Files
DeepRL/agent/DDPG_agent.py
T

109 lines
4.4 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 #
#######################################################################
import numpy as np
import torch.multiprocessing as mp
from network import *
from utils import *
from component import *
import pickle
import os
import time
from .BaseAgent import *
class DDPGAgent(BaseAgent):
def __init__(self, config):
BaseAgent.__init__(self, config)
self.config = config
self.task = config.task_fn()
self.network = DisjointActorCriticWrapper(self.task.state_dim, self.task.action_dim,
config.actor_network_fn, config.critic_network_fn)
self.actor = self.network.actor
self.critic = self.network.critic
self.target_network = DisjointActorCriticWrapper(self.task.state_dim, self.task.action_dim,
config.actor_network_fn, config.critic_network_fn)
self.target_network.load_state_dict(self.network.state_dict())
self.actor_opt = config.actor_optimizer_fn(self.actor.parameters())
self.critic_opt = config.critic_optimizer_fn(self.critic.parameters())
self.replay = config.replay_fn()
self.random_process = config.random_process_fn(self.task.action_dim)
self.total_steps = 0
def soft_update(self, target, src):
for target_param, param in zip(target.parameters(), src.parameters()):
target_param.detach_()
target_param.copy_(target_param * (1.0 - self.config.target_network_mix) +
param * self.config.target_network_mix)
def evaluation_action(self, state):
self.config.state_normalizer.set_read_only()
state = np.stack([self.config.state_normalizer(state)])
action = self.actor.predict(state, to_numpy=True).flatten()
self.config.state_normalizer.unset_read_only()
return action
def episode(self, deterministic=False, video_recorder=None):
self.random_process.reset_states()
state = self.task.reset()
state = self.config.state_normalizer(state)
config = self.config
actor = self.network.actor
critic = self.network.critic
target_actor = self.target_network.actor
target_critic = self.target_network.critic
steps = 0
total_reward = 0.0
while True:
action = actor.predict(np.stack([state]), True).flatten()
if not deterministic:
action += self.random_process.sample()
next_state, reward, done, info = self.task.step(action)
if video_recorder is not None:
video_recorder.capture_frame()
next_state = self.config.state_normalizer(next_state)
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
self.evaluate()
if not deterministic and self.replay.size() >= config.min_memory_size:
experiences = self.replay.sample()
states, actions, rewards, next_states, terminals = experiences
q_next = target_critic.predict(next_states, target_actor.predict(next_states))
terminals = critic.tensor(terminals).unsqueeze(1)
rewards = critic.tensor(rewards).unsqueeze(1)
q_next = config.discount * q_next * (1 - terminals)
q_next.add_(rewards)
q_next = q_next.detach()
q = critic.predict(states, actions)
critic_loss = (q - q_next).pow(2).mul(0.5).sum(-1).mean()
self.critic_opt.zero_grad()
critic_loss.backward()
self.critic_opt.step()
policy_loss = -critic.predict(states, actor.predict(states)).mean()
self.actor_opt.zero_grad()
policy_loss.backward()
self.actor_opt.step()
self.soft_update(self.target_network, self.network)
if done:
break
return total_reward, steps