Files
pytorch-a2c-ppo-acktr/main.py
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2017-09-16 20:57:06 -04:00

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Python
Executable File

import argparse
import glob
import os
import gym
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
import torch.optim as optim
from torch.autograd import Variable
from baselines.common.vec_env.subproc_vec_env import SubprocVecEnv
from envs import make_env
from model import ActorCritic
from vizualize_atari import visdom_plot
parser = argparse.ArgumentParser(description='A2C')
parser.add_argument('--lr', type=float, default=7e-4,
help='learning rate (default: 7e-4)')
parser.add_argument('--eps', type=float, default=1e-5,
help='RMSprop optimizer epsilon (default: 1e-5)')
parser.add_argument('--alpha', type=float, default=0.99,
help='RMSprop optimizer apha (default: 0.99)')
parser.add_argument('--gamma', type=float, default=0.99,
help='discount factor for rewards (default: 0.99)')
parser.add_argument('--use-gae', action='store_true', default=False,
help='use generalized advantage estimation')
parser.add_argument('--tau', type=float, default=0.95,
help='gae parameter (default: 0.95)')
parser.add_argument('--entropy-coef', type=float, default=0.01,
help='entropy term coefficient (default: 0.01)')
parser.add_argument('--value-loss-coef', type=float, default=0.5,
help='value loss coefficient (default: 0.5)')
parser.add_argument('--max-grad-norm', type=float, default=0.5,
help='value loss coefficient (default: 0.5)')
parser.add_argument('--seed', type=int, default=1,
help='random seed (default: 1)')
parser.add_argument('--num-processes', type=int, default=16,
help='how many training CPU processes to use (default: 16)')
parser.add_argument('--num-steps', type=int, default=5,
help='number of forward steps in A2C (default: 5)')
parser.add_argument('--num-stack', type=int, default=4,
help='number of frames to stack (default: 4)')
parser.add_argument('--log-interval', type=int, default=10,
help='log interval, one log per n updates (default: 10)')
parser.add_argument('--vis-interval', type=int, default=100,
help='vis interval, one log per n updates (default: 100)')
parser.add_argument('--num-frames', type=int, default=10e6,
help='number of frames to train (default: 10e6)')
parser.add_argument('--env-name', default='PongNoFrameskip-v4',
help='environment to train on (default: PongNoFrameskip-v4)')
parser.add_argument('--log-dir', default='/tmp/gym/',
help='directory to save agent logs (default: /tmp/gym)')
parser.add_argument('--no-cuda', action='store_true', default=False,
help='disables CUDA training')
parser.add_argument('--no-vis', action='store_true', default=False,
help='disables visdom visualization')
args = parser.parse_args()
args.cuda = not args.no_cuda and torch.cuda.is_available()
args.vis = not args.no_vis
num_updates = int(args.num_frames) // args.num_steps // args.num_processes
torch.manual_seed(args.seed)
if args.cuda:
torch.cuda.manual_seed(args.seed)
try:
os.makedirs(args.log_dir)
except OSError:
files = glob.glob(os.path.join(args.log_dir, '*.monitor.json'))
for f in files:
os.remove(f)
def main():
print("#######")
print("WARNING: All rewards are clipped so you need to use a monitor (see envs.py) or visdom plot to get true rewards")
print("#######")
os.environ['OMP_NUM_THREADS'] = '1'
if args.vis:
from visdom import Visdom
viz = Visdom()
win = None
envs = SubprocVecEnv([
make_env(args.env_name, args.seed, i, args.log_dir)
for i in range(args.num_processes)
])
actor_critic = ActorCritic(envs.observation_space.shape[0] * args.num_stack, envs.action_space)
if args.cuda:
actor_critic.cuda()
optimizer = optim.RMSprop(actor_critic.parameters(), args.lr, eps=args.eps, alpha=args.alpha)
obs_shape = envs.observation_space.shape
obs_shape = (obs_shape[0] * args.num_stack, obs_shape[1], obs_shape[2])
states = torch.zeros(args.num_steps + 1, args.num_processes, *obs_shape)
current_state = torch.zeros(args.num_processes, *obs_shape)
counts = 0
def update_current_state(state):
state = torch.from_numpy(np.stack(state)).float()
current_state[:, :-1] = current_state[:, 1:]
current_state[:, -1] = state
state = envs.reset()
update_current_state(state)
rewards = torch.zeros(args.num_steps, args.num_processes, 1)
value_preds = torch.zeros(args.num_steps + 1, args.num_processes, 1)
returns = torch.zeros(args.num_steps + 1, args.num_processes, 1)
actions = torch.LongTensor(args.num_steps, args.num_processes)
masks = torch.zeros(args.num_steps, args.num_processes, 1)
# These variables are used to compute average rewards for all processes.
episode_rewards = torch.zeros([args.num_processes, 1])
final_rewards = torch.zeros([args.num_processes, 1])
if args.cuda:
states = states.cuda()
current_state = current_state.cuda()
rewards = rewards.cuda()
value_preds = value_preds.cuda()
returns = returns.cuda()
actions = actions.cuda()
masks = masks.cuda()
for j in range(num_updates):
for step in range(args.num_steps):
# Sample actions
value, logits = actor_critic(Variable(states[step], volatile=True))
probs = F.softmax(logits)
log_probs = F.log_softmax(logits).data
actions[step] = probs.multinomial().data
cpu_actions = actions[step].cpu()
cpu_actions = cpu_actions.numpy()
# Obser reward and next state
state, reward, done, info = envs.step(cpu_actions)
reward = torch.from_numpy(np.expand_dims(np.stack(reward), 1)).float()
episode_rewards += reward
np_masks = np.array([0.0 if done_ else 1.0 for done_ in done])
# If done then clean the history of observations.
pt_masks = torch.from_numpy(np_masks.reshape(np_masks.shape[0], 1, 1, 1)).float()
if args.cuda:
pt_masks = pt_masks.cuda()
current_state *= pt_masks
update_current_state(state)
states[step + 1].copy_(current_state)
value_preds[step].copy_(value.data)
rewards[step].copy_(reward)
masks[step].copy_(torch.from_numpy(np_masks).unsqueeze(1))
final_rewards *= masks[step].cpu()
final_rewards += (1 - masks[step].cpu()) * episode_rewards
episode_rewards *= masks[step].cpu()
if args.use_gae:
value_preds[-1] = actor_critic(Variable(states[-1], volatile=True))[0].data
gae = 0
for step in reversed(range(args.num_steps)):
delta = rewards[step] + args.gamma * value_preds[step + 1] * masks[step] - value_preds[step]
gae = delta + args.gamma * args.tau * masks[step] * gae
returns[step] = gae + value_preds[step]
else:
returns[-1] = actor_critic(Variable(states[-1], volatile=True))[0].data
for step in reversed(range(args.num_steps)):
returns[step] = returns[step + 1] * \
args.gamma * masks[step] + rewards[step]
# Reshape to do in a single forward pass for all steps
values, logits = actor_critic(Variable(states[:-1].view(-1, *states.size()[-3:])))
log_probs = F.log_softmax(logits)
probs = F.softmax(logits)
# Unreshape
logits_size = (args.num_steps, args.num_processes, logits.size(-1))
log_probs = F.log_softmax(logits).view(logits_size)
probs = F.softmax(logits).view(logits_size)
values = values.view(args.num_steps, args.num_processes, 1)
logits = logits.view(logits_size)
action_log_probs = log_probs.gather(2, Variable(actions.unsqueeze(2)))
dist_entropy = -(log_probs * probs).sum(-1).mean()
advantages = Variable(returns[:-1]) - values
value_loss = advantages.pow(2).mean()
action_loss = -(Variable(advantages.data) * action_log_probs).mean()
optimizer.zero_grad()
(value_loss * args.value_loss_coef + action_loss - dist_entropy * args.entropy_coef).backward()
nn.utils.clip_grad_norm(actor_critic.parameters(), args.max_grad_norm)
optimizer.step()
states[0].copy_(states[-1])
if j % args.log_interval == 0:
print("Updates {}, num frames {}, mean/median reward {:.1f}/{:.1f}, min/max reward {:.1f}/{:.1f}, entropy {:.5f}, value loss {:.5f}, policy loss {:.5f}".
format(j, j * args.num_processes * args.num_steps,
final_rewards.mean(),
final_rewards.median(),
final_rewards.min(),
final_rewards.max(), -dist_entropy.data[0],
value_loss.data[0], action_loss.data[0]))
if j % args.vis_interval == 0:
win = visdom_plot(viz, win, args.log_dir, args.env_name, 'a2c')
if __name__ == "__main__":
main()