"""
Asynchronous Advantage Actor Critic (A3C) + RNN with continuous action space, Reinforcement Learning.
The Pendulum example.
View more on my tutorial page: https://morvanzhou.github.io/tutorials/
Using:
tensorflow 1.8.0
gym 0.10.5
"""
import multiprocessing
import threading
import tensorflow as tf
import numpy as np
import gym
import os
import shutil
import matplotlib.pyplot as plt
GAME = 'Pendulum-v0'
OUTPUT_GRAPH = True
LOG_DIR = './log'
N_WORKERS = multiprocessing.cpu_count()
MAX_EP_STEP = 200
MAX_GLOBAL_EP = 1500
GLOBAL_NET_SCOPE = 'Global_Net'
UPDATE_GLOBAL_ITER = 5
GAMMA = 0.9
ENTROPY_BETA = 0.01
LR_A = 0.0001 # learning rate for actor
LR_C = 0.001 # learning rate for critic
GLOBAL_RUNNING_R = []
GLOBAL_EP = 0
env = gym.make(GAME)
N_S = env.observation_space.shape[0]
N_A = env.action_space.shape[0]
A_BOUND = [env.action_space.low, env.action_space.high]
class ACNet(object):
def __init__(self, scope, globalAC=None):
if scope == GLOBAL_NET_SCOPE: # get global network
with tf.variable_scope(scope):
self.s = tf.placeholder(tf.float32, [None, N_S], 'S')
self.a_params, self.c_params = self._build_net(scope)[-2:]
else: # local net, calculate losses
with tf.variable_scope(scope):
self.s = tf.placeholder(tf.float32, [None, N_S], 'S')
self.a_his = tf.placeholder(tf.float32, [None, N_A], 'A')
self.v_target = tf.placeholder(tf.float32, [None, 1], 'Vtarget')
mu, sigma, self.v, self.a_params, self.c_params = self._build_net(scope)
td = tf.subtract(self.v_target, self.v, name='TD_error')
with tf.name_scope('c_loss'):
self.c_loss = tf.reduce_mean(tf.square(td))
with tf.name_scope('wrap_a_out'):
mu, sigma = mu * A_BOUND[1], sigma + 1e-4
normal_dist = tf.distributions.Normal(mu, sigma)
with tf.name_scope('a_loss'):
log_prob = normal_dist.log_prob(self.a_his)
exp_v = log_prob * tf.stop_gradient(td)
entropy = normal_dist.entropy() # encourage exploration
self.exp_v = ENTROPY_BETA * entropy + exp_v
self.a_loss = tf.reduce_mean(-self.exp_v)
with tf.name_scope('choose_a'): # use local params to choose action
self.A = tf.clip_by_value(tf.squeeze(normal_dist.sample(1), axis=[0, 1]), A_BOUND[0], A_BOUND[1])
with tf.name_scope('local_grad'):
self.a_grads = tf.gradients(self.a_loss, self.a_params)
self.c_grads = tf.gradients(self.c_loss, self.c_params)
with tf.name_scope('sync'):
with tf.name_scope('pull'):
self.pull_a_params_op = [l_p.assign(g_p) for l_p, g_p in zip(self.a_params, globalAC.a_params)]
self.pull_c_params_op = [l_p.assign(g_p) for l_p, g_p in zip(self.c_params, globalAC.c_params)]
with tf.name_scope('push'):
self.update_a_op = OPT_A.apply_gradients(zip(self.a_grads, globalAC.a_params))
self.update_c_op = OPT_C.apply_gradients(zip(self.c_grads, globalAC.c_params))
def _build_net(self, scope):
w_init = tf.random_normal_initializer(0., .1)
with tf.variable_scope('critic'): # only critic controls the rnn update
cell_size = 64
s = tf.expand_dims(self.s, axis=1,
name='timely_input') # [time_step, feature] => [time_step, batch, feature]
rnn_cell = tf.contrib.rnn.BasicRNNCell(cell_size)
self.init_state = rnn_cell.zero_state(batch_size=1, dtype=tf.float32)
outputs, self.final_state = tf.nn.dynamic_rnn(
cell=rnn_cell, inputs=s, initial_state=self.init_state, time_major=True)
cell_out = tf.reshape(outputs, [-1, cell_size], name='flatten_rnn_outputs') # joined state representation
l_c = tf.layers.dense(cell_out, 50, tf.nn.relu6, kernel_initializer=w_init, name='lc')
v = tf.layers.dense(l_c, 1, kernel_initializer=w_init, name='v') # state value
with tf.variable_scope('actor'): # state representation is based on critic
l_a = tf.layers.dense(cell_out, 80, tf.nn.relu6, kernel_initializer=w_init, name='la')
mu = tf.layers.dense(l_a, N_A, tf.nn.tanh, kernel_initializer=w_init, name='mu')
sigma = tf.layers.dense(l_a, N_A, tf.nn.softplus, kernel_initializer=w_init, name='sigma')
a_params = tf.get_collection(tf.GraphKeys.TRAINABLE_VARIABLES, scope=scope + '/actor')
c_params = tf.get_collection(tf.GraphKeys.TRAINABLE_VARIABLES, scope=scope + '/critic')
return mu, sigma, v, a_params, c_params
def update_global(self, feed_dict): # run by a local
SESS.run([self.update_a_op, self.update_c_op], feed_dict) # local grads applies to global net
def pull_global(self): # run by a local
SESS.run([self.pull_a_params_op, self.pull_c_params_op])
def choose_action(self, s, cell_state): # run by a local
s = s[np.newaxis, :]
a, cell_state = SESS.run([self.A, self.final_state], {self.s: s, self.init_state: cell_state})
return a, cell_state
class Worker(object):
def __init__(self, name, globalAC):
self.env = gym.make(GAME).unwrapped
self.name = name
self.AC = ACNet(name, globalAC)
def work(self):
global GLOBAL_RUNNING_R, GLOBAL_EP
total_step = 1
buffer_s, buffer_a, buffer_r = [], [], []
while not COORD.should_stop() and GLOBAL_EP < MAX_GLOBAL_EP:
s = self.env.reset()
ep_r = 0
rnn_state = SESS.run(self.AC.init_state) # zero rnn state at beginning
keep_state = rnn_state.copy() # keep rnn state for updating global net
for ep_t in range(MAX_EP_STEP):
if self.name == 'W_0':
self.env.render()
a, rnn_state_ = self.AC.choose_action(s, rnn_state) # get the action and next rnn state
s_, r, done, info = self.env.step(a)
done = True if ep_t == MAX_EP_STEP - 1 else False
ep_r += r
buffer_s.append(s)
buffer_a.append(a)
buffer_r.append((r+8)/8) # normalize
if total_step % UPDATE_GLOBAL_ITER == 0 or done: # update global and assign to local net
if done:
v_s_ = 0 # terminal
else:
v_s_ = SESS.run(self.AC.v, {self.AC.s: s_[np.newaxis, :], self.AC.init_state: rnn_state_})[0, 0]
buffer_v_target = []
for r in buffer_r[::-1]: # reverse buffer r
v_s_ = r + GAMMA * v_s_
buffer_v_target.append(v_s_)
buffer_v_target.reverse()
buffer_s, buffer_a, buffer_v_target = np.vstack(buffer_s), np.vstack(buffer_a), np.vstack(buffer_v_target)
feed_dict = {
self.AC.s: buffer_s,
self.AC.a_his: buffer_a,
self.AC.v_target: buffer_v_target,
self.AC.init_state: keep_state,
}
self.AC.update_global(feed_dict)
buffer_s, buffer_a, buffer_r = [], [], []
self.AC.pull_global()
keep_state = rnn_state_.copy() # replace the keep_state as the new initial rnn state_
s = s_
rnn_state = rnn_state_ # renew rnn state
total_step += 1
if done:
if len(GLOBAL_RUNNING_R) == 0: # record running episode reward
GLOBAL_RUNNING_R.ap
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