class Learner:
"""
Learner class.
"""
def __init__(self, args):
"""
Seeds everything.
Initialises: logger, environments, policy (+storage +optimiser).
"""
self.args = args
# make sure everything has the same seed
utl.seed(self.args.seed)
# initialise environment
self.env = make_env(
self.args.env_name,
self.args.max_rollouts_per_task,
seed=self.args.seed,
n_tasks=1,
modify_init_state_dist=self.args.modify_init_state_dist
if 'modify_init_state_dist' in self.args else False,
on_circle_init_state=self.args.on_circle_init_state
if 'on_circle_init_state' in self.args else True)
# saving buffer with task in name folder
if hasattr(self.args, 'save_buffer') and self.args.save_buffer:
env_dir = os.path.join(self.args.main_save_dir,
'{}'.format(self.args.env_name))
goal = self.env.unwrapped._goal
self.output_dir = os.path.join(
env_dir, self.args.save_dir,
'seed_{}_'.format(self.args.seed) +
off_utl.create_goal_path_ext_from_goal(goal))
if self.args.save_models or self.args.save_buffer:
os.makedirs(self.output_dir, exist_ok=True)
config_utl.save_config_file(args, self.output_dir)
# initialize tensorboard logger
if self.args.log_tensorboard:
self.tb_logger = TBLogger(self.args)
# if not self.args.log_tensorboard:
# self.save_config_json_file()
# unwrapped env to get some info about the environment
unwrapped_env = self.env.unwrapped
# calculate what the maximum length of the trajectories is
args.max_trajectory_len = unwrapped_env._max_episode_steps
args.max_trajectory_len *= self.args.max_rollouts_per_task
self.args.max_trajectory_len = args.max_trajectory_len
# get action / observation dimensions
if isinstance(self.env.action_space, gym.spaces.discrete.Discrete):
self.args.action_dim = 1
else:
self.args.action_dim = self.env.action_space.shape[0]
self.args.obs_dim = self.env.observation_space.shape[0]
self.args.num_states = unwrapped_env.num_states if hasattr(
unwrapped_env, 'num_states') else None
self.args.act_space = self.env.action_space
# simulate env step to get reward types
_, _, _, info = unwrapped_env.step(unwrapped_env.action_space.sample())
reward_types = [
reward_type for reward_type in list(info.keys())
if reward_type.startswith('reward')
]
# support dense rewards training (if exists)
self.args.dense_train_sparse_test = self.args.dense_train_sparse_test \
if 'dense_train_sparse_test' in self.args else False
# initialize policy
self.initialize_policy()
# initialize buffer for RL updates
self.policy_storage = MultiTaskPolicyStorage(
max_replay_buffer_size=int(self.args.policy_buffer_size),
obs_dim=self.args.obs_dim,
action_space=self.env.action_space,
tasks=[0],
trajectory_len=args.max_trajectory_len,
num_reward_arrays=len(reward_types)
if reward_types and self.args.dense_train_sparse_test else 1,
reward_types=reward_types,
)
self.args.belief_reward = False # initialize arg to not use belief rewards
def initialize_policy(self):
if self.args.policy == 'dqn':
assert self.args.act_space.__class__.__name__ == "Discrete", (
"Can't train DQN with continuous action space!")
q_network = FlattenMlp(input_size=self.args.obs_dim,
output_size=self.args.act_space.n,
hidden_sizes=self.args.dqn_layers)
self.agent = DQN(
q_network,
# optimiser_vae=self.optimizer_vae,
lr=self.args.policy_lr,
gamma=self.args.gamma,
eps_init=self.args.dqn_epsilon_init,
eps_final=self.args.dqn_epsilon_final,
exploration_iters=self.args.dqn_exploration_iters,
tau=self.args.soft_target_tau,
).to(ptu.device)
# elif self.args.policy == 'ddqn':
# assert self.args.act_space.__class__.__name__ == "Discrete", (
# "Can't train DDQN with continuous action space!")
# q_network = FlattenMlp(input_size=self.args.obs_dim,
# output_size=self.args.act_space.n,
# hidden_sizes=self.args.dqn_layers)
# self.agent = DoubleDQN(
# q_network,
# # optimiser_vae=self.optimizer_vae,
# lr=self.args.policy_lr,
# eps_optim=self.args.dqn_eps,
# alpha_optim=self.args.dqn_alpha,
# gamma=self.args.gamma,
# eps_init=self.args.dqn_epsilon_init,
# eps_final=self.args.dqn_epsilon_final,
# exploration_iters=self.args.dqn_exploration_iters,
# tau=self.args.soft_target_tau,
# ).to(ptu.device)
elif self.args.policy == 'sac':
assert self.args.act_space.__class__.__name__ == "Box", (
"Can't train SAC with discrete action space!")
q1_network = FlattenMlp(input_size=self.args.obs_dim +
self.args.action_dim,
output_size=1,
hidden_sizes=self.args.dqn_layers)
q2_network = FlattenMlp(input_size=self.args.obs_dim +
self.args.action_dim,
output_size=1,
hidden_sizes=self.args.dqn_layers)
policy = TanhGaussianPolicy(obs_dim=self.args.obs_dim,
action_dim=self.args.action_dim,
hidden_sizes=self.args.policy_layers)
self.agent = SAC(
policy,
q1_network,
q2_network,
actor_lr=self.args.actor_lr,
critic_lr=self.args.critic_lr,
gamma=self.args.gamma,
tau=self.args.soft_target_tau,
entropy_alpha=self.args.entropy_alpha,
automatic_entropy_tuning=self.args.automatic_entropy_tuning,
alpha_lr=self.args.alpha_lr).to(ptu.device)
else:
raise NotImplementedError
def train(self):
"""
meta-training loop
"""
self._start_training()
self.task_idx = 0
for iter_ in range(self.args.num_iters):
self.training_mode(True)
if iter_ == 0:
print('Collecting initial pool of data..')
self.env.reset_task(idx=self.task_idx)
self.collect_rollouts(
num_rollouts=self.args.num_init_rollouts_pool,
random_actions=True)
print('Done!')
# collect data from subset of train tasks
self.env.reset_task(idx=self.task_idx)
self.collect_rollouts(num_rollouts=self.args.num_rollouts_per_iter)
# update
train_stats = self.update([self.task_idx])
self.training_mode(False)
if self.args.policy == 'dqn':
self.agent.set_exploration_parameter(iter_ + 1)
# evaluate and log
if (iter_ + 1) % self.args.log_interval == 0:
self.log(iter_ + 1, train_stats)
def update(self, tasks):
'''
RL updates
:param tasks: list/array of task indices. perform update based on the tasks
:return:
'''
# --- RL TRAINING ---
rl_losses_agg = {}
for update in range(self.args.rl_updates_per_iter):
# sample random RL batch
obs, actions, rewards, next_obs, terms = self.sample_rl_batch(
tasks, self.args.batch_size)
# flatten out task dimension
t, b, _ = obs.size()
obs = obs.view(t * b, -1)
actions = actions.view(t * b, -1)
rewards = rewards.view(t * b, -1)
next_obs = next_obs.view(t * b, -1)
terms = terms.view(t * b, -1)
# RL update
rl_losses = self.agent.update(obs, actions, rewards, next_obs,
terms)
for k, v in rl_losses.items():
if update == 0: # first iterate - create list
rl_losses_agg[k] = [v]
else: # append values
rl_losses_agg[k].append(v)
# take mean
for k in rl_losses_agg:
rl_losses_agg[k] = np.mean(rl_losses_agg[k])
self._n_rl_update_steps_total += self.args.rl_updates_per_iter
return rl_losses_agg
def evaluate(self, tasks):
num_episodes = self.args.max_rollouts_per_task
num_steps_per_episode = self.env.unwrapped._max_episode_steps
returns_per_episode = np.zeros((len(tasks), num_episodes))
success_rate = np.zeros(len(tasks))
if self.args.policy == 'dqn':
values = np.zeros((len(tasks), self.args.max_trajectory_len))
else:
obs_size = self.env.unwrapped.observation_space.shape[0]
observations = np.zeros(
(len(tasks), self.args.max_trajectory_len + 1, obs_size))
log_probs = np.zeros((len(tasks), self.args.max_trajectory_len))
for task_idx, task in enumerate(tasks):
obs = ptu.from_numpy(self.env.reset(task))
obs = obs.reshape(-1, obs.shape[-1])
step = 0
if self.args.policy == 'sac':
observations[task_idx,
step, :] = ptu.get_numpy(obs[0, :obs_size])
for episode_idx in range(num_episodes):
running_reward = 0.
for step_idx in range(num_steps_per_episode):
# add distribution parameters to observation - policy is conditioned on posterior
if self.args.policy == 'dqn':
action, value = self.agent.act(obs=obs,
deterministic=True)
else:
action, _, _, log_prob = self.agent.act(
obs=obs,
deterministic=self.args.eval_deterministic,
return_log_prob=True)
# observe reward and next obs
next_obs, reward, done, info = utl.env_step(
self.env, action.squeeze(dim=0))
running_reward += reward.item()
if self.args.policy == 'dqn':
values[task_idx, step] = value.item()
else:
observations[task_idx, step + 1, :] = ptu.get_numpy(
next_obs[0, :obs_size])
log_probs[task_idx, step] = ptu.get_numpy(log_prob[0])
if "is_goal_state" in dir(
self.env.unwrapped
) and self.env.unwrapped.is_goal_state():
success_rate[task_idx] = 1.
# set: obs <- next_obs
obs = next_obs.clone()
step += 1
returns_per_episode[task_idx, episode_idx] = running_reward
if self.args.policy == 'dqn':
return returns_per_episode, success_rate, values
else:
return returns_per_episode, success_rate, log_probs, observations
def log(self, iteration, train_stats):
# --- save models ---
if iteration % self.args.save_interval == 0:
if self.args.save_models:
if self.args.log_tensorboard:
save_path = os.path.join(self.tb_logger.full_output_folder,
'models')
else:
save_path = os.path.join(self.output_dir, 'models')
if not os.path.exists(save_path):
os.mkdir(save_path)
torch.save(
self.agent.state_dict(),
os.path.join(save_path, "agent{0}.pt".format(iteration)))
if hasattr(self.args, 'save_buffer') and self.args.save_buffer:
self.save_buffer()
# evaluate to get more stats
if self.args.policy == 'dqn':
# get stats on train tasks
returns_train, success_rate_train, values = self.evaluate([0])
else:
# get stats on train tasks
returns_train, success_rate_train, log_probs, observations = self.evaluate(
[0])
if self.args.log_tensorboard:
if self.args.policy != 'dqn':
# self.env.reset(0)
# self.tb_logger.writer.add_figure('policy_vis_train/task_0',
# utl_eval.plot_rollouts(observations[0, :], self.env),
# self._n_env_steps_total)
# obs, _, _, _, _ = self.sample_rl_batch(tasks=[0],
# batch_size=self.policy_storage.task_buffers[0].size())
# self.tb_logger.writer.add_figure('state_space_coverage/task_0',
# utl_eval.plot_visited_states(ptu.get_numpy(obs[0][:, :2]), self.env),
# self._n_env_steps_total)
pass
# some metrics
self.tb_logger.writer.add_scalar(
'metrics/successes_in_buffer',
self._successes_in_buffer / self._n_env_steps_total,
self._n_env_steps_total)
if self.args.max_rollouts_per_task > 1:
for episode_idx in range(self.args.max_rollouts_per_task):
self.tb_logger.writer.add_scalar(
'returns_multi_episode/episode_{}'.format(episode_idx +
1),
np.mean(returns_train[:, episode_idx]),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'returns_multi_episode/sum',
np.mean(np.sum(returns_train, axis=-1)),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'returns_multi_episode/success_rate',
np.mean(success_rate_train), self._n_env_steps_total)
else:
self.tb_logger.writer.add_scalar('returns/returns_mean_train',
np.mean(returns_train),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar('returns/returns_std_train',
np.std(returns_train),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar('returns/success_rate_train',
np.mean(success_rate_train),
self._n_env_steps_total)
# policy
if self.args.policy == 'dqn':
self.tb_logger.writer.add_scalar('policy/value_init',
np.mean(values[:, 0]),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'policy/value_halfway',
np.mean(values[:, int(values.shape[-1] / 2)]),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar('policy/value_final',
np.mean(values[:, -1]),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar('policy/exploration_epsilon',
self.agent.eps,
self._n_env_steps_total)
# RL losses
self.tb_logger.writer.add_scalar(
'rl_losses/qf_loss_vs_n_updates', train_stats['qf_loss'],
self._n_rl_update_steps_total)
self.tb_logger.writer.add_scalar(
'rl_losses/qf_loss_vs_n_env_steps', train_stats['qf_loss'],
self._n_env_steps_total)
else:
self.tb_logger.writer.add_scalar('policy/log_prob',
np.mean(log_probs),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar('rl_losses/qf1_loss',
train_stats['qf1_loss'],
self._n_env_steps_total)
self.tb_logger.writer.add_scalar('rl_losses/qf2_loss',
train_stats['qf2_loss'],
self._n_env_steps_total)
self.tb_logger.writer.add_scalar('rl_losses/policy_loss',
train_stats['policy_loss'],
self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'rl_losses/alpha_entropy_loss',
train_stats['alpha_entropy_loss'], self._n_env_steps_total)
# weights and gradients
if self.args.policy == 'dqn':
self.tb_logger.writer.add_scalar(
'weights/q_network',
list(self.agent.qf.parameters())[0].mean(),
self._n_env_steps_total)
if list(self.agent.qf.parameters())[0].grad is not None:
param_list = list(self.agent.qf.parameters())
self.tb_logger.writer.add_scalar(
'gradients/q_network',
sum([
param_list[i].grad.mean()
for i in range(len(param_list))
]), self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'weights/q_target',
list(self.agent.target_qf.parameters())[0].mean(),
self._n_env_steps_total)
if list(self.agent.target_qf.parameters())[0].grad is not None:
param_list = list(self.agent.target_qf.parameters())
self.tb_logger.writer.add_scalar(
'gradients/q_target',
sum([
param_list[i].grad.mean()
for i in range(len(param_list))
]), self._n_env_steps_total)
else:
self.tb_logger.writer.add_scalar(
'weights/q1_network',
list(self.agent.qf1.parameters())[0].mean(),
self._n_env_steps_total)
if list(self.agent.qf1.parameters())[0].grad is not None:
param_list = list(self.agent.qf1.parameters())
self.tb_logger.writer.add_scalar(
'gradients/q1_network',
sum([
param_list[i].grad.mean()
for i in range(len(param_list))
]), self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'weights/q1_target',
list(self.agent.qf1_target.parameters())[0].mean(),
self._n_env_steps_total)
if list(self.agent.qf1_target.parameters()
)[0].grad is not None:
param_list = list(self.agent.qf1_target.parameters())
self.tb_logger.writer.add_scalar(
'gradients/q1_target',
sum([
param_list[i].grad.mean()
for i in range(len(param_list))
]), self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'weights/q2_network',
list(self.agent.qf2.parameters())[0].mean(),
self._n_env_steps_total)
if list(self.agent.qf2.parameters())[0].grad is not None:
param_list = list(self.agent.qf2.parameters())
self.tb_logger.writer.add_scalar(
'gradients/q2_network',
sum([
param_list[i].grad.mean()
for i in range(len(param_list))
]), self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'weights/q2_target',
list(self.agent.qf2_target.parameters())[0].mean(),
self._n_env_steps_total)
if list(self.agent.qf2_target.parameters()
)[0].grad is not None:
param_list = list(self.agent.qf2_target.parameters())
self.tb_logger.writer.add_scalar(
'gradients/q2_target',
sum([
param_list[i].grad.mean()
for i in range(len(param_list))
]), self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'weights/policy',
list(self.agent.policy.parameters())[0].mean(),
self._n_env_steps_total)
if list(self.agent.policy.parameters())[0].grad is not None:
param_list = list(self.agent.policy.parameters())
self.tb_logger.writer.add_scalar(
'gradients/policy',
sum([
param_list[i].grad.mean()
for i in range(len(param_list))
]), self._n_env_steps_total)
print(
"Iteration -- {}, Success rate -- {:.3f}, Avg. return -- {:.3f}, Elapsed time {:5d}[s]"
.format(iteration, np.mean(success_rate_train),
np.mean(np.sum(returns_train, axis=-1)),
int(time.time() - self._start_time)))
# output to user
# print("Iteration -- {:3d}, Num. RL updates -- {:6d}, Elapsed time {:5d}[s]".
# format(iteration,
# self._n_rl_update_steps_total,
# int(time.time() - self._start_time)))
def training_mode(self, mode):
self.agent.train(mode)
def collect_rollouts(self, num_rollouts, random_actions=False):
'''
:param num_rollouts:
:param random_actions: whether to use policy to sample actions, or randomly sample action space
:return:
'''
for rollout in range(num_rollouts):
obs = ptu.from_numpy(self.env.reset(self.task_idx))
obs = obs.reshape(-1, obs.shape[-1])
done_rollout = False
while not done_rollout:
if random_actions:
if self.args.policy == 'dqn':
action = ptu.FloatTensor([[[
self.env.action_space.sample()
]]]).long() # Sample random action
else:
action = ptu.FloatTensor([
self.env.action_space.sample()
]) # Sample random action
else:
if self.args.policy == 'dqn':
action, _ = self.agent.act(obs=obs) # DQN
else:
action, _, _, _ = self.agent.act(obs=obs) # SAC
# observe reward and next obs
next_obs, reward, done, info = utl.env_step(
self.env, action.squeeze(dim=0))
done_rollout = False if ptu.get_numpy(
done[0][0]) == 0. else True
# add data to policy buffer - (s+, a, r, s'+, term)
term = self.env.unwrapped.is_goal_state(
) if "is_goal_state" in dir(self.env.unwrapped) else False
if self.args.dense_train_sparse_test:
rew_to_buffer = {
rew_type: rew
for rew_type, rew in info.items()
if rew_type.startswith('reward')
}
else:
rew_to_buffer = ptu.get_numpy(reward.squeeze(dim=0))
self.policy_storage.add_sample(
task=self.task_idx,
observation=ptu.get_numpy(obs.squeeze(dim=0)),
action=ptu.get_numpy(action.squeeze(dim=0)),
reward=rew_to_buffer,
terminal=np.array([term], dtype=float),
next_observation=ptu.get_numpy(next_obs.squeeze(dim=0)))
# set: obs <- next_obs
obs = next_obs.clone()
# update statistics
self._n_env_steps_total += 1
if "is_goal_state" in dir(
self.env.unwrapped
) and self.env.unwrapped.is_goal_state(): # count successes
self._successes_in_buffer += 1
self._n_rollouts_total += 1
def sample_rl_batch(self, tasks, batch_size):
''' sample batch of unordered rl training data from a list/array of tasks '''
# this batch consists of transitions sampled randomly from replay buffer
batches = [
ptu.np_to_pytorch_batch(
self.policy_storage.random_batch(task, batch_size))
for task in tasks
]
unpacked = [utl.unpack_batch(batch) for batch in batches]
# group elements together
unpacked = [[x[i] for x in unpacked] for i in range(len(unpacked[0]))]
unpacked = [torch.cat(x, dim=0) for x in unpacked]
return unpacked
def _start_training(self):
self._n_env_steps_total = 0
self._n_rl_update_steps_total = 0
self._n_vae_update_steps_total = 0
self._n_rollouts_total = 0
self._successes_in_buffer = 0
self._start_time = time.time()
def load_model(self, device='cpu', **kwargs):
if "agent_path" in kwargs:
self.agent.load_state_dict(
torch.load(kwargs["agent_path"], map_location=device))
self.training_mode(False)
def save_buffer(self):
size = self.policy_storage.task_buffers[0].size()
np.save(os.path.join(self.output_dir, 'obs'),
self.policy_storage.task_buffers[0]._observations[:size])
np.save(os.path.join(self.output_dir, 'actions'),
self.policy_storage.task_buffers[0]._actions[:size])
if self.args.dense_train_sparse_test:
for reward_type, reward_arr in self.policy_storage.task_buffers[
0]._rewards.items():
np.save(os.path.join(self.output_dir, reward_type),
reward_arr[:size])
else:
np.save(os.path.join(self.output_dir, 'rewards'),
self.policy_storage.task_buffers[0]._rewards[:size])
np.save(os.path.join(self.output_dir, 'next_obs'),
self.policy_storage.task_buffers[0]._next_obs[:size])
np.save(os.path.join(self.output_dir, 'terminals'),
self.policy_storage.task_buffers[0]._terminals[:size])
class MetaLearnerSACMER:
"""
Meta-Learner class.
"""
def __init__(self, args):
"""
Seeds everything.
Initialises: logger, environments, policy (+storage +optimiser).
"""
self.args = args
# make sure everything has the same seed
utl.seed(self.args.seed)
# initialize tensorboard logger
if self.args.log_tensorboard:
self.tb_logger = TBLogger(self.args)
# initialise environment
self.env = make_env(self.args.env_name,
self.args.max_rollouts_per_task,
seed=self.args.seed,
n_tasks=self.args.num_tasks)
# unwrapped env to get some info about the environment
unwrapped_env = self.env.unwrapped
# split to train/eval tasks
shuffled_tasks = np.random.permutation(
unwrapped_env.get_all_task_idx())
self.train_tasks = shuffled_tasks[:self.args.num_train_tasks]
if self.args.num_eval_tasks > 0:
self.eval_tasks = shuffled_tasks[-self.args.num_eval_tasks:]
else:
self.eval_tasks = []
# calculate what the maximum length of the trajectories is
args.max_trajectory_len = unwrapped_env._max_episode_steps
args.max_trajectory_len *= self.args.max_rollouts_per_task
self.args.max_trajectory_len = args.max_trajectory_len
# get action / observation dimensions
if isinstance(self.env.action_space, gym.spaces.discrete.Discrete):
self.args.action_dim = 1
else:
self.args.action_dim = self.env.action_space.shape[0]
self.args.obs_dim = self.env.observation_space.shape[0]
self.args.num_states = unwrapped_env.num_states if hasattr(
unwrapped_env, 'num_states') else None
self.args.act_space = self.env.action_space
# initialize policy
self.initialize_policy()
# initialize buffer for RL updates
self.policy_storage = MultiTaskPolicyStorage(
max_replay_buffer_size=int(self.args.policy_buffer_size),
obs_dim=self._get_augmented_obs_dim(),
action_space=self.env.action_space,
tasks=self.train_tasks,
trajectory_len=args.max_trajectory_len,
)
self.current_experience_storage = None
self.args.belief_reward = False # initialize arg to not use belief rewards
def initialize_current_experience_storage(self):
self.current_experience_storage = MultiTaskPolicyStorage(
max_replay_buffer_size=int(self.args.num_tasks_sample *
self.args.num_rollouts_per_iter *
self.args.max_trajectory_len),
obs_dim=self._get_augmented_obs_dim(),
action_space=self.env.action_space,
tasks=self.train_tasks,
trajectory_len=self.args.max_trajectory_len,
)
def initialize_policy(self):
if self.args.policy == 'dqn':
assert self.args.act_space.__class__.__name__ == "Discrete", (
"Can't train DQN with continuous action space!")
q_network = FlattenMlp(input_size=self._get_augmented_obs_dim(),
output_size=self.args.act_space.n,
hidden_sizes=self.args.dqn_layers)
self.agent = DQN(
q_network,
# optimiser_vae=self.optimizer_vae,
lr=self.args.policy_lr,
eps_optim=self.args.dqn_eps,
alpha_optim=self.args.dqn_alpha,
gamma=self.args.gamma,
eps_init=self.args.dqn_epsilon_init,
eps_final=self.args.dqn_epsilon_final,
exploration_iters=self.args.dqn_exploration_iters,
tau=self.args.soft_target_tau,
).to(ptu.device)
elif self.args.policy == 'ddqn':
assert self.args.act_space.__class__.__name__ == "Discrete", (
"Can't train DDQN with continuous action space!")
q_network = FlattenMlp(input_size=self._get_augmented_obs_dim(),
output_size=self.args.act_space.n,
hidden_sizes=self.args.dqn_layers)
self.agent = DoubleDQN(
q_network,
# optimiser_vae=self.optimizer_vae,
lr=self.args.policy_lr,
eps_optim=self.args.dqn_eps,
alpha_optim=self.args.dqn_alpha,
gamma=self.args.gamma,
eps_init=self.args.dqn_epsilon_init,
eps_final=self.args.dqn_epsilon_final,
exploration_iters=self.args.dqn_exploration_iters,
tau=self.args.soft_target_tau,
).to(ptu.device)
elif self.args.policy == 'sac':
assert self.args.act_space.__class__.__name__ == "Box", (
"Can't train SAC with discrete action space!")
q1_network = FlattenMlp(input_size=self._get_augmented_obs_dim() +
self.args.action_dim,
output_size=1,
hidden_sizes=self.args.dqn_layers)
q2_network = FlattenMlp(input_size=self._get_augmented_obs_dim() +
self.args.action_dim,
output_size=1,
hidden_sizes=self.args.dqn_layers)
policy = TanhGaussianPolicy(obs_dim=self._get_augmented_obs_dim(),
action_dim=self.args.action_dim,
hidden_sizes=self.args.policy_layers)
self.agent = SAC(
policy,
q1_network,
q2_network,
actor_lr=self.args.actor_lr,
critic_lr=self.args.critic_lr,
gamma=self.args.gamma,
tau=self.args.soft_target_tau,
entropy_alpha=self.args.entropy_alpha,
automatic_entropy_tuning=self.args.automatic_entropy_tuning,
alpha_lr=self.args.alpha_lr).to(ptu.device)
else:
raise NotImplementedError
def train(self):
"""
meta-training loop
"""
self._start_training()
for iter_ in range(self.args.num_iters):
self.training_mode(True)
# switch to belief reward
if self.args.switch_to_belief_reward is not None and iter_ >= self.args.switch_to_belief_reward:
self.args.belief_reward = True
if iter_ == 0:
print('Collecting initial pool of data..')
for task in self.train_tasks:
self.task_idx = task
self.env.reset_task(idx=task)
# self.collect_rollouts(num_rollouts=self.args.num_init_rollouts_pool)
self.collect_rollouts(
num_rollouts=self.args.num_init_rollouts_pool,
random_actions=True)
print('Done!')
# collect data from subset of train tasks
tasks_to_collect = [
self.train_tasks[np.random.randint(len(self.train_tasks))]
for _ in range(self.args.num_tasks_sample)
]
self.initialize_current_experience_storage()
for i in range(self.args.num_tasks_sample):
task = tasks_to_collect[i]
self.task_idx = task
self.env.reset_task(idx=task)
self.collect_rollouts(
num_rollouts=self.args.num_rollouts_per_iter)
# update
indices = np.random.choice(self.train_tasks, self.args.meta_batch)
train_stats = self.update(indices,
current_task_indices=tasks_to_collect)
self.training_mode(False)
if self.args.policy == 'dqn':
self.agent.set_exploration_parameter(iter_ + 1)
# evaluate and log
if (iter_ + 1) % self.args.log_interval == 0:
self.log(iter_ + 1, train_stats)
def update(self, tasks, current_task_indices=[]):
'''
Meta-update
:param tasks: list/array of task indices. perform update based on the tasks
:param current_task_indices: indices that the last rollout collected
:return:
'''
# --- RL TRAINING ---
rl_losses_agg = {}
prev_qf1 = copy.deepcopy(self.agent.qf1).to(ptu.device)
prev_qf2 = copy.deepcopy(self.agent.qf2).to(ptu.device)
prev_qf1_target = copy.deepcopy(self.agent.qf1_target).to(ptu.device)
prev_qf2_target = copy.deepcopy(self.agent.qf2_target).to(ptu.device)
prev_policy = copy.deepcopy(self.agent.policy).to(ptu.device)
# prev_alpha = copy.deepcopy(self.agent.log_alpha_entropy) # not relevant when alpha is const
prev_nets = [
prev_qf1, prev_qf2, prev_qf1_target, prev_qf2_target, prev_policy
]
updates_from_current_experience = np.random.choice(
self.args.rl_updates_per_iter, self.args.mer_s, replace=False)
for update in range(self.args.rl_updates_per_iter):
# sample random RL batch
obs, actions, rewards, next_obs, terms = self.sample_rl_batch(
tasks if update not in updates_from_current_experience else
current_task_indices,
self.args.batch_size,
is_sample_from_current_experience=(
update in updates_from_current_experience))
# flatten out task dimension
t, b, _ = obs.size()
obs = obs.view(t * b, -1)
actions = actions.view(t * b, -1)
rewards = rewards.view(t * b, -1)
next_obs = next_obs.view(t * b, -1)
terms = terms.view(t * b, -1)
# RL update
rl_losses = self.agent.update(obs, actions, rewards, next_obs,
terms)
for k, v in rl_losses.items():
if update == 0: # first iterate - create list
rl_losses_agg[k] = [v]
else: # append values
rl_losses_agg[k].append(v)
# reptile update
new_nets = [
self.agent.qf1, self.agent.qf2, self.agent.qf1_target,
self.agent.qf2_target, self.agent.policy
]
for new_net, prev_net in zip(new_nets, prev_nets):
ptu.soft_update_from_to(new_net, prev_net,
self.args.mer_gamma_policy)
ptu.copy_model_params_from_to(prev_net, new_net)
# take mean
for k in rl_losses_agg:
rl_losses_agg[k] = np.mean(rl_losses_agg[k])
self._n_rl_update_steps_total += self.args.rl_updates_per_iter
train_stats = {
**rl_losses_agg,
}
return train_stats
def evaluate(self, tasks):
num_episodes = self.args.max_rollouts_per_task
num_steps_per_episode = self.env.unwrapped._max_episode_steps
returns_per_episode = np.zeros((len(tasks), num_episodes))
success_rate = np.zeros(len(tasks))
if self.args.policy == 'dqn':
values = np.zeros((len(tasks), self.args.max_trajectory_len))
else:
rewards = np.zeros((len(tasks), self.args.max_trajectory_len))
obs_size = self.env.unwrapped.observation_space.shape[0]
observations = np.zeros(
(len(tasks), self.args.max_trajectory_len + 1, obs_size))
for task_idx, task in enumerate(tasks):
obs = ptu.from_numpy(self.env.reset(task))
obs = obs.reshape(-1, obs.shape[-1])
step = 0
if self.args.policy == 'dqn':
raise NotImplementedError
else:
observations[task_idx,
step, :] = ptu.get_numpy(obs[0, :obs_size])
for episode_idx in range(num_episodes):
running_reward = 0.
for step_idx in range(num_steps_per_episode):
# add distribution parameters to observation - policy is conditioned on posterior
augmented_obs = self.get_augmented_obs(obs=obs)
if self.args.policy == 'dqn':
action, value = self.agent.act(obs=augmented_obs,
deterministic=True)
else:
action, _, _, log_prob = self.agent.act(
obs=augmented_obs,
deterministic=self.args.eval_deterministic,
return_log_prob=True)
# observe reward and next obs
next_obs, reward, done, info = utl.env_step(
self.env, action.squeeze(dim=0))
running_reward += reward.item()
if self.args.policy == 'dqn':
values[task_idx, step] = value.item()
else:
rewards[task_idx, step] = reward.item()
observations[task_idx, step + 1, :] = ptu.get_numpy(
next_obs[0, :obs_size])
if "is_goal_state" in dir(
self.env.unwrapped
) and self.env.unwrapped.is_goal_state():
success_rate[task_idx] = 1.
# set: obs <- next_obs
obs = next_obs.clone()
step += 1
returns_per_episode[task_idx, episode_idx] = running_reward
if self.args.policy == 'dqn':
return returns_per_episode, success_rate, values,
else:
return returns_per_episode, success_rate, observations, rewards,
def log(self, iteration, train_stats):
# --- save models ---
if iteration % self.args.save_interval == 0:
save_path = os.path.join(self.tb_logger.full_output_folder,
'models')
if not os.path.exists(save_path):
os.mkdir(save_path)
torch.save(
self.agent.state_dict(),
os.path.join(save_path, "agent{0}.pt".format(iteration)))
# evaluate to get more stats
if self.args.policy == 'dqn':
# get stats on train tasks
returns_train, success_rate_train, values = self.evaluate(
self.train_tasks)
else:
# get stats on train tasks
returns_train, success_rate_train, observations, rewards_train = self.evaluate(
self.train_tasks[:len(self.eval_tasks)])
returns_eval, success_rate_eval, observations_eval, rewards_eval = self.evaluate(
self.eval_tasks)
if self.args.log_tensorboard:
# some metrics
self.tb_logger.writer.add_scalar(
'metrics/successes_in_buffer',
self._successes_in_buffer / self._n_env_steps_total,
self._n_env_steps_total)
if self.args.max_rollouts_per_task > 1:
for episode_idx in range(self.args.max_rollouts_per_task):
self.tb_logger.writer.add_scalar(
'returns_multi_episode/episode_{}'.format(episode_idx +
1),
np.mean(returns_train[:, episode_idx]),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'returns_multi_episode/sum',
np.mean(np.sum(returns_train, axis=-1)),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'returns_multi_episode/success_rate',
np.mean(success_rate_train), self._n_env_steps_total)
if self.args.policy != 'dqn':
self.tb_logger.writer.add_scalar(
'returns_multi_episode/sum_eval',
np.mean(np.sum(returns_eval, axis=-1)),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'returns_multi_episode/success_rate_eval',
np.mean(success_rate_eval), self._n_env_steps_total)
else:
# self.tb_logger.writer.add_scalar('returns/returns_mean', np.mean(returns),
# self._n_env_steps_total)
# self.tb_logger.writer.add_scalar('returns/returns_std', np.std(returns),
# self._n_env_steps_total)
self.tb_logger.writer.add_scalar('returns/returns_mean_train',
np.mean(returns_train),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar('returns/returns_std_train',
np.std(returns_train),
self._n_env_steps_total)
# self.tb_logger.writer.add_scalar('returns/success_rate', np.mean(success_rate),
# self._n_env_steps_total)
self.tb_logger.writer.add_scalar('returns/success_rate_train',
np.mean(success_rate_train),
self._n_env_steps_total)
# policy
if self.args.policy == 'dqn':
self.tb_logger.writer.add_scalar('policy/value_init',
np.mean(values[:, 0]),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'policy/value_halfway',
np.mean(values[:, int(values.shape[-1] / 2)]),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar('policy/value_final',
np.mean(values[:, -1]),
self._n_env_steps_total)
self.tb_logger.writer.add_scalar('policy/exploration_epsilon',
self.agent.eps,
self._n_env_steps_total)
# RL losses
self.tb_logger.writer.add_scalar(
'rl_losses/qf_loss_vs_n_updates', train_stats['qf_loss'],
self._n_rl_update_steps_total)
self.tb_logger.writer.add_scalar(
'rl_losses/qf_loss_vs_n_env_steps', train_stats['qf_loss'],
self._n_env_steps_total)
else:
self.tb_logger.writer.add_scalar('rl_losses/qf1_loss',
train_stats['qf1_loss'],
self._n_env_steps_total)
self.tb_logger.writer.add_scalar('rl_losses/qf2_loss',
train_stats['qf2_loss'],
self._n_env_steps_total)
self.tb_logger.writer.add_scalar('rl_losses/policy_loss',
train_stats['policy_loss'],
self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'rl_losses/alpha_loss', train_stats['alpha_entropy_loss'],
self._n_env_steps_total)
# weights and gradients
if self.args.policy == 'dqn':
self.tb_logger.writer.add_scalar(
'weights/q_network',
list(self.agent.qf.parameters())[0].mean(),
self._n_env_steps_total)
if list(self.agent.qf.parameters())[0].grad is not None:
param_list = list(self.agent.qf.parameters())
self.tb_logger.writer.add_scalar(
'gradients/q_network',
sum([
param_list[i].grad.mean()
for i in range(len(param_list))
]), self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'weights/q_target',
list(self.agent.target_qf.parameters())[0].mean(),
self._n_env_steps_total)
if list(self.agent.target_qf.parameters())[0].grad is not None:
param_list = list(self.agent.target_qf.parameters())
self.tb_logger.writer.add_scalar(
'gradients/q_target',
sum([
param_list[i].grad.mean()
for i in range(len(param_list))
]), self._n_env_steps_total)
else:
self.tb_logger.writer.add_scalar(
'weights/q1_network',
list(self.agent.qf1.parameters())[0].mean(),
self._n_env_steps_total)
if list(self.agent.qf1.parameters())[0].grad is not None:
param_list = list(self.agent.qf1.parameters())
self.tb_logger.writer.add_scalar(
'gradients/q1_network',
sum([
param_list[i].grad.mean()
for i in range(len(param_list))
]), self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'weights/q1_target',
list(self.agent.qf1_target.parameters())[0].mean(),
self._n_env_steps_total)
if list(self.agent.qf1_target.parameters()
)[0].grad is not None:
param_list = list(self.agent.qf1_target.parameters())
self.tb_logger.writer.add_scalar(
'gradients/q1_target',
sum([
param_list[i].grad.mean()
for i in range(len(param_list))
]), self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'weights/q2_network',
list(self.agent.qf2.parameters())[0].mean(),
self._n_env_steps_total)
if list(self.agent.qf2.parameters())[0].grad is not None:
param_list = list(self.agent.qf2.parameters())
self.tb_logger.writer.add_scalar(
'gradients/q2_network',
sum([
param_list[i].grad.mean()
for i in range(len(param_list))
]), self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'weights/q2_target',
list(self.agent.qf2_target.parameters())[0].mean(),
self._n_env_steps_total)
if list(self.agent.qf2_target.parameters()
)[0].grad is not None:
param_list = list(self.agent.qf2_target.parameters())
self.tb_logger.writer.add_scalar(
'gradients/q2_target',
sum([
param_list[i].grad.mean()
for i in range(len(param_list))
]), self._n_env_steps_total)
self.tb_logger.writer.add_scalar(
'weights/policy',
list(self.agent.policy.parameters())[0].mean(),
self._n_env_steps_total)
if list(self.agent.policy.parameters())[0].grad is not None:
param_list = list(self.agent.policy.parameters())
self.tb_logger.writer.add_scalar(
'gradients/policy',
sum([
param_list[i].grad.mean()
for i in range(len(param_list))
]), self._n_env_steps_total)
#log iteration
self.tb_logger.writer.add_scalar('iteration', iteration,
self._n_env_steps_total)
# output to user
# print("Iteration -- {:3d}, Num. RL updates -- {:6d}, Elapsed time {:5d}[s]".
# format(iteration,
# self._n_rl_update_steps_total,
# int(time.time() - self._start_time)))
print(
"Iteration -- {}, Success rate train -- {:.3f}, Success rate eval.-- {:.3f}, "
"Avg. return train -- {:.3f}, Avg. return eval. -- {:.3f}, Elapsed time {:5d}[s]"
.format(iteration, np.mean(success_rate_train),
np.mean(success_rate_eval),
np.mean(np.sum(returns_train, axis=-1)),
np.mean(np.sum(returns_eval, axis=-1)),
int(time.time() - self._start_time)))
def training_mode(self, mode):
# policy
self.agent.train(mode)
def collect_rollouts(self, num_rollouts, random_actions=False):
'''
:param num_rollouts:
:param random_actions: whether to use policy to sample actions, or randomly sample action space
:return:
'''
for rollout in range(num_rollouts):
obs = ptu.from_numpy(self.env.reset(self.task_idx))
obs = obs.reshape(-1, obs.shape[-1])
done_rollout = False
# self.policy_storage.reset_running_episode(self.task_idx)
# if self.args.fixed_latent_params:
# assert 2 ** self.args.task_embedding_size >= self.args.num_tasks
# task_mean = ptu.FloatTensor(utl.vertices(self.args.task_embedding_size)[self.task_idx])
# task_logvar = -2. * ptu.ones_like(task_logvar) # arbitrary negative enough number
# add distribution parameters to observation - policy is conditioned on posterior
augmented_obs = self.get_augmented_obs(obs=obs)
while not done_rollout:
if random_actions:
if self.args.policy == 'dqn':
action = ptu.FloatTensor([[
self.env.action_space.sample()
]]).type(torch.long) # Sample random action
else:
action = ptu.FloatTensor(
[self.env.action_space.sample()])
else:
if self.args.policy == 'dqn':
action, _ = self.agent.act(obs=augmented_obs) # DQN
else:
action, _, _, _ = self.agent.act(
obs=augmented_obs) # SAC
# observe reward and next obs
next_obs, reward, done, info = utl.env_step(
self.env, action.squeeze(dim=0))
done_rollout = False if ptu.get_numpy(
done[0][0]) == 0. else True
# get augmented next obs
augmented_next_obs = self.get_augmented_obs(obs=next_obs)
# add data to policy buffer - (s+, a, r, s'+, term)
term = self.env.unwrapped.is_goal_state(
) if "is_goal_state" in dir(self.env.unwrapped) else False
self.policy_storage.add_sample(
task=self.task_idx,
observation=ptu.get_numpy(augmented_obs.squeeze(dim=0)),
action=ptu.get_numpy(action.squeeze(dim=0)),
reward=ptu.get_numpy(reward.squeeze(dim=0)),
terminal=np.array([term], dtype=float),
next_observation=ptu.get_numpy(
augmented_next_obs.squeeze(dim=0)))
if not random_actions:
self.current_experience_storage.add_sample(
task=self.task_idx,
observation=ptu.get_numpy(
augmented_obs.squeeze(dim=0)),
action=ptu.get_numpy(action.squeeze(dim=0)),
reward=ptu.get_numpy(reward.squeeze(dim=0)),
terminal=np.array([term], dtype=float),
next_observation=ptu.get_numpy(
augmented_next_obs.squeeze(dim=0)))
# set: obs <- next_obs
obs = next_obs.clone()
augmented_obs = augmented_next_obs.clone()
# update statistics
self._n_env_steps_total += 1
if "is_goal_state" in dir(
self.env.unwrapped
) and self.env.unwrapped.is_goal_state(): # count successes
self._successes_in_buffer += 1
self._n_rollouts_total += 1
def get_augmented_obs(self, obs):
augmented_obs = obs.clone()
return augmented_obs
def _get_augmented_obs_dim(self):
dim = utl.get_dim(self.env.observation_space)
return dim
def sample_rl_batch(self,
tasks,
batch_size,
is_sample_from_current_experience=False):
''' sample batch of unordered rl training data from a list/array of tasks '''
# this batch consists of transitions sampled randomly from replay buffer
if is_sample_from_current_experience:
batches = [
ptu.np_to_pytorch_batch(
self.current_experience_storage.random_batch(
task, batch_size)) for task in tasks
]
else:
batches = [
ptu.np_to_pytorch_batch(
self.policy_storage.random_batch(task, batch_size))
for task in tasks
]
unpacked = [utl.unpack_batch(batch) for batch in batches]
# group elements together
unpacked = [[x[i] for x in unpacked] for i in range(len(unpacked[0]))]
unpacked = [torch.cat(x, dim=0) for x in unpacked]
return unpacked
def _start_training(self):
self._n_env_steps_total = 0
self._n_rl_update_steps_total = 0
self._n_rollouts_total = 0
self._successes_in_buffer = 0
self._start_time = time.time()
def load_model(self, device='cpu', **kwargs):
if "agent_path" in kwargs:
self.agent.load_state_dict(
torch.load(kwargs["agent_path"], map_location=device))
self.training_mode(False)