theano variables
    logger.info('Creating theano variables')
    source_sentence = tensor.lmatrix('source')
    source_sentence_mask = tensor.matrix('source_mask')

    # Note that the _names_ are changed from normal NMT
    # for IMT training, we use only the suffix as the reference
    target_sentence = tensor.lmatrix('target_suffix')
    target_sentence_mask = tensor.matrix('target_suffix_mask')
    # TODO: change names back to *_suffix, there is currently a theano function name error
    # TODO: in the GradientDescent Algorithm

    target_prefix = tensor.lmatrix('target_prefix')
    target_prefix_mask = tensor.matrix('target_prefix_mask')

    # Construct model
    logger.info('Building RNN encoder-decoder')
    encoder = BidirectionalEncoder(config['src_vocab_size'],
                                   config['enc_embed'], config['enc_nhids'])

    decoder = NMTPrefixDecoder(config['trg_vocab_size'],
                               config['dec_embed'],
                               config['dec_nhids'],
                               config['enc_nhids'] * 2,
                               loss_function='cross_entropy')

    # rename to match baseline NMT systems
    decoder.name = 'decoder'

    # TODO: change the name of `target_sentence` to `target_suffix` for more clarity
    cost = decoder.cost(encoder.apply(source_sentence, source_sentence_mask),
                        source_sentence_mask, target_sentence,
                        target_sentence_mask, target_prefix,
                        target_prefix_mask)

    logger.info('Creating computational graph')
    cg = ComputationGraph(cost)

    # INITIALIZATION
    logger.info('Initializing model')
    encoder.weights_init = decoder.weights_init = IsotropicGaussian(
        config['weight_scale'])
    encoder.biases_init = decoder.biases_init = Constant(0)
    encoder.push_initialization_config()
    decoder.push_initialization_config()
    encoder.bidir.prototype.weights_init = Orthogonal()
    decoder.transition.weights_init = Orthogonal()
    encoder.initialize()
    decoder.initialize()

    # apply dropout for regularization
    if config['dropout'] < 1.0:
        # dropout is applied to the output of maxout in ghog
        # this is the probability of dropping out, so you probably want to make it <=0.5
        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'])

    trainable_params = cg.parameters

    # target_embeddings = model.get_parameter_dict()['/target_recurrent_lm_with_alignments/target_embeddings.W']
    # trainable_params.remove(source_embeddings)
    # trainable_params.remove(target_embeddings)

    # TODO: fixed dropout mask for recurrent params?
    # 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)))

    # Print parameter names
    enc_dec_param_dict = merge(
        Selector(encoder).get_parameters(),
        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)))

    # Set up training model
    logger.info("Building model")
    training_model = Model(cost)

    # create the training directory, and copy this config there if directory doesn't exist
    if not os.path.isdir(config['saveto']):
        os.makedirs(config['saveto'])
        shutil.copy(config['config_file'], config['saveto'])

    # Set extensions
    logger.info("Initializing extensions")
    extensions = [
        FinishAfter(after_n_batches=config['finish_after']),
        TrainingDataMonitoring([cost], after_batch=True),
        # TrainingDataMonitoring(trainable_params, after_batch=True),
        Printing(after_batch=True),
        CheckpointNMT(config['saveto'], every_n_batches=config['save_freq'])
    ]

    # Set up the sampling graph for validation during training
    # Theano variables for the sampling graph
    sampling_vars = load_params_and_get_beam_search(config,
                                                    encoder=encoder,
                                                    decoder=decoder)
    beam_search, search_model, samples, sampling_input, sampling_prefix = sampling_vars

    if config['hook_samples'] >= 1:
        logger.info("Building sampler")
        extensions.append(
            Sampler(model=search_model,
                    data_stream=tr_stream,
                    hook_samples=config['hook_samples'],
                    every_n_batches=config['sampling_freq'],
                    src_vocab=source_vocab,
                    trg_vocab=target_vocab,
                    src_vocab_size=config['src_vocab_size']))

    # Add early stopping based on bleu
    if config['bleu_script'] is not None:
        logger.info("Building bleu validator")
        extensions.append(
            BleuValidator(sampling_input,
                          sampling_prefix,
                          samples=samples,
                          config=config,
                          model=search_model,
                          data_stream=dev_stream,
                          src_vocab=source_vocab,
                          trg_vocab=target_vocab,
                          normalize=config['normalized_bleu'],
                          every_n_batches=config['bleu_val_freq']))

    # TODO: add first-word accuracy validation
    # TODO: add IMT meteor early stopping
    if config.get('imt_f1_validation', None) is not None:
        logger.info("Building imt F1 validator")
        extensions.append(
            IMT_F1_Validator(sampling_input,
                             sampling_prefix,
                             samples=samples,
                             config=config,
                             model=search_model,
                             data_stream=dev_stream,
                             src_vocab=source_vocab,
                             trg_vocab=target_vocab,
                             normalize=config['normalized_bleu'],
                             every_n_batches=config['bleu_val_freq']))

    # Reload model if necessary
    if config['reload']:
        extensions.append(LoadNMT(config['saveto']))

    # Plot cost in bokeh if necessary
    if use_bokeh and BOKEH_AVAILABLE:
        extensions.append(
            Plot(config['model_save_directory'],
                 channels=[['decoder_cost_cost'],
                           [
                               'validation_set_bleu_score',
                               'validation_set_imt_f1_score'
                           ]],
                 every_n_batches=10))

    # Set up training algorithm
    logger.info("Initializing training algorithm")

    # WORKING: implement confidence model
    # if there is dropout or random noise, we need to use the output of the modified graph
    if config['dropout'] < 1.0 or config['weight_noise_ff'] > 0.0:
        algorithm = GradientDescent(
            cost=cg.outputs[0],
            parameters=trainable_params,
            step_rule=CompositeRule([
                StepClipping(config['step_clipping']),
                eval(config['step_rule'])()
            ]),
            # step_rule=CompositeRule([StepClipping(10.0), Scale(0.01)]),
            on_unused_sources='warn')
    else:
        algorithm = GradientDescent(cost=cost,
                                    parameters=cg.parameters,
                                    step_rule=CompositeRule([
                                        StepClipping(config['step_clipping']),
                                        eval(config['step_rule'])()
                                    ]),
                                    on_unused_sources='warn')
    # END WORKING: implement confidence model

    # enrich the logged information
    extensions.append(Timing(every_n_batches=100))

    # for i, (k,v) in enumerate(algorithm.updates):
    #     v.name = k.name + '_{}'.format(i)
    #
    # aux_vars = [v for v in cg.auxiliary_variables[-3:]]
    # import ipdb; ipdb.set_trace()

    extensions.extend([
        TrainingDataMonitoring([cost], after_batch=True),
        # TrainingDataMonitoring([v for k,v in algorithm.updates[:2]], after_batch=True),
        # TrainingDataMonitoring(aux_vars, after_batch=True),
        TrainingDataMonitoring(trainable_params, after_batch=True),
        Printing(after_batch=True)
    ])

    # Initialize main loop
    logger.info("Initializing main loop")
    main_loop = MainLoop(model=training_model,
                         algorithm=algorithm,
                         data_stream=tr_stream,
                         extensions=extensions)

    # Train!
    main_loop.run()
Esempio n. 5
0
def main(model, cost, config, tr_stream, dev_stream, use_bokeh=False):

    # Set the parameters from a trained models (.npz file)
    logger.info("Loading parameters from model: {}".format(
        exp_config['saved_parameters']))
    # Note the brick delimeter='-' is here for legacy reasons because blocks changed the serialization API
    param_values = LoadNMT.load_parameter_values(
        exp_config['saved_parameters'],
        brick_delimiter=exp_config.get('brick_delimiter', None))
    LoadNMT.set_model_parameters(model, param_values)

    logger.info('Creating computational graph')
    cg = ComputationGraph(cost)

    # GRAPH TRANSFORMATIONS FOR BETTER TRAINING
    if config.get('l2_regularization', False) is True:
        l2_reg_alpha = config['l2_regularization_alpha']
        logger.info(
            'Applying l2 regularization with alpha={}'.format(l2_reg_alpha))
        model_weights = VariableFilter(roles=[WEIGHT])(cg.variables)

        for W in model_weights:
            cost = cost + (l2_reg_alpha * (W**2).sum())

        # why do we need to rename the cost variable? Where did the original name come from?
        cost.name = 'decoder_cost_cost'

    cg = ComputationGraph(cost)

    # apply dropout for regularization
    # Note dropout variables are hard-coded here
    if config['dropout'] < 1.0:
        # dropout is applied to the output of maxout in ghog
        # this is the probability of dropping out, so you probably want to make it <=0.5
        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'])

    # create the training directory, and copy this config there if directory doesn't exist
    if not os.path.isdir(config['saveto']):
        os.makedirs(config['saveto'])
        # TODO: mv the actual config file once we switch to .yaml for min-risk
        # shutil.copy(config['config_file'], config['saveto'])
        # shutil.copy(config['config_file'], config['saveto'])

        # TODO: this breaks when we directly reference a class in the config obj instead of using reflection
        with codecs.open(os.path.join(config['saveto'], 'config.yaml'),
                         'w',
                         encoding='utf8') as yaml_out:
            yaml_out.write(yaml.dump(config))

    # Set extensions
    logger.info("Initializing extensions")
    extensions = [
        FinishAfter(after_n_batches=config['finish_after']),
        TrainingDataMonitoring([cost], after_batch=True),
        Printing(after_batch=True),
        CheckpointNMT(config['saveto'], every_n_batches=config['save_freq'])
    ]

    # Set up beam search and sampling computation graphs if necessary
    # TODO: change the if statement here
    if config['hook_samples'] >= 1 or config['bleu_script'] is not None:
        logger.info("Building sampling model")
        sampling_representation = train_encoder.apply(
            theano_sampling_source_input,
            tensor.ones(theano_sampling_source_input.shape))
        # TODO: the generated output actually contains several more values, ipdb to see what they are
        generated = train_decoder.generate(theano_sampling_source_input,
                                           sampling_representation,
                                           theano_sampling_context_input)
        search_model = Model(generated)
        _, samples = VariableFilter(
            bricks=[train_decoder.sequence_generator], name="outputs")(
                ComputationGraph(generated[1]))  # generated[1] is next_outputs

    # Add sampling -- TODO: sampling is broken for min-risk
    #if config['hook_samples'] >= 1:
    #    logger.info("Building sampler")
    #    extensions.append(
    #        Sampler(model=search_model, data_stream=tr_stream,
    #                hook_samples=config['hook_samples'],
    #                every_n_batches=config['sampling_freq'],
    #                src_vocab_size=config['src_vocab_size']))

    # Add early stopping based on bleu
    # TODO: use multimodal meteor and BLEU validator
    # Add early stopping based on bleu
    if config.get('bleu_script', None) is not None:
        logger.info("Building bleu validator")
        extensions.append(
            BleuValidator(theano_sampling_source_input,
                          theano_sampling_context_input,
                          samples=samples,
                          config=config,
                          model=search_model,
                          data_stream=dev_stream,
                          src_vocab=src_vocab,
                          trg_vocab=trg_vocab,
                          normalize=config['normalized_bleu'],
                          every_n_batches=config['bleu_val_freq']))

    # Add early stopping based on Meteor
    if config.get('meteor_directory', None) is not None:
        logger.info("Building meteor validator")
        extensions.append(
            MeteorValidator(theano_sampling_source_input,
                            theano_sampling_context_input,
                            samples=samples,
                            config=config,
                            model=search_model,
                            data_stream=dev_stream,
                            src_vocab=src_vocab,
                            trg_vocab=trg_vocab,
                            normalize=config['normalized_bleu'],
                            every_n_batches=config['bleu_val_freq']))

    # Reload model if necessary
    if config['reload']:
        extensions.append(LoadNMT(config['saveto']))

    # Plot cost in bokeh if necessary
    if use_bokeh and BOKEH_AVAILABLE:
        extensions.append(
            Plot(config['model_save_directory'],
                 channels=[[
                     'decoder_cost_cost', 'validation_set_bleu_score',
                     'validation_set_meteor_score'
                 ]],
                 every_n_batches=10))

    # Set up training algorithm
    logger.info("Initializing training algorithm")

    # if there is l2_regularization, dropout or random noise, we need to use the output of the modified graph
    if config['dropout'] < 1.0:
        algorithm = GradientDescent(cost=cg.outputs[0],
                                    parameters=cg.parameters,
                                    step_rule=CompositeRule([
                                        StepClipping(config['step_clipping']),
                                        eval(config['step_rule'])()
                                    ]),
                                    on_unused_sources='warn')
    else:
        algorithm = GradientDescent(cost=cost,
                                    parameters=cg.parameters,
                                    step_rule=CompositeRule([
                                        StepClipping(config['step_clipping']),
                                        eval(config['step_rule'])()
                                    ]),
                                    on_unused_sources='warn')

    #algorithm = GradientDescent(
    #    cost=cost, parameters=cg.parameters,
    #    step_rule=CompositeRule([StepClipping(config['step_clipping']),
    #                             eval(config['step_rule'])()],
    #                           ),
    #    on_unused_sources='warn'
    #)

    # enrich the logged information
    extensions.append(Timing(every_n_batches=100))

    # Initialize main loop
    logger.info("Initializing main loop")
    main_loop = MainLoop(model=model,
                         algorithm=algorithm,
                         data_stream=tr_stream,
                         extensions=extensions)

    # Train!
    main_loop.run()
Esempio n. 6
0
def main(config,
         tr_stream,
         dev_stream,
         use_bokeh=False,
         src_vocab=None,
         trg_vocab=None):

    # 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')
    sampling_input = tensor.lmatrix('input')

    # Construct model
    logger.info('Building RNN encoder-decoder')
    encoder = BidirectionalEncoder(config['src_vocab_size'],
                                   config['enc_embed'], config['enc_nhids'])
    decoder = Decoder(config['trg_vocab_size'], config['dec_embed'],
                      config['dec_nhids'], config['enc_nhids'] * 2)
    cost = decoder.cost(encoder.apply(source_sentence, source_sentence_mask),
                        source_sentence_mask, target_sentence,
                        target_sentence_mask)

    # Initialize model
    logger.info('Initializing model')
    encoder.weights_init = decoder.weights_init = IsotropicGaussian(
        config['weight_scale'])
    encoder.biases_init = decoder.biases_init = Constant(0)
    encoder.push_initialization_config()
    decoder.push_initialization_config()
    encoder.bidir.prototype.weights_init = Orthogonal()
    decoder.transition.weights_init = Orthogonal()
    encoder.initialize()
    decoder.initialize()

    logger.info('Creating computational graph')
    cg = ComputationGraph(cost)

    # GRAPH TRANSFORMATIONS FOR BETTER TRAINING

    # TODO: allow user to remove some params from the graph, for example if embeddings should be kept static
    if config.get('l2_regularization', False) is True:
        l2_reg_alpha = config['l2_regularization_alpha']
        logger.info(
            'Applying l2 regularization with alpha={}'.format(l2_reg_alpha))
        model_weights = VariableFilter(roles=[WEIGHT])(cg.variables)

        for W in model_weights:
            cost = cost + (l2_reg_alpha * (W**2).sum())

        # why do we need to name the cost variable? Where did the original name come from?
        cost.name = 'decoder_cost_cost'

    cg = ComputationGraph(cost)

    # apply dropout for regularization
    if config['dropout'] < 1.0:
        # dropout is applied to the output of maxout in ghog
        # this is the probability of dropping out, so you probably want to make it <=0.5
        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)))

    # Print parameter names
    enc_dec_param_dict = merge(
        Selector(encoder).get_parameters(),
        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)))

    # Set up training model
    logger.info("Building model")
    training_model = Model(cost)

    # allow user to externally initialize some params
    model_params = training_model.get_parameter_dict()
    if config.get('external_embeddings', None) is not None:
        for key in config['external_embeddings']:
            path_to_params = config['external_embeddings'][key]
            logger.info(
                'Replacing {} parameters with external params at: {}'.format(
                    key, path_to_params))
            external_params = numpy.load(path_to_params)
            len_external_idx = external_params.shape[0]
            print(external_params.shape)
            # Working: look in the dictionary and overwrite the correct rows
            existing_params = model_params[key].get_value()
            if key == '/bidirectionalencoder/embeddings.W':
                vocab = src_vocab
            elif key == '/decoder/sequencegenerator/readout/lookupfeedbackwmt15/lookuptable.W':
                vocab = trg_vocab
            else:
                raise KeyError(
                    'Unknown embedding parameter key: {}'.format(key))
            for k, i in vocab.items():
                if i < len_external_idx:
                    existing_params[i] = external_params[i]

            # model_params_shape = model_params[key].get_value().shape
            # assert model_params[key].get_value().shape == external_params.shape, ("Parameter dims must not change,"
            #                                                                       "shapes {} and {} do not match".
            #                                                                       format(model_params_shape,
            #                                                                              external_params.shape))
            model_params[key].set_value(existing_params)

    # create the training directory, and copy this config there if directory doesn't exist
    if not os.path.isdir(config['saveto']):
        os.makedirs(config['saveto'])
        shutil.copy(config['config_file'], config['saveto'])

    # Set extensions
    logger.info("Initializing extensions")
    extensions = []

    # Set up beam search and sampling computation graphs if necessary
    if config['hook_samples'] >= 1 or config['bleu_script'] is not None:
        logger.info("Building sampling model")
        sampling_representation = encoder.apply(
            sampling_input, tensor.ones(sampling_input.shape))
        # note that generated containes several different outputs
        generated = decoder.generate(sampling_input, sampling_representation)
        search_model = Model(generated)
        _, samples = VariableFilter(
            bricks=[decoder.sequence_generator], name="outputs")(
                ComputationGraph(generated[1]))  # generated[1] is next_outputs

    # Add sampling
    # Note: this is broken for unicode chars
    #if config['hook_samples'] >= 1:
    #    logger.info("Building sampler")
    #    extensions.append(
    #        Sampler(model=search_model, data_stream=tr_stream,
    #                hook_samples=config['hook_samples'],
    #                every_n_batches=config['sampling_freq'],
    #                src_vocab_size=config['src_vocab_size']))

    # WORKING: remove these validators in favor of Async
    # TODO: implement burn-in in the validation extension (don't fire until we're past the burn-in iteration)
    # Add early stopping based on bleu
    # if config.get('bleu_script', None) is not None:
    #     logger.info("Building bleu validator")
    #     extensions.append(
    #         BleuValidator(sampling_input, samples=samples, config=config,
    #                       model=search_model, data_stream=dev_stream,
    #                       normalize=config['normalized_bleu'],
    #                       every_n_batches=config['bleu_val_freq']))

    # Add early stopping based on Meteor
    # if config.get('meteor_directory', None) is not None:
    #     logger.info("Building meteor validator")
    #     extensions.append(
    #         MeteorValidator(sampling_input, samples=samples, config=config,
    #                       model=search_model, data_stream=dev_stream,
    #                       normalize=config['normalized_bleu'],
    #                       every_n_batches=config['bleu_val_freq']))

    # Reload model if necessary
    if config['reload']:
        extensions.append(LoadNMT(config['saveto']))

    # Set up training algorithm
    logger.info("Initializing training algorithm")
    # if there is dropout or random noise, we need to use the output of the modified graph
    if config['dropout'] < 1.0 or config['weight_noise_ff'] > 0.0:
        algorithm = GradientDescent(cost=cg.outputs[0],
                                    parameters=cg.parameters,
                                    step_rule=CompositeRule([
                                        StepClipping(config['step_clipping']),
                                        eval(config['step_rule'])()
                                    ]))
    else:
        algorithm = GradientDescent(cost=cost,
                                    parameters=cg.parameters,
                                    step_rule=CompositeRule([
                                        StepClipping(config['step_clipping']),
                                        eval(config['step_rule'])()
                                    ]))

    # enrich the logged information
    extensions.extend([
        Timing(every_n_batches=100),
        FinishAfter(after_n_batches=config['finish_after']),
        TrainingDataMonitoring([cost], after_batch=True),
        Printing(after_batch=True),
        CheckpointNMT(config['saveto'], every_n_batches=config['save_freq'])
    ])

    # External non-blocking validation
    extensions.append(
        RunExternalValidation(config=config,
                              every_n_batches=config['bleu_val_freq']))

    # Plot cost in bokeh if necessary
    if use_bokeh and BOKEH_AVAILABLE:
        extensions.append(
            Plot(config['model_save_directory'],
                 channels=[['decoder_cost_cost'],
                           ['validation_set_bleu_score'],
                           ['validation_set_meteor_score']],
                 every_n_batches=1))

    # Initialize main loop
    logger.info("Initializing main loop")
    main_loop = MainLoop(model=training_model,
                         algorithm=algorithm,
                         data_stream=tr_stream,
                         extensions=extensions)

    # Train!
    main_loop.run()
Esempio n. 7
0
def main(mode, config, use_bokeh=False):

    # Construct model
    logger.info('Building RNN encoder-decoder')
    encoder = BidirectionalEncoder(config['src_vocab_size'],
                                   config['enc_embed'], config['enc_nhids'])
    decoder = Decoder(config['trg_vocab_size'], config['dec_embed'],
                      config['dec_nhids'], config['enc_nhids'] * 2)

    if mode == "train":

        # 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')
        sampling_input = tensor.lmatrix('input')

        # Get training and development set streams
        tr_stream = get_tr_stream(**config)
        dev_stream = get_dev_stream(**config)

        # Get cost of the model
        cost = decoder.cost(
            encoder.apply(source_sentence, source_sentence_mask),
            source_sentence_mask, target_sentence, target_sentence_mask)

        logger.info('Creating computational graph')
        cg = ComputationGraph(cost)

        # Initialize model
        logger.info('Initializing model')
        encoder.weights_init = decoder.weights_init = IsotropicGaussian(
            config['weight_scale'])
        encoder.biases_init = decoder.biases_init = Constant(0)
        encoder.push_initialization_config()
        decoder.push_initialization_config()
        encoder.bidir.prototype.weights_init = Orthogonal()
        decoder.transition.weights_init = Orthogonal()
        encoder.initialize()
        decoder.initialize()

        # 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'])

        # Apply weight noise for regularization
        if config['weight_noise_ff'] > 0.0:
            logger.info('Applying weight noise to ff layers')
            enc_params = Selector(encoder.lookup).get_params().values()
            enc_params += Selector(encoder.fwd_fork).get_params().values()
            enc_params += Selector(encoder.back_fork).get_params().values()
            dec_params = Selector(
                decoder.sequence_generator.readout).get_params().values()
            dec_params += Selector(
                decoder.sequence_generator.fork).get_params().values()
            dec_params += Selector(decoder.state_init).get_params().values()
            cg = apply_noise(cg, enc_params + dec_params,
                             config['weight_noise_ff'])

        # 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)))

        # Print parameter names
        enc_dec_param_dict = merge(
            Selector(encoder).get_parameters(),
            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)))

        # Set up training model
        logger.info("Building model")
        training_model = Model(cost)

        # Set extensions
        logger.info("Initializing extensions")
        extensions = [
            FinishAfter(after_n_batches=config['finish_after']),
            TrainingDataMonitoring([cost], after_batch=True),
            Printing(after_batch=True),
            CheckpointNMT(config['saveto'],
                          every_n_batches=config['save_freq'])
        ]

        # Set up beam search and sampling computation graphs if necessary
        if config['hook_samples'] >= 1 or config['bleu_script'] is not None:
            logger.info("Building sampling model")
            sampling_representation = encoder.apply(
                sampling_input, tensor.ones(sampling_input.shape))
            generated = decoder.generate(sampling_input,
                                         sampling_representation)
            search_model = Model(generated)
            _, samples = VariableFilter(bricks=[decoder.sequence_generator],
                                        name="outputs")(ComputationGraph(
                                            generated[1]))

        # Add sampling
        if config['hook_samples'] >= 1:
            logger.info("Building sampler")
            extensions.append(
                Sampler(model=search_model,
                        data_stream=tr_stream,
                        hook_samples=config['hook_samples'],
                        every_n_batches=config['sampling_freq'],
                        src_vocab_size=config['src_vocab_size']))

        # Add early stopping based on bleu
        if config['bleu_script'] is not None:
            logger.info("Building bleu validator")
            extensions.append(
                BleuValidator(sampling_input,
                              samples=samples,
                              config=config,
                              model=search_model,
                              data_stream=dev_stream,
                              normalize=config['normalized_bleu'],
                              every_n_batches=config['bleu_val_freq']))

        # Reload model if necessary
        if config['reload']:
            extensions.append(LoadNMT(config['saveto']))

        # Plot cost in bokeh if necessary
        if use_bokeh and BOKEH_AVAILABLE:
            extensions.append(
                Plot('Cs-En',
                     channels=[['decoder_cost_cost']],
                     after_batch=True))

        # 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=training_model,
                             algorithm=algorithm,
                             data_stream=tr_stream,
                             extensions=extensions)

        # Train!
        main_loop.run()

    elif mode == 'translate':

        # Create Theano variables
        logger.info('Creating theano variables')
        sampling_input = tensor.lmatrix('source')

        # Get test set stream
        test_stream = get_dev_stream(config['test_set'], config['src_vocab'],
                                     config['src_vocab_size'],
                                     config['unk_id'])
        ftrans = open(config['test_set'] + '.trans.out', 'w')

        # Helper utilities
        sutils = SamplingBase()
        unk_idx = config['unk_id']
        src_eos_idx = config['src_vocab_size'] - 1
        trg_eos_idx = config['trg_vocab_size'] - 1

        # Get beam search
        logger.info("Building sampling model")
        sampling_representation = encoder.apply(
            sampling_input, tensor.ones(sampling_input.shape))
        generated = decoder.generate(sampling_input, sampling_representation)
        _, samples = VariableFilter(
            bricks=[decoder.sequence_generator], name="outputs")(
                ComputationGraph(generated[1]))  # generated[1] is next_outputs
        beam_search = BeamSearch(samples=samples)

        logger.info("Loading the model..")
        model = Model(generated)
        loader = LoadNMT(config['saveto'])
        loader.set_model_parameters(model, loader.load_parameters())

        # Get target vocabulary
        trg_vocab = _ensure_special_tokens(pickle.load(
            open(config['trg_vocab'])),
                                           bos_idx=0,
                                           eos_idx=trg_eos_idx,
                                           unk_idx=unk_idx)
        trg_ivocab = {v: k for k, v in trg_vocab.items()}

        logger.info("Started translation: ")
        total_cost = 0.0

        for i, line in enumerate(test_stream.get_epoch_iterator()):

            seq = sutils._oov_to_unk(line[0], config['src_vocab_size'],
                                     unk_idx)
            input_ = numpy.tile(seq, (config['beam_size'], 1))

            # draw sample, checking to ensure we don't get an empty string back
            trans, costs = \
                beam_search.search(
                    input_values={sampling_input: input_},
                    max_length=3*len(seq), eol_symbol=src_eos_idx,
                    ignore_first_eol=True)

            # normalize costs according to the sequence lengths
            if config['normalized_bleu']:
                lengths = numpy.array([len(s) for s in trans])
                costs = costs / lengths

            best = numpy.argsort(costs)[0]
            try:
                total_cost += costs[best]
                trans_out = trans[best]

                # convert idx to words
                trans_out = sutils._idx_to_word(trans_out, trg_ivocab)

            except ValueError:
                logger.info(
                    "Can NOT find a translation for line: {}".format(i + 1))
                trans_out = '<UNK>'

            print(trans_out, file=ftrans)

            if i != 0 and i % 100 == 0:
                logger.info("Translated {} lines of test set...".format(i))

        logger.info("Total cost of the test: {}".format(total_cost))
        ftrans.close()
Esempio n. 8
0
def main(config,
         tr_stream,
         dev_stream,
         source_vocab,
         target_vocab,
         use_bokeh=False):

    # add the tags from this function to the IMT datastream
    # prediction function signature
    # [target_suffix, source_mask, source, target_prefix_mask, target_prefix, target_suffix_mask]
    prediction_function = get_prediction_function(exp_config=config)

    tr_stream = Mapping(
        tr_stream,
        CallPredictionFunctionOnStream(prediction_function,
                                       [1, 0, 5, 4, 7, 6]),
        #tr_stream = Mapping(tr_stream, CallFunctionOnStream(prediction_function, [6, 1, 0, 5, 4, 7]),
        add_sources=('predictions', 'orig_readouts', 'prediction_tags'))

    # now datastream has 11 things
    import ipdb
    ipdb.set_trace()

    # WORKING: call prediction function twice to get new readouts on predictions instead of reference suffs
    # the only difference is the index of the suffix
    tr_stream = Mapping(tr_stream,
                        CallPredictionFunctionOnStream(prediction_function,
                                                       [1, 0, 5, 4, 7, 8]),
                        add_sources=('dummy_predictions', 'readouts',
                                     'dummy_prediction_tags'))

    import ipdb
    ipdb.set_trace()

    # Create the prediction confidence model
    # the first draft of this model uses the readout output (before the post-merge step) as the per-timestep state vector

    # Create Theano variables
    logger.info('Creating theano variables')
    source_sentence = tensor.lmatrix('source')
    source_sentence_mask = tensor.matrix('source_mask')

    # Note that the _names_ are changed from normal NMT
    # for IMT training, we use only the suffix as the reference
    target_sentence = tensor.lmatrix('target_suffix')
    target_sentence_mask = tensor.matrix('target_suffix_mask')

    target_prefix = tensor.lmatrix('target_prefix')
    target_prefix_mask = tensor.matrix('target_prefix_mask')

    # symbolic variable which tags each timestep as GOOD/BAD
    # Note: later this might be tags for a hypothesis i.e. from TER(p), right now the timesteps are actually determined by the reference
    # By zipping the confidence model output with the reference, we get the model's confidence that this reference word
    # will be predicted correctly
    prediction_tags = tensor.matrix('prediction_tags')
    readouts = tensor.tensor3('readouts')

    # Construct model
    logger.info('Building RNN encoder-decoder')
    encoder = BidirectionalEncoder(config['src_vocab_size'],
                                   config['enc_embed'], config['enc_nhids'])

    decoder = NMTPrefixDecoder(config['trg_vocab_size'],
                               config['dec_embed'],
                               config['dec_nhids'],
                               config['enc_nhids'] * 2,
                               loss_function='cross_entropy')

    # rename to match baseline NMT systems
    decoder.name = 'decoder'

    cost = decoder.confidence_cost(
        encoder.apply(source_sentence, source_sentence_mask),
        source_sentence_mask, target_sentence, target_sentence_mask,
        target_prefix, target_prefix_mask, readouts, prediction_tags)

    # WORKING: add l2 regularization

    logger.info('Creating computational graph')
    # working: implement cost for confidence model
    cg = ComputationGraph(cost)

    # INITIALIZATION
    logger.info('Initializing model')
    encoder.weights_init = decoder.weights_init = IsotropicGaussian(
        config['weight_scale'])
    encoder.biases_init = decoder.biases_init = Constant(0)
    encoder.push_initialization_config()
    decoder.push_initialization_config()
    encoder.bidir.prototype.weights_init = Orthogonal()
    decoder.transition.weights_init = Orthogonal()
    encoder.initialize()
    decoder.initialize()

    #cost_cg = ComputationGraph(cost)
    if config['l2_reg']:
        l2_reg_alpha = config['l2_reg_alpha']
        model_weights = VariableFilter(roles=[WEIGHT])(cg.variables)
        for W in model_weights:
            cost = cost + (l2_reg_alpha * (W**2).sum())
        # do we need to name the cost variable again?
        cost.name = 'cost'
        cg = ComputationGraph(cost)

    # apply dropout for regularization
    if config['dropout'] < 1.0:
        # dropout is applied to the output of maxout in ghog
        # this is the probability of dropping out, so you probably want to make it <=0.5
        logger.info('Applying dropout')
        dropout_inputs = [
            x for x in cg.intermediary_variables if x.name in set([
                'confidence_model1_apply_output',
                'confidence_model2_apply_output',
                'confidence_model3_apply_output'
            ])
        ]
        # if x.name == 'maxout_apply_output']
        # if x.name == 'maxout_apply_output']
        cg = apply_dropout(cg, dropout_inputs, config['dropout'])

    # WORKING: implement confidence -- remove all params except output model
    cost_model = Model(cost)

    model_params = cost_model.get_parameter_dict()
    trainable_params = cg.parameters
    import ipdb
    ipdb.set_trace()
    print('trainable params')
    #params_to_remove = [model_params[k] for k in model_params.keys() if 'confidence' not in k]
    #for p in params_to_remove:
    #    trainable_params.remove(p)

    # target_embeddings = model.get_parameter_dict()['/target_recurrent_lm_with_alignments/target_embeddings.W']
    # trainable_params.remove(source_embeddings)
    # trainable_params.remove(target_embeddings)
    # END WORKING: implement confidence -- remove all params except output model

    # TODO: fixed dropout mask for recurrent params?
    # 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)))

    # Print parameter names
    # enc_dec_param_dict = merge(Selector(encoder).get_parameters(),
    #                            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)))

    # Set up training model
    logger.info("Building model")
    training_model = Model(cost)

    # create the training directory, and copy this config there if directory doesn't exist
    if not os.path.isdir(config['saveto']):
        os.makedirs(config['saveto'])
        shutil.copy(config['config_file'], config['saveto'])

    # Set extensions
    logger.info("Initializing extensions")
    extensions = [
        FinishAfter(after_n_batches=config['finish_after']),
        TrainingDataMonitoring([cost], after_batch=True),
        # TrainingDataMonitoring(trainable_params, after_batch=True),
        # Printing(after_batch=True),
        CheckpointNMT(config['saveto'], every_n_batches=config['save_freq'])
    ]

    # WORKING: confidence prediction
    #monitor everything that could possibly be relevant

    # Set up the sampling graph for validation during training
    # Theano variables for the sampling graph
    # Note this also loads the model parameters
    sampling_vars = load_params_and_get_beam_search(config,
                                                    encoder=encoder,
                                                    decoder=decoder)
    beam_search, search_model, samples, sampling_input, sampling_prefix = sampling_vars

    #if config['hook_samples'] >= 1:
    #    logger.info("Building sampler")
    #    extensions.append(
    #        Sampler(model=search_model, data_stream=tr_stream,
    #                hook_samples=config['hook_samples'],
    #                every_n_batches=config['sampling_freq'],
    #                src_vocab=source_vocab,
    #                trg_vocab=target_vocab,
    #                src_vocab_size=config['src_vocab_size']))

    # Add early stopping based on bleu
    #if config['bleu_script'] is not None:
    #    logger.info("Building bleu validator")
    #    extensions.append(
    #        BleuValidator(sampling_input, sampling_prefix, samples=samples, config=config,
    #                      model=search_model, data_stream=dev_stream,
    #                      src_vocab=source_vocab,
    #                      trg_vocab=target_vocab,
    #                      normalize=config['normalized_bleu'],
    #                      every_n_batches=config['bleu_val_freq']))

    # TODO: add first-word accuracy validation
    # TODO: add IMT meteor early stopping
    #if config.get('imt_f1_validation', None) is not None:
    #    logger.info("Building imt F1 validator")
    #    extensions.append(
    #        IMT_F1_Validator(sampling_input, sampling_prefix,
    #                         samples=samples,
    #                         config=config,
    #                         model=search_model, data_stream=dev_stream,
    #                         src_vocab=source_vocab,
    #                         trg_vocab=target_vocab,
    #                         normalize=config['normalized_bleu'],
    #                         every_n_batches=config['bleu_val_freq']))

    # Reload model if necessary
    if config['reload']:
        extensions.append(LoadNMT(config['saveto']))

    # TODO: hacking here: get the predictions of the confidence model using the `readouts` source of the data_stream

    # Note that the parameters of this model must be pretrained, otherwise this doesn't make sense
    # confidence_predictions = decoder.get_confidence(readouts)
    # confidence_prediction_model = Model(confidence_predictions)
    #
    # confidence_param_values = LoadNMT.load_parameter_values(config['confidence_saved_parameters'], brick_delimiter=None)
    # LoadNMT.set_model_parameters(confidence_prediction_model, confidence_param_values)
    #
    # confidence_prediction_func = confidence_prediction_model.get_theano_function()

    # import ipdb; ipdb.set_trace()

    # Plot cost in bokeh if necessary
    if use_bokeh and BOKEH_AVAILABLE:
        extensions.append(
            # Plot(config['model_save_directory'], channels=[['decoder_confidence_cost_cost']],
            Plot(config['model_save_directory'],
                 channels=[['cost']],
                 every_n_batches=10))

    # Set up training algorithm
    logger.info("Initializing training algorithm")

    # WORKING: implement confidence model
    # if there is dropout or random noise, we need to use the output of the modified graph
    algorithm = GradientDescent(
        cost=cg.outputs[0],
        parameters=trainable_params,
        step_rule=CompositeRule([
            StepClipping(config['step_clipping']),
            eval(config['step_rule'])()
        ]),
        # eval(config['step_rule'])(), RemoveNotFinite()]),
        # step_rule=CompositeRule([StepClipping(10.0), Scale(0.01)]),
        on_unused_sources='warn')
    #if config['dropout'] < 1.0:
    #   algorithm = GradientDescent(
    #       cost=cg.outputs[0], parameters=trainable_params,
    #       step_rule=CompositeRule([StepClipping(config['step_clipping']),
    #                         eval(config['step_rule'])(), RemoveNotFinite()]),
    #       # step_rule=CompositeRule([StepClipping(10.0), Scale(0.01)]),
    #       on_unused_sources='warn'
    #   )
    #else:
    #   algorithm = GradientDescent(
    #       cost=cost, parameters=cg.parameters,
    #       step_rule=CompositeRule([StepClipping(config['step_clipping']),
    #                                eval(config['step_rule'])()]),
    #       on_unused_sources='warn'
    #   )
    # END WORKING: implement confidence model

    import ipdb
    ipdb.set_trace()

    # enrich the logged information
    extensions.append(Timing(every_n_batches=100))

    # WORKING: debugging confidence
    # get theano function from model
    # WORKING: implement word-level confidence cost
    #   @application(inputs=['representation', 'source_sentence_mask',
    #                                'target_sentence_mask', 'target_sentence', 'target_prefix_mask', 'target_prefix'],
    #                                                 outputs=['cost'])
    #       def confidence_cost(self, representation, source_sentence_mask,
    #                            target_sentence, target_sentence_mask, target_prefix, target_prefix_mask):

    logger.info('Creating theano variables')

    # WORKING: 26.9.16 -- get confidence outputs directly from (source, prefix, suffix) inputs
    # This is equivalent to forced alignment --> confidence scores
    # Note: but this section should probably be in "evaluate" mode, not here in "train"

    # source_sentence = tensor.lmatrix('source')
    # source_sentence_mask = tensor.matrix('source_mask')

    # Note that the _names_ are changed from normal NMT
    # for IMT training, we use only the suffix as the reference
    #target_sentence = tensor.lmatrix('target_suffix')
    #target_sentence_mask = tensor.matrix('target_suffix_mask')
    # TODO: change names back to *_suffix, there is currently a theano function name error
    # TODO: in the GradientDescent Algorithm

    #target_prefix = tensor.lmatrix('target_prefix')
    #target_prefix_mask = tensor.matrix('target_prefix_mask')

    # confidence_output = decoder.confidence_cost(
    #     encoder.apply(source_sentence, source_sentence_mask),
    #     source_sentence_mask, target_sentence, target_sentence_mask,
    #     target_prefix, target_prefix_mask)

    # confidence_model = Model(confidence_output)

    # t_cost_func = confidence_model.get_theano_function()
    # inputs
    # [source_mask, source, target_prefix_mask, target_prefix, target_suffix_mask, target_suffix]

    #import ipdb;ipdb.set_trace()

    # get the right args from the datastream
    # TODO: just print source, prefix, suffix, prediction, correct to new files -- this makes sure everything is aligned
    # OUTPUT_DIR = '/media/1tb_drive/imt_models/word_prediction_accuracy_experiments/en-de/exp_1'
    # for the_file in os.listdir(OUTPUT_DIR):
    #     file_path = os.path.join(OUTPUT_DIR, the_file)
    #     try:
    #         if os.path.isfile(file_path):
    #             os.unlink(file_path)
    #     except Exception as e:
    #         print(e)
    #
    # def write_file_truncate_mask(filename, data, mask, mode='a'):
    #     ''' data is list of list '''
    #
    #     assert len(data) == len(mask)
    #     with codecs.open(filename, mode, encoding='utf8') as out:
    #         for l, m in zip(data, mask):
    #             output = u' '.join(l[:int(m.sum())]) + u'\n'
    #             out.write(output)
    #     logger.info('Wrote file: {}'.format(filename))
    #
    #
    # target_ivocab = {k:v.decode('utf8') for v,k in target_vocab.items()}
    # source_ivocab = {k:v.decode('utf8') for v,k in source_vocab.items()}
    # import ipdb; ipdb.set_trace()
    # tag_ivocab = {1: 'True', 0: 'False'}
    #
    # test_iter = tr_stream.get_epoch_iterator()
    # it = 0
    # for t_source, t_source_mask, t_target, t_target_mask, t_target_prefix, t_target_prefix_mask, t_target_suffix, t_target_suffix_mask in test_iter:
    #     if it <= 1000:
    #         it += 1
    #         t_cost = t_cost_func(t_source_mask, t_source, t_target_prefix_mask, t_target_prefix, t_target_suffix_mask, t_target_suffix)
    #         readouts = t_cost[0]
    #         preds = readouts.argmax(axis=2)
    #         correct = preds.T == t_target_suffix
    #
    #
    #         source_output = os.path.join(OUTPUT_DIR,'sources.en')
    #         prefix_output = os.path.join(OUTPUT_DIR,'prefixes.de')
    #         suffix_output = os.path.join(OUTPUT_DIR,'suffixes.de')
    #         prediction_output = os.path.join(OUTPUT_DIR,'predictions.de')
    #         correct_output = os.path.join(OUTPUT_DIR,'prefix_word_prediction_acc.out')
    #
    #         source_text = [[source_ivocab[w] for w in s] for s in t_source]
    #         prefix_text = [[target_ivocab[w] for w in s] for s in t_target_prefix]
    #         suffix_text = [[target_ivocab[w] for w in s] for s in t_target_suffix]
    #         pred_text = [[target_ivocab[w] for w in s] for s in preds.T]
    #         correct_text = [[tag_ivocab[w] for w in s] for s in correct]
    #
    #
    #         for triple in zip([source_output, prefix_output, suffix_output, prediction_output, correct_output],
    #                           [source_text, prefix_text, suffix_text, pred_text, correct_text],
    #                           [t_source_mask, t_target_prefix_mask, t_target_suffix_mask, t_target_suffix_mask, t_target_suffix_mask]):
    #             write_file_truncate_mask(*triple)
    #     else:
    #         break
    #
    # import ipdb; ipdb.set_trace()

    #t_cost = t_cost_func(t_source, t_target_prefix)
    #t_cost = t_cost_func(t_target_suffix, t_source_mask, t_source, t_target_prefix_mask, t_target_prefix, t_target_suffix_mask)
    #t_cost = t_cost_func(t_source_mask, t_source, t_target_prefix_mask, t_target_prefix, t_target_suffix_mask, t_target_suffix)

    #    return confidence_cost, flat_y, confidence_logits, readouts

    #predictions = t_cost[0].argmax(axis=2)

    # TODO: next step -- print gradients and weights during training find out where nan is coming from
    # TODO: look at the gradient of this function with respect to parameters? -- see here: http://deeplearning.net/software/theano/tutorial/gradients.html

    # TODO: function which adds right/wrong tags for model predictions to the datastream. In this case we can learn a simple linear model as a baseline
    # TODO: print predictions for each batch for each timestep to file -- _dont shuffle_ so that we get the right order

    # import ipdb;ipdb.set_trace()

    # from blocks reverse_words example
    # 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, parameter in trainable_params.items():
    #     observables.append(parameter.norm(2).copy(name + "_norm"))
    #     observables.append(algorithm.gradients[parameter].norm(2).copy(
    #         name + "_grad_norm"))

    for i, (k, v) in enumerate(algorithm.updates):
        v.name = k.name + '_{}'.format(i)

    aux_vars = [v for v in cg.auxiliary_variables[-3:]]
    # import ipdb; ipdb.set_trace()

    extensions.extend([
        TrainingDataMonitoring([cost], after_batch=True),
        # TrainingDataMonitoring([v for k,v in algorithm.updates[:2]], after_batch=True),
        # TrainingDataMonitoring(aux_vars, after_batch=True),
        # TrainingDataMonitoring(trainable_params, after_batch=True),
        Printing(after_batch=True)
    ])

    # Initialize main loop
    logger.info("Initializing main loop")
    main_loop = MainLoop(model=training_model,
                         algorithm=algorithm,
                         data_stream=tr_stream,
                         extensions=extensions)
    import ipdb
    ipdb.set_trace()

    # Train!
    main_loop.run()
def main(config, tr_stream, dev_stream, use_bokeh=False):

    # 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')
    initial_context = tensor.matrix('initial_context')

    # Construct model
    logger.info('Building RNN encoder-decoder')
    encoder = BidirectionalEncoder(
        config['src_vocab_size'], config['enc_embed'], config['enc_nhids'])

    decoder = InitialContextDecoder(
        config['trg_vocab_size'], config['dec_embed'], config['dec_nhids'],
        config['enc_nhids'] * 2, config['context_dim'])
    
    cost = decoder.cost(
        encoder.apply(source_sentence, source_sentence_mask),
        source_sentence_mask, target_sentence, target_sentence_mask, initial_context)

    cost.name = 'decoder_cost'

    logger.info('Creating computational graph')
    cg = ComputationGraph(cost)

    # Initialize model
    logger.info('Initializing model')
    encoder.weights_init = decoder.weights_init = IsotropicGaussian(
        config['weight_scale'])
    encoder.biases_init = decoder.biases_init = Constant(0)
    encoder.push_initialization_config()
    decoder.push_initialization_config()
    encoder.bidir.prototype.weights_init = Orthogonal()
    decoder.transition.weights_init = Orthogonal()
    encoder.initialize()
    decoder.initialize()

    # apply dropout for regularization
    if config['dropout'] < 1.0:
        # dropout is applied to the output of maxout in ghog
        # this is the probability of dropping out, so you probably want to make it <=0.5
        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'])

    # Apply weight noise for regularization
    if config['weight_noise_ff'] > 0.0:
        logger.info('Applying weight noise to ff layers')
        enc_params = Selector(encoder.lookup).get_parameters().values()
        enc_params += Selector(encoder.fwd_fork).get_parameters().values()
        enc_params += Selector(encoder.back_fork).get_parameters().values()
        dec_params = Selector(
            decoder.sequence_generator.readout).get_parameters().values()
        dec_params += Selector(
            decoder.sequence_generator.fork).get_parameters().values()
        dec_params += Selector(decoder.transition.initial_transformer).get_parameters().values()
        cg = apply_noise(cg, enc_params+dec_params, config['weight_noise_ff'])

    # TODO: weight noise for recurrent params isn't currently implemented -- see config['weight_noise_rec']
    # 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)))

    # Print parameter names
    enc_dec_param_dict = merge(Selector(encoder).get_parameters(),
                               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)))

    # Set up training model
    logger.info("Building model")
    training_model = Model(cost)

    # create the training directory, and copy this config there if directory doesn't exist
    if not os.path.isdir(config['saveto']):
        os.makedirs(config['saveto'])
        shutil.copy(config['config_file'], config['saveto'])

    # Set extensions

    # TODO: add checking for existing model and loading
    logger.info("Initializing extensions")
    extensions = [
        FinishAfter(after_n_batches=config['finish_after']),
        TrainingDataMonitoring([cost], after_batch=True),
        Printing(after_batch=True),
        CheckpointNMT(config['saveto'],
                      every_n_batches=config['save_freq'])
    ]

    # Create the theano variables that we need for the sampling graph
    sampling_input = tensor.lmatrix('input')
    sampling_context = tensor.matrix('context_input')
    
    # WORKING: change this part to account for the new initial context for decoder
    # Set up beam search and sampling computation graphs if necessary
    if config['hook_samples'] >= 1 or config['bleu_script'] is not None:
        logger.info("Building sampling model")
        sampling_representation = encoder.apply(
            sampling_input, tensor.ones(sampling_input.shape))
        
        generated = decoder.generate(sampling_input, sampling_representation, sampling_context)
        search_model = Model(generated)
        _, samples = VariableFilter(
            bricks=[decoder.sequence_generator], name="outputs")(
                ComputationGraph(generated[1]))  # generated[1] is next_outputs

    # Add sampling
    # TODO: currently commented because we need to modify the sampler to use the contexts
    if config['hook_samples'] >= 1:
        logger.info("Building sampler")
        extensions.append(
            Sampler(model=search_model, data_stream=tr_stream,
                    hook_samples=config['hook_samples'],
                    every_n_batches=config['sampling_freq'],
                    src_vocab=source_vocab,
                    trg_vocab=target_vocab,
                    src_vocab_size=config['src_vocab_size'],
                   ))


    # TODO: add sampling_context to BleuValidator and Sampler
    # Add early stopping based on bleu
    if config['bleu_script'] is not None:
        logger.info("Building bleu validator")
        extensions.append(
            BleuValidator(sampling_input, sampling_context, samples=samples, config=config,
                          model=search_model, data_stream=dev_stream,
                          src_vocab=source_vocab,
                          trg_vocab=target_vocab,
                          normalize=config['normalized_bleu'],
                          every_n_batches=config['bleu_val_freq']))

    # Reload model if necessary
    if config['reload']:
        extensions.append(LoadNMT(config['saveto']))

    # Plot cost in bokeh if necessary
    if use_bokeh and BOKEH_AVAILABLE:
        extensions.append(
            Plot(config['model_save_directory'], channels=[['decoder_cost', 'validation_set_bleu_score']],
                 every_n_batches=10))

    # Set up training algorithm
    logger.info("Initializing training algorithm")
    # if there is dropout or random noise, we need to use the output of the modified graph
    if config['dropout'] < 1.0 or config['weight_noise_ff'] > 0.0:
        algorithm = GradientDescent(
            cost=cg.outputs[0], parameters=cg.parameters,
            step_rule=CompositeRule([StepClipping(config['step_clipping']),
                                     eval(config['step_rule'])()])
        )
    else:
        algorithm = GradientDescent(
            cost=cost, parameters=cg.parameters,
            step_rule=CompositeRule([StepClipping(config['step_clipping']),
                                     eval(config['step_rule'])()])
        )

    # enrich the logged information
    extensions.append(
        Timing(every_n_batches=100)
    )

    # Initialize main loop
    logger.info("Initializing main loop")
    main_loop = MainLoop(
        model=training_model,
        algorithm=algorithm,
        data_stream=tr_stream,
        extensions=extensions
    )

    # Train!
    main_loop.run()
Esempio n. 10
0
# Print number of params
logger.info("Number of parameters: {}"
            .format(sum(reduce(lambda a, b: a * b, p.get_value().shape) for p in cg.parameters)))

# Set up training model
logger.info("Building model")
training_model = Model(cost)

# Set extensions
logger.info("Initializing extensions")
extensions = [
    FinishAfter(after_n_batches=config['finish_after']),
    TrainingDataMonitoring([cost], after_batch=True),
    Printing(after_batch=True),
    CheckpointNMT(config['saveto'],
                  every_n_batches=config['save_freq'])
]

# Set up beam search and sampling computation graphs if necessary
if config['hook_samples'] >= 1 or config['bleu_script'] is not None:
    logger.info("Building sampling model")
    sampling_representation = encoder.apply(sampling_input, tensor.ones(sampling_input.shape))
    generated = decoder.generate(sampling_input, sampling_representation)
    search_model = Model(generated)

    _, samples = VariableFilter(
        bricks=[decoder.sequence_generator], name="outputs")(
            ComputationGraph(generated[1]))  # generated[1] is next_outputs

# Add sampling
if config['hook_samples'] >= 1: