Files
DeepRL/deep_rl/agent/CategoricalDQN_agent.py
2018-05-07 16:49:01 -06:00

113 lines
5.7 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 ..component import *
from ..utils import *
import time
from .BaseAgent import *
class CategoricalDQNAgent(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.criterion = nn.MSELoss()
self.target_network.load_state_dict(self.network.state_dict())
self.replay = config.replay_fn()
self.policy = config.policy_fn()
self.total_steps = 0
self.atoms = self.network.tensor(
np.linspace(config.categorical_v_min,
config.categorical_v_max,
config.categorical_n_atoms))
self.delta_atom = (config.categorical_v_max - config.categorical_v_min) / float(config.categorical_n_atoms - 1)
def evaluation_action(self, state):
value = self.network.predict(np.stack([self.config.state_normalizer(state)])).squeeze(0).detach()
value = (value * self.atoms).sum(-1).cpu().detach().numpy().flatten()
return np.argmax(value)
def episode(self, deterministic=False):
episode_start_time = time.time()
state = self.task.reset()
total_reward = 0.0
steps = 0
while True:
value = self.network.predict(np.stack([self.config.state_normalizer(state)])).squeeze(0).detach()
# self.config.logger.histo_summary('prob', value, self.total_steps)
value = (value * self.atoms).sum(-1).cpu().detach().numpy().flatten()
# self.config.logger.histo_summary('q', value, self.total_steps)
if deterministic:
action = np.argmax(value)
elif self.total_steps < self.config.exploration_steps:
action = np.random.randint(0, len(value))
else:
action = self.policy.sample(value)
next_state, reward, done, _ = self.task.step(action)
total_reward += reward
reward = self.config.reward_normalizer(reward)
if not deterministic:
self.replay.feed([state, action, reward, next_state, int(done)])
self.total_steps += 1
steps += 1
state = next_state
if not deterministic and self.total_steps > self.config.exploration_steps:
experiences = self.replay.sample()
states, actions, rewards, next_states, terminals = experiences
states = self.config.state_normalizer(states)
next_states = self.config.state_normalizer(next_states)
prob_next = self.target_network.predict(next_states).detach()
q_next = (prob_next * self.atoms).sum(-1)
# self.config.logger.histo_summary('q next', q_next.cpu().detach().numpy(), self.total_steps)
_, a_next = torch.max(q_next, dim=1)
a_next = a_next.view(-1, 1, 1).expand(-1, -1, prob_next.size(2))
prob_next = prob_next.gather(1, a_next).squeeze(1)
# self.config.logger.histo_summary('prob next', prob_next.cpu().detach().numpy(), self.total_steps)
rewards = self.network.tensor(rewards)
terminals = self.network.tensor(terminals)
atoms_next = rewards.view(-1, 1) + self.config.discount * (1 - terminals.view(-1, 1)) * self.atoms.view(1, -1)
# epsilon = 1e-5
atoms_next.clamp_(self.config.categorical_v_min, self.config.categorical_v_max)
b = (atoms_next - self.config.categorical_v_min) / self.delta_atom
l = b.floor()
u = b.ceil()
d_m_l = (u + (l == u).float() - b) * prob_next
d_m_u = (b - l) * prob_next
target_prob = self.network.tensor(np.zeros(prob_next.size()))
for i in range(target_prob.size(0)):
target_prob[i].index_add_(0, l[i].long(), d_m_l[i])
target_prob[i].index_add_(0, u[i].long(), d_m_u[i])
prob = self.network.predict(states)
actions = self.network.tensor(actions).long()
actions = actions.view(-1, 1, 1).expand(-1, -1, prob.size(2))
prob = prob.gather(1, actions).squeeze(1)
loss = -(target_prob * prob.log()).sum(-1).mean()
self.optimizer.zero_grad()
loss.backward()
nn.utils.clip_grad_norm_(self.network.parameters(), self.config.gradient_clip)
self.optimizer.step()
self.evaluate()
if not deterministic and self.total_steps % self.config.target_network_update_freq == 0:
self.target_network.load_state_dict(self.network.state_dict())
if not deterministic and self.total_steps > self.config.exploration_steps:
self.policy.update_epsilon()
if done:
break
episode_time = time.time() - episode_start_time
self.config.logger.debug('episode steps %d, episode time %f, time per step %f' %
(steps, episode_time, episode_time / float(steps)))
return total_reward, steps