Files
DeepRL/deep_rl/agent/OptionCritic_agent.py

115 lines
6.0 KiB
Python

#######################################################################
# Copyright (C) 2017 Shangtong Zhang(zhangshangtong.cpp@gmail.com) #
# Permission given to modify the code as long as you keep this #
# declaration at the top #
#######################################################################
from ..network import *
from .BaseAgent import *
class OptionCriticAgent(BaseAgent):
def __init__(self, config):
BaseAgent.__init__(self, config)
self.config = config
self.task = config.task_fn()
self.network = config.network_fn(self.task.state_dim, self.task.action_dim)
self.target_network = config.network_fn(self.task.state_dim, self.task.action_dim)
self.optimizer = config.optimizer_fn(self.network.parameters())
self.target_network.load_state_dict(self.network.state_dict())
self.policy = config.policy_fn()
self.episode_rewards = np.zeros(config.num_workers)
self.last_episode_rewards = np.zeros(config.num_workers)
self.total_steps = 0
states = self.config.state_normalizer(self.task.reset())
self.q_options, self.betas, self.log_pi = self.network.predict(states)
self.options = np.asarray([self.policy.sample(q) for q in self.q_options.detach().cpu().numpy()])
self.is_initial_betas = np.ones(self.config.num_workers)
self.prev_options = np.copy(self.options)
def iteration(self):
config = self.config
rollout = []
q_options, betas, options, log_pi = self.q_options, self.betas, self.options, self.log_pi
for _ in range(config.rollout_length):
var_options = self.network.tensor(options).long()
worker_index = self.network.tensor(np.arange(config.num_workers)).long()
intra_log_pi = log_pi[worker_index, var_options, :]
dist = torch.distributions.Categorical(intra_log_pi.exp())
actions = dist.sample()
next_states, rewards, terminals, _ = self.task.step(actions.cpu().detach().numpy().flatten())
next_states = config.state_normalizer(next_states)
self.episode_rewards += rewards
rewards = config.reward_normalizer(rewards)
q_options_next, betas_next, log_pi_next = self.network.predict(next_states)
rollout.append([q_options, betas, options, self.prev_options, rewards, 1 - terminals, np.copy(self.is_initial_betas), intra_log_pi, actions])
self.is_initial_betas = np.asarray(terminals, dtype=np.float32)
np_q_options_next = q_options_next.cpu().detach().numpy()
np_betas_next = betas_next.gather(1, var_options.unsqueeze(1)).cpu().detach().numpy().flatten()
options_next = np.copy(options)
dice = np.random.rand(len(options_next))
for j in range(len(dice)):
if dice[j] < np_betas_next[j] or terminals[j]:
options_next[j] = self.policy.sample(np_q_options_next[j])
for i, terminal in enumerate(terminals):
if terminals[i]:
self.last_episode_rewards[i] = self.episode_rewards[i]
self.episode_rewards[i] = 0
self.prev_options = options
options = options_next
q_options = q_options_next
betas = betas_next
log_pi = log_pi_next
self.policy.update_epsilon()
self.total_steps += config.num_workers
if self.total_steps / config.num_workers % config.target_network_update_freq == 0:
self.target_network.load_state_dict(self.network.state_dict())
self.options = options
self.q_options = q_options
self.betas = betas
self.log_pi = log_pi
target_q_options, _, _ = self.target_network.predict(next_states)
prev_options = self.network.tensor(self.prev_options).long().unsqueeze(1)
betas_prev_options = betas.gather(1, prev_options)
returns = (1 - betas_prev_options) * target_q_options.gather(1, prev_options) +\
betas_prev_options * torch.max(target_q_options, dim=1, keepdim=True)[0]
returns = returns.detach()
processed_rollout = [None] * (len(rollout))
for i in reversed(range(len(rollout))):
q_options, betas, options, prev_options, rewards, terminals, is_initial_betas, log_pi, actions = rollout[i]
options = self.network.tensor(options).unsqueeze(1).long()
prev_options = self.network.tensor(prev_options).unsqueeze(1).long()
terminals = self.network.tensor(terminals).unsqueeze(1)
rewards = self.network.tensor(rewards).unsqueeze(1)
is_initial_betas = self.network.tensor(is_initial_betas).unsqueeze(1)
returns = rewards + config.discount * terminals * returns
q_omg = q_options.gather(1, options)
log_action_prob = log_pi.gather(1, actions.unsqueeze(1))
entropy_loss = (log_pi.exp() * log_pi).sum(-1).unsqueeze(1)
q_prev_omg = q_options.gather(1, prev_options)
v_prev_omg = torch.max(q_options, dim=1, keepdim=True)[0]
advantage_omg = q_prev_omg - v_prev_omg
advantage_omg.add_(config.termination_regularizer)
betas = betas.gather(1, prev_options)
betas = betas * (1 - is_initial_betas)
processed_rollout[i] = [q_omg, returns, betas, advantage_omg.detach(), log_action_prob, entropy_loss]
q_omg, returns, beta_omg, advantage_omg, log_action_prob, entropy_loss = map(lambda x: torch.cat(x, dim=0), zip(*processed_rollout))
pi_loss = -log_action_prob * (returns - q_omg.detach()) + config.entropy_weight * entropy_loss
pi_loss = pi_loss.mean()
q_loss = 0.5 * (q_omg - returns).pow(2).mean()
beta_loss = (advantage_omg * beta_omg).mean()
self.optimizer.zero_grad()
(pi_loss + q_loss + beta_loss).backward()
nn.utils.clip_grad_norm_(self.network.parameters(), config.gradient_clip)
self.optimizer.step()