2018-04-12 21:10:50 +08:00

109 lines
3.5 KiB
Python

#!/usr/bin/env python
import tensorflow as tf
import gym
import numpy as np
import time
import logging
logging.basicConfig(level=logging.INFO)
# our lib imports here! It's ok to append path in examples
import sys
sys.path.append('..')
from tianshou.core import losses
import tianshou.data.advantage_estimation as advantage_estimation
import tianshou.core.policy.dqn as policy
import tianshou.core.value_function.action_value as value_function
from tianshou.data.data_buffer.vanilla import VanillaReplayBuffer
from tianshou.data.data_collector import DataCollector
from tianshou.data.tester import test_policy_in_env
if __name__ == '__main__':
env = gym.make('CartPole-v0')
observation_dim = env.observation_space.shape
action_dim = env.action_space.n
### 1. build network with pure tf
observation_ph = tf.placeholder(tf.float32, shape=(None,) + observation_dim)
def my_network():
net = tf.layers.dense(observation_ph, 32, activation=tf.nn.tanh)
net = tf.layers.dense(net, 32, activation=tf.nn.tanh)
action_values = tf.layers.dense(net, action_dim, activation=None)
return None, action_values # no policy head
### 2. build policy, loss, optimizer
dqn = value_function.DQN(my_network, observation_placeholder=observation_ph, has_old_net=True)
pi = policy.DQN(dqn)
dqn_loss = losses.qlearning(dqn)
total_loss = dqn_loss
optimizer = tf.train.AdamOptimizer(1e-4)
train_op = optimizer.minimize(total_loss, var_list=list(dqn.trainable_variables))
### 3. define data collection
replay_buffer = VanillaReplayBuffer(capacity=2e4, nstep=1)
process_functions = [advantage_estimation.nstep_q_return(1, dqn)]
managed_networks = [dqn]
data_collector = DataCollector(
env=env,
policy=pi,
data_buffer=replay_buffer,
process_functions=process_functions,
managed_networks=managed_networks
)
### 4. start training
# hyper-parameters
batch_size = 32
replay_buffer_warmup = 1000
epsilon_decay_interval = 500
epsilon = 0.6
test_interval = 5000
target_network_update_interval = 800
seed = 123
np.random.seed(seed)
tf.set_random_seed(seed)
config = tf.ConfigProto()
config.gpu_options.allow_growth = True
with tf.Session(config=config) as sess:
sess.run(tf.global_variables_initializer())
# assign actor to pi_old
pi.sync_weights()
start_time = time.time()
pi.set_epsilon_train(epsilon)
data_collector.collect(num_timesteps=replay_buffer_warmup)
for i in range(int(1e8)): # number of training steps
# anneal epsilon step-wise
if (i + 1) % epsilon_decay_interval == 0 and epsilon > 0.1:
epsilon -= 0.1
pi.set_epsilon_train(epsilon)
# collect data
data_collector.collect(num_timesteps=4)
# update network
feed_dict = data_collector.next_batch(batch_size)
sess.run(train_op, feed_dict=feed_dict)
# test every 1000 training steps
# tester could share some code with batch!
if i % test_interval == 0:
print('Step {}, elapsed time: {:.1f} min'.format(i, (time.time() - start_time) / 60))
# epsilon 0.05 as in nature paper
pi.set_epsilon_test(0.05)
test_policy_in_env(pi, env, num_timesteps=1000)
if i % target_network_update_interval == 0:
pi.sync_weights()