class BCTrainer(Trainer):
"""The BCTrainer is an implementation of Behavioral Cloning."""
def __init__(self, brain, trainer_parameters, training, load, seed, run_id):
"""
Responsible for collecting experiences and training PPO model.
:param trainer_parameters: The parameters for the trainer (dictionary).
:param training: Whether the trainer is set for training.
:param load: Whether the model should be loaded.
:param seed: The seed the model will be initialized with
:param run_id: The The identifier of the current run
"""
super(BCTrainer, self).__init__(brain, trainer_parameters, training, run_id)
self.policy = BCPolicy(seed, brain, trainer_parameters, load)
self.n_sequences = 1
self.cumulative_rewards = {}
self.episode_steps = {}
self.stats = {'Losses/Cloning Loss': [], 'Environment/Episode Length': [],
'Environment/Cumulative Reward': []}
self.summary_path = trainer_parameters['summary_path']
self.batches_per_epoch = trainer_parameters['batches_per_epoch']
if not os.path.exists(self.summary_path):
os.makedirs(self.summary_path)
self.demonstration_buffer = Buffer()
self.evaluation_buffer = Buffer()
self.summary_writer = tf.summary.FileWriter(self.summary_path)
@property
def parameters(self):
"""
Returns the trainer parameters of the trainer.
"""
return self.trainer_parameters
@property
def get_max_steps(self):
"""
Returns the maximum number of steps. Is used to know when the trainer should be stopped.
:return: The maximum number of steps of the trainer
"""
return float(self.trainer_parameters['max_steps'])
@property
def get_step(self):
"""
Returns the number of steps the trainer has performed
:return: the step count of the trainer
"""
return self.policy.get_current_step()
@property
def get_last_reward(self):
"""
Returns the last reward the trainer has had
:return: the new last reward
"""
if len(self.stats['Environment/Cumulative Reward']) > 0:
return np.mean(self.stats['Environment/Cumulative Reward'])
else:
return 0
def increment_step_and_update_last_reward(self):
"""
Increment the step count of the trainer and Updates the last reward
"""
self.policy.increment_step()
return
def add_experiences(self, curr_info: AllBrainInfo, next_info: AllBrainInfo,
take_action_outputs):
"""
Adds experiences to each agent's experience history.
:param curr_info: Current AllBrainInfo (Dictionary of all current brains and corresponding BrainInfo).
:param next_info: Next AllBrainInfo (Dictionary of all current brains and corresponding BrainInfo).
:param take_action_outputs: The outputs of the take action method.
"""
# Used to collect information about student performance.
info_student = curr_info[self.brain_name]
next_info_student = next_info[self.brain_name]
for agent_id in info_student.agents:
self.evaluation_buffer[agent_id].last_brain_info = info_student
for agent_id in next_info_student.agents:
stored_info_student = self.evaluation_buffer[agent_id].last_brain_info
if stored_info_student is None:
continue
else:
next_idx = next_info_student.agents.index(agent_id)
if agent_id not in self.cumulative_rewards:
self.cumulative_rewards[agent_id] = 0
self.cumulative_rewards[agent_id] += next_info_student.rewards[next_idx]
if not next_info_student.local_done[next_idx]:
if agent_id not in self.episode_steps:
self.episode_steps[agent_id] = 0
self.episode_steps[agent_id] += 1
def process_experiences(self, current_info: AllBrainInfo, next_info: AllBrainInfo):
"""
Checks agent histories for processing condition, and processes them as necessary.
Processing involves calculating value and advantage targets for model updating step.
:param current_info: Current AllBrainInfo
:param next_info: Next AllBrainInfo
"""
info_student = next_info[self.brain_name]
for l in range(len(info_student.agents)):
if info_student.local_done[l]:
agent_id = info_student.agents[l]
self.stats['Environment/Cumulative Reward'].append(
self.cumulative_rewards.get(agent_id, 0))
self.stats['Environment/Episode Length'].append(
self.episode_steps.get(agent_id, 0))
self.cumulative_rewards[agent_id] = 0
self.episode_steps[agent_id] = 0
def end_episode(self):
"""
A signal that the Episode has ended. The buffer must be reset.
Get only called when the academy resets.
"""
self.evaluation_buffer.reset_local_buffers()
for agent_id in self.cumulative_rewards:
self.cumulative_rewards[agent_id] = 0
for agent_id in self.episode_steps:
self.episode_steps[agent_id] = 0
def is_ready_update(self):
"""
Returns whether or not the trainer has enough elements to run update model
:return: A boolean corresponding to whether or not update_model() can be run
"""
return len(self.demonstration_buffer.update_buffer['actions']) > self.n_sequences
def update_policy(self):
"""
Updates the policy.
"""
self.demonstration_buffer.update_buffer.shuffle()
batch_losses = []
num_batches = min(len(self.demonstration_buffer.update_buffer['actions']) //
self.n_sequences, self.batches_per_epoch)
for i in range(num_batches):
update_buffer = self.demonstration_buffer.update_buffer
start = i * self.n_sequences
end = (i + 1) * self.n_sequences
mini_batch = update_buffer.make_mini_batch(start, end)
run_out = self.policy.update(mini_batch, self.n_sequences)
loss = run_out['policy_loss']
batch_losses.append(loss)
if len(batch_losses) > 0:
self.stats['Losses/Cloning Loss'].append(np.mean(batch_losses))
else:
self.stats['Losses/Cloning Loss'].append(0)
class BehavioralCloningTrainer(Trainer):
"""The ImitationTrainer is an implementation of the imitation learning."""
def __init__(self, sess, brain, trainer_parameters, training, seed, run_id):
"""
Responsible for collecting experiences and training PPO model.
:param sess: Tensorflow session.
:param trainer_parameters: The parameters for the trainer (dictionary).
:param training: Whether the trainer is set for training.
"""
super(BehavioralCloningTrainer, self).__init__(sess, brain, trainer_parameters, training, run_id)
self.param_keys = ['brain_to_imitate', 'batch_size', 'time_horizon',
'graph_scope', 'summary_freq', 'max_steps',
'batches_per_epoch', 'use_recurrent',
'hidden_units','learning_rate', 'num_layers',
'sequence_length', 'memory_size']
for k in self.param_keys:
if k not in trainer_parameters:
raise UnityTrainerException("The hyperparameter {0} could not be found for the Imitation trainer of "
"brain {1}.".format(k, brain.brain_name))
self.policy = BCPolicy(seed, brain, trainer_parameters, sess)
self.brain_name = brain.brain_name
self.brain_to_imitate = trainer_parameters['brain_to_imitate']
self.batches_per_epoch = trainer_parameters['batches_per_epoch']
self.n_sequences = max(int(trainer_parameters['batch_size'] / self.policy.sequence_length), 1)
self.cumulative_rewards = {}
self.episode_steps = {}
self.stats = {'losses': [], 'episode_length': [], 'cumulative_reward': []}
self.training_buffer = Buffer()
self.summary_path = trainer_parameters['summary_path']
if not os.path.exists(self.summary_path):
os.makedirs(self.summary_path)
self.summary_writer = tf.summary.FileWriter(self.summary_path)
def __str__(self):
return '''Hyperparameters for the Imitation Trainer of brain {0}: \n{1}'''.format(
self.brain_name, '\n'.join(['\t{0}:\t{1}'.format(x, self.trainer_parameters[x]) for x in self.param_keys]))
@property
def parameters(self):
"""
Returns the trainer parameters of the trainer.
"""
return self.trainer_parameters
@property
def get_max_steps(self):
"""
Returns the maximum number of steps. Is used to know when the trainer should be stopped.
:return: The maximum number of steps of the trainer
"""
return float(self.trainer_parameters['max_steps'])
@property
def get_step(self):
"""
Returns the number of steps the trainer has performed
:return: the step count of the trainer
"""
return self.policy.get_current_step()
@property
def get_last_reward(self):
"""
Returns the last reward the trainer has had
:return: the new last reward
"""
if len(self.stats['cumulative_reward']) > 0:
return np.mean(self.stats['cumulative_reward'])
else:
return 0
def increment_step_and_update_last_reward(self):
"""
Increment the step count of the trainer and Updates the last reward
"""
self.policy.increment_step()
return
def take_action(self, all_brain_info: AllBrainInfo):
"""
Decides actions using policy given current brain info.
:param all_brain_info: AllBrainInfo from environment.
:return: a tuple containing action, memories, values and an object
to be passed to add experiences
"""
if len(all_brain_info[self.brain_name].agents) == 0:
return [], [], [], None, None
agent_brain = all_brain_info[self.brain_name]
run_out = self.policy.evaluate(agent_brain)
if self.policy.use_recurrent:
return run_out['action'], run_out['memory_out'], None, None, None
else:
return run_out['action'], None, None, None, None
def add_experiences(self, curr_info: AllBrainInfo, next_info: AllBrainInfo, take_action_outputs):
"""
Adds experiences to each agent's experience history.
:param curr_info: Current AllBrainInfo (Dictionary of all current brains and corresponding BrainInfo).
:param next_info: Next AllBrainInfo (Dictionary of all current brains and corresponding BrainInfo).
:param take_action_outputs: The outputs of the take action method.
"""
# Used to collect teacher experience into training buffer
info_teacher = curr_info[self.brain_to_imitate]
next_info_teacher = next_info[self.brain_to_imitate]
for agent_id in info_teacher.agents:
self.training_buffer[agent_id].last_brain_info = info_teacher
for agent_id in next_info_teacher.agents:
stored_info_teacher = self.training_buffer[agent_id].last_brain_info
if stored_info_teacher is None:
continue
else:
idx = stored_info_teacher.agents.index(agent_id)
next_idx = next_info_teacher.agents.index(agent_id)
if stored_info_teacher.text_observations[idx] != "":
info_teacher_record, info_teacher_reset = \
stored_info_teacher.text_observations[idx].lower().split(",")
next_info_teacher_record, next_info_teacher_reset = next_info_teacher.text_observations[idx].\
lower().split(",")
if next_info_teacher_reset == "true":
self.training_buffer.reset_update_buffer()
else:
info_teacher_record, next_info_teacher_record = "true", "true"
if info_teacher_record == "true" and next_info_teacher_record == "true":
if not stored_info_teacher.local_done[idx]:
for i in range(self.policy.vis_obs_size):
self.training_buffer[agent_id]['visual_obs%d' % i]\
.append(stored_info_teacher.visual_observations[i][idx])
if self.policy.use_vec_obs:
self.training_buffer[agent_id]['vector_obs']\
.append(stored_info_teacher.vector_observations[idx])
if self.policy.use_recurrent:
if stored_info_teacher.memories.shape[1] == 0:
stored_info_teacher.memories = np.zeros((len(stored_info_teacher.agents),
self.policy.m_size))
self.training_buffer[agent_id]['memory'].append(stored_info_teacher.memories[idx])
self.training_buffer[agent_id]['actions'].append(next_info_teacher.
previous_vector_actions[next_idx])
info_student = curr_info[self.brain_name]
next_info_student = next_info[self.brain_name]
for agent_id in info_student.agents:
self.training_buffer[agent_id].last_brain_info = info_student
# Used to collect information about student performance.
for agent_id in next_info_student.agents:
stored_info_student = self.training_buffer[agent_id].last_brain_info
if stored_info_student is None:
continue
else:
next_idx = next_info_student.agents.index(agent_id)
if agent_id not in self.cumulative_rewards:
self.cumulative_rewards[agent_id] = 0
self.cumulative_rewards[agent_id] += next_info_student.rewards[next_idx]
if not next_info_student.local_done[next_idx]:
if agent_id not in self.episode_steps:
self.episode_steps[agent_id] = 0
self.episode_steps[agent_id] += 1
def process_experiences(self, current_info: AllBrainInfo, next_info: AllBrainInfo):
"""
Checks agent histories for processing condition, and processes them as necessary.
Processing involves calculating value and advantage targets for model updating step.
:param current_info: Current AllBrainInfo
:param next_info: Next AllBrainInfo
"""
info_teacher = next_info[self.brain_to_imitate]
for l in range(len(info_teacher.agents)):
teacher_action_list = len(self.training_buffer[info_teacher.agents[l]]['actions'])
horizon_reached = teacher_action_list > self.trainer_parameters['time_horizon']
teacher_filled = len(self.training_buffer[info_teacher.agents[l]]['actions']) > 0
if ((info_teacher.local_done[l] or horizon_reached) and teacher_filled):
agent_id = info_teacher.agents[l]
self.training_buffer.append_update_buffer(
agent_id, batch_size=None, training_length=self.policy.sequence_length)
self.training_buffer[agent_id].reset_agent()
info_student = next_info[self.brain_name]
for l in range(len(info_student.agents)):
if info_student.local_done[l]:
agent_id = info_student.agents[l]
self.stats['cumulative_reward'].append(
self.cumulative_rewards.get(agent_id, 0))
self.stats['episode_length'].append(
self.episode_steps.get(agent_id, 0))
self.cumulative_rewards[agent_id] = 0
self.episode_steps[agent_id] = 0
def end_episode(self):
"""
A signal that the Episode has ended. The buffer must be reset.
Get only called when the academy resets.
"""
self.training_buffer.reset_all()
for agent_id in self.cumulative_rewards:
self.cumulative_rewards[agent_id] = 0
for agent_id in self.episode_steps:
self.episode_steps[agent_id] = 0
def is_ready_update(self):
"""
Returns whether or not the trainer has enough elements to run update model
:return: A boolean corresponding to whether or not update_model() can be run
"""
return len(self.training_buffer.update_buffer['actions']) > self.n_sequences
def update_policy(self):
"""
Updates the policy.
"""
self.training_buffer.update_buffer.shuffle()
batch_losses = []
num_batches = min(len(self.training_buffer.update_buffer['actions']) //
self.n_sequences, self.batches_per_epoch)
for i in range(num_batches):
buffer = self.training_buffer.update_buffer
start = i * self.n_sequences
end = (i + 1) * self.n_sequences
mini_batch = buffer.make_mini_batch(start, end)
run_out = self.policy.update(mini_batch, self.n_sequences)
loss = run_out['policy_loss']
batch_losses.append(loss)
if len(batch_losses) > 0:
self.stats['losses'].append(np.mean(batch_losses))
else:
self.stats['losses'].append(0)