Esempio n. 1
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  def testLearnerRaiseExceptionOnMismatchingBatchSetup(self):
    obs_spec = tensor_spec.TensorSpec([2], tf.float32)
    time_step_spec = ts.time_step_spec(obs_spec)
    action_spec = tensor_spec.BoundedTensorSpec([], tf.int32, 0, 1)
    flat_action_spec = tf.nest.flatten(action_spec)[0]
    num_actions = flat_action_spec.maximum - flat_action_spec.minimum + 1

    network = sequential.Sequential([
        tf.keras.layers.Dense(num_actions, dtype=tf.float32),
        inner_reshape.InnerReshape([None], [num_actions])
    ])

    agent = behavioral_cloning_agent.BehavioralCloningAgent(
        time_step_spec, action_spec, cloning_network=network, optimizer=None)

    with self.assertRaisesRegex(
        RuntimeError,
        (r'The slot variable initialization failed. The learner assumes all '
         r'experience tensors required an `outer_rank = \(None, '
         r'agent.train_sequence_length\)`\. If that\'s not the case for your '
         r'agent try setting `run_optimizer_variable_init=False`\.')):
      learner.Learner(
          root_dir=os.path.join(self.create_tempdir().full_path, 'learner'),
          train_step=train_utils.create_train_step(),
          agent=agent)
Esempio n. 2
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  def _build_components(self, rb_port):
    env = suite_gym.load('CartPole-v0')

    _, action_tensor_spec, time_step_tensor_spec = (
        spec_utils.get_tensor_specs(env))
    train_step = train_utils.create_train_step()

    q_net = dist_test_utils.build_dummy_sequential_net(
        fc_layer_params=(100,), action_spec=action_tensor_spec)

    agent = dqn_agent.DqnAgent(
        time_step_tensor_spec,
        action_tensor_spec,
        q_network=q_net,
        optimizer=tf.compat.v1.train.AdamOptimizer(learning_rate=0.001),
        train_step_counter=train_step)

    replay_buffer, rb_observer = (
        replay_buffer_utils.get_reverb_buffer_and_observer(
            agent.collect_data_spec,
            sequence_length=2,
            replay_capacity=1000,
            port=rb_port))

    return env, agent, train_step, replay_buffer, rb_observer
Esempio n. 3
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    def _build_learner_with_strategy(self,
                                     create_agent_and_dataset_fn,
                                     strategy,
                                     sample_batch_size=2):
        if strategy is None:
            # Get default strategy if None provided.
            strategy = tf.distribute.get_strategy()

        with strategy.scope():
            tf_env = tf_py_environment.TFPyEnvironment(
                suite_gym.load('CartPole-v0'))

            train_step = train_utils.create_train_step()
            agent, dataset, dataset_fn, _ = create_agent_and_dataset_fn(
                tf_env.action_spec(), tf_env.time_step_spec(), train_step,
                sample_batch_size)

            root_dir = os.path.join(self.create_tempdir().full_path, 'learner')

            test_learner = learner.Learner(root_dir=root_dir,
                                           train_step=train_step,
                                           agent=agent,
                                           experience_dataset_fn=dataset_fn)
            variables = agent.collect_policy.variables()
        return test_learner, dataset, variables, train_step
Esempio n. 4
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    def testLearnerRaiseExceptionOnMismatchingBatchSetup(self):
        obs_spec = tensor_spec.TensorSpec([2], tf.float32)
        time_step_spec = ts.time_step_spec(obs_spec)
        action_spec = tensor_spec.BoundedTensorSpec([], tf.int32, 0, 1)
        flat_action_spec = tf.nest.flatten(action_spec)[0]
        num_actions = flat_action_spec.maximum - flat_action_spec.minimum + 1

        network = sequential.Sequential([
            tf.keras.layers.Dense(num_actions, dtype=tf.float32),
            inner_reshape.InnerReshape([None], [num_actions])
        ])

        agent = behavioral_cloning_agent.BehavioralCloningAgent(
            time_step_spec,
            action_spec,
            cloning_network=network,
            optimizer=None)

        with self.assertRaisesRegex(
                ValueError,
                'All of the Tensors in `value` must have one outer dimension.'
        ):
            learner.Learner(root_dir=os.path.join(
                self.create_tempdir().full_path, 'learner'),
                            train_step=train_utils.create_train_step(),
                            agent=agent)
Esempio n. 5
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def collect(summary_dir: Text,
            environment_name: Text,
            collect_policy: py_tf_eager_policy.PyTFEagerPolicyBase,
            replay_buffer_server_address: Text,
            variable_container_server_address: Text,
            suite_load_fn: Callable[
                [Text], py_environment.PyEnvironment] = suite_mujoco.load,
            initial_collect_steps: int = 10000,
            max_train_steps: int = 2000000) -> None:
  """Collects experience using a policy updated after every episode."""
  # Create the environment. For now support only single environment collection.
  collect_env = suite_load_fn(environment_name)

  # Create the variable container.
  train_step = train_utils.create_train_step()
  variables = {
      reverb_variable_container.POLICY_KEY: collect_policy.variables(),
      reverb_variable_container.TRAIN_STEP_KEY: train_step
  }
  variable_container = reverb_variable_container.ReverbVariableContainer(
      variable_container_server_address,
      table_names=[reverb_variable_container.DEFAULT_TABLE])
  variable_container.update(variables)

  # Create the replay buffer observer.
  rb_observer = reverb_utils.ReverbAddTrajectoryObserver(
      reverb.Client(replay_buffer_server_address),
      table_name=reverb_replay_buffer.DEFAULT_TABLE,
      sequence_length=2,
      stride_length=1)

  random_policy = random_py_policy.RandomPyPolicy(collect_env.time_step_spec(),
                                                  collect_env.action_spec())
  initial_collect_actor = actor.Actor(
      collect_env,
      random_policy,
      train_step,
      steps_per_run=initial_collect_steps,
      observers=[rb_observer])
  logging.info('Doing initial collect.')
  initial_collect_actor.run()

  env_step_metric = py_metrics.EnvironmentSteps()
  collect_actor = actor.Actor(
      collect_env,
      collect_policy,
      train_step,
      steps_per_run=1,
      metrics=actor.collect_metrics(10),
      summary_dir=summary_dir,
      observers=[rb_observer, env_step_metric])

  # Run the experience collection loop.
  while train_step.numpy() < max_train_steps:
    logging.info('Collecting with policy at step: %d', train_step.numpy())
    collect_actor.run()
    variable_container.update(variables)
    def test_after_train_step_fn_with_fresh_data_only(self,
                                                      create_strategy_fn):
        strategy = create_strategy_fn()
        with strategy.scope():
            # Prepare the test context context.
            train_step = train_utils.create_train_step()
            train_step.assign(225)
            train_steps_per_policy_update = 100

            # Create the after train function to test, and the test input.
            after_train_step_fn = (
                train_utils.create_staleness_metrics_after_train_step_fn(
                    train_step,
                    train_steps_per_policy_update=train_steps_per_policy_update
                ))
            observation_train_steps = np.array([[200], [200], [200]],
                                               dtype=np.int64)

            # Define the expectations (expected scalar summary calls).
            expected_scalar_summary_calls = [
                mock.call(name='staleness/max_train_step_delta_in_batch',
                          data=0,
                          step=225),
                mock.call(name='staleness/max_policy_update_delta_in_batch',
                          data=0,
                          step=225),
                mock.call(name='staleness/num_stale_obserations_in_batch',
                          data=0,
                          step=225)
            ]

            # Call the after train function and check the expectations.
            with mock.patch.object(tf.summary, 'scalar',
                                   autospec=True) as mock_scalar_summary:
                # Call the `after_train_function` on the test input. Assumed the
                # observation train steps are stored in the field `priority` of the
                # the sample info of Reverb.
                strategy.run(after_train_step_fn,
                             args=((None,
                                    reverb.replay_sample.SampleInfo(
                                        key=None,
                                        probability=None,
                                        table_size=None,
                                        priority=observation_train_steps)),
                                   None))

                # Check if the expected calls happened on the scalar summary.
                mock_scalar_summary.assert_has_calls(
                    expected_scalar_summary_calls, any_order=False)
Esempio n. 7
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    def __init__(self, collect_env: YGOEnvironment,
                 eval_env: YGOEnvironment) -> None:
        self._collect_env: YGOEnvironment = collect_env
        self._eval_env: YGOEnvironment = eval_env

        # hyper parameters
        self._actor_fc_layer_params: List[int] = [256, 256]
        self._critic_joint_fc_layer_params: List[int] = [256, 256]
        self._critic_learning_rate: float = 3e-4
        self._actor_learning_rate: float = 3e-4
        self._alpha_learning_rate: float = 3e-4
        self._target_update_tau: float = 0.005
        self._target_update_period: int = 1
        self._gamma: float = 0.99
        self._reward_scale_factor: float = 1.0
        table_name: str = 'uniform_table'

        # Agent
        train_step = train_utils.create_train_step()
        self._agent: SacAgent = _create_agent(self, train_step)
        # reverb
        self._reverb_server: reverb.Server = _create_reverb_server(table_name)
        self._reverb_replay_buffer: ReverbReplayBuffer = _create_replay_buffer(
            self._agent.collect_data_spec, self._reverb_server, table_name)
        # policy
        self._eval_policy: PyTFEagerPolicy = PyTFEagerPolicy(
            self._agent.policy, use_tf_function=True)
        self._collect_policy: PyTFEagerPolicy = PyTFEagerPolicy(
            self._agent.collect_policy, use_tf_function=True)
        # actor
        self._rb_observer: ReverbAddTrajectoryObserver = _create_rb_observer(
            self._reverb_replay_buffer, table_name)
        self._collect_actor: actor.Actor = _create_collect_actor(
            self._collect_env, self._collect_policy, train_step,
            self._rb_observer)
        self._eval_actor: actor.Actor = _create_eval_actor(
            self._eval_env, self._eval_policy, train_step)
        # learner
        self._agent_learner: learner.Learner = _create_agent_learner(
            self._agent, train_step, self._reverb_replay_buffer)
Esempio n. 8
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  def build_and_run_actor():
    root_dir = test_case.create_tempdir().full_path
    env, action_tensor_spec, time_step_tensor_spec = (
        get_cartpole_env_and_specs())

    train_step = train_utils.create_train_step()

    q_net = build_dummy_sequential_net(fc_layer_params=(100,),
                                       action_spec=action_tensor_spec)

    agent = dqn_agent.DqnAgent(
        time_step_tensor_spec,
        action_tensor_spec,
        q_network=q_net,
        optimizer=tf.keras.optimizers.Adam(learning_rate=0.001),
        train_step_counter=train_step)

    _, rb_observer = (
        replay_buffer_utils.get_reverb_buffer_and_observer(
            agent.collect_data_spec,
            table_name=reverb_replay_buffer.DEFAULT_TABLE,
            sequence_length=2,
            reverb_server_address='localhost:{}'.format(reverb_server_port)))

    variable_container = reverb_variable_container.ReverbVariableContainer(
        server_address='localhost:{}'.format(reverb_server_port),
        table_names=[reverb_variable_container.DEFAULT_TABLE])

    test_actor = build_actor(
        root_dir, env, agent, rb_observer, train_step)

    variables_dict = {
        reverb_variable_container.POLICY_KEY: agent.collect_policy.variables(),
        reverb_variable_container.TRAIN_STEP_KEY: train_step
    }
    variable_container.update(variables_dict)

    for _ in range(num_iterations):
      test_actor.run()
Esempio n. 9
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def train_eval(
        root_dir,
        env_name,
        # Training params
        train_sequence_length,
        initial_collect_steps=1000,
        collect_steps_per_iteration=1,
        num_iterations=100000,
        # RNN params.
        q_network_fn=q_lstm_network,  # defaults to q_lstm_network.
        # Agent params
    epsilon_greedy=0.1,
        batch_size=64,
        learning_rate=1e-3,
        gamma=0.99,
        target_update_tau=0.05,
        target_update_period=5,
        reward_scale_factor=1.0,
        # Replay params
        reverb_port=None,
        replay_capacity=100000,
        # Others
        policy_save_interval=1000,
        eval_interval=1000,
        eval_episodes=10):
    """Trains and evaluates DQN."""

    collect_env = suite_gym.load(env_name)
    eval_env = suite_gym.load(env_name)

    unused_observation_tensor_spec, action_tensor_spec, time_step_tensor_spec = (
        spec_utils.get_tensor_specs(collect_env))

    train_step = train_utils.create_train_step()

    num_actions = action_tensor_spec.maximum - action_tensor_spec.minimum + 1
    q_net = q_network_fn(num_actions=num_actions)

    sequence_length = train_sequence_length + 1
    agent = dqn_agent.DqnAgent(
        time_step_tensor_spec,
        action_tensor_spec,
        q_network=q_net,
        epsilon_greedy=epsilon_greedy,
        # n-step updates aren't supported with RNNs yet.
        n_step_update=1,
        target_update_tau=target_update_tau,
        target_update_period=target_update_period,
        optimizer=tf.keras.optimizers.Adam(learning_rate=learning_rate),
        td_errors_loss_fn=common.element_wise_squared_loss,
        gamma=gamma,
        reward_scale_factor=reward_scale_factor,
        train_step_counter=train_step)

    table_name = 'uniform_table'
    table = reverb.Table(table_name,
                         max_size=replay_capacity,
                         sampler=reverb.selectors.Uniform(),
                         remover=reverb.selectors.Fifo(),
                         rate_limiter=reverb.rate_limiters.MinSize(1))
    reverb_server = reverb.Server([table], port=reverb_port)
    reverb_replay = reverb_replay_buffer.ReverbReplayBuffer(
        agent.collect_data_spec,
        sequence_length=sequence_length,
        table_name=table_name,
        local_server=reverb_server)
    rb_observer = reverb_utils.ReverbAddTrajectoryObserver(
        reverb_replay.py_client,
        table_name,
        sequence_length=sequence_length,
        stride_length=1,
        pad_end_of_episodes=True)

    def experience_dataset_fn():
        return reverb_replay.as_dataset(sample_batch_size=batch_size,
                                        num_steps=sequence_length)

    saved_model_dir = os.path.join(root_dir, learner.POLICY_SAVED_MODEL_DIR)
    env_step_metric = py_metrics.EnvironmentSteps()

    learning_triggers = [
        triggers.PolicySavedModelTrigger(
            saved_model_dir,
            agent,
            train_step,
            interval=policy_save_interval,
            metadata_metrics={triggers.ENV_STEP_METADATA_KEY:
                              env_step_metric}),
        triggers.StepPerSecondLogTrigger(train_step, interval=100),
    ]

    dqn_learner = learner.Learner(root_dir,
                                  train_step,
                                  agent,
                                  experience_dataset_fn,
                                  triggers=learning_triggers)

    # If we haven't trained yet make sure we collect some random samples first to
    # fill up the Replay Buffer with some experience.
    random_policy = random_py_policy.RandomPyPolicy(
        collect_env.time_step_spec(), collect_env.action_spec())
    initial_collect_actor = actor.Actor(collect_env,
                                        random_policy,
                                        train_step,
                                        steps_per_run=initial_collect_steps,
                                        observers=[rb_observer])
    logging.info('Doing initial collect.')
    initial_collect_actor.run()

    tf_collect_policy = agent.collect_policy
    collect_policy = py_tf_eager_policy.PyTFEagerPolicy(tf_collect_policy,
                                                        use_tf_function=True)

    collect_actor = actor.Actor(
        collect_env,
        collect_policy,
        train_step,
        steps_per_run=collect_steps_per_iteration,
        observers=[rb_observer, env_step_metric],
        metrics=actor.collect_metrics(10),
        summary_dir=os.path.join(root_dir, learner.TRAIN_DIR),
    )

    tf_greedy_policy = agent.policy
    greedy_policy = py_tf_eager_policy.PyTFEagerPolicy(tf_greedy_policy,
                                                       use_tf_function=True)

    eval_actor = actor.Actor(
        eval_env,
        greedy_policy,
        train_step,
        episodes_per_run=eval_episodes,
        metrics=actor.eval_metrics(eval_episodes),
        summary_dir=os.path.join(root_dir, 'eval'),
    )

    if eval_interval:
        logging.info('Evaluating.')
        eval_actor.run_and_log()

    logging.info('Training.')
    for _ in range(num_iterations):
        collect_actor.run()
        dqn_learner.run(iterations=1)

        if eval_interval and dqn_learner.train_step_numpy % eval_interval == 0:
            logging.info('Evaluating.')
            eval_actor.run_and_log()

    rb_observer.close()
    reverb_server.stop()
Esempio n. 10
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def main(_):
    logging.set_verbosity(logging.INFO)

    # Wait for the collect policy to become available, then load it.
    collect_policy_dir = os.path.join(FLAGS.root_dir,
                                      learner.POLICY_SAVED_MODEL_DIR,
                                      learner.COLLECT_POLICY_SAVED_MODEL_DIR)
    collect_policy = train_utils.wait_for_policy(collect_policy_dir,
                                                 load_specs_from_pbtxt=True)

    samples_per_insert = FLAGS.samples_per_insert
    min_table_size_before_sampling = FLAGS.min_table_size_before_sampling

    # Create the signature for the variable container holding the policy weights.
    train_step = train_utils.create_train_step()
    variables = {
        reverb_variable_container.POLICY_KEY: collect_policy.variables(),
        reverb_variable_container.TRAIN_STEP_KEY: train_step
    }
    variable_container_signature = tf.nest.map_structure(
        lambda variable: tf.TensorSpec(variable.shape, dtype=variable.dtype),
        variables)
    logging.info('Signature of variables: \n%s', variable_container_signature)

    # Create the signature for the replay buffer holding observed experience.
    replay_buffer_signature = tensor_spec.from_spec(
        collect_policy.collect_data_spec)
    replay_buffer_signature = tf.nest.map_structure(
        lambda s: tf.TensorSpec((None, ) + s.shape, s.dtype, s.name),
        replay_buffer_signature)
    logging.info('Signature of experience: \n%s', replay_buffer_signature)

    if samples_per_insert is not None:
        # Use SamplesPerInsertRatio limiter
        samples_per_insert_tolerance = (_SAMPLES_PER_INSERT_TOLERANCE_RATIO *
                                        samples_per_insert)
        error_buffer = min_table_size_before_sampling * samples_per_insert_tolerance

        experience_rate_limiter = reverb.rate_limiters.SampleToInsertRatio(
            min_size_to_sample=min_table_size_before_sampling,
            samples_per_insert=samples_per_insert,
            error_buffer=error_buffer)
    else:
        # Use MinSize limiter
        experience_rate_limiter = reverb.rate_limiters.MinSize(
            min_table_size_before_sampling)

    # Crete and start the replay buffer and variable container server.
    server = reverb.Server(
        tables=[
            reverb.Table(  # Replay buffer storing experience.
                name=reverb_replay_buffer.DEFAULT_TABLE,
                sampler=reverb.selectors.Uniform(),
                remover=reverb.selectors.Fifo(),
                rate_limiter=experience_rate_limiter,
                max_size=FLAGS.replay_buffer_capacity,
                max_times_sampled=0,
                signature=replay_buffer_signature,
            ),
            reverb.Table(  # Variable container storing policy parameters.
                name=reverb_variable_container.DEFAULT_TABLE,
                sampler=reverb.selectors.Uniform(),
                remover=reverb.selectors.Fifo(),
                rate_limiter=reverb.rate_limiters.MinSize(1),
                max_size=1,
                max_times_sampled=0,
                signature=variable_container_signature,
            ),
        ],
        port=FLAGS.port)
    server.wait()
Esempio n. 11
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def train_eval(
    root_dir,
    env_name='Pong-v0',
    # Training params
    update_frequency=4,  # Number of collect steps per policy update
    initial_collect_steps=50000,  # 50k collect steps
    num_iterations=50000000,  # 50M collect steps
    # Taken from Rainbow as it's not specified in Mnih,15.
    max_episode_frames_collect=50000,  # env frames observed by the agent
    max_episode_frames_eval=108000,  # env frames observed by the agent
    # Agent params
    epsilon_greedy=0.1,
    epsilon_decay_period=250000,  # 1M collect steps / update_frequency
    batch_size=32,
    learning_rate=0.00025,
    n_step_update=1,
    gamma=0.99,
    target_update_tau=1.0,
    target_update_period=2500,  # 10k collect steps / update_frequency
    reward_scale_factor=1.0,
    # Replay params
    reverb_port=None,
    replay_capacity=1000000,
    # Others
    policy_save_interval=250000,
    eval_interval=1000,
    eval_episodes=30,
    debug_summaries=True):
  """Trains and evaluates DQN."""

  collect_env = suite_atari.load(
      env_name,
      max_episode_steps=max_episode_frames_collect,
      gym_env_wrappers=suite_atari.DEFAULT_ATARI_GYM_WRAPPERS_WITH_STACKING)
  eval_env = suite_atari.load(
      env_name,
      max_episode_steps=max_episode_frames_eval,
      gym_env_wrappers=suite_atari.DEFAULT_ATARI_GYM_WRAPPERS_WITH_STACKING)

  unused_observation_tensor_spec, action_tensor_spec, time_step_tensor_spec = (
      spec_utils.get_tensor_specs(collect_env))

  train_step = train_utils.create_train_step()

  num_actions = action_tensor_spec.maximum - action_tensor_spec.minimum + 1
  epsilon = tf.compat.v1.train.polynomial_decay(
      1.0,
      train_step,
      epsilon_decay_period,
      end_learning_rate=epsilon_greedy)
  agent = dqn_agent.DqnAgent(
      time_step_tensor_spec,
      action_tensor_spec,
      q_network=create_q_network(num_actions),
      epsilon_greedy=epsilon,
      n_step_update=n_step_update,
      target_update_tau=target_update_tau,
      target_update_period=target_update_period,
      optimizer=tf.compat.v1.train.RMSPropOptimizer(
          learning_rate=learning_rate,
          decay=0.95,
          momentum=0.95,
          epsilon=0.01,
          centered=True),
      td_errors_loss_fn=common.element_wise_huber_loss,
      gamma=gamma,
      reward_scale_factor=reward_scale_factor,
      train_step_counter=train_step,
      debug_summaries=debug_summaries)

  table_name = 'uniform_table'
  table = reverb.Table(
      table_name,
      max_size=replay_capacity,
      sampler=reverb.selectors.Uniform(),
      remover=reverb.selectors.Fifo(),
      rate_limiter=reverb.rate_limiters.MinSize(1))
  reverb_server = reverb.Server([table], port=reverb_port)
  reverb_replay = reverb_replay_buffer.ReverbReplayBuffer(
      agent.collect_data_spec,
      sequence_length=2,
      table_name=table_name,
      local_server=reverb_server)
  rb_observer = reverb_utils.ReverbAddTrajectoryObserver(
      reverb_replay.py_client, table_name,
      sequence_length=2,
      stride_length=1)

  dataset = reverb_replay.as_dataset(
      sample_batch_size=batch_size, num_steps=2).prefetch(3)
  experience_dataset_fn = lambda: dataset

  saved_model_dir = os.path.join(root_dir, learner.POLICY_SAVED_MODEL_DIR)
  env_step_metric = py_metrics.EnvironmentSteps()

  learning_triggers = [
      triggers.PolicySavedModelTrigger(
          saved_model_dir,
          agent,
          train_step,
          interval=policy_save_interval,
          metadata_metrics={triggers.ENV_STEP_METADATA_KEY: env_step_metric}),
      triggers.StepPerSecondLogTrigger(train_step, interval=100),
  ]

  dqn_learner = learner.Learner(
      root_dir,
      train_step,
      agent,
      experience_dataset_fn,
      triggers=learning_triggers)

  # If we haven't trained yet make sure we collect some random samples first to
  # fill up the Replay Buffer with some experience.
  random_policy = random_py_policy.RandomPyPolicy(collect_env.time_step_spec(),
                                                  collect_env.action_spec())
  initial_collect_actor = actor.Actor(
      collect_env,
      random_policy,
      train_step,
      steps_per_run=initial_collect_steps,
      observers=[rb_observer])
  logging.info('Doing initial collect.')
  initial_collect_actor.run()

  tf_collect_policy = agent.collect_policy
  collect_policy = py_tf_eager_policy.PyTFEagerPolicy(tf_collect_policy,
                                                      use_tf_function=True)

  collect_actor = actor.Actor(
      collect_env,
      collect_policy,
      train_step,
      steps_per_run=update_frequency,
      observers=[rb_observer, env_step_metric],
      metrics=actor.collect_metrics(10),
      reference_metrics=[env_step_metric],
      summary_dir=os.path.join(root_dir, learner.TRAIN_DIR),
  )

  tf_greedy_policy = agent.policy
  greedy_policy = py_tf_eager_policy.PyTFEagerPolicy(tf_greedy_policy,
                                                     use_tf_function=True)

  eval_actor = actor.Actor(
      eval_env,
      greedy_policy,
      train_step,
      episodes_per_run=eval_episodes,
      metrics=actor.eval_metrics(eval_episodes),
      reference_metrics=[env_step_metric],
      summary_dir=os.path.join(root_dir, 'eval'),
  )

  if eval_interval:
    logging.info('Evaluating.')
    eval_actor.run_and_log()

  logging.info('Training.')
  for _ in range(num_iterations):
    collect_actor.run()
    dqn_learner.run(iterations=1)

    if eval_interval and dqn_learner.train_step_numpy % eval_interval == 0:
      logging.info('Evaluating.')
      eval_actor.run_and_log()

  rb_observer.close()
  reverb_server.stop()
Esempio n. 12
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def train_eval(
        root_dir,
        strategy: tf.distribute.Strategy,
        env_name='HalfCheetah-v2',
        # Training params
        initial_collect_steps=10000,
        num_iterations=3200000,
        actor_fc_layers=(256, 256),
        critic_obs_fc_layers=None,
        critic_action_fc_layers=None,
        critic_joint_fc_layers=(256, 256),
        # Agent params
        batch_size=256,
        actor_learning_rate=3e-4,
        critic_learning_rate=3e-4,
        alpha_learning_rate=3e-4,
        gamma=0.99,
        target_update_tau=0.005,
        target_update_period=1,
        reward_scale_factor=0.1,
        # Replay params
        reverb_port=None,
        replay_capacity=1000000,
        # Others
        policy_save_interval=10000,
        replay_buffer_save_interval=100000,
        eval_interval=10000,
        eval_episodes=30,
        debug_summaries=False,
        summarize_grads_and_vars=False):
    """Trains and evaluates SAC."""
    logging.info('Training SAC on: %s', env_name)
    collect_env = suite_mujoco.load(env_name)
    eval_env = suite_mujoco.load(env_name)

    _, action_tensor_spec, time_step_tensor_spec = (
        spec_utils.get_tensor_specs(collect_env))

    actor_net = create_sequential_actor_network(
        actor_fc_layers=actor_fc_layers, action_tensor_spec=action_tensor_spec)

    critic_net = create_sequential_critic_network(
        obs_fc_layer_units=critic_obs_fc_layers,
        action_fc_layer_units=critic_action_fc_layers,
        joint_fc_layer_units=critic_joint_fc_layers)

    with strategy.scope():
        train_step = train_utils.create_train_step()
        agent = sac_agent.SacAgent(
            time_step_tensor_spec,
            action_tensor_spec,
            actor_network=actor_net,
            critic_network=critic_net,
            actor_optimizer=tf.keras.optimizers.Adam(
                learning_rate=actor_learning_rate),
            critic_optimizer=tf.keras.optimizers.Adam(
                learning_rate=critic_learning_rate),
            alpha_optimizer=tf.keras.optimizers.Adam(
                learning_rate=alpha_learning_rate),
            target_update_tau=target_update_tau,
            target_update_period=target_update_period,
            td_errors_loss_fn=tf.math.squared_difference,
            gamma=gamma,
            reward_scale_factor=reward_scale_factor,
            gradient_clipping=None,
            debug_summaries=debug_summaries,
            summarize_grads_and_vars=summarize_grads_and_vars,
            train_step_counter=train_step)
        agent.initialize()

    table_name = 'uniform_table'
    table = reverb.Table(table_name,
                         max_size=replay_capacity,
                         sampler=reverb.selectors.Uniform(),
                         remover=reverb.selectors.Fifo(),
                         rate_limiter=reverb.rate_limiters.MinSize(1))

    reverb_checkpoint_dir = os.path.join(root_dir, learner.TRAIN_DIR,
                                         learner.REPLAY_BUFFER_CHECKPOINT_DIR)
    reverb_checkpointer = reverb.platform.checkpointers_lib.DefaultCheckpointer(
        path=reverb_checkpoint_dir)
    reverb_server = reverb.Server([table],
                                  port=reverb_port,
                                  checkpointer=reverb_checkpointer)
    reverb_replay = reverb_replay_buffer.ReverbReplayBuffer(
        agent.collect_data_spec,
        sequence_length=2,
        table_name=table_name,
        local_server=reverb_server)
    rb_observer = reverb_utils.ReverbAddTrajectoryObserver(
        reverb_replay.py_client,
        table_name,
        sequence_length=2,
        stride_length=1)

    def experience_dataset_fn():
        return reverb_replay.as_dataset(sample_batch_size=batch_size,
                                        num_steps=2).prefetch(50)

    saved_model_dir = os.path.join(root_dir, learner.POLICY_SAVED_MODEL_DIR)
    env_step_metric = py_metrics.EnvironmentSteps()
    learning_triggers = [
        triggers.PolicySavedModelTrigger(
            saved_model_dir,
            agent,
            train_step,
            interval=policy_save_interval,
            metadata_metrics={triggers.ENV_STEP_METADATA_KEY:
                              env_step_metric}),
        triggers.ReverbCheckpointTrigger(
            train_step,
            interval=replay_buffer_save_interval,
            reverb_client=reverb_replay.py_client),
        # TODO(b/165023684): Add SIGTERM handler to checkpoint before preemption.
        triggers.StepPerSecondLogTrigger(train_step, interval=1000),
    ]

    agent_learner = learner.Learner(root_dir,
                                    train_step,
                                    agent,
                                    experience_dataset_fn,
                                    triggers=learning_triggers,
                                    strategy=strategy)

    random_policy = random_py_policy.RandomPyPolicy(
        collect_env.time_step_spec(), collect_env.action_spec())
    initial_collect_actor = actor.Actor(collect_env,
                                        random_policy,
                                        train_step,
                                        steps_per_run=initial_collect_steps,
                                        observers=[rb_observer])
    logging.info('Doing initial collect.')
    initial_collect_actor.run()

    tf_collect_policy = agent.collect_policy
    collect_policy = py_tf_eager_policy.PyTFEagerPolicy(tf_collect_policy,
                                                        use_tf_function=True)

    collect_actor = actor.Actor(collect_env,
                                collect_policy,
                                train_step,
                                steps_per_run=1,
                                metrics=actor.collect_metrics(10),
                                summary_dir=os.path.join(
                                    root_dir, learner.TRAIN_DIR),
                                observers=[rb_observer, env_step_metric])

    tf_greedy_policy = greedy_policy.GreedyPolicy(agent.policy)
    eval_greedy_policy = py_tf_eager_policy.PyTFEagerPolicy(
        tf_greedy_policy, use_tf_function=True)

    eval_actor = actor.Actor(
        eval_env,
        eval_greedy_policy,
        train_step,
        episodes_per_run=eval_episodes,
        metrics=actor.eval_metrics(eval_episodes),
        summary_dir=os.path.join(root_dir, 'eval'),
    )

    if eval_interval:
        logging.info('Evaluating.')
        eval_actor.run_and_log()

    logging.info('Training.')
    for _ in range(num_iterations):
        collect_actor.run()
        agent_learner.run(iterations=1)

        if eval_interval and agent_learner.train_step_numpy % eval_interval == 0:
            logging.info('Evaluating.')
            eval_actor.run_and_log()

    rb_observer.close()
    reverb_server.stop()
Esempio n. 13
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def train(
    root_dir: Text,
    environment_name: Text,
    strategy: tf.distribute.Strategy,
    replay_buffer_server_address: Text,
    variable_container_server_address: Text,
    suite_load_fn: Callable[[Text],
                            py_environment.PyEnvironment] = suite_mujoco.load,
    # Training params
    learning_rate: float = 3e-4,
    batch_size: int = 256,
    num_iterations: int = 2000000,
    learner_iterations_per_call: int = 1) -> None:
  """Trains a DQN agent."""
  # Get the specs from the environment.
  logging.info('Training SAC with learning rate: %f', learning_rate)
  env = suite_load_fn(environment_name)
  observation_tensor_spec, action_tensor_spec, time_step_tensor_spec = (
      spec_utils.get_tensor_specs(env))

  # Create the agent.
  with strategy.scope():
    train_step = train_utils.create_train_step()
    agent = _create_agent(
        train_step=train_step,
        observation_tensor_spec=observation_tensor_spec,
        action_tensor_spec=action_tensor_spec,
        time_step_tensor_spec=time_step_tensor_spec,
        learning_rate=learning_rate)

  # Create the policy saver which saves the initial model now, then it
  # periodically checkpoints the policy weigths.
  saved_model_dir = os.path.join(root_dir, learner.POLICY_SAVED_MODEL_DIR)
  save_model_trigger = triggers.PolicySavedModelTrigger(
      saved_model_dir, agent, train_step, interval=1000)

  # Create the variable container.
  variables = {
      reverb_variable_container.POLICY_KEY: agent.collect_policy.variables(),
      reverb_variable_container.TRAIN_STEP_KEY: train_step
  }
  variable_container = reverb_variable_container.ReverbVariableContainer(
      variable_container_server_address,
      table_names=[reverb_variable_container.DEFAULT_TABLE])
  variable_container.push(variables)

  # Create the replay buffer.
  reverb_replay = reverb_replay_buffer.ReverbReplayBuffer(
      agent.collect_data_spec,
      sequence_length=2,
      table_name=reverb_replay_buffer.DEFAULT_TABLE,
      server_address=replay_buffer_server_address)

  # Initialize the dataset.
  def experience_dataset_fn():
    with strategy.scope():
      return reverb_replay.as_dataset(
          sample_batch_size=batch_size, num_steps=2).prefetch(3)

  # Create the learner.
  learning_triggers = [
      save_model_trigger,
      triggers.StepPerSecondLogTrigger(train_step, interval=1000)
  ]
  sac_learner = learner.Learner(
      root_dir,
      train_step,
      agent,
      experience_dataset_fn,
      triggers=learning_triggers,
      strategy=strategy)

  # Run the training loop.
  while train_step.numpy() < num_iterations:
    sac_learner.run(iterations=learner_iterations_per_call)
    variable_container.push(variables)
Esempio n. 14
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def evaluate(
    summary_dir: Text,
    environment_name: Text,
    policy: py_tf_eager_policy.PyTFEagerPolicyBase,
    variable_container: reverb_variable_container.ReverbVariableContainer,
    suite_load_fn: Callable[[Text],
                            py_environment.PyEnvironment] = suite_mujoco.load,
    additional_metrics: Optional[Iterable[py_metric.PyStepMetric]] = None,
    is_running: Optional[Callable[[], bool]] = None,
    eval_interval: int = 1000,
    eval_episodes: int = 1,
    # TODO(b/178225158): Deprecate in favor of the reporting libray when ready.
    return_reporting_fn: Optional[Callable[[int, float], None]] = None
) -> None:
    """Evaluates a policy iteratively fetching weights from variable container.

  Args:
    summary_dir: Directory which is used to store the summaries.
    environment_name: Name of the environment used to evaluate the policy.
    policy: The policy being evaluated. The weights of this policy are fetched
      from the variable container periodically.
    variable_container: Provides weights for the policy.
    suite_load_fn: Function that loads the environment (by calling it with the
      name of the environment) from a particular suite.
    additional_metrics: Optional collection of metrics that are computed as well
      during the evaluation. By default (`None`) it is empty.
    is_running: Optional callable which controls the running of the main
      evaluation loop (including fetching weights from the variable container
      and running the eval actor periodically). By default (`None`) this is a
      callable always returning `True` resulting in an infinite evaluation loop.
    eval_interval: If set, eval is done at the given step interval or as close
      as possible based on polling.
    eval_episodes: Number of episodes to eval.
    return_reporting_fn: Optional callback function of the form `fn(train_step,
      average_return)` which reports the average return to a custom destination.
  """
    additional_metrics = additional_metrics or []
    is_running = is_running or (lambda: True)
    environment = suite_load_fn(environment_name)

    # Create the variable container.
    train_step = train_utils.create_train_step()
    variables = {
        reverb_variable_container.POLICY_KEY: policy.variables(),
        reverb_variable_container.TRAIN_STEP_KEY: train_step
    }
    variable_container.update(variables)
    prev_train_step_value = train_step.numpy()

    # Create the evaluator actor.
    metrics = actor.collect_metrics(buffer_size=eval_episodes)

    if return_reporting_fn:
        for m in metrics:
            if isinstance(m, py_metrics.AverageReturnMetric):
                average_return_metric = m
                break

    eval_actor = actor.Actor(environment,
                             policy,
                             train_step,
                             episodes_per_run=eval_episodes,
                             summary_dir=summary_dir,
                             summary_interval=eval_interval,
                             metrics=metrics + additional_metrics,
                             name='eval_actor')

    # Run the experience evaluation loop.
    last_eval_step = 0
    while is_running():

        # Eval every step if no `eval_interval` is set, or if on the first step, or
        # if the step is equal or greater than `last_eval_step` + `eval_interval`.
        # It is very possible when logging a specific interval that the steps evaled
        # will not be exact, e.g. 1001 and then 2003 vs. 1000 and then 2000.
        if (train_step.numpy() == 0
                or train_step.numpy() >= eval_interval + last_eval_step):
            logging.info('Evaluating using greedy policy at step: %d',
                         train_step.numpy())
            eval_actor.run()
            last_eval_step = train_step.numpy()

        def is_train_step_the_same_or_behind():
            # Checks if the `train_step` received from variable conainer is the same
            # (or behind) the latest evaluated train step (`prev_train_step_value`).
            variable_container.update(variables)
            return train_step.numpy() <= prev_train_step_value

        train_utils.wait_for_predicate(
            wait_predicate_fn=is_train_step_the_same_or_behind)
        prev_train_step_value = train_step.numpy()

        # Optionally report the average return metric via a callback.
        if return_reporting_fn:
            return_reporting_fn(train_step.numpy(),
                                average_return_metric.result())
Esempio n. 15
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        observation_fc_layer_params=None,
        action_fc_layer_params=None,
        joint_fc_layer_params=critic_joint_fc_layer_params,
        kernel_initializer='glorot_uniform',
        last_kernel_initializer='glorot_uniform')

with strategy.scope():
    actor_net = actor_distribution_network.ActorDistributionNetwork(
        observation_spec,
        action_spec,
        fc_layer_params=actor_fc_layer_params,
        continuous_projection_net=(
            tanh_normal_projection_network.TanhNormalProjectionNetwork))

with strategy.scope():
    train_step = train_utils.create_train_step()

    tf_agent = sac_agent.SacAgent(
        time_step_spec,
        action_spec,
        actor_network=actor_net,
        critic_network=critic_net,
        actor_optimizer=tf.compat.v1.train.AdamOptimizer(
            learning_rate=actor_learning_rate),
        critic_optimizer=tf.compat.v1.train.AdamOptimizer(
            learning_rate=critic_learning_rate),
        alpha_optimizer=tf.compat.v1.train.AdamOptimizer(
            learning_rate=alpha_learning_rate),
        target_update_tau=target_update_tau,
        target_update_period=target_update_period,
        td_errors_loss_fn=tf.math.squared_difference,
Esempio n. 16
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def train_eval(
        root_dir,
        env_name='CartPole-v0',
        # Training params
        initial_collect_steps=1000,
        num_iterations=100000,
        fc_layer_params=(100, ),
        # Agent params
        epsilon_greedy=0.1,
        batch_size=64,
        learning_rate=1e-3,
        n_step_update=1,
        gamma=0.99,
        target_update_tau=0.05,
        target_update_period=5,
        reward_scale_factor=1.0,
        # Replay params
        reverb_port=None,
        replay_capacity=100000,
        # Others
        policy_save_interval=1000,
        eval_interval=1000,
        eval_episodes=10):
    """Trains and evaluates DQN."""
    collect_env = suite_gym.load(env_name)
    eval_env = suite_gym.load(env_name)

    time_step_tensor_spec = tensor_spec.from_spec(collect_env.time_step_spec())
    action_tensor_spec = tensor_spec.from_spec(collect_env.action_spec())

    train_step = train_utils.create_train_step()
    num_actions = action_tensor_spec.maximum - action_tensor_spec.minimum + 1

    # Define a helper function to create Dense layers configured with the right
    # activation and kernel initializer.
    def dense_layer(num_units):
        return tf.keras.layers.Dense(
            num_units,
            activation=tf.keras.activations.relu,
            kernel_initializer=tf.keras.initializers.VarianceScaling(
                scale=2.0, mode='fan_in', distribution='truncated_normal'))

    # QNetwork consists of a sequence of Dense layers followed by a dense layer
    # with `num_actions` units to generate one q_value per available action as
    # it's output.
    dense_layers = [dense_layer(num_units) for num_units in fc_layer_params]
    q_values_layer = tf.keras.layers.Dense(
        num_actions,
        activation=None,
        kernel_initializer=tf.keras.initializers.RandomUniform(minval=-0.03,
                                                               maxval=0.03),
        bias_initializer=tf.keras.initializers.Constant(-0.2))
    q_net = sequential.Sequential(dense_layers + [q_values_layer])

    agent = dqn_agent.DqnAgent(
        time_step_tensor_spec,
        action_tensor_spec,
        q_network=q_net,
        epsilon_greedy=epsilon_greedy,
        n_step_update=n_step_update,
        target_update_tau=target_update_tau,
        target_update_period=target_update_period,
        optimizer=tf.keras.optimizers.Adam(learning_rate=learning_rate),
        td_errors_loss_fn=common.element_wise_squared_loss,
        gamma=gamma,
        reward_scale_factor=reward_scale_factor,
        train_step_counter=train_step)

    table_name = 'uniform_table'
    table = reverb.Table(table_name,
                         max_size=replay_capacity,
                         sampler=reverb.selectors.Uniform(),
                         remover=reverb.selectors.Fifo(),
                         rate_limiter=reverb.rate_limiters.MinSize(1))
    reverb_server = reverb.Server([table], port=reverb_port)
    reverb_replay = reverb_replay_buffer.ReverbReplayBuffer(
        agent.collect_data_spec,
        sequence_length=2,
        table_name=table_name,
        local_server=reverb_server)
    rb_observer = reverb_utils.ReverbAddTrajectoryObserver(
        reverb_replay.py_client,
        table_name,
        sequence_length=2,
        stride_length=1)

    dataset = reverb_replay.as_dataset(num_parallel_calls=3,
                                       sample_batch_size=batch_size,
                                       num_steps=2).prefetch(3)
    experience_dataset_fn = lambda: dataset

    saved_model_dir = os.path.join(root_dir, learner.POLICY_SAVED_MODEL_DIR)
    env_step_metric = py_metrics.EnvironmentSteps()

    learning_triggers = [
        triggers.PolicySavedModelTrigger(
            saved_model_dir,
            agent,
            train_step,
            interval=policy_save_interval,
            metadata_metrics={triggers.ENV_STEP_METADATA_KEY:
                              env_step_metric}),
        triggers.StepPerSecondLogTrigger(train_step, interval=100),
    ]

    dqn_learner = learner.Learner(root_dir,
                                  train_step,
                                  agent,
                                  experience_dataset_fn,
                                  triggers=learning_triggers)

    # If we haven't trained yet make sure we collect some random samples first to
    # fill up the Replay Buffer with some experience.
    random_policy = random_py_policy.RandomPyPolicy(
        collect_env.time_step_spec(), collect_env.action_spec())
    initial_collect_actor = actor.Actor(collect_env,
                                        random_policy,
                                        train_step,
                                        steps_per_run=initial_collect_steps,
                                        observers=[rb_observer])
    logging.info('Doing initial collect.')
    initial_collect_actor.run()

    tf_collect_policy = agent.collect_policy
    collect_policy = py_tf_eager_policy.PyTFEagerPolicy(tf_collect_policy,
                                                        use_tf_function=True)

    collect_actor = actor.Actor(
        collect_env,
        collect_policy,
        train_step,
        steps_per_run=1,
        observers=[rb_observer, env_step_metric],
        metrics=actor.collect_metrics(10),
        summary_dir=os.path.join(root_dir, learner.TRAIN_DIR),
    )

    tf_greedy_policy = agent.policy
    greedy_policy = py_tf_eager_policy.PyTFEagerPolicy(tf_greedy_policy,
                                                       use_tf_function=True)

    eval_actor = actor.Actor(
        eval_env,
        greedy_policy,
        train_step,
        episodes_per_run=eval_episodes,
        metrics=actor.eval_metrics(eval_episodes),
        summary_dir=os.path.join(root_dir, 'eval'),
    )

    if eval_interval:
        logging.info('Evaluating.')
        eval_actor.run_and_log()

    logging.info('Training.')
    for _ in range(num_iterations):
        collect_actor.run()
        dqn_learner.run(iterations=1)

        if eval_interval and dqn_learner.train_step_numpy % eval_interval == 0:
            logging.info('Evaluating.')
            eval_actor.run_and_log()

    rb_observer.close()
    reverb_server.stop()
Esempio n. 17
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def evaluate(
        summary_dir: Text,
        environment_name: Text,
        policy: py_tf_eager_policy.PyTFEagerPolicyBase,
        variable_container: reverb_variable_container.ReverbVariableContainer,
        suite_load_fn: Callable[
            [Text], py_environment.PyEnvironment] = suite_mujoco.load,
        additional_metrics: Optional[Iterable[py_metric.PyStepMetric]] = None,
        is_running: Optional[Callable[[], bool]] = None) -> None:
    """Evaluates a policy iteratively fetching weights from variable container.

  Args:
    summary_dir: Directory which is used to store the summaries.
    environment_name: Name of the environment used to evaluate the policy.
    policy: The policy being evaluated. The weights of this policy are fetched
      from the variable container periodically.
    variable_container: Provides weights for the policy.
    suite_load_fn: Function that loads the environment (by calling it with the
      name of the environment) from a particular suite.
    additional_metrics: Optional collection of metrics that are computed as well
      during the evaluation. By default (`None`) it is empty.
    is_running: Optional callable which controls the running of the main
      evaluation loop (including fetching weights from the variable container
      and running the eval actor periodically). By default (`None`) this is a
      callable always returning `True` resulting in an infinite evaluation loop.
  """
    additional_metrics = additional_metrics or []
    is_running = is_running or (lambda: True)
    environment = suite_load_fn(environment_name)

    # Create the variable container.
    train_step = train_utils.create_train_step()
    variables = {
        reverb_variable_container.POLICY_KEY: policy.variables(),
        reverb_variable_container.TRAIN_STEP_KEY: train_step
    }
    variable_container.update(variables)
    prev_train_step_value = train_step.numpy()

    # Create the evaluator actor.
    eval_actor = actor.Actor(environment,
                             policy,
                             train_step,
                             episodes_per_run=1,
                             summary_dir=summary_dir,
                             metrics=actor.collect_metrics(buffer_size=1) +
                             additional_metrics,
                             name='eval_actor')

    # Run the experience evaluation loop.
    while is_running():
        eval_actor.run()
        logging.info('Evaluating using greedy policy at step: %d',
                     train_step.numpy())

        def is_train_step_the_same_or_behind():
            # Checks if the `train_step` received from variable conainer is the same
            # (or behind) the latest evaluated train step (`prev_train_step_value`).
            variable_container.update(variables)
            return train_step.numpy() <= prev_train_step_value

        train_utils.wait_for_predicate(
            wait_predicate_fn=is_train_step_the_same_or_behind)
        prev_train_step_value = train_step.numpy()
Esempio n. 18
0
    num_actions = action_tensor_spec.shape[0]

    with strategy.scope():
        collect_policy = tf.saved_model.load(
            '/tmp/models/expert/AntBulletEnv-v0')

        dense_layers = [
            Dense(num_units, activation=relu) for num_units in fc_layer_params
        ]

        output_layer = Dense(num_actions, activation=None)

        cloning_net = Sequential(dense_layers + [output_layer])
        optimizer = Adam(learning_rate=learning_rate)
        train_step_counter = train_utils.create_train_step()
        agent = BehavioralCloningAgent(env.time_step_spec(),
                                       env.action_spec(),
                                       cloning_network=cloning_net,
                                       optimizer=optimizer)

    policy = agent.policy

    replay_buffer = TFUniformReplayBuffer(data_spec=agent.collect_data_spec,
                                          batch_size=env.batch_size,
                                          max_length=replay_buffer_capacity)

    agent.train_step_counter.assign(0)

    replay_observer = [replay_buffer.add_batch]
    with strategy.scope():
Esempio n. 19
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def train_eval(
    root_dir,
    env_name='HalfCheetah-v2',
    # Training params
    num_iterations=1600,
    actor_fc_layers=(64, 64),
    value_fc_layers=(64, 64),
    learning_rate=3e-4,
    collect_sequence_length=2048,
    minibatch_size=64,
    num_epochs=10,
    # Agent params
    importance_ratio_clipping=0.2,
    lambda_value=0.95,
    discount_factor=0.99,
    entropy_regularization=0.,
    value_pred_loss_coef=0.5,
    use_gae=True,
    use_td_lambda_return=True,
    gradient_clipping=0.5,
    value_clipping=None,
    # Replay params
    reverb_port=None,
    replay_capacity=10000,
    # Others
    policy_save_interval=5000,
    summary_interval=1000,
    eval_interval=10000,
    eval_episodes=100,
    debug_summaries=False,
    summarize_grads_and_vars=False):
  """Trains and evaluates PPO (Importance Ratio Clipping).

  Args:
    root_dir: Main directory path where checkpoints, saved_models, and summaries
      will be written to.
    env_name: Name for the Mujoco environment to load.
    num_iterations: The number of iterations to perform collection and training.
    actor_fc_layers: List of fully_connected parameters for the actor network,
      where each item is the number of units in the layer.
    value_fc_layers: : List of fully_connected parameters for the value network,
      where each item is the number of units in the layer.
    learning_rate: Learning rate used on the Adam optimizer.
    collect_sequence_length: Number of steps to take in each collect run.
    minibatch_size: Number of elements in each mini batch. If `None`, the entire
      collected sequence will be treated as one batch.
    num_epochs: Number of iterations to repeat over all collected data per data
      collection step. (Schulman,2017) sets this to 10 for Mujoco, 15 for
      Roboschool and 3 for Atari.
    importance_ratio_clipping: Epsilon in clipped, surrogate PPO objective. For
      more detail, see explanation at the top of the doc.
    lambda_value: Lambda parameter for TD-lambda computation.
    discount_factor: Discount factor for return computation. Default to `0.99`
      which is the value used for all environments from (Schulman, 2017).
    entropy_regularization: Coefficient for entropy regularization loss term.
      Default to `0.0` because no entropy bonus was used in (Schulman, 2017).
    value_pred_loss_coef: Multiplier for value prediction loss to balance with
      policy gradient loss. Default to `0.5`, which was used for all
      environments in the OpenAI baseline implementation. This parameters is
      irrelevant unless you are sharing part of actor_net and value_net. In that
      case, you would want to tune this coeeficient, whose value depends on the
      network architecture of your choice.
    use_gae: If True (default False), uses generalized advantage estimation for
      computing per-timestep advantage. Else, just subtracts value predictions
      from empirical return.
    use_td_lambda_return: If True (default False), uses td_lambda_return for
      training value function; here: `td_lambda_return = gae_advantage +
        value_predictions`. `use_gae` must be set to `True` as well to enable TD
        -lambda returns. If `use_td_lambda_return` is set to True while
        `use_gae` is False, the empirical return will be used and a warning will
        be logged.
    gradient_clipping: Norm length to clip gradients.
    value_clipping: Difference between new and old value predictions are clipped
      to this threshold. Value clipping could be helpful when training
      very deep networks. Default: no clipping.
    reverb_port: Port for reverb server, if None, use a randomly chosen unused
      port.
    replay_capacity: The maximum number of elements for the replay buffer. Items
      will be wasted if this is smalled than collect_sequence_length.
    policy_save_interval: How often, in train_steps, the policy will be saved.
    summary_interval: How often to write data into Tensorboard.
    eval_interval: How often to run evaluation, in train_steps.
    eval_episodes: Number of episodes to evaluate over.
    debug_summaries: Boolean for whether to gather debug summaries.
    summarize_grads_and_vars: If true, gradient summaries will be written.
  """
  collect_env = suite_mujoco.load(env_name)
  eval_env = suite_mujoco.load(env_name)
  num_environments = 1

  observation_tensor_spec, action_tensor_spec, time_step_tensor_spec = (
      spec_utils.get_tensor_specs(collect_env))
  # TODO(b/172267869): Remove this conversion once TensorNormalizer stops
  # converting float64 inputs to float32.
  observation_tensor_spec = tf.TensorSpec(
      dtype=tf.float32, shape=observation_tensor_spec.shape)

  train_step = train_utils.create_train_step()
  actor_net_builder = ppo_actor_network.PPOActorNetwork()
  actor_net = actor_net_builder.create_sequential_actor_net(
      actor_fc_layers, action_tensor_spec)
  value_net = value_network.ValueNetwork(
      observation_tensor_spec,
      fc_layer_params=value_fc_layers,
      kernel_initializer=tf.keras.initializers.Orthogonal())

  current_iteration = tf.Variable(0, dtype=tf.int64)
  def learning_rate_fn():
    # Linearly decay the learning rate.
    return learning_rate * (1 - current_iteration / num_iterations)

  agent = ppo_clip_agent.PPOClipAgent(
      time_step_tensor_spec,
      action_tensor_spec,
      optimizer=tf.keras.optimizers.Adam(
          learning_rate=learning_rate_fn, epsilon=1e-5),
      actor_net=actor_net,
      value_net=value_net,
      importance_ratio_clipping=importance_ratio_clipping,
      lambda_value=lambda_value,
      discount_factor=discount_factor,
      entropy_regularization=entropy_regularization,
      value_pred_loss_coef=value_pred_loss_coef,
      # This is a legacy argument for the number of times we repeat the data
      # inside of the train function, incompatible with mini batch learning.
      # We set the epoch number from the replay buffer and tf.Data instead.
      num_epochs=1,
      use_gae=use_gae,
      use_td_lambda_return=use_td_lambda_return,
      gradient_clipping=gradient_clipping,
      value_clipping=value_clipping,
      # TODO(b/150244758): Default compute_value_and_advantage_in_train to False
      # after Reverb open source.
      compute_value_and_advantage_in_train=False,
      # Skips updating normalizers in the agent, as it's handled in the learner.
      update_normalizers_in_train=False,
      debug_summaries=debug_summaries,
      summarize_grads_and_vars=summarize_grads_and_vars,
      train_step_counter=train_step)
  agent.initialize()

  reverb_server = reverb.Server(
      [
          reverb.Table(  # Replay buffer storing experience for training.
              name='training_table',
              sampler=reverb.selectors.Fifo(),
              remover=reverb.selectors.Fifo(),
              rate_limiter=reverb.rate_limiters.MinSize(1),
              max_size=replay_capacity,
              max_times_sampled=1,
          ),
          reverb.Table(  # Replay buffer storing experience for normalization.
              name='normalization_table',
              sampler=reverb.selectors.Fifo(),
              remover=reverb.selectors.Fifo(),
              rate_limiter=reverb.rate_limiters.MinSize(1),
              max_size=replay_capacity,
              max_times_sampled=1,
          )
      ],
      port=reverb_port)

  # Create the replay buffer.
  reverb_replay_train = reverb_replay_buffer.ReverbReplayBuffer(
      agent.collect_data_spec,
      sequence_length=collect_sequence_length,
      table_name='training_table',
      server_address='localhost:{}'.format(reverb_server.port),
      # The only collected sequence is used to populate the batches.
      max_cycle_length=1,
      rate_limiter_timeout_ms=1000)
  reverb_replay_normalization = reverb_replay_buffer.ReverbReplayBuffer(
      agent.collect_data_spec,
      sequence_length=collect_sequence_length,
      table_name='normalization_table',
      server_address='localhost:{}'.format(reverb_server.port),
      # The only collected sequence is used to populate the batches.
      max_cycle_length=1,
      rate_limiter_timeout_ms=1000)

  rb_observer = reverb_utils.ReverbTrajectorySequenceObserver(
      reverb_replay_train.py_client, ['training_table', 'normalization_table'],
      sequence_length=collect_sequence_length,
      stride_length=collect_sequence_length)

  saved_model_dir = os.path.join(root_dir, learner.POLICY_SAVED_MODEL_DIR)
  collect_env_step_metric = py_metrics.EnvironmentSteps()
  learning_triggers = [
      triggers.PolicySavedModelTrigger(
          saved_model_dir,
          agent,
          train_step,
          interval=policy_save_interval,
          metadata_metrics={
              triggers.ENV_STEP_METADATA_KEY: collect_env_step_metric
          }),
      triggers.StepPerSecondLogTrigger(train_step, interval=summary_interval),
  ]

  def training_dataset_fn():
    return reverb_replay_train.as_dataset(
        sample_batch_size=num_environments,
        sequence_preprocess_fn=agent.preprocess_sequence)

  def normalization_dataset_fn():
    return reverb_replay_normalization.as_dataset(
        sample_batch_size=num_environments,
        sequence_preprocess_fn=agent.preprocess_sequence)

  agent_learner = ppo_learner.PPOLearner(
      root_dir,
      train_step,
      agent,
      experience_dataset_fn=training_dataset_fn,
      normalization_dataset_fn=normalization_dataset_fn,
      num_samples=1,
      num_epochs=num_epochs,
      minibatch_size=minibatch_size,
      shuffle_buffer_size=collect_sequence_length,
      triggers=learning_triggers)

  tf_collect_policy = agent.collect_policy
  collect_policy = py_tf_eager_policy.PyTFEagerPolicy(
      tf_collect_policy, use_tf_function=True)

  collect_actor = actor.Actor(
      collect_env,
      collect_policy,
      train_step,
      steps_per_run=collect_sequence_length,
      observers=[rb_observer],
      metrics=actor.collect_metrics(buffer_size=10) + [collect_env_step_metric],
      reference_metrics=[collect_env_step_metric],
      summary_dir=os.path.join(root_dir, learner.TRAIN_DIR),
      summary_interval=summary_interval)

  eval_greedy_policy = py_tf_eager_policy.PyTFEagerPolicy(
      agent.policy, use_tf_function=True)

  if eval_interval:
    logging.info('Intial evaluation.')
    eval_actor = actor.Actor(
        eval_env,
        eval_greedy_policy,
        train_step,
        metrics=actor.eval_metrics(eval_episodes),
        reference_metrics=[collect_env_step_metric],
        summary_dir=os.path.join(root_dir, 'eval'),
        episodes_per_run=eval_episodes)

    eval_actor.run_and_log()

  logging.info('Training on %s', env_name)
  last_eval_step = 0
  for i in range(num_iterations):
    collect_actor.run()
    rb_observer.flush()
    agent_learner.run()
    reverb_replay_train.clear()
    reverb_replay_normalization.clear()
    current_iteration.assign_add(1)

    # Eval only if `eval_interval` has been set. Then, eval if the current train
    # step is equal or greater than the `last_eval_step` + `eval_interval` or if
    # this is the last iteration. This logic exists because agent_learner.run()
    # does not return after every train step.
    if (eval_interval and
        (agent_learner.train_step_numpy >= eval_interval + last_eval_step
         or i == num_iterations - 1)):
      logging.info('Evaluating.')
      eval_actor.run_and_log()
      last_eval_step = agent_learner.train_step_numpy

  rb_observer.close()
  reverb_server.stop()
Esempio n. 20
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def train_eval(
        root_dir,
        dataset_path,
        env_name,
        # Training params
        tpu=False,
        use_gpu=False,
        num_gradient_updates=1000000,
        actor_fc_layers=(256, 256),
        critic_joint_fc_layers=(256, 256, 256),
        # Agent params
        batch_size=256,
        bc_steps=0,
        actor_learning_rate=3e-5,
        critic_learning_rate=3e-4,
        alpha_learning_rate=3e-4,
        reward_scale_factor=1.0,
        cql_alpha_learning_rate=3e-4,
        cql_alpha=5.0,
        cql_tau=10.0,
        num_cql_samples=10,
        reward_noise_variance=0.0,
        include_critic_entropy_term=False,
        use_lagrange_cql_alpha=True,
        log_cql_alpha_clipping=None,
        softmax_temperature=1.0,
        # Data params
        reward_shift=0.0,
        action_clipping=None,
        use_trajectories=False,
        data_shuffle_buffer_size_per_record=1,
        data_shuffle_buffer_size=100,
        data_num_shards=1,
        data_block_length=10,
        data_parallel_reads=None,
        data_parallel_calls=10,
        data_prefetch=10,
        data_cycle_length=10,
        # Others
        policy_save_interval=10000,
        eval_interval=10000,
        summary_interval=1000,
        learner_iterations_per_call=1,
        eval_episodes=10,
        debug_summaries=False,
        summarize_grads_and_vars=False,
        seed=None):
    """Trains and evaluates CQL-SAC."""
    logging.info('Training CQL-SAC on: %s', env_name)
    tf.random.set_seed(seed)
    np.random.seed(seed)

    # Load environment.
    env = load_d4rl(env_name)
    tf_env = tf_py_environment.TFPyEnvironment(env)
    strategy = strategy_utils.get_strategy(tpu, use_gpu)

    if not dataset_path.endswith('.tfrecord'):
        dataset_path = os.path.join(dataset_path, env_name,
                                    '%s*.tfrecord' % env_name)
    logging.info('Loading dataset from %s', dataset_path)
    dataset_paths = tf.io.gfile.glob(dataset_path)

    # Create dataset.
    with strategy.scope():
        dataset = create_tf_record_dataset(
            dataset_paths,
            batch_size,
            shuffle_buffer_size_per_record=data_shuffle_buffer_size_per_record,
            shuffle_buffer_size=data_shuffle_buffer_size,
            num_shards=data_num_shards,
            cycle_length=data_cycle_length,
            block_length=data_block_length,
            num_parallel_reads=data_parallel_reads,
            num_parallel_calls=data_parallel_calls,
            num_prefetch=data_prefetch,
            strategy=strategy,
            reward_shift=reward_shift,
            action_clipping=action_clipping,
            use_trajectories=use_trajectories)

    # Create agent.
    time_step_spec = tf_env.time_step_spec()
    observation_spec = time_step_spec.observation
    action_spec = tf_env.action_spec()
    with strategy.scope():
        train_step = train_utils.create_train_step()

        actor_net = actor_distribution_network.ActorDistributionNetwork(
            observation_spec,
            action_spec,
            fc_layer_params=actor_fc_layers,
            continuous_projection_net=tanh_normal_projection_network.
            TanhNormalProjectionNetwork)

        critic_net = critic_network.CriticNetwork(
            (observation_spec, action_spec),
            joint_fc_layer_params=critic_joint_fc_layers,
            kernel_initializer='glorot_uniform',
            last_kernel_initializer='glorot_uniform')

        agent = cql_sac_agent.CqlSacAgent(
            time_step_spec,
            action_spec,
            actor_network=actor_net,
            critic_network=critic_net,
            actor_optimizer=tf.keras.optimizers.Adam(
                learning_rate=actor_learning_rate),
            critic_optimizer=tf.keras.optimizers.Adam(
                learning_rate=critic_learning_rate),
            alpha_optimizer=tf.keras.optimizers.Adam(
                learning_rate=alpha_learning_rate),
            cql_alpha=cql_alpha,
            num_cql_samples=num_cql_samples,
            include_critic_entropy_term=include_critic_entropy_term,
            use_lagrange_cql_alpha=use_lagrange_cql_alpha,
            cql_alpha_learning_rate=cql_alpha_learning_rate,
            target_update_tau=5e-3,
            target_update_period=1,
            random_seed=seed,
            cql_tau=cql_tau,
            reward_noise_variance=reward_noise_variance,
            num_bc_steps=bc_steps,
            td_errors_loss_fn=tf.math.squared_difference,
            gamma=0.99,
            reward_scale_factor=reward_scale_factor,
            gradient_clipping=None,
            log_cql_alpha_clipping=log_cql_alpha_clipping,
            softmax_temperature=softmax_temperature,
            debug_summaries=debug_summaries,
            summarize_grads_and_vars=summarize_grads_and_vars,
            train_step_counter=train_step)
        agent.initialize()

    # Create learner.
    saved_model_dir = os.path.join(root_dir, learner.POLICY_SAVED_MODEL_DIR)
    collect_env_step_metric = py_metrics.EnvironmentSteps()
    learning_triggers = [
        triggers.PolicySavedModelTrigger(saved_model_dir,
                                         agent,
                                         train_step,
                                         interval=policy_save_interval,
                                         metadata_metrics={
                                             triggers.ENV_STEP_METADATA_KEY:
                                             collect_env_step_metric
                                         }),
        triggers.StepPerSecondLogTrigger(train_step, interval=100)
    ]
    cql_learner = learner.Learner(root_dir,
                                  train_step,
                                  agent,
                                  experience_dataset_fn=lambda: dataset,
                                  triggers=learning_triggers,
                                  summary_interval=summary_interval,
                                  strategy=strategy)

    # Create actor for evaluation.
    tf_greedy_policy = greedy_policy.GreedyPolicy(agent.policy)
    eval_greedy_policy = py_tf_eager_policy.PyTFEagerPolicy(
        tf_greedy_policy, use_tf_function=True)
    eval_actor = actor.Actor(env,
                             eval_greedy_policy,
                             train_step,
                             metrics=actor.eval_metrics(eval_episodes),
                             summary_dir=os.path.join(root_dir, 'eval'),
                             episodes_per_run=eval_episodes)

    # Run.
    dummy_trajectory = trajectory.mid((), (), (), 0., 1.)
    num_learner_iterations = int(num_gradient_updates /
                                 learner_iterations_per_call)
    for _ in range(num_learner_iterations):
        # Mimic collecting environment steps since we loaded a static dataset.
        for _ in range(learner_iterations_per_call):
            collect_env_step_metric(dummy_trajectory)

        cql_learner.run(iterations=learner_iterations_per_call)
        if eval_interval and train_step.numpy() % eval_interval == 0:
            eval_actor.run_and_log()
Esempio n. 21
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def train_eval(
        root_dir,
        env_name='HalfCheetah-v2',
        # Training params
        initial_collect_steps=10000,
        num_iterations=3200000,
        actor_fc_layers=(256, 256),
        critic_obs_fc_layers=None,
        critic_action_fc_layers=None,
        critic_joint_fc_layers=(256, 256),
        # Agent params
        batch_size=256,
        actor_learning_rate=3e-4,
        critic_learning_rate=3e-4,
        alpha_learning_rate=3e-4,
        gamma=0.99,
        target_update_tau=0.005,
        target_update_period=1,
        reward_scale_factor=0.1,
        # Replay params
        reverb_port=None,
        replay_capacity=1000000,
        # Others
        # Defaults to not checkpointing saved policy. If you wish to enable this,
        # please note the caveat explained in README.md.
        policy_save_interval=-1,
        eval_interval=10000,
        eval_episodes=30,
        debug_summaries=False,
        summarize_grads_and_vars=False):
    """Trains and evaluates SAC."""
    logging.info('Training SAC on: %s', env_name)
    collect_env = suite_mujoco.load(env_name)
    eval_env = suite_mujoco.load(env_name)

    observation_tensor_spec, action_tensor_spec, time_step_tensor_spec = (
        spec_utils.get_tensor_specs(collect_env))

    train_step = train_utils.create_train_step()

    actor_net = actor_distribution_network.ActorDistributionNetwork(
        observation_tensor_spec,
        action_tensor_spec,
        fc_layer_params=actor_fc_layers,
        continuous_projection_net=tanh_normal_projection_network.
        TanhNormalProjectionNetwork)
    critic_net = critic_network.CriticNetwork(
        (observation_tensor_spec, action_tensor_spec),
        observation_fc_layer_params=critic_obs_fc_layers,
        action_fc_layer_params=critic_action_fc_layers,
        joint_fc_layer_params=critic_joint_fc_layers,
        kernel_initializer='glorot_uniform',
        last_kernel_initializer='glorot_uniform')

    agent = sac_agent.SacAgent(
        time_step_tensor_spec,
        action_tensor_spec,
        actor_network=actor_net,
        critic_network=critic_net,
        actor_optimizer=tf.compat.v1.train.AdamOptimizer(
            learning_rate=actor_learning_rate),
        critic_optimizer=tf.compat.v1.train.AdamOptimizer(
            learning_rate=critic_learning_rate),
        alpha_optimizer=tf.compat.v1.train.AdamOptimizer(
            learning_rate=alpha_learning_rate),
        target_update_tau=target_update_tau,
        target_update_period=target_update_period,
        td_errors_loss_fn=tf.math.squared_difference,
        gamma=gamma,
        reward_scale_factor=reward_scale_factor,
        gradient_clipping=None,
        debug_summaries=debug_summaries,
        summarize_grads_and_vars=summarize_grads_and_vars,
        train_step_counter=train_step)
    agent.initialize()

    table_name = 'uniform_table'
    table = reverb.Table(table_name,
                         max_size=replay_capacity,
                         sampler=reverb.selectors.Uniform(),
                         remover=reverb.selectors.Fifo(),
                         rate_limiter=reverb.rate_limiters.MinSize(1))

    reverb_server = reverb.Server([table], port=reverb_port)
    reverb_replay = reverb_replay_buffer.ReverbReplayBuffer(
        agent.collect_data_spec,
        sequence_length=2,
        table_name=table_name,
        local_server=reverb_server)
    rb_observer = reverb_utils.ReverbAddTrajectoryObserver(
        reverb_replay.py_client,
        table_name,
        sequence_length=2,
        stride_length=1)

    dataset = reverb_replay.as_dataset(sample_batch_size=batch_size,
                                       num_steps=2).prefetch(50)
    experience_dataset_fn = lambda: dataset

    saved_model_dir = os.path.join(root_dir, learner.POLICY_SAVED_MODEL_DIR)
    env_step_metric = py_metrics.EnvironmentSteps()
    learning_triggers = [
        triggers.PolicySavedModelTrigger(
            saved_model_dir,
            agent,
            train_step,
            interval=policy_save_interval,
            metadata_metrics={triggers.ENV_STEP_METADATA_KEY:
                              env_step_metric}),
        triggers.StepPerSecondLogTrigger(train_step, interval=1000),
    ]

    agent_learner = learner.Learner(root_dir,
                                    train_step,
                                    agent,
                                    experience_dataset_fn,
                                    triggers=learning_triggers)

    random_policy = random_py_policy.RandomPyPolicy(
        collect_env.time_step_spec(), collect_env.action_spec())
    initial_collect_actor = actor.Actor(collect_env,
                                        random_policy,
                                        train_step,
                                        steps_per_run=initial_collect_steps,
                                        observers=[rb_observer])
    logging.info('Doing initial collect.')
    initial_collect_actor.run()

    tf_collect_policy = agent.collect_policy
    collect_policy = py_tf_eager_policy.PyTFEagerPolicy(tf_collect_policy,
                                                        use_tf_function=True)

    collect_actor = actor.Actor(collect_env,
                                collect_policy,
                                train_step,
                                steps_per_run=1,
                                metrics=actor.collect_metrics(10),
                                summary_dir=os.path.join(
                                    root_dir, learner.TRAIN_DIR),
                                observers=[rb_observer, env_step_metric])

    tf_greedy_policy = greedy_policy.GreedyPolicy(agent.policy)
    eval_greedy_policy = py_tf_eager_policy.PyTFEagerPolicy(
        tf_greedy_policy, use_tf_function=True)

    eval_actor = actor.Actor(
        eval_env,
        eval_greedy_policy,
        train_step,
        episodes_per_run=eval_episodes,
        metrics=actor.eval_metrics(eval_episodes),
        summary_dir=os.path.join(root_dir, 'eval'),
    )

    if eval_interval:
        logging.info('Evaluating.')
        eval_actor.run_and_log()

    logging.info('Training.')
    for _ in range(num_iterations):
        collect_actor.run()
        agent_learner.run(iterations=1)

        if eval_interval and agent_learner.train_step_numpy % eval_interval == 0:
            logging.info('Evaluating.')
            eval_actor.run_and_log()

    rb_observer.close()
    reverb_server.stop()
Esempio n. 22
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def train_eval(
        root_dir,
        # Dataset params
        env_name,
        data_dir=None,
        load_pretrained=False,
        pretrained_model_dir=None,
        img_pad=4,
        frame_shape=(84, 84, 3),
        frame_stack=3,
        num_augmentations=2,  # K and M in DrQ
        # Training params
    contrastive_loss_weight=1.0,
        contrastive_loss_temperature=0.5,
        image_encoder_representation=True,
        initial_collect_steps=1000,
        num_train_steps=3000000,
        actor_fc_layers=(1024, 1024),
        critic_joint_fc_layers=(1024, 1024),
        # Agent params
        batch_size=256,
        actor_learning_rate=1e-3,
        critic_learning_rate=1e-3,
        alpha_learning_rate=1e-3,
        encoder_learning_rate=1e-3,
        actor_update_freq=2,
        gamma=0.99,
        target_update_tau=0.01,
        target_update_period=2,
        reward_scale_factor=1.0,
        # Replay params
        reverb_port=None,
        replay_capacity=100000,
        # Others
        checkpoint_interval=10000,
        policy_save_interval=5000,
        eval_interval=10000,
        summary_interval=250,
        debug_summaries=False,
        eval_episodes_per_run=10,
        summarize_grads_and_vars=False):
    """Trains and evaluates SAC."""
    collect_env = env_utils.load_dm_env_for_training(env_name,
                                                     frame_shape,
                                                     frame_stack=frame_stack)
    eval_env = env_utils.load_dm_env_for_eval(env_name,
                                              frame_shape,
                                              frame_stack=frame_stack)

    logging.info('Data directory: %s', data_dir)
    logging.info('Num train steps: %d', num_train_steps)
    logging.info('Contrastive loss coeff: %.2f', contrastive_loss_weight)
    logging.info('Contrastive loss temperature: %.4f',
                 contrastive_loss_temperature)
    logging.info('load_pretrained: %s', 'yes' if load_pretrained else 'no')
    logging.info('encoder representation: %s',
                 'yes' if image_encoder_representation else 'no')

    load_episode_data = (contrastive_loss_weight > 0)
    observation_tensor_spec, action_tensor_spec, time_step_tensor_spec = (
        spec_utils.get_tensor_specs(collect_env))

    train_step = train_utils.create_train_step()
    image_encoder = networks.ImageEncoder(observation_tensor_spec)

    actor_net = model_utils.Actor(
        observation_tensor_spec,
        action_tensor_spec,
        image_encoder=image_encoder,
        fc_layers=actor_fc_layers,
        image_encoder_representation=image_encoder_representation)

    critic_net = networks.Critic((observation_tensor_spec, action_tensor_spec),
                                 image_encoder=image_encoder,
                                 joint_fc_layers=critic_joint_fc_layers)
    critic_net_2 = networks.Critic(
        (observation_tensor_spec, action_tensor_spec),
        image_encoder=image_encoder,
        joint_fc_layers=critic_joint_fc_layers)

    target_image_encoder = networks.ImageEncoder(observation_tensor_spec)
    target_critic_net_1 = networks.Critic(
        (observation_tensor_spec, action_tensor_spec),
        image_encoder=target_image_encoder)
    target_critic_net_2 = networks.Critic(
        (observation_tensor_spec, action_tensor_spec),
        image_encoder=target_image_encoder)

    agent = pse_drq_agent.DrQSacModifiedAgent(
        time_step_tensor_spec,
        action_tensor_spec,
        actor_network=actor_net,
        critic_network=critic_net,
        critic_network_2=critic_net_2,
        target_critic_network=target_critic_net_1,
        target_critic_network_2=target_critic_net_2,
        actor_update_frequency=actor_update_freq,
        actor_optimizer=tf.compat.v1.train.AdamOptimizer(
            learning_rate=actor_learning_rate),
        critic_optimizer=tf.compat.v1.train.AdamOptimizer(
            learning_rate=critic_learning_rate),
        alpha_optimizer=tf.compat.v1.train.AdamOptimizer(
            learning_rate=alpha_learning_rate),
        contrastive_optimizer=tf.compat.v1.train.AdamOptimizer(
            learning_rate=encoder_learning_rate),
        contrastive_loss_weight=contrastive_loss_weight,
        contrastive_loss_temperature=contrastive_loss_temperature,
        target_update_tau=target_update_tau,
        target_update_period=target_update_period,
        td_errors_loss_fn=tf.math.squared_difference,
        gamma=gamma,
        reward_scale_factor=reward_scale_factor,
        use_log_alpha_in_alpha_loss=False,
        gradient_clipping=None,
        debug_summaries=debug_summaries,
        summarize_grads_and_vars=summarize_grads_and_vars,
        train_step_counter=train_step,
        num_augmentations=num_augmentations)
    agent.initialize()

    # Setup the replay buffer.
    reverb_replay, rb_observer = (
        replay_buffer_utils.get_reverb_buffer_and_observer(
            agent.collect_data_spec,
            sequence_length=2,
            replay_capacity=replay_capacity,
            port=reverb_port))

    # pylint: disable=g-long-lambda
    if num_augmentations == 0:
        image_aug = lambda traj, meta: (dict(
            experience=traj, augmented_obs=[], augmented_next_obs=[]), meta)
    else:
        image_aug = lambda traj, meta: pse_drq_agent.image_aug(
            traj, meta, img_pad, num_augmentations)
    augmented_dataset = reverb_replay.as_dataset(sample_batch_size=batch_size,
                                                 num_steps=2).unbatch().map(
                                                     image_aug,
                                                     num_parallel_calls=3)
    augmented_iterator = iter(augmented_dataset)

    trajs = augmented_dataset.batch(batch_size).prefetch(50)
    if load_episode_data:
        # Load full episodes and zip them
        episodes = dataset_utils.load_episodes(
            os.path.join(data_dir, 'episodes2'), img_pad)
        episode_iterator = iter(episodes)
        dataset = tf.data.Dataset.zip((trajs, episodes)).prefetch(10)
    else:
        dataset = trajs
    experience_dataset_fn = lambda: dataset

    saved_model_dir = os.path.join(root_dir, learner.POLICY_SAVED_MODEL_DIR)
    learning_triggers = [
        triggers.PolicySavedModelTrigger(saved_model_dir,
                                         agent,
                                         train_step,
                                         interval=policy_save_interval),
        triggers.StepPerSecondLogTrigger(train_step,
                                         interval=summary_interval),
    ]

    agent_learner = model_utils.Learner(
        root_dir,
        train_step,
        agent,
        experience_dataset_fn=experience_dataset_fn,
        triggers=learning_triggers,
        checkpoint_interval=checkpoint_interval,
        summary_interval=summary_interval,
        load_episode_data=load_episode_data,
        use_kwargs_in_agent_train=True,
        # Turn off the initialization of the optimizer variables since, the agent
        # expects different batching for the `training_data_spec` and
        # `train_argspec` which can't be handled in general by the initialization
        # logic in the learner.
        run_optimizer_variable_init=False)

    # If we haven't trained yet make sure we collect some random samples first to
    # fill up the Replay Buffer with some experience.
    train_dir = os.path.join(root_dir, learner.TRAIN_DIR)

    # Code for loading pretrained policy.
    if load_pretrained:
        # Note that num_train_steps is same as the max_train_step we want to
        # load the pretrained policy for our experiments
        pretrained_policy = model_utils.load_pretrained_policy(
            pretrained_model_dir, num_train_steps)
        initial_collect_policy = pretrained_policy

        agent.policy.update_partial(pretrained_policy)
        agent.collect_policy.update_partial(pretrained_policy)
        logging.info('Restored pretrained policy.')
    else:
        initial_collect_policy = random_py_policy.RandomPyPolicy(
            collect_env.time_step_spec(), collect_env.action_spec())
    initial_collect_actor = actor.Actor(collect_env,
                                        initial_collect_policy,
                                        train_step,
                                        steps_per_run=initial_collect_steps,
                                        observers=[rb_observer])
    logging.info('Doing initial collect.')
    initial_collect_actor.run()

    tf_collect_policy = agent.collect_policy
    collect_policy = py_tf_eager_policy.PyTFEagerPolicy(tf_collect_policy,
                                                        use_tf_function=True)

    collect_actor = actor.Actor(collect_env,
                                collect_policy,
                                train_step,
                                steps_per_run=1,
                                observers=[rb_observer],
                                metrics=actor.collect_metrics(buffer_size=10),
                                summary_dir=train_dir,
                                summary_interval=summary_interval,
                                name='CollectActor')

    # If restarting with train_step > 0, the replay buffer will be empty
    # except for random experience. Populate the buffer with some on-policy
    # experience.
    if load_pretrained or (agent_learner.train_step_numpy > 0):
        for _ in range(batch_size * 50):
            collect_actor.run()

    tf_greedy_policy = agent.policy
    greedy_policy = py_tf_eager_policy.PyTFEagerPolicy(tf_greedy_policy,
                                                       use_tf_function=True)

    eval_actor = actor.Actor(eval_env,
                             greedy_policy,
                             train_step,
                             episodes_per_run=eval_episodes_per_run,
                             metrics=actor.eval_metrics(buffer_size=10),
                             summary_dir=os.path.join(root_dir, 'eval'),
                             summary_interval=-1,
                             name='EvalTrainActor')

    if eval_interval:
        logging.info('Evaluating.')
        img_summary(
            next(augmented_iterator)[0], eval_actor.summary_writer, train_step)
        if load_episode_data:
            contrastive_img_summary(next(episode_iterator), agent,
                                    eval_actor.summary_writer, train_step)
        eval_actor.run_and_log()

    logging.info('Saving operative gin config file.')
    gin_path = os.path.join(train_dir, 'train_operative_gin_config.txt')
    with tf.io.gfile.GFile(gin_path, mode='w') as f:
        f.write(gin.operative_config_str())

    logging.info('Training Staring at: %r', train_step.numpy())
    while train_step < num_train_steps:
        collect_actor.run()
        agent_learner.run(iterations=1)
        if (not eval_interval) and (train_step % 10000 == 0):
            img_summary(
                next(augmented_iterator)[0],
                agent_learner.train_summary_writer, train_step)
        if eval_interval and agent_learner.train_step_numpy % eval_interval == 0:
            logging.info('Evaluating.')
            img_summary(
                next(augmented_iterator)[0], eval_actor.summary_writer,
                train_step)
            if load_episode_data:
                contrastive_img_summary(next(episode_iterator), agent,
                                        eval_actor.summary_writer, train_step)
            eval_actor.run_and_log()