Example #1
0
def rollout_generator(hparams,
                      inputs,
                      input_present,
                      is_training,
                      is_validating,
                      reuse=None):
    """Define the Generator graph which does rollouts.

    G will now impute tokens that have been masked from the input seqeunce.
  """
    rollouts = []

    with tf.variable_scope('gen_rollout'):
        for n in xrange(FLAGS.num_rollouts):
            if n > 0:
                # TODO(liamfedus): Why is it necessary here to manually set reuse?
                reuse = True
                tf.get_variable_scope().reuse_variables()

            [sequence, logits,
             log_probs] = model_construction.create_generator(hparams,
                                                              inputs,
                                                              input_present,
                                                              is_training,
                                                              is_validating,
                                                              reuse=reuse)

            rollouts.append([sequence, logits, log_probs])

    # Length assertion.
    assert len(rollouts) == FLAGS.num_rollouts

    return rollouts
Example #2
0
def rollout_generator(hparams,
                      inputs,
                      input_present,
                      is_training,
                      is_validating,
                      reuse=None):
  """Define the Generator graph which does rollouts.

    G will now impute tokens that have been masked from the input seqeunce.
  """
  rollouts = []

  with tf.variable_scope('gen_rollout'):
    for n in xrange(FLAGS.num_rollouts):
      if n > 0:
        # TODO(liamfedus): Why is it necessary here to manually set reuse?
        reuse = True
        tf.get_variable_scope().reuse_variables()

      [sequence, logits, log_probs] = model_construction.create_generator(
          hparams,
          inputs,
          input_present,
          is_training,
          is_validating,
          reuse=reuse)

      rollouts.append([sequence, logits, log_probs])

  # Length assertion.
  assert len(rollouts) == FLAGS.num_rollouts

  return rollouts
Example #3
0
def create_rollout_MaskGAN(hparams, is_training):
    """Create the MaskGAN model.

  Args:
    hparams:  Hyperparameters for the MaskGAN.
    is_training:  Boolean indicating operational mode (train/inference).
      evaluated with a teacher forcing regime.

  Return:
    model:  Namedtuple for specifying the MaskGAN."""
    global_step = tf.Variable(0, name='global_step', trainable=False)

    new_learning_rate = tf.placeholder(tf.float32, [],
                                       name='new_learning_rate')
    learning_rate = tf.Variable(0.0, name='learning_rate', trainable=False)
    learning_rate_update = tf.assign(learning_rate, new_learning_rate)

    new_rate = tf.placeholder(tf.float32, [], name='new_rate')
    percent_real_var = tf.Variable(0.0, trainable=False)
    percent_real_update = tf.assign(percent_real_var, new_rate)

    ## Placeholders.
    inputs = tf.placeholder(tf.int32,
                            shape=[FLAGS.batch_size, FLAGS.sequence_length])
    present = tf.placeholder(tf.bool,
                             shape=[FLAGS.batch_size, FLAGS.sequence_length])
    inv_present = tf.placeholder(
        tf.bool, shape=[FLAGS.batch_size, FLAGS.sequence_length])

    ## Rollout Generator.
    fwd_gen_rollouts = rollout_generator(hparams,
                                         inputs,
                                         present,
                                         is_training=is_training,
                                         is_validating=False)
    inv_gen_rollouts = rollout_generator(hparams,
                                         inputs,
                                         inv_present,
                                         is_training=is_training,
                                         is_validating=False,
                                         reuse=True)

    ## Rollout Discriminator.
    fwd_dis_rollouts = rollout_discriminator(hparams,
                                             fwd_gen_rollouts,
                                             is_training=is_training)
    inv_dis_rollouts = rollout_discriminator(hparams,
                                             inv_gen_rollouts,
                                             is_training=is_training,
                                             reuse=True)

    ## Discriminator Loss.
    [dis_loss, dis_loss_pred,
     dis_loss_inv_pred] = rollout_discriminator_loss(fwd_dis_rollouts, present,
                                                     inv_dis_rollouts,
                                                     inv_present)

    ## Average log-perplexity for only missing words.  However, to do this,
    # the logits are still computed using teacher forcing, that is, the ground
    # truth tokens are fed in at each time point to be valid.
    # TODO(liamfedus): Fix the naming convention.
    with tf.variable_scope('gen_rollout'):
        _, fwd_eval_logits, _ = model_construction.create_generator(
            hparams,
            inputs,
            present,
            is_training=False,
            is_validating=True,
            reuse=True)

    avg_log_perplexity = model_losses.calculate_log_perplexity(
        fwd_eval_logits, inputs, present)

    ## Generator Loss.
    # 1.  Cross Entropy losses on missing tokens.
    [fwd_cross_entropy_losses, inv_cross_entropy_losses
     ] = rollout_masked_cross_entropy_loss(inputs, present, inv_present,
                                           fwd_gen_rollouts, inv_gen_rollouts)

    # 2.  GAN losses on missing tokens.
    [fwd_RL_loss, fwd_RL_statistics,
     fwd_averages_op] = rollout_reinforce_objective(hparams, fwd_gen_rollouts,
                                                    fwd_dis_rollouts, present)
    [inv_RL_loss, inv_RL_statistics,
     inv_averages_op] = rollout_reinforce_objective(hparams, inv_gen_rollouts,
                                                    inv_dis_rollouts,
                                                    inv_present)

    # TODO(liamfedus):  Generalize this to use all logs.
    [fwd_sequence, fwd_logits, fwd_log_probs] = fwd_gen_rollouts[-1]
    [inv_sequence, inv_logits, inv_log_probs] = inv_gen_rollouts[-1]

    # TODO(liamfedus):  Generalize this to use all logs.
    fwd_predictions = fwd_dis_rollouts[-1]
    inv_predictions = inv_dis_rollouts[-1]

    # TODO(liamfedus):  Generalize this to use all logs.
    [fwd_log_probs, fwd_rewards, fwd_advantages,
     fwd_baselines] = fwd_RL_statistics[-1]
    [inv_log_probs, inv_rewards, inv_advantages,
     inv_baselines] = inv_RL_statistics[-1]

    ## Pre-training.
    if FLAGS.gen_pretrain_steps:
        # TODO(liamfedus): Rewrite this.
        fwd_cross_entropy_loss = tf.reduce_mean(fwd_cross_entropy_losses)
        gen_pretrain_op = model_optimization.create_gen_pretrain_op(
            hparams, fwd_cross_entropy_loss, global_step)
    else:
        gen_pretrain_op = tf.no_op('gen_pretrain_no_op')
    if FLAGS.dis_pretrain_steps:
        dis_pretrain_op = model_optimization.create_dis_pretrain_op(
            hparams, dis_loss, global_step)
    else:
        dis_pretrain_op = tf.no_op('dis_pretrain_no_op')

    ##  Generator Train Op.
    # 1.  Cross-Entropy.
    if FLAGS.gen_training_strategy == 'cross_entropy':
        gen_loss = tf.reduce_mean(fwd_cross_entropy_losses +
                                  inv_cross_entropy_losses) / 2.
        [gen_train_op, gen_grads,
         gen_vars] = model_optimization.create_gen_train_op(hparams,
                                                            learning_rate,
                                                            gen_loss,
                                                            global_step,
                                                            mode='MINIMIZE')

    # 2.  GAN (REINFORCE)
    elif FLAGS.gen_training_strategy == 'reinforce':
        gen_loss = (fwd_RL_loss + inv_RL_loss) / 2.
        [gen_train_op, gen_grads,
         gen_vars] = model_optimization.create_reinforce_gen_train_op(
             hparams, learning_rate, gen_loss, fwd_averages_op,
             inv_averages_op, global_step)

    else:
        raise NotImplementedError

    ## Discriminator Train Op.
    dis_train_op, dis_grads, dis_vars = model_optimization.create_dis_train_op(
        hparams, dis_loss, global_step)

    ## Summaries.
    with tf.name_scope('general'):
        tf.summary.scalar('percent_real', percent_real_var)
        tf.summary.scalar('learning_rate', learning_rate)

    with tf.name_scope('generator_losses'):
        tf.summary.scalar('gen_loss', tf.reduce_mean(gen_loss))
        tf.summary.scalar('gen_loss_fwd_cross_entropy',
                          tf.reduce_mean(fwd_cross_entropy_losses))
        tf.summary.scalar('gen_loss_inv_cross_entropy',
                          tf.reduce_mean(inv_cross_entropy_losses))

    with tf.name_scope('REINFORCE'):
        with tf.name_scope('objective'):
            tf.summary.scalar('fwd_RL_loss', tf.reduce_mean(fwd_RL_loss))
            tf.summary.scalar('inv_RL_loss', tf.reduce_mean(inv_RL_loss))

        with tf.name_scope('rewards'):
            helper.variable_summaries(fwd_rewards, 'fwd_rewards')
            helper.variable_summaries(inv_rewards, 'inv_rewards')

        with tf.name_scope('advantages'):
            helper.variable_summaries(fwd_advantages, 'fwd_advantages')
            helper.variable_summaries(inv_advantages, 'inv_advantages')

        with tf.name_scope('baselines'):
            helper.variable_summaries(fwd_baselines, 'fwd_baselines')
            helper.variable_summaries(inv_baselines, 'inv_baselines')

        with tf.name_scope('log_probs'):
            helper.variable_summaries(fwd_log_probs, 'fwd_log_probs')
            helper.variable_summaries(inv_log_probs, 'inv_log_probs')

    with tf.name_scope('discriminator_losses'):
        tf.summary.scalar('dis_loss', dis_loss)
        tf.summary.scalar('dis_loss_fwd_sequence', dis_loss_pred)
        tf.summary.scalar('dis_loss_inv_sequence', dis_loss_inv_pred)

    with tf.name_scope('logits'):
        helper.variable_summaries(fwd_logits, 'fwd_logits')
        helper.variable_summaries(inv_logits, 'inv_logits')

    for v, g in zip(gen_vars, gen_grads):
        helper.variable_summaries(v, v.op.name)
        helper.variable_summaries(g, 'grad/' + v.op.name)

    for v, g in zip(dis_vars, dis_grads):
        helper.variable_summaries(v, v.op.name)
        helper.variable_summaries(g, 'grad/' + v.op.name)

    merge_summaries_op = tf.summary.merge_all()

    # Model saver.
    saver = tf.train.Saver(keep_checkpoint_every_n_hours=1, max_to_keep=5)

    # Named tuple that captures elements of the MaskGAN model.
    Model = collections.namedtuple('Model', [
        'inputs', 'present', 'inv_present', 'percent_real_update', 'new_rate',
        'fwd_sequence', 'fwd_logits', 'fwd_rewards', 'fwd_advantages',
        'fwd_log_probs', 'fwd_predictions', 'fwd_cross_entropy_losses',
        'inv_sequence', 'inv_logits', 'inv_rewards', 'inv_advantages',
        'inv_log_probs', 'inv_predictions', 'inv_cross_entropy_losses',
        'avg_log_perplexity', 'dis_loss', 'gen_loss', 'dis_train_op',
        'gen_train_op', 'gen_pretrain_op', 'dis_pretrain_op',
        'merge_summaries_op', 'global_step', 'new_learning_rate',
        'learning_rate_update', 'saver'
    ])

    model = Model(inputs, present, inv_present, percent_real_update, new_rate,
                  fwd_sequence, fwd_logits, fwd_rewards, fwd_advantages,
                  fwd_log_probs, fwd_predictions, fwd_cross_entropy_losses,
                  inv_sequence, inv_logits, inv_rewards, inv_advantages,
                  inv_log_probs, inv_predictions, inv_cross_entropy_losses,
                  avg_log_perplexity, dis_loss, gen_loss, dis_train_op,
                  gen_train_op, gen_pretrain_op, dis_pretrain_op,
                  merge_summaries_op, global_step, new_learning_rate,
                  learning_rate_update, saver)
    return model
def create_MaskGAN(hparams, is_training):
  """Create the MaskGAN model.

  Args:
    hparams:  Hyperparameters for the MaskGAN.
    is_training:  Boolean indicating operational mode (train/inference).
      evaluated with a teacher forcing regime.

  Return:
    model:  Namedtuple for specifying the MaskGAN.
  """
  global_step = tf.Variable(0, name='global_step', trainable=False)

  new_learning_rate = tf.placeholder(tf.float32, [], name='new_learning_rate')
  learning_rate = tf.Variable(0.0, name='learning_rate', trainable=False)
  learning_rate_update = tf.assign(learning_rate, new_learning_rate)

  new_rate = tf.placeholder(tf.float32, [], name='new_rate')
  percent_real_var = tf.Variable(0.0, trainable=False)
  percent_real_update = tf.assign(percent_real_var, new_rate)

  ## Placeholders.
  inputs = tf.placeholder(
      tf.int32, shape=[FLAGS.batch_size, FLAGS.sequence_length])
  targets = tf.placeholder(
      tf.int32, shape=[FLAGS.batch_size, FLAGS.sequence_length])
  present = tf.placeholder(
      tf.bool, shape=[FLAGS.batch_size, FLAGS.sequence_length])
  # TODO(adai): Placeholder for IMDB label.

  ## Real Sequence is the targets.
  real_sequence = targets

  ## Fakse Sequence from the Generator.
  # TODO(adai):  Generator must have IMDB labels placeholder.
  (fake_sequence, fake_logits, fake_log_probs, fake_gen_initial_state,
   fake_gen_final_state, _) = model_construction.create_generator(
       hparams,
       inputs,
       targets,
       present,
       is_training=is_training,
       is_validating=False)
  (_, eval_logits, _, eval_initial_state, eval_final_state,
   _) = model_construction.create_generator(
       hparams,
       inputs,
       targets,
       present,
       is_training=False,
       is_validating=True,
       reuse=True)

  ## Discriminator.
  fake_predictions = model_construction.create_discriminator(
      hparams,
      fake_sequence,
      is_training=is_training,
      inputs=inputs,
      present=present)
  real_predictions = model_construction.create_discriminator(
      hparams,
      real_sequence,
      is_training=is_training,
      reuse=True,
      inputs=inputs,
      present=present)

  ## Critic.
  # The critic will be used to estimate the forward rewards to the Generator.
  if FLAGS.baseline_method == 'critic':
    est_state_values = model_construction.create_critic(
        hparams, fake_sequence, is_training=is_training)
  else:
    est_state_values = None

  ## Discriminator Loss.
  [dis_loss, dis_loss_fake, dis_loss_real] = model_losses.create_dis_loss(
      fake_predictions, real_predictions, present)

  ## Average log-perplexity for only missing words.  However, to do this,
  # the logits are still computed using teacher forcing, that is, the ground
  # truth tokens are fed in at each time point to be valid.
  avg_log_perplexity = model_losses.calculate_log_perplexity(
      eval_logits, targets, present)

  ## Generator Objective.
  # 1.  Cross Entropy losses on missing tokens.
  fake_cross_entropy_losses = model_losses.create_masked_cross_entropy_loss(
      targets, present, fake_logits)

  #  2.  GAN REINFORCE losses.
  [
      fake_RL_loss, fake_log_probs, fake_rewards, fake_advantages,
      fake_baselines, fake_averages_op, critic_loss, cumulative_rewards
  ] = model_losses.calculate_reinforce_objective(
      hparams, fake_log_probs, fake_predictions, present, est_state_values)

  ## Pre-training.
  if FLAGS.gen_pretrain_steps:
    raise NotImplementedError
    # # TODO(liamfedus): Rewrite this.
    # fwd_cross_entropy_loss = tf.reduce_mean(fwd_cross_entropy_losses)
    # gen_pretrain_op = model_optimization.create_gen_pretrain_op(
    #     hparams, fwd_cross_entropy_loss, global_step)
  else:
    gen_pretrain_op = None
  if FLAGS.dis_pretrain_steps:
    dis_pretrain_op = model_optimization.create_dis_pretrain_op(
        hparams, dis_loss, global_step)
  else:
    dis_pretrain_op = None

  ##  Generator Train Op.
  # 1.  Cross-Entropy.
  if FLAGS.gen_training_strategy == 'cross_entropy':
    gen_loss = tf.reduce_mean(fake_cross_entropy_losses)
    [gen_train_op, gen_grads,
     gen_vars] = model_optimization.create_gen_train_op(
         hparams, learning_rate, gen_loss, global_step, mode='MINIMIZE')

  # 2.  GAN (REINFORCE)
  elif FLAGS.gen_training_strategy == 'reinforce':
    gen_loss = fake_RL_loss
    [gen_train_op, gen_grads,
     gen_vars] = model_optimization.create_reinforce_gen_train_op(
         hparams, learning_rate, gen_loss, fake_averages_op, global_step)

  else:
    raise NotImplementedError

  ## Discriminator Train Op.
  dis_train_op, dis_grads, dis_vars = model_optimization.create_dis_train_op(
      hparams, dis_loss, global_step)

  ## Critic Train Op.
  if critic_loss is not None:
    [critic_train_op, _, _] = model_optimization.create_critic_train_op(
        hparams, critic_loss, global_step)
    dis_train_op = tf.group(dis_train_op, critic_train_op)

  ## Summaries.
  with tf.name_scope('general'):
    tf.summary.scalar('percent_real', percent_real_var)
    tf.summary.scalar('learning_rate', learning_rate)

  with tf.name_scope('generator_objectives'):
    tf.summary.scalar('gen_objective', tf.reduce_mean(gen_loss))
    tf.summary.scalar('gen_loss_cross_entropy',
                      tf.reduce_mean(fake_cross_entropy_losses))

  with tf.name_scope('REINFORCE'):
    with tf.name_scope('objective'):
      tf.summary.scalar('fake_RL_loss', tf.reduce_mean(fake_RL_loss))

    with tf.name_scope('rewards'):
      helper.variable_summaries(cumulative_rewards, 'rewards')

    with tf.name_scope('advantages'):
      helper.variable_summaries(fake_advantages, 'advantages')

    with tf.name_scope('baselines'):
      helper.variable_summaries(fake_baselines, 'baselines')

    with tf.name_scope('log_probs'):
      helper.variable_summaries(fake_log_probs, 'log_probs')

  with tf.name_scope('discriminator_losses'):
    tf.summary.scalar('dis_loss', dis_loss)
    tf.summary.scalar('dis_loss_fake_sequence', dis_loss_fake)
    tf.summary.scalar('dis_loss_prob_fake_sequence', tf.exp(-dis_loss_fake))
    tf.summary.scalar('dis_loss_real_sequence', dis_loss_real)
    tf.summary.scalar('dis_loss_prob_real_sequence', tf.exp(-dis_loss_real))

  if critic_loss is not None:
    with tf.name_scope('critic_losses'):
      tf.summary.scalar('critic_loss', critic_loss)

  with tf.name_scope('logits'):
    helper.variable_summaries(fake_logits, 'fake_logits')

  for v, g in zip(gen_vars, gen_grads):
    helper.variable_summaries(v, v.op.name)
    helper.variable_summaries(g, 'grad/' + v.op.name)

  for v, g in zip(dis_vars, dis_grads):
    helper.variable_summaries(v, v.op.name)
    helper.variable_summaries(g, 'grad/' + v.op.name)

  merge_summaries_op = tf.summary.merge_all()
  text_summary_placeholder = tf.placeholder(tf.string)
  text_summary_op = tf.summary.text('Samples', text_summary_placeholder)

  # Model saver.
  saver = tf.train.Saver(keep_checkpoint_every_n_hours=1, max_to_keep=5)

  # Named tuple that captures elements of the MaskGAN model.
  Model = collections.namedtuple('Model', [
      'inputs', 'targets', 'present', 'percent_real_update', 'new_rate',
      'fake_sequence', 'fake_logits', 'fake_rewards', 'fake_baselines',
      'fake_advantages', 'fake_log_probs', 'fake_predictions',
      'real_predictions', 'fake_cross_entropy_losses', 'fake_gen_initial_state',
      'fake_gen_final_state', 'eval_initial_state', 'eval_final_state',
      'avg_log_perplexity', 'dis_loss', 'gen_loss', 'critic_loss',
      'cumulative_rewards', 'dis_train_op', 'gen_train_op', 'gen_pretrain_op',
      'dis_pretrain_op', 'merge_summaries_op', 'global_step',
      'new_learning_rate', 'learning_rate_update', 'saver', 'text_summary_op',
      'text_summary_placeholder'
  ])

  model = Model(
      inputs, targets, present, percent_real_update, new_rate, fake_sequence,
      fake_logits, fake_rewards, fake_baselines, fake_advantages,
      fake_log_probs, fake_predictions, real_predictions,
      fake_cross_entropy_losses, fake_gen_initial_state, fake_gen_final_state,
      eval_initial_state, eval_final_state, avg_log_perplexity, dis_loss,
      gen_loss, critic_loss, cumulative_rewards, dis_train_op, gen_train_op,
      gen_pretrain_op, dis_pretrain_op, merge_summaries_op, global_step,
      new_learning_rate, learning_rate_update, saver, text_summary_op,
      text_summary_placeholder)
  return model
Example #5
0
def create_rollout_MaskGAN(hparams, is_training):
  """Create the MaskGAN model.

  Args:
    hparams:  Hyperparameters for the MaskGAN.
    is_training:  Boolean indicating operational mode (train/inference).
      evaluated with a teacher forcing regime.

  Return:
    model:  Namedtuple for specifying the MaskGAN."""
  global_step = tf.Variable(0, name='global_step', trainable=False)

  new_learning_rate = tf.placeholder(tf.float32, [], name='new_learning_rate')
  learning_rate = tf.Variable(0.0, name='learning_rate', trainable=False)
  learning_rate_update = tf.assign(learning_rate, new_learning_rate)

  new_rate = tf.placeholder(tf.float32, [], name='new_rate')
  percent_real_var = tf.Variable(0.0, trainable=False)
  percent_real_update = tf.assign(percent_real_var, new_rate)

  ## Placeholders.
  inputs = tf.placeholder(
      tf.int32, shape=[FLAGS.batch_size, FLAGS.sequence_length])
  present = tf.placeholder(
      tf.bool, shape=[FLAGS.batch_size, FLAGS.sequence_length])
  inv_present = tf.placeholder(
      tf.bool, shape=[FLAGS.batch_size, FLAGS.sequence_length])

  ## Rollout Generator.
  fwd_gen_rollouts = rollout_generator(
      hparams, inputs, present, is_training=is_training, is_validating=False)
  inv_gen_rollouts = rollout_generator(
      hparams,
      inputs,
      inv_present,
      is_training=is_training,
      is_validating=False,
      reuse=True)

  ## Rollout Discriminator.
  fwd_dis_rollouts = rollout_discriminator(
      hparams, fwd_gen_rollouts, is_training=is_training)
  inv_dis_rollouts = rollout_discriminator(
      hparams, inv_gen_rollouts, is_training=is_training, reuse=True)

  ## Discriminator Loss.
  [dis_loss, dis_loss_pred, dis_loss_inv_pred] = rollout_discriminator_loss(
      fwd_dis_rollouts, present, inv_dis_rollouts, inv_present)

  ## Average log-perplexity for only missing words.  However, to do this,
  # the logits are still computed using teacher forcing, that is, the ground
  # truth tokens are fed in at each time point to be valid.
  # TODO(liamfedus): Fix the naming convention.
  with tf.variable_scope('gen_rollout'):
    _, fwd_eval_logits, _ = model_construction.create_generator(
        hparams,
        inputs,
        present,
        is_training=False,
        is_validating=True,
        reuse=True)

  avg_log_perplexity = model_losses.calculate_log_perplexity(
      fwd_eval_logits, inputs, present)

  ## Generator Loss.
  # 1.  Cross Entropy losses on missing tokens.
  [fwd_cross_entropy_losses,
   inv_cross_entropy_losses] = rollout_masked_cross_entropy_loss(
       inputs, present, inv_present, fwd_gen_rollouts, inv_gen_rollouts)

  # 2.  GAN losses on missing tokens.
  [fwd_RL_loss,
   fwd_RL_statistics, fwd_averages_op] = rollout_reinforce_objective(
       hparams, fwd_gen_rollouts, fwd_dis_rollouts, present)
  [inv_RL_loss,
   inv_RL_statistics, inv_averages_op] = rollout_reinforce_objective(
       hparams, inv_gen_rollouts, inv_dis_rollouts, inv_present)

  # TODO(liamfedus):  Generalize this to use all logs.
  [fwd_sequence, fwd_logits, fwd_log_probs] = fwd_gen_rollouts[-1]
  [inv_sequence, inv_logits, inv_log_probs] = inv_gen_rollouts[-1]

  # TODO(liamfedus):  Generalize this to use all logs.
  fwd_predictions = fwd_dis_rollouts[-1]
  inv_predictions = inv_dis_rollouts[-1]

  # TODO(liamfedus):  Generalize this to use all logs.
  [fwd_log_probs, fwd_rewards, fwd_advantages,
   fwd_baselines] = fwd_RL_statistics[-1]
  [inv_log_probs, inv_rewards, inv_advantages,
   inv_baselines] = inv_RL_statistics[-1]

  ## Pre-training.
  if FLAGS.gen_pretrain_steps:
    # TODO(liamfedus): Rewrite this.
    fwd_cross_entropy_loss = tf.reduce_mean(fwd_cross_entropy_losses)
    gen_pretrain_op = model_optimization.create_gen_pretrain_op(
        hparams, fwd_cross_entropy_loss, global_step)
  else:
    gen_pretrain_op = tf.no_op('gen_pretrain_no_op')
  if FLAGS.dis_pretrain_steps:
    dis_pretrain_op = model_optimization.create_dis_pretrain_op(
        hparams, dis_loss, global_step)
  else:
    dis_pretrain_op = tf.no_op('dis_pretrain_no_op')

  ##  Generator Train Op.
  # 1.  Cross-Entropy.
  if FLAGS.gen_training_strategy == 'cross_entropy':
    gen_loss = tf.reduce_mean(
        fwd_cross_entropy_losses + inv_cross_entropy_losses) / 2.
    [gen_train_op, gen_grads,
     gen_vars] = model_optimization.create_gen_train_op(
         hparams, learning_rate, gen_loss, global_step, mode='MINIMIZE')

  # 2.  GAN (REINFORCE)
  elif FLAGS.gen_training_strategy == 'reinforce':
    gen_loss = (fwd_RL_loss + inv_RL_loss) / 2.
    [gen_train_op, gen_grads,
     gen_vars] = model_optimization.create_reinforce_gen_train_op(
         hparams, learning_rate, gen_loss, fwd_averages_op, inv_averages_op,
         global_step)

  else:
    raise NotImplementedError

  ## Discriminator Train Op.
  dis_train_op, dis_grads, dis_vars = model_optimization.create_dis_train_op(
      hparams, dis_loss, global_step)

  ## Summaries.
  with tf.name_scope('general'):
    tf.summary.scalar('percent_real', percent_real_var)
    tf.summary.scalar('learning_rate', learning_rate)

  with tf.name_scope('generator_losses'):
    tf.summary.scalar('gen_loss', tf.reduce_mean(gen_loss))
    tf.summary.scalar('gen_loss_fwd_cross_entropy',
                      tf.reduce_mean(fwd_cross_entropy_losses))
    tf.summary.scalar('gen_loss_inv_cross_entropy',
                      tf.reduce_mean(inv_cross_entropy_losses))

  with tf.name_scope('REINFORCE'):
    with tf.name_scope('objective'):
      tf.summary.scalar('fwd_RL_loss', tf.reduce_mean(fwd_RL_loss))
      tf.summary.scalar('inv_RL_loss', tf.reduce_mean(inv_RL_loss))

    with tf.name_scope('rewards'):
      helper.variable_summaries(fwd_rewards, 'fwd_rewards')
      helper.variable_summaries(inv_rewards, 'inv_rewards')

    with tf.name_scope('advantages'):
      helper.variable_summaries(fwd_advantages, 'fwd_advantages')
      helper.variable_summaries(inv_advantages, 'inv_advantages')

    with tf.name_scope('baselines'):
      helper.variable_summaries(fwd_baselines, 'fwd_baselines')
      helper.variable_summaries(inv_baselines, 'inv_baselines')

    with tf.name_scope('log_probs'):
      helper.variable_summaries(fwd_log_probs, 'fwd_log_probs')
      helper.variable_summaries(inv_log_probs, 'inv_log_probs')

  with tf.name_scope('discriminator_losses'):
    tf.summary.scalar('dis_loss', dis_loss)
    tf.summary.scalar('dis_loss_fwd_sequence', dis_loss_pred)
    tf.summary.scalar('dis_loss_inv_sequence', dis_loss_inv_pred)

  with tf.name_scope('logits'):
    helper.variable_summaries(fwd_logits, 'fwd_logits')
    helper.variable_summaries(inv_logits, 'inv_logits')

  for v, g in zip(gen_vars, gen_grads):
    helper.variable_summaries(v, v.op.name)
    helper.variable_summaries(g, 'grad/' + v.op.name)

  for v, g in zip(dis_vars, dis_grads):
    helper.variable_summaries(v, v.op.name)
    helper.variable_summaries(g, 'grad/' + v.op.name)

  merge_summaries_op = tf.summary.merge_all()

  # Model saver.
  saver = tf.train.Saver(keep_checkpoint_every_n_hours=1, max_to_keep=5)

  # Named tuple that captures elements of the MaskGAN model.
  Model = collections.namedtuple('Model', [
      'inputs', 'present', 'inv_present', 'percent_real_update', 'new_rate',
      'fwd_sequence', 'fwd_logits', 'fwd_rewards', 'fwd_advantages',
      'fwd_log_probs', 'fwd_predictions', 'fwd_cross_entropy_losses',
      'inv_sequence', 'inv_logits', 'inv_rewards', 'inv_advantages',
      'inv_log_probs', 'inv_predictions', 'inv_cross_entropy_losses',
      'avg_log_perplexity', 'dis_loss', 'gen_loss', 'dis_train_op',
      'gen_train_op', 'gen_pretrain_op', 'dis_pretrain_op',
      'merge_summaries_op', 'global_step', 'new_learning_rate',
      'learning_rate_update', 'saver'
  ])

  model = Model(
      inputs, present, inv_present, percent_real_update, new_rate, fwd_sequence,
      fwd_logits, fwd_rewards, fwd_advantages, fwd_log_probs, fwd_predictions,
      fwd_cross_entropy_losses, inv_sequence, inv_logits, inv_rewards,
      inv_advantages, inv_log_probs, inv_predictions, inv_cross_entropy_losses,
      avg_log_perplexity, dis_loss, gen_loss, dis_train_op, gen_train_op,
      gen_pretrain_op, dis_pretrain_op, merge_summaries_op, global_step,
      new_learning_rate, learning_rate_update, saver)
  return model
Example #6
0
def create_MaskGAN(hparams, is_training):
  """Create the MaskGAN model.

  Args:
    hparams:  Hyperparameters for the MaskGAN.
    is_training:  Boolean indicating operational mode (train/inference).
      evaluated with a teacher forcing regime.

  Return:
    model:  Namedtuple for specifying the MaskGAN.
  """
  global_step = tf.Variable(0, name='global_step', trainable=False)

  new_learning_rate = tf.placeholder(tf.float32, [], name='new_learning_rate')
  learning_rate = tf.Variable(0.0, name='learning_rate', trainable=False)
  learning_rate_update = tf.assign(learning_rate, new_learning_rate)

  new_rate = tf.placeholder(tf.float32, [], name='new_rate')
  percent_real_var = tf.Variable(0.0, trainable=False)
  percent_real_update = tf.assign(percent_real_var, new_rate)

  ## Placeholders.
  inputs = tf.placeholder(
      tf.int32, shape=[FLAGS.batch_size, FLAGS.sequence_length])
  targets = tf.placeholder(
      tf.int32, shape=[FLAGS.batch_size, FLAGS.sequence_length])
  present = tf.placeholder(
      tf.bool, shape=[FLAGS.batch_size, FLAGS.sequence_length])
  # TODO(adai): Placeholder for IMDB label.

  ## Real Sequence is the targets.
  real_sequence = targets

  ## Fakse Sequence from the Generator.
  # TODO(adai):  Generator must have IMDB labels placeholder.
  (fake_sequence, fake_logits, fake_log_probs, fake_gen_initial_state,
   fake_gen_final_state, _) = model_construction.create_generator(
       hparams,
       inputs,
       targets,
       present,
       is_training=is_training,
       is_validating=False)
  (_, eval_logits, _, eval_initial_state, eval_final_state,
   _) = model_construction.create_generator(
       hparams,
       inputs,
       targets,
       present,
       is_training=False,
       is_validating=True,
       reuse=True)

  ## Discriminator.
  fake_predictions = model_construction.create_discriminator(
      hparams,
      fake_sequence,
      is_training=is_training,
      inputs=inputs,
      present=present)
  real_predictions = model_construction.create_discriminator(
      hparams,
      real_sequence,
      is_training=is_training,
      reuse=True,
      inputs=inputs,
      present=present)

  ## Critic.
  # The critic will be used to estimate the forward rewards to the Generator.
  if FLAGS.baseline_method == 'critic':
    est_state_values = model_construction.create_critic(
        hparams, fake_sequence, is_training=is_training)
  else:
    est_state_values = None

  ## Discriminator Loss.
  [dis_loss, dis_loss_fake, dis_loss_real] = model_losses.create_dis_loss(
      fake_predictions, real_predictions, present)

  ## Average log-perplexity for only missing words.  However, to do this,
  # the logits are still computed using teacher forcing, that is, the ground
  # truth tokens are fed in at each time point to be valid.
  avg_log_perplexity = model_losses.calculate_log_perplexity(
      eval_logits, targets, present)

  ## Generator Objective.
  # 1.  Cross Entropy losses on missing tokens.
  fake_cross_entropy_losses = model_losses.create_masked_cross_entropy_loss(
      targets, present, fake_logits)

  #  2.  GAN REINFORCE losses.
  [
      fake_RL_loss, fake_log_probs, fake_rewards, fake_advantages,
      fake_baselines, fake_averages_op, critic_loss, cumulative_rewards
  ] = model_losses.calculate_reinforce_objective(
      hparams, fake_log_probs, fake_predictions, present, est_state_values)

  ## Pre-training.
  if FLAGS.gen_pretrain_steps:
    raise NotImplementedError
    # # TODO(liamfedus): Rewrite this.
    # fwd_cross_entropy_loss = tf.reduce_mean(fwd_cross_entropy_losses)
    # gen_pretrain_op = model_optimization.create_gen_pretrain_op(
    #     hparams, fwd_cross_entropy_loss, global_step)
  else:
    gen_pretrain_op = None
  if FLAGS.dis_pretrain_steps:
    dis_pretrain_op = model_optimization.create_dis_pretrain_op(
        hparams, dis_loss, global_step)
  else:
    dis_pretrain_op = None

  ##  Generator Train Op.
  # 1.  Cross-Entropy.
  if FLAGS.gen_training_strategy == 'cross_entropy':
    gen_loss = tf.reduce_mean(fake_cross_entropy_losses)
    [gen_train_op, gen_grads,
     gen_vars] = model_optimization.create_gen_train_op(
         hparams, learning_rate, gen_loss, global_step, mode='MINIMIZE')

  # 2.  GAN (REINFORCE)
  elif FLAGS.gen_training_strategy == 'reinforce':
    gen_loss = fake_RL_loss
    [gen_train_op, gen_grads,
     gen_vars] = model_optimization.create_reinforce_gen_train_op(
         hparams, learning_rate, gen_loss, fake_averages_op, global_step)

  else:
    raise NotImplementedError

  ## Discriminator Train Op.
  dis_train_op, dis_grads, dis_vars = model_optimization.create_dis_train_op(
      hparams, dis_loss, global_step)

  ## Critic Train Op.
  if critic_loss is not None:
    [critic_train_op, _, _] = model_optimization.create_critic_train_op(
        hparams, critic_loss, global_step)
    dis_train_op = tf.group(dis_train_op, critic_train_op)

  ## Summaries.
  with tf.name_scope('general'):
    tf.summary.scalar('percent_real', percent_real_var)
    tf.summary.scalar('learning_rate', learning_rate)

  with tf.name_scope('generator_objectives'):
    tf.summary.scalar('gen_objective', tf.reduce_mean(gen_loss))
    tf.summary.scalar('gen_loss_cross_entropy',
                      tf.reduce_mean(fake_cross_entropy_losses))

  with tf.name_scope('REINFORCE'):
    with tf.name_scope('objective'):
      tf.summary.scalar('fake_RL_loss', tf.reduce_mean(fake_RL_loss))

    with tf.name_scope('rewards'):
      helper.variable_summaries(cumulative_rewards, 'rewards')

    with tf.name_scope('advantages'):
      helper.variable_summaries(fake_advantages, 'advantages')

    with tf.name_scope('baselines'):
      helper.variable_summaries(fake_baselines, 'baselines')

    with tf.name_scope('log_probs'):
      helper.variable_summaries(fake_log_probs, 'log_probs')

  with tf.name_scope('discriminator_losses'):
    tf.summary.scalar('dis_loss', dis_loss)
    tf.summary.scalar('dis_loss_fake_sequence', dis_loss_fake)
    tf.summary.scalar('dis_loss_prob_fake_sequence', tf.exp(-dis_loss_fake))
    tf.summary.scalar('dis_loss_real_sequence', dis_loss_real)
    tf.summary.scalar('dis_loss_prob_real_sequence', tf.exp(-dis_loss_real))

  if critic_loss is not None:
    with tf.name_scope('critic_losses'):
      tf.summary.scalar('critic_loss', critic_loss)

  with tf.name_scope('logits'):
    helper.variable_summaries(fake_logits, 'fake_logits')

  for v, g in zip(gen_vars, gen_grads):
    helper.variable_summaries(v, v.op.name)
    helper.variable_summaries(g, 'grad/' + v.op.name)

  for v, g in zip(dis_vars, dis_grads):
    helper.variable_summaries(v, v.op.name)
    helper.variable_summaries(g, 'grad/' + v.op.name)

  merge_summaries_op = tf.summary.merge_all()
  text_summary_placeholder = tf.placeholder(tf.string)
  text_summary_op = tf.summary.text('Samples', text_summary_placeholder)

  # Model saver.
  saver = tf.train.Saver(keep_checkpoint_every_n_hours=1, max_to_keep=5)

  # Named tuple that captures elements of the MaskGAN model.
  Model = collections.namedtuple('Model', [
      'inputs', 'targets', 'present', 'percent_real_update', 'new_rate',
      'fake_sequence', 'fake_logits', 'fake_rewards', 'fake_baselines',
      'fake_advantages', 'fake_log_probs', 'fake_predictions',
      'real_predictions', 'fake_cross_entropy_losses', 'fake_gen_initial_state',
      'fake_gen_final_state', 'eval_initial_state', 'eval_final_state',
      'avg_log_perplexity', 'dis_loss', 'gen_loss', 'critic_loss',
      'cumulative_rewards', 'dis_train_op', 'gen_train_op', 'gen_pretrain_op',
      'dis_pretrain_op', 'merge_summaries_op', 'global_step',
      'new_learning_rate', 'learning_rate_update', 'saver', 'text_summary_op',
      'text_summary_placeholder'
  ])

  model = Model(
      inputs, targets, present, percent_real_update, new_rate, fake_sequence,
      fake_logits, fake_rewards, fake_baselines, fake_advantages,
      fake_log_probs, fake_predictions, real_predictions,
      fake_cross_entropy_losses, fake_gen_initial_state, fake_gen_final_state,
      eval_initial_state, eval_final_state, avg_log_perplexity, dis_loss,
      gen_loss, critic_loss, cumulative_rewards, dis_train_op, gen_train_op,
      gen_pretrain_op, dis_pretrain_op, merge_summaries_op, global_step,
      new_learning_rate, learning_rate_update, saver, text_summary_op,
      text_summary_placeholder)
  return model