Exemplo n.º 1
0
    def test_run_simple_model(self):
        vocab_size = 6
        mask_model = shakespeare_models.create_recurrent_model(
            vocab_size, sequence_length=5)
        mask_model.compile(optimizer='sgd',
                           loss='sparse_categorical_crossentropy',
                           metrics=[keras_metrics.MaskedCategoricalAccuracy()])

        no_mask_model = shakespeare_models.create_recurrent_model(
            vocab_size, sequence_length=5, mask_zero=False)
        no_mask_model.compile(
            optimizer='sgd',
            loss='sparse_categorical_crossentropy',
            metrics=[keras_metrics.MaskedCategoricalAccuracy()])

        constant_test_weights = tf.nest.map_structure(tf.ones_like,
                                                      mask_model.weights)
        mask_model.set_weights(constant_test_weights)
        no_mask_model.set_weights(constant_test_weights)

        # `tf.data.Dataset.from_tensor_slices` aggresively coalesces the input into
        # a single tensor, but we want a tuple of two tensors per example, so we
        # apply a transformation to split.
        def split_to_tuple(t):
            return (t[0, :], t[1, :])

        data = tf.data.Dataset.from_tensor_slices([
            ([0, 1, 2, 3, 4], [1, 2, 3, 4, 0]),
            ([2, 3, 4, 0, 1], [3, 4, 0, 1, 2]),
        ]).map(split_to_tuple).batch(2)
        mask_metrics = mask_model.evaluate(data)
        no_mask_metrics = no_mask_model.evaluate(data)

        self.assertNotAllClose(mask_metrics, no_mask_metrics, atol=1e-3)
def run_centralized(optimizer: tf.keras.optimizers.Optimizer,
                    experiment_name: str,
                    root_output_dir: str,
                    num_epochs: int,
                    batch_size: int,
                    decay_epochs: Optional[int] = None,
                    lr_decay: Optional[float] = None,
                    hparams_dict: Optional[Mapping[str, Any]] = None,
                    sequence_length: Optional[int] = 80,
                    max_batches: Optional[int] = None):
    """Trains a two-layer RNN on Shakespeare next-character-prediction.

  Args:
    optimizer: A `tf.keras.optimizers.Optimizer` used to perform training.
    experiment_name: The name of the experiment. Part of the output directory.
    root_output_dir: The top-level output directory for experiment runs. The
      `experiment_name` argument will be appended, and the directory will
      contain tensorboard logs, metrics written as CSVs, and a CSV of
      hyperparameter choices (if `hparams_dict` is used).
    num_epochs: The number of training epochs.
    batch_size: The batch size, used for train, validation, and test.
    decay_epochs: The number of epochs of training before decaying the learning
      rate. If None, no decay occurs.
    lr_decay: The amount to decay the learning rate by after `decay_epochs`
      training epochs have occurred.
    hparams_dict: A mapping with string keys representing the hyperparameters
      and their values. If not None, this is written to CSV.
    sequence_length: The sequence length used for Shakespeare preprocessing.
    max_batches: If set to a positive integer, datasets are capped to at most
      that many batches. If set to None or a nonpositive integer, the full
      datasets are used.
  """

    train_dataset, eval_dataset = shakespeare_dataset.get_centralized_datasets(
        train_batch_size=batch_size,
        max_train_batches=max_batches,
        max_test_batches=max_batches,
        sequence_length=sequence_length)

    pad_token, _, _, _ = shakespeare_dataset.get_special_tokens()
    model = shakespeare_models.create_recurrent_model(
        vocab_size=VOCAB_SIZE, sequence_length=sequence_length)
    model.compile(
        optimizer=optimizer,
        loss=tf.keras.losses.SparseCategoricalCrossentropy(from_logits=True),
        metrics=[
            keras_metrics.MaskedCategoricalAccuracy(masked_tokens=[pad_token])
        ])

    centralized_training_loop.run(keras_model=model,
                                  train_dataset=train_dataset,
                                  validation_dataset=eval_dataset,
                                  experiment_name=experiment_name,
                                  root_output_dir=root_output_dir,
                                  num_epochs=num_epochs,
                                  hparams_dict=hparams_dict,
                                  decay_epochs=decay_epochs,
                                  lr_decay=lr_decay)
def main(argv):
    if len(argv) > 1:
        raise app.UsageError('Too many command-line arguments.')

    train_client_data, test_client_data = (
        tff.simulation.datasets.shakespeare.load_data())

    def preprocess(ds):
        return shakespeare_dataset.convert_snippets_to_character_sequence_examples(
            dataset=ds,
            batch_size=FLAGS.batch_size,
            epochs=1,
            shuffle_buffer_size=0,
            sequence_length=FLAGS.shakespeare_sequence_length)

    train_dataset = train_client_data.create_tf_dataset_from_all_clients()
    if FLAGS.shuffle_train_data:
        train_dataset = train_dataset.shuffle(buffer_size=10000)
    train_dataset = preprocess(train_dataset)

    eval_dataset = preprocess(
        test_client_data.create_tf_dataset_from_all_clients())

    optimizer = optimizer_utils.create_optimizer_fn_from_flags('centralized')()

    pad_token, _, _, _ = shakespeare_dataset.get_special_tokens()
    model = shakespeare_models.create_recurrent_model(
        vocab_size=VOCAB_SIZE,
        sequence_length=FLAGS.shakespeare_sequence_length)
    model.compile(
        optimizer=optimizer,
        loss=tf.keras.losses.SparseCategoricalCrossentropy(from_logits=True),
        metrics=[
            keras_metrics.MaskedCategoricalAccuracy(masked_tokens=[pad_token])
        ])

    hparams_dict = collections.OrderedDict([(name, FLAGS[name].value)
                                            for name in hparam_flags])

    centralized_training_loop.run(keras_model=model,
                                  train_dataset=train_dataset,
                                  validation_dataset=eval_dataset,
                                  experiment_name=FLAGS.experiment_name,
                                  root_output_dir=FLAGS.root_output_dir,
                                  num_epochs=FLAGS.num_epochs,
                                  hparams_dict=hparams_dict,
                                  decay_epochs=FLAGS.decay_epochs,
                                  lr_decay=FLAGS.lr_decay)
Exemplo n.º 4
0
def main(argv):
    if len(argv) > 1:
        raise app.UsageError('Too many command-line arguments.')

    experiment_output_dir = FLAGS.root_output_dir
    tensorboard_dir = os.path.join(experiment_output_dir, 'logdir',
                                   FLAGS.experiment_name)
    results_dir = os.path.join(experiment_output_dir, 'results',
                               FLAGS.experiment_name)

    for path in [experiment_output_dir, tensorboard_dir, results_dir]:
        try:
            tf.io.gfile.makedirs(path)
        except tf.errors.OpError:
            pass  # Directory already exists.

    hparam_dict = collections.OrderedDict([(name, FLAGS[name].value)
                                           for name in hparam_flags])
    hparam_dict['results_file'] = results_dir
    hparams_file = os.path.join(results_dir, 'hparams.csv')
    logging.info('Saving hyper parameters to: [%s]', hparams_file)
    utils_impl.atomic_write_to_csv(pd.Series(hparam_dict), hparams_file)

    train_client_data, test_client_data = (
        tff.simulation.datasets.shakespeare.load_data())

    def preprocess(ds):
        return shakespeare_dataset.convert_snippets_to_character_sequence_examples(
            ds, FLAGS.batch_size, epochs=1).cache()

    train_dataset = train_client_data.create_tf_dataset_from_all_clients()
    if FLAGS.shuffle_train_data:
        train_dataset = train_dataset.shuffle(buffer_size=10000)
    train_dataset = preprocess(train_dataset)

    eval_dataset = preprocess(
        test_client_data.create_tf_dataset_from_all_clients())

    optimizer = optimizer_utils.create_optimizer_fn_from_flags('centralized')()

    pad_token, _, _, _ = shakespeare_dataset.get_special_tokens()

    # Vocabulary with one OOV ID and zero for the mask.
    vocab_size = len(shakespeare_dataset.CHAR_VOCAB) + 2
    model = shakespeare_models.create_recurrent_model(
        vocab_size=vocab_size, batch_size=FLAGS.batch_size)
    model.compile(
        optimizer=optimizer,
        loss=tf.keras.losses.SparseCategoricalCrossentropy(from_logits=True),
        metrics=[
            keras_metrics.MaskedCategoricalAccuracy(masked_tokens=[pad_token])
        ])

    logging.info('Training model:')
    logging.info(model.summary())

    csv_logger_callback = keras_callbacks.AtomicCSVLogger(results_dir)
    tensorboard_callback = tf.keras.callbacks.TensorBoard(
        log_dir=tensorboard_dir)

    # Reduce the learning rate every 20 epochs.
    def decay_lr(epoch, lr):
        if (epoch + 1) % 20 == 0:
            return lr * 0.1
        else:
            return lr

    lr_callback = tf.keras.callbacks.LearningRateScheduler(decay_lr, verbose=1)

    history = model.fit(
        train_dataset,
        validation_data=eval_dataset,
        epochs=FLAGS.num_epochs,
        callbacks=[lr_callback, tensorboard_callback, csv_logger_callback])

    logging.info('Final metrics:')
    for name in ['loss', 'accuracy']:
        metric = history.history['val_{}'.format(name)][-1]
        logging.info('\t%s: %.4f', name, metric)
Exemplo n.º 5
0
def model_builder():
    """Constructs a `tf.keras.Model` to train."""
    return shakespeare_models.create_recurrent_model(
        vocab_size=VOCAB_SIZE, sequence_length=FLAGS.sequence_length)