def test_polyak():
param1, param2 = th.nn.Parameter(th.ones((5, 5))), th.nn.Parameter(th.zeros((5, 5)))
target1, target2 = th.nn.Parameter(th.ones((5, 5))), th.nn.Parameter(th.zeros((5, 5)))
tau = 0.1
polyak_update([param1], [param2], tau)
with th.no_grad():
for param, target_param in zip([target1], [target2]):
target_param.data.copy_(tau * param.data + (1 - tau) * target_param.data)
assert th.allclose(param1, target1)
assert th.allclose(param2, target2)
def _on_step(self) -> None:
"""
Update the exploration rate and target network if needed.
This method is called in ``collect_rollouts()`` after each step in the environment.
"""
if self.num_timesteps % self.target_update_interval == 0:
polyak_update(self.q_net.parameters(),
self.q_net_target.parameters(), self.tau)
self.exploration_rate = self.exploration_schedule(
self._current_progress_remaining)
logger.record("rollout/exploration rate", self.exploration_rate)
def train(self, gradient_steps: int, batch_size: int = 100) -> None:
# Update learning rate according to lr schedule
self._update_learning_rate([self.actor.optimizer, self.critic.optimizer])
actor_losses, critic_losses = [], []
for gradient_step in range(gradient_steps):
# Sample replay buffer
replay_data = self.replay_buffer.sample(batch_size, env=self._vec_normalize_env)
with th.no_grad():
# Select action according to policy and add clipped noise
noise = replay_data.actions.clone().data.normal_(0, self.target_policy_noise)
noise = noise.clamp(-self.target_noise_clip, self.target_noise_clip)
next_actions = (self.actor_target(replay_data.next_observations) + noise).clamp(-1, 1)
# Compute the target Q value: min over all critics targets
targets = th.cat(self.critic_target(replay_data.next_observations, next_actions), dim=1)
target_q, _ = th.min(targets, dim=1, keepdim=True)
target_q = replay_data.rewards + (1 - replay_data.dones) * self.gamma * target_q
# Get current Q estimates for each critic network
current_q_estimates = self.critic(replay_data.observations, replay_data.actions)
# Compute critic loss
critic_loss = sum([F.mse_loss(current_q, target_q) for current_q in current_q_estimates])
critic_losses.append(critic_loss.item())
# Optimize the critics
self.critic.optimizer.zero_grad()
critic_loss.backward()
self.critic.optimizer.step()
# Delayed policy updates
if gradient_step % self.policy_delay == 0:
# Compute actor loss
actor_loss = -self.critic.q1_forward(replay_data.observations, self.actor(replay_data.observations)).mean()
actor_losses.append(actor_loss.item())
# Optimize the actor
self.actor.optimizer.zero_grad()
actor_loss.backward()
self.actor.optimizer.step()
polyak_update(self.critic.parameters(), self.critic_target.parameters(), self.tau)
polyak_update(self.actor.parameters(), self.actor_target.parameters(), self.tau)
self._n_updates += gradient_steps
logger.record("train/n_updates", self._n_updates, exclude="tensorboard")
logger.record("train/actor_loss", np.mean(actor_losses))
logger.record("train/critic_loss", np.mean(critic_losses))
def learn_step(self, idxs, transition_batch, weights):
Otm1, old_action, env_rew, done, Ot = transition_batch
batch_size = len(Ot)
observations = (torch.tensor(Otm1, device=self.device))
actions = torch.tensor(old_action, device=self.device)
rewards = torch.tensor(env_rew, device=self.device)
done = torch.tensor(done, device=self.device).float().to(self.device)
next_observations = (torch.tensor(Ot, device=self.device))
# weights = torch.tensor(weights, device=self.device)
with torch.no_grad():
actions_pred, log_probs_pred = self.policy(observations)
ent_coef = torch.exp(self.log_ent_coef.detach())
ent_coef_loss = -(self.log_ent_coef * (log_probs_pred + self.target_entropy).detach()).mean()
self.ent_coef_optimizer.zero_grad()
ent_coef_loss.backward()
self.ent_coef_optimizer.step()
with th.no_grad():
next_actions, next_log_prob = self.policy(next_observations)
targets = self.policy.critic_target(next_observations, next_actions)
targets = torch.stack(targets, dim=1)
target_q, _ = torch.min(targets,dim=1)
target_q = target_q - ent_coef * next_log_prob
# td error + entropy term
q_backup = rewards + (1 - done) * self.gamma * target_q
current_q_estimates = self.policy.critic(observations, actions)
critic_loss = mean([F.mse_loss(current_q, q_backup) for current_q in current_q_estimates])
self.critic_optimizer.zero_grad()
critic_loss.backward()
self.critic_optimizer.step()
q_values_pi = th.stack(self.policy.critic.forward(observations, actions_pred), dim=1)
min_qf_pi, _ = th.min(q_values_pi, dim=1, keepdim=True)
actor_loss = (ent_coef * log_probs_pred - min_qf_pi).mean()
self.policy_optimizer.zero_grad()
actor_loss.backward()
self.policy_optimizer.step()
polyak_update(self.policy.critic.parameters(), self.policy.critic_target.parameters(), self.tau)
logger = self.logger
logger.record_mean("ent_coef_loss",ent_coef_loss.item())
logger.record_mean("critic_loss",critic_loss.item())
logger.record_mean("actor_loss",actor_loss.item())
logger.record_mean("q_backup",q_backup.mean().item())
logger.record("policy_lr",self.policy_optimizer.get_last_lr())
def _on_update(self) -> None:
if self._n_updates % self.target_update_interval == 0:
polyak_update(self.q_net.parameters(), self.q_net_target.parameters(), self.tau)
if not self.share:
polyak_update(self.v_mlp_extractor.parameters(), self.v_mlp_extractor_target.parameters(), self.tau)
if self.KL:
if self._n_updates % 2 == 0:
# if self.vloss_tracker.full and self.vloss_tracker.mean() < 5:
self.train_mode='policy'
'''
careful that train() will call _on_update()
so must clear before train
'''
self.vloss_tracker.clear()
self.train(gradient_steps=self.gradient_steps, batch_size=self.batch_size)
# self.train(gradient_steps=self.replay_buffer.size()*2//self.batch_size, batch_size=self.batch_size)
self.train_mode='value'
# print("policy updated")
if self._n_updates % self.behav_update_interval == 0:
polyak_update(self.action_net.parameters(), self.behav_net.parameters(), tau=self.behav_tau)
if not self.share:
polyak_update(self.a_mlp_extractor.parameters(), self.a_mlp_extractor_target.parameters(), tau=self.behav_tau)
self.trajectories = [Trajectory(self.device) for i in range(self.n_envs)]
self.trajectory_buffer.reset()
self.exploration_rate = self.exploration_schedule(self._current_progress_remaining)
def train(self, gradient_steps: int, batch_size: int = 64) -> None:
# Switch to train mode (this affects batch norm / dropout)
self.policy.set_training_mode(True)
# Update optimizers learning rate
optimizers = [self.actor.optimizer, self.critic.optimizer]
if self.ent_coef_optimizer is not None:
optimizers += [self.ent_coef_optimizer]
# Update learning rate according to lr schedule
self._update_learning_rate(optimizers)
ent_coef_losses, ent_coefs = [], []
actor_losses, critic_losses = [], []
for gradient_step in range(gradient_steps):
# Sample replay buffer
replay_data = self.replay_buffer.sample(batch_size, env=self._vec_normalize_env)
# We need to sample because `log_std` may have changed between two gradient steps
if self.use_sde:
self.actor.reset_noise()
# Action by the current actor for the sampled state
actions_pi, log_prob = self.actor.action_log_prob(replay_data.observations)
log_prob = log_prob.reshape(-1, 1)
ent_coef_loss = None
if self.ent_coef_optimizer is not None:
# Important: detach the variable from the graph
# so we don't change it with other losses
# see https://github.com/rail-berkeley/softlearning/issues/60
ent_coef = th.exp(self.log_ent_coef.detach())
ent_coef_loss = -(self.log_ent_coef * (log_prob + self.target_entropy).detach()).mean()
ent_coef_losses.append(ent_coef_loss.item())
else:
ent_coef = self.ent_coef_tensor
ent_coefs.append(ent_coef.item())
# Optimize entropy coefficient, also called
# entropy temperature or alpha in the paper
if ent_coef_loss is not None:
self.ent_coef_optimizer.zero_grad()
ent_coef_loss.backward()
self.ent_coef_optimizer.step()
with th.no_grad():
# Select action according to policy
next_actions, next_log_prob = self.actor.action_log_prob(replay_data.next_observations)
# Compute the next Q values: min over all critics targets
next_q_values = th.cat(self.critic_target(replay_data.next_observations, next_actions), dim=1)
next_q_values, _ = th.min(next_q_values, dim=1, keepdim=True)
# add entropy term
next_q_values = next_q_values - ent_coef * next_log_prob.reshape(-1, 1)
# td error + entropy term
target_q_values = replay_data.rewards + (1 - replay_data.dones) * self.gamma * next_q_values
# Get current Q-values estimates for each critic network
# using action from the replay buffer
current_q_values = self.critic(replay_data.observations, replay_data.actions)
# Compute critic loss
critic_loss = 0.5 * sum([F.mse_loss(current_q, target_q_values) for current_q in current_q_values])
critic_losses.append(critic_loss.item())
# Optimize the critic
self.critic.optimizer.zero_grad()
critic_loss.backward()
self.critic.optimizer.step()
# Compute actor loss
# Alternative: actor_loss = th.mean(log_prob - qf1_pi)
# Mean over all critic networks
q_values_pi = th.cat(self.critic.forward(replay_data.observations, actions_pi), dim=1)
min_qf_pi, _ = th.min(q_values_pi, dim=1, keepdim=True)
actor_loss = (ent_coef * log_prob - min_qf_pi).mean()
actor_losses.append(actor_loss.item())
# Optimize the actor
self.actor.optimizer.zero_grad()
actor_loss.backward()
self.actor.optimizer.step()
# Update target networks
if gradient_step % self.target_update_interval == 0:
polyak_update(self.critic.parameters(), self.critic_target.parameters(), self.tau)
self._n_updates += gradient_steps
self.logger.record("train/n_updates", self._n_updates, exclude="tensorboard")
self.logger.record("train/ent_coef", np.mean(ent_coefs))
self.logger.record("train/actor_loss", np.mean(actor_losses))
self.logger.record("train/critic_loss", np.mean(critic_losses))
if len(ent_coef_losses) > 0:
self.logger.record("train/ent_coef_loss", np.mean(ent_coef_losses))
def train(self, gradient_steps: int, batch_size: int) -> None:
# Set mppisac coeficient (either constant or using schedule)
if isinstance(self.mppisac_coef, float):
mppisac_coef = self.mppisac_coef
assert (mppisac_coef <=
1.0) and (mppisac_coef >=
0.0), "MPPISAC_coef should be between 0.0 to 1.0"
else:
mppisac_coef = self.mppisac_coef_schedule.value(
step=self.num_timesteps - self.learning_starts,
total_steps=self._total_timesteps)
# Update optimizers learning rate
optimizers = [self.actor.optimizer, self.critic.optimizer]
if self.ent_coef_optimizer is not None:
optimizers += [self.ent_coef_optimizer]
# Update learning rate according to lr schedule
self._update_learning_rate(optimizers)
ent_coef_losses, ent_coefs = [], []
actor_losses, critic_losses, mppisac_losses = [], [], []
mb_train_losses, mb_valid_losses = [], []
for gradient_step in range(gradient_steps):
# Sample replay buffer
replay_data = self.replay_buffer.sample(
batch_size, env=self._vec_normalize_env)
# train model based MPPICTRL dynamic model
if mppisac_coef > 0.0:
mb_valid_loss = self.mbctrl.validate(
states=replay_data.observations,
next_states=replay_data.next_observations,
actions=replay_data.actions,
)
mb_valid_losses.append(mb_valid_loss)
mb_train_loss = self.mbctrl.train(
states=replay_data.observations,
next_states=replay_data.next_observations,
actions=replay_data.actions,
)
mb_train_losses.append(np.mean(mb_train_loss))
# MPPICTRL's suggested actions for observations
# t1 = time.time()
if self.mppisac_nprocesses == 1:
actions_mb = self.mbctrl.act(replay_data.observations)
else:
with Pool(self.mppisac_nprocesses) as pool:
actions_mb_mp = pool.map(self.mbctrl.act,
replay_data.observations)
actions_mb = torch.stack(actions_mb_mp)
# t2 = time.time()
# to_log = f"Processing {replay_data.observations.shape[0]} observations in {t2-t1:.2f} seconds [{(t2-t1)/replay_data.observations.shape[0]:.3f}sec/action] using {self.mppisac_nprocesses} cpus"
# logger.log(to_log, level=20)
actions_mb = self.policy.scale_action(actions_mb)
# Deterministic actions from current SAC actor to be used for behavioral cloning loss
actions_pi_deterministic = self.actor(
obs=replay_data.observations, deterministic=True)
# We need to sample because `log_std` may have changed between two gradient steps
if self.use_sde:
self.actor.reset_noise()
# Action by the current actor for the sampled state
actions_pi, log_prob = self.actor.action_log_prob(
replay_data.observations)
log_prob = log_prob.reshape(-1, 1)
ent_coef_loss = None
if self.ent_coef_optimizer is not None:
# Important: detach the variable from the graph
# so we don't change it with other losses
# see https://github.com/rail-berkeley/softlearning/issues/60
ent_coef = torch.exp(self.log_ent_coef.detach())
ent_coef_loss = -(
self.log_ent_coef *
(log_prob + self.target_entropy).detach()).mean()
ent_coef_losses.append(ent_coef_loss.item())
else:
ent_coef = self.ent_coef_tensor
ent_coefs.append(ent_coef.item())
# Optimize entropy coefficient, also called
# entropy temperature or alpha in the paper
if ent_coef_loss is not None:
self.ent_coef_optimizer.zero_grad()
ent_coef_loss.backward()
self.ent_coef_optimizer.step()
with torch.no_grad():
# Select action according to policy
next_actions, next_log_prob = self.actor.action_log_prob(
replay_data.next_observations)
# Compute the target Q value: min over all critics targets
targets = torch.cat(self.critic_target(
replay_data.next_observations, next_actions),
dim=1)
target_q, _ = torch.min(targets, dim=1, keepdim=True)
# add entropy term
target_q = target_q - ent_coef * next_log_prob.reshape(-1, 1)
# td error + entropy term
q_backup = replay_data.rewards + (
1 - replay_data.dones) * self.gamma * target_q
# q(s, MPPI_action) FOR USING DIFF Qs
if mppisac_coef > 0.0 and self.mppisac_use_qdiff:
actions_mb_qs = torch.cat(self.critic_target(
replay_data.observations, actions_mb),
dim=1)
actions_mb_q, _ = torch.min(actions_mb_qs,
dim=1,
keepdim=True)
# Get current Q estimates for each critic network
# using action from the replay buffer
current_q_estimates = self.critic(replay_data.observations,
replay_data.actions)
# Compute critic loss
critic_loss = 0.5 * sum([
F.mse_loss(current_q, q_backup)
for current_q in current_q_estimates
])
critic_losses.append(critic_loss.item())
# Optimize the critic
self.critic.optimizer.zero_grad()
critic_loss.backward()
self.critic.optimizer.step()
# Compute actor loss
# Alternative: actor_loss = th.mean(log_prob - qf1_pi)
# Mean over all critic networks
q_values_pi = torch.cat(self.critic.forward(
replay_data.observations, actions_pi),
dim=1)
min_qf_pi, _ = torch.min(q_values_pi, dim=1, keepdim=True)
sac_actor_loss = (ent_coef * log_prob - min_qf_pi).mean()
# --- Behavioral Cloning (MPPISAC) loss ---
if mppisac_coef > 0.0 and self.mppisac_use_qdiff:
mppisac_loss = F.mse_loss(min_qf_pi,
actions_mb_q,
reduction="none").mean() # using qs
elif mppisac_coef > 0.0:
mppisac_loss = F.mse_loss(
actions_pi_deterministic, actions_mb,
reduction="none").mean() # using actions
else:
mppisac_loss = torch.tensor(0.0)
mppisac_losses.append(mppisac_loss.item())
actor_loss = (1.0 - mppisac_coef
) * sac_actor_loss + mppisac_coef * mppisac_loss
actor_losses.append(actor_loss.item())
# Optimize the actor
self.actor.optimizer.zero_grad()
actor_loss.backward()
self.actor.optimizer.step()
# Update target networks
if gradient_step % self.target_update_interval == 0:
polyak_update(self.critic.parameters(),
self.critic_target.parameters(), self.tau)
self._n_updates += gradient_steps
logger.record("train/n_updates",
self._n_updates,
exclude="tensorboard")
logger.record("train/ent_coef", np.mean(ent_coefs))
logger.record("train/actor_loss", np.mean(actor_losses))
logger.record("train/critic_loss", np.mean(critic_losses))
logger.record("train/mppi-sac_loss", np.mean(mppisac_losses))
logger.record("train/mppi-sac_coef", mppisac_coef)
logger.record("mbctrl/train_loss", np.mean(mb_train_losses))
logger.record("mbctrl/valid_loss", np.mean(mb_valid_losses))
if len(ent_coef_losses) > 0:
logger.record("train/ent_coef_loss", np.mean(ent_coef_losses))
self._dump_logs()
def train(self, gradient_steps: int, batch_size: int = 64) -> None:
# Update optimizers learning rate
optimizers = [self.actor.optimizer, self.critic.optimizer]
# Update learning rate according to lr schedule
self._update_learning_rate(optimizers)
actor_losses, critic_losses = [], []
for gradient_step in range(gradient_steps):
# Sample replay buffer
replay_data = self.replay_buffer.sample(
batch_size, env=self._vec_normalize_env)
batch_size = replay_data.observations.size(0)
# Critic update
with th.no_grad():
target_next_actions = self.actor_target.forward(
replay_data.next_observations)
target_next_actions_q, _ = self.critic_target.forward(
replay_data.next_observations, target_next_actions,
self.action_dist_samples)
target_next_actions_q = target_next_actions_q.transpose(1, 2)
target_expected_Q = replay_data.rewards.unsqueeze(-1) + \
(1 - replay_data.dones.unsqueeze(-1)) * self.gamma * target_next_actions_q
expected_Q, taus = self.critic.forward(replay_data.observations,
replay_data.actions,
self.action_dist_samples)
# Quantile Huber loss
td_error = target_expected_Q - expected_Q
huber_1 = calculate_huber_loss(td_error, 1.0)
quantil_1 = abs(taus -
(td_error.detach() < 0).float()) * huber_1 / 1.0
critic_loss = (quantil_1.sum(dim=1).mean(dim=1, keepdim=True) *
replay_data.weights).mean()
critic_losses.append(critic_loss.item())
# Optimize critic
self.critic.optimizer.zero_grad()
critic_loss.backward()
clip_grad_norm_(self.critic.parameters(), 1)
self.critic.optimizer.step()
# Actor update
actions = self.actor.forward(replay_data.observations)
actions_q = self.critic.get_qvalues(replay_data.observations,
actions)
actor_loss = -actions_q.mean()
self.actor.optimizer.zero_grad()
actor_loss.backward()
self.actor.optimizer.step()
actor_losses.append(actor_loss.item())
self.replay_buffer.update_priorities(
replay_data.indices,
np.clip(
abs(
td_error.sum(dim=1).mean(
dim=1, keepdim=True).data.cpu().numpy()), -1, 1))
if gradient_step % self.target_update_interval == 0:
polyak_update(self.actor.parameters(),
self.actor_target.parameters(), self.tau)
polyak_update(self.critic.parameters(),
self.critic_target.parameters(), self.tau)
self._n_updates += gradient_steps
logger.record("train/n_updates",
self._n_updates,
exclude="tensorboard")
logger.record("train/actor_loss", np.mean(actor_losses))
logger.record("train/critic_loss", np.mean(critic_losses))
def train(self, gradient_steps: int, batch_size: int = 100) -> None:
# Update learning rate according to lr schedule
self._update_learning_rate(
[self.actor.optimizer, self.critic.optimizer])
actor_losses, critic_losses = [], []
for i in range(gradient_steps):
use_bc_loss = False
self._n_updates += 1
updatas = 0
# Sample replay buffer
#if self.use_expert_demonstration =True and updatas< (gradient_steps/2):
#self.use_expert_demonstration=0
if self._n_updates % 2 == 0 and self.use_expert_demonstration == 1:
replay_data = self.expert_buffer.sample(
batch_size, env=self._vec_normalize_env)
use_bc_loss = True
#print('buffer_sample')
#print(replay_data.actions)
else:
replay_data = self.replay_buffer.sample(
batch_size, env=self._vec_normalize_env)
#print('replay_sample')
#print(replay_data.actions)
#replay_expert_data=self.expert_buffer.sample(batch_size, env=self._vec_normalize_env)
#replay_data=self.replay_buffer.sample(batch_size,env=self._vec_normalize_env)
#print(test_data.next_observations[0])
#replay_data = self.expert_buffer.sample(batch_size, env=self._vec_normalize_env)
#print(type(replay_data.next_observations))
# replay_data = self.expert_buffer.sample(batch_size, env=self._vec_normalize_env)
#use_bc_loss=True
with th.no_grad():
# Select action according to policy and add clipped noise
noise = replay_data.actions.clone().data.normal_(
0, self.target_policy_noise)
noise = noise.clamp(-self.target_noise_clip,
self.target_noise_clip)
next_actions = (
self.actor_target(replay_data.next_observations) +
noise).clamp(-1, 1)
# Compute the next Q-values: min over all critics targets
next_q_values = th.cat(self.critic_target(
replay_data.next_observations, next_actions),
dim=1)
next_q_values, _ = th.min(next_q_values, dim=1, keepdim=True)
target_q_values = replay_data.rewards + (
1 - replay_data.dones) * self.gamma * next_q_values
# Get current Q-values estimates for each critic network
current_q_values = self.critic(replay_data.observations,
replay_data.actions)
# Compute critic loss
critic_loss = sum([
F.mse_loss(current_q, target_q_values)
for current_q in current_q_values
])
critic_losses.append(critic_loss.item())
# Optimize the critics
self.critic.optimizer.zero_grad()
critic_loss.backward()
self.critic.optimizer.step()
# Delayed policy updates
if self._n_updates % self.policy_delay == 0:
if use_bc_loss == True:
# Compute actor loss#
current_actions = self.actor(replay_data.observations)
bc_loss = sum([
F.mse_loss(current_action, replay_data.actions)
for current_action in current_actions
])
actor_loss = -self.critic.q1_forward(
replay_data.observations,
self.actor(replay_data.observations)).mean() + bc_loss
actor_losses.append(actor_loss.item())
else:
actor_loss = -self.critic.q1_forward(
replay_data.observations,
self.actor(replay_data.observations)).mean()
actor_losses.append(actor_loss.item())
# Optimize the actor
self.actor.optimizer.zero_grad()
actor_loss.backward()
self.actor.optimizer.step()
polyak_update(self.critic.parameters(),
self.critic_target.parameters(), self.tau)
polyak_update(self.actor.parameters(),
self.actor_target.parameters(), self.tau)
logger.record("train/n_updates",
self._n_updates,
exclude="tensorboard")
if len(actor_losses) > 0:
logger.record("train/actor_loss", np.mean(actor_losses))
logger.record("train/critic_loss", np.mean(critic_losses))
def run(params: argparse.Namespace):
Task.init()
sb3_utils.set_random_seed(params.seed, using_cuda=use_cuda)
writer = helper.get_summary_writer(__file__, params)
env = helper.make_env(params, 'env')
q = network.get_model_class(params)(env).to(device)
q_hat = network.get_model_class(params)(env).to(device)
q_hat.load_state_dict(q.state_dict())
replay_buffer = ReplayBuffer(params.replay_size)
# todo check optimizer
opt = optim.Adam(q.parameters(), lr=params.learning_rate)
all_rewards = []
state = env.reset()
episode_reward = [0]
episode_no = 0
for t in range(1, params.max_ts + 1):
# order of terms important so that the call to 'next(eps)'
# does not decrease epsilon
epsilon = get_epsilon(params.epsilon_start, params.epsilon_end,
params.epsilon_decay, t)
if random.random() < epsilon:
a = random.randrange(env.action_space.n)
else:
val = q(np.expand_dims(state, axis=0))
a = torch.argmax(val).item()
# equivalent to q(...).max(1)[1].data[0]
# (selects max tensor with .max(1) and its index with ...[1])
s_tp1, r, done, infos = env.step(a)
episode_reward = list(map(add, episode_reward, [r]))
replay_buffer.add(state, a, r, s_tp1, done)
state = s_tp1
if done:
state = env.reset()
all_rewards.append(episode_reward)
episode_reward = [0]
episode_no += 1
# replay buffer reached minimum capacity
if len(replay_buffer) > params.start_train_ts:
obses_t, actions, rewards, obses_tp1, dones = \
replay_buffer.sample(params.batch_size)
rewards = torch.tensor(rewards, dtype=torch.float32) \
.unsqueeze(1).to(device)
actions = torch.tensor(actions).unsqueeze(1).to(device)
dones = torch.tensor(dones).unsqueeze(1).to(device)
if True:
with torch.no_grad():
# Compute the target Q values
target_q = q_hat(obses_tp1)
# Follow greedy policy: use the one with the highest value
target_q, _ = target_q.max(dim=1)
# Avoid potential broadcast issue
target_q = target_q.reshape(-1, 1)
# 1-step TD target
target_q = rewards + ~dones * params.gamma * target_q
# Get current Q estimates
current_q = q(obses_t)
# Retrieve the q-values for the actions from the replay buffer
current_q = torch.gather(current_q,
dim=1,
index=actions.long())
# Compute Huber loss (less sensitive to outliers)
loss = F.smooth_l1_loss(current_q, target_q)
else:
val_tp1 = q(obses_tp1)
val_t = q(obses_t)
val_hat_tp1 = q_hat(obses_tp1)
# .T to iterate over columns of the array: https://stackoverflow.com/a/10148855/256002
r = torch.from_numpy(rewards).to(device)
#if params.summed_q:
# head = heads[idx]
#else:
# head = heads[mirrored_envs.use_for_decisions_idx]
a = torch.argmax(val_tp1, dim=1)
td_errors = r + ~dones * params.gamma * val_hat_tp1.gather(
1, a.unsqueeze(1)).squeeze()
q_vals = val_t.gather(1, actions).squeeze()
#loss = (td_errors.detach() - q_vals).pow(2).mean()
loss = F.smooth_l1_loss(q_vals, td_errors.detach())
if done:
writer.add_scalar("loss_idx", loss.data, episode_no)
writer.add_scalar("total_loss", loss.data, episode_no)
# Optimize the policy
opt.zero_grad()
loss.backward()
# Clip gradient norm
torch.nn.utils.clip_grad_norm_(q.parameters(),
params.max_grad_norm)
opt.step()
if t % params.target_network_update_f == 0:
print('weights copied')
sb3_utils.polyak_update(q.parameters(), q_hat.parameters(),
1.0)
if done:
for idx, ep_reward in enumerate(all_rewards[-1]):
helper.add_scalar(writer, "episode_reward_idx{}".format(idx),
ep_reward, episode_no, params)
helper.add_scalar(writer, "steps_count", infos['steps_count'],
episode_no, params)
if episode_no % params.log_interval == 0:
#print('replaybuffer size:', len(replay_buffer))
out_str = "Timestep {}".format(t)
if len(all_rewards) > 0:
out_str += ",Reward:{}".format(all_rewards[-1])
out_str += ", done: {}".format(done)
out_str += ', steps_count {}'.format(infos['steps_count'])
out_str += ', epsilon {}'.format(epsilon)
print(out_str)
helper.close_summary_writer(writer)
def train(self, gradient_steps: int, batch_size: int = 64) -> None:
# Update optimizers learning rate
optimizers = [self.actor.optimizer, self.critic.optimizer]
if self.ent_coef_optimizer is not None:
optimizers += [self.ent_coef_optimizer]
# Update learning rate according to lr schedule
self._update_learning_rate(optimizers)
ent_coef_losses, ent_coefs = [], []
actor_losses, critic_losses = [], []
for gradient_step in range(gradient_steps):
# Sample replay buffer
replay_data = self.replay_buffer.sample(
batch_size, env=self._vec_normalize_env)
# We need to sample because `log_std` may have changed between two gradient steps
if self.use_sde:
self.actor.reset_noise()
# Action by the current actor for the sampled state
actions_pi, log_prob = self.actor.action_log_prob(
replay_data.observations)
log_prob = log_prob.reshape(-1, 1)
ent_coef_loss = None
if self.ent_coef_optimizer is not None:
# Important: detach the variable from the graph
# so we don't change it with other losses
# see https://github.com/rail-berkeley/softlearning/issues/60
ent_coef = th.exp(self.log_ent_coef.detach())
ent_coef_loss = -(
self.log_ent_coef *
(log_prob + self.target_entropy).detach()).mean()
ent_coef_losses.append(ent_coef_loss.item())
else:
ent_coef = self.ent_coef_tensor
ent_coefs.append(ent_coef.item())
self.replay_buffer.ent_coef = ent_coef.item()
# Optimize entropy coefficient, also called
# entropy temperature or alpha in the paper
if ent_coef_loss is not None:
self.ent_coef_optimizer.zero_grad()
ent_coef_loss.backward()
self.ent_coef_optimizer.step()
with th.no_grad():
# Select action according to policy
next_actions, next_log_prob = self.actor.action_log_prob(
replay_data.next_observations)
# Compute and cut quantiles at the next state
# batch x nets x quantiles
next_quantiles = self.critic_target(
replay_data.next_observations, next_actions)
# Sort and drop top k quantiles to control overestimation.
n_target_quantiles = self.critic.quantiles_total - self.top_quantiles_to_drop_per_net * self.critic.n_critics
next_quantiles, _ = th.sort(
next_quantiles.reshape(batch_size, -1))
next_quantiles = next_quantiles[:, :n_target_quantiles]
# td error + entropy term
target_quantiles = next_quantiles - ent_coef * next_log_prob.reshape(
-1, 1)
target_quantiles = replay_data.rewards + (
1 - replay_data.dones) * self.gamma * target_quantiles
# Make target_quantiles broadcastable to (batch_size, n_critics, n_target_quantiles).
target_quantiles.unsqueeze_(dim=1)
# Get current Quantile estimates using action from the replay buffer
current_quantiles = self.critic(replay_data.observations,
replay_data.actions)
# Compute critic loss, not summing over the quantile dimension as in the paper.
critic_loss = quantile_huber_loss(current_quantiles,
target_quantiles,
sum_over_quantiles=False)
critic_losses.append(critic_loss.item())
# Optimize the critic
self.critic.optimizer.zero_grad()
critic_loss.backward()
self.critic.optimizer.step()
# Compute actor loss
qf_pi = self.critic(replay_data.observations,
actions_pi).mean(dim=2).mean(dim=1,
keepdim=True)
actor_loss = (ent_coef * log_prob - qf_pi).mean()
actor_losses.append(actor_loss.item())
# Optimize the actor
self.actor.optimizer.zero_grad()
actor_loss.backward()
self.actor.optimizer.step()
# Update target networks
if gradient_step % self.target_update_interval == 0:
polyak_update(self.critic.parameters(),
self.critic_target.parameters(), self.tau)
self._n_updates += gradient_steps
logger.record("train/n_updates",
self._n_updates,
exclude="tensorboard")
logger.record("train/ent_coef", np.mean(ent_coefs))
logger.record("train/actor_loss", np.mean(actor_losses))
logger.record("train/critic_loss", np.mean(critic_losses))
if len(ent_coef_losses) > 0:
logger.record("train/ent_coef_loss", np.mean(ent_coef_losses))
def train_mer(self, gradient_steps: int, batch_size: int = 64) -> None:
optimizers = [self.actor.optimizer, self.critic.optimizer]
if self.ent_coef_optimizer is not None:
optimizers += [self.ent_coef_optimizer]
optimizers_to_reset = optimizers
# Reset optimizers:
for i_optimizer, optimizer in enumerate(optimizers_to_reset):
optimizer.__init__(optimizer.param_groups[0]['params'])
optimizers[i_optimizer] = optimizer
# Update optimizers learning rate
base_lr = self.lr_schedule(self._current_progress_remaining)
ent_coef_losses, ent_coefs = [], []
actor_losses, critic_losses = [], []
# Save initial weights of model - for actor and critic but not for critic_target
models_to_update = [self.actor, self.critic]
initial_state_dicts = [
deepcopy(model.state_dict()) for model in models_to_update
]
initial_log_ent_coef = self.log_ent_coef.detach().clone()
current_example_ind = randint(0, gradient_steps - 1)
for gradient_step in range(gradient_steps):
# Sample replay buffer or current example, and update learning rate accordingly
if gradient_step == current_example_ind:
replay_data = self.current_experience_buffer.sample(
1, env=self._vec_normalize_env)
for optimizer in optimizers:
update_learning_rate(optimizer, base_lr * self.mer_s)
else:
replay_data = self.replay_buffer.sample(
batch_size, env=self._vec_normalize_env)
for optimizer in optimizers:
update_learning_rate(optimizer, base_lr)
# We need to sample because `log_std` may have changed between two gradient steps
if self.use_sde:
self.actor.reset_noise()
# Action by the current actor for the sampled state
actions_pi, log_prob = self.actor.action_log_prob(
replay_data.observations)
log_prob = log_prob.reshape(-1, 1)
ent_coef_loss = None
if self.ent_coef_optimizer is not None:
# Important: detach the variable from the graph
# so we don't change it with other losses
# see https://github.com/rail-berkeley/softlearning/issues/60
ent_coef = th.exp(self.log_ent_coef.detach())
ent_coef_loss = -(
self.log_ent_coef *
(log_prob + self.target_entropy).detach()).mean()
ent_coef_losses.append(ent_coef_loss.item())
else:
ent_coef = self.ent_coef_tensor
ent_coefs.append(ent_coef.item())
# Optimize entropy coefficient, also called
# entropy temperature or alpha in the paper
if ent_coef_loss is not None:
self.ent_coef_optimizer.zero_grad()
ent_coef_loss.backward()
self.ent_coef_optimizer.step()
with th.no_grad():
# Select action according to policy
next_actions, next_log_prob = self.actor.action_log_prob(
replay_data.next_observations)
# Compute the target Q value: min over all critics targets
targets = th.cat(self.critic_target(
replay_data.next_observations, next_actions),
dim=1)
target_q, _ = th.min(targets, dim=1, keepdim=True)
# add entropy term
target_q = target_q - ent_coef * next_log_prob.reshape(-1, 1)
# td error + entropy term
q_backup = replay_data.rewards + (
1 - replay_data.dones) * self.gamma * target_q
# Get current Q estimates for each critic network
# using action from the replay buffer
current_q_estimates = self.critic(replay_data.observations,
replay_data.actions)
# Compute critic loss
critic_loss = 0.5 * sum([
F.mse_loss(current_q, q_backup)
for current_q in current_q_estimates
])
critic_losses.append(critic_loss.item())
# Optimize the critic
self.critic.optimizer.zero_grad()
critic_loss.backward()
self.critic.optimizer.step()
# Compute actor loss
# Alternative: actor_loss = th.mean(log_prob - qf1_pi)
# Mean over all critic networks
q_values_pi = th.cat(self.critic.forward(replay_data.observations,
actions_pi),
dim=1)
min_qf_pi, _ = th.min(q_values_pi, dim=1, keepdim=True)
actor_loss = (ent_coef * log_prob - min_qf_pi).mean()
actor_losses.append(actor_loss.item())
# Optimize the actor
self.actor.optimizer.zero_grad()
actor_loss.backward()
self.actor.optimizer.step()
# Perform Reptile step
for i_model, model in enumerate(models_to_update):
self.reptile_step_state_dict(model, initial_state_dicts[i_model])
self.log_ent_coef.data = self.reptile_step_tensor(
self.log_ent_coef.data, initial_log_ent_coef.data)
# Update target networks
polyak_update(self.critic.parameters(),
self.critic_target.parameters(), self.tau)
self._n_updates += gradient_steps
logger.record("train/n_updates",
self._n_updates,
exclude="tensorboard")
logger.record("train/ent_coef", np.mean(ent_coefs))
logger.record("train/actor_loss", np.mean(actor_losses))
logger.record("train/critic_loss", np.mean(critic_losses))
if len(ent_coef_losses) > 0:
logger.record("train/ent_coef_loss", np.mean(ent_coef_losses))
def train(self, gradient_steps: int, batch_size: int = 64) -> None:
# Update optimizers learning rate
optimizers = [self.actor.optimizer, self.critic.optimizer]
# Update learning rate according to lr schedule
self._update_learning_rate(optimizers)
mean_loss_q, mean_loss_p, mean_loss_l, max_kl_μ, max_kl_Σ, max_kl = [], [], [], [], [], []
actor_losses, critic_losses = [], []
for gradient_step in range(gradient_steps):
# Sample replay buffer
replay_data = self.replay_buffer.sample(
batch_size, env=self._vec_normalize_env)
batch_size = replay_data.observations.size(0)
with th.no_grad():
# Sample "action_samples" num additional actions
target_next_action_mean, target_next_action_cholesky, _ = self.actor_target.get_action_dist_params(
replay_data.next_observations)
target_next_action_dist = MultivariateNormal(
target_next_action_mean,
scale_tril=target_next_action_cholesky)
target_sampled_next_actions = target_next_action_dist.sample(
(self.action_samples, )).transpose(0, 1)
# Compute mean of q values for the samples
# Expand next_observation to match self.action_samples
expanded_next_observations = replay_data.next_observations[:, None, :].expand(
-1, self.action_samples, -1)
target_sampled_next_actions_expected_q = get_min_critic_tensor(
self.critic_target.forward(
expanded_next_observations.reshape(
-1, self.features_dim),
target_sampled_next_actions.reshape(
-1, self.action_dim))).reshape(
batch_size, self.action_samples).mean(dim=1)
# Compute total expected return
target_sampled_expected_return = replay_data.rewards.squeeze() + (1 - replay_data.dones.squeeze()) * self.gamma * \
target_sampled_next_actions_expected_q
# Optimize the critic
critic_qs = self.critic.forward(replay_data.observations,
replay_data.actions)
critic_loss = 0.5 * sum([
self.critic_loss(current_q.squeeze(),
target_sampled_expected_return)
for current_q in critic_qs
])
critic_losses.append(critic_loss.item())
self.critic.optimizer.zero_grad()
critic_loss.backward()
self.critic.optimizer.step()
# Sample additional actions for E-Step
with th.no_grad():
target_action_mean, target_action_cholesky, _ = self.actor_target.get_action_dist_params(
replay_data.observations)
target_action_dist = MultivariateNormal(
target_action_mean, scale_tril=target_action_cholesky)
sampled_actions = target_action_dist.sample(
(self.action_samples, ))
# Compute q values for the samples
# Expand next_observation to match self.action_samples
expanded_observations = replay_data.observations[
None, ...].expand(self.action_samples, -1, -1)
target_sampled_actions_expected_q = get_min_critic_tensor(
self.critic_target.forward(
expanded_observations.reshape(-1, self.features_dim),
sampled_actions.reshape(-1, self.action_dim))).reshape(
self.action_samples, batch_size)
target_sampled_actions_expected_q_np = target_sampled_actions_expected_q.cpu(
).numpy()
# Define dual function
def dual(η):
max_q = np.max(target_sampled_actions_expected_q_np, 0)
return η * self.ε_dual + np.mean(max_q) \
+ η * np.mean(np.log(np.mean(np.exp((target_sampled_actions_expected_q_np - max_q) / η), axis=0)))
bounds = [(1e-6, None)]
self.η = np.max([self.η, 1e-6])
res = minimize(dual,
np.array([self.η]),
method='SLSQP',
bounds=bounds)
self.η = res.x[0]
qij = th.softmax(target_sampled_actions_expected_q / self.η, dim=0)
# M-Step
for _ in range(self.lagrange_iterations):
action_mean, action_cholesky, _ = self.actor.get_action_dist_params(
replay_data.observations)
π1 = MultivariateNormal(action_mean,
scale_tril=target_action_cholesky)
π2 = MultivariateNormal(target_action_mean,
scale_tril=action_cholesky)
loss_p = th.mean(qij * (π1.expand(
(self.action_samples,
batch_size)).log_prob(sampled_actions) + π2.expand(
(self.action_samples,
batch_size)).log_prob(sampled_actions)))
mean_loss_p.append((-loss_p).item())
kl_μ, kl_Σ = gaussian_kl(μ_target=target_action_mean,
μ=action_mean,
A_target=target_action_cholesky,
A=action_cholesky)
max_kl_μ.append(kl_μ.item())
max_kl_Σ.append(kl_Σ.item())
self.η_kl_μ -= self.α * (self.ε_kl_μ - kl_μ).detach().item()
self.η_kl_Σ -= self.α * (self.ε_kl_Σ - kl_Σ).detach().item()
if self.η_kl_μ < 0.0:
self.η_kl_μ = 0.0
if self.η_kl_Σ < 0.0:
self.η_kl_Σ = 0.0
self.actor.optimizer.zero_grad()
actor_loss = -(loss_p + self.η_kl_μ *
(self.ε_kl_μ - kl_μ) + self.η_kl_Σ *
(self.ε_kl_Σ - kl_Σ))
actor_losses.append(actor_loss.item())
# Optimize actor
actor_loss.backward()
clip_grad_norm_(self.actor.parameters(), 0.1)
self.actor.optimizer.step()
if gradient_step % self.target_update_interval == 0:
polyak_update(self.actor.parameters(),
self.actor_target.parameters(), self.tau)
polyak_update(self.critic.parameters(),
self.critic_target.parameters(), self.tau)
self._n_updates += gradient_steps
logger.record("train/n_updates",
self._n_updates,
exclude="tensorboard")
logger.record("train/actor_loss", np.mean(actor_losses))
logger.record("train/critic_loss", np.mean(critic_losses))
logger.record("train/actor_policy_loss", np.mean(mean_loss_p))
logger.record("train/max_kl_mean", np.max(max_kl_μ))
logger.record("train/mean_kl_mean", np.mean(max_kl_μ))
logger.record("train/max_kl_std", np.max(max_kl_Σ))
logger.record("train/mean_kl_std", np.mean(max_kl_Σ))