Tianshou/examples/atari/atari_wrapper.py
yingchengyang 5b49192a48
DQN Atari examples (#187)
This PR aims to provide the script of Atari DQN setting:
- A speedrun of PongNoFrameskip-v4 (finished, about half an hour in i7-8750 + GTX1060 with 1M environment steps)
- A general script for all atari game
Since we use multiple env for simulation, the result is slightly different from the original paper, but consider to be acceptable.

It also adds another parameter save_only_last_obs for replay buffer in order to save the memory.

Co-authored-by: Trinkle23897 <463003665@qq.com>
2020-08-30 05:48:09 +08:00

238 lines
7.6 KiB
Python

# Borrow a lot from openai baselines:
# https://github.com/openai/baselines/blob/master/baselines/common/atari_wrappers.py
import cv2
import gym
import numpy as np
from collections import deque
class NoopResetEnv(gym.Wrapper):
"""Sample initial states by taking random number of no-ops on reset.
No-op is assumed to be action 0.
:param gym.Env env: the environment to wrap.
:param int noop_max: the maximum value of no-ops to run.
"""
def __init__(self, env, noop_max=30):
super().__init__(env)
self.noop_max = noop_max
self.noop_action = 0
assert env.unwrapped.get_action_meanings()[0] == 'NOOP'
def reset(self):
self.env.reset()
noops = np.random.randint(1, self.noop_max + 1)
for _ in range(noops):
obs, _, done, _ = self.env.step(self.noop_action)
if done:
obs = self.env.reset()
return obs
class MaxAndSkipEnv(gym.Wrapper):
"""Return only every `skip`-th frame (frameskipping) using most recent raw
observations (for max pooling across time steps)
:param gym.Env env: the environment to wrap.
:param int skip: number of `skip`-th frame.
"""
def __init__(self, env, skip=4):
super().__init__(env)
self._skip = skip
def step(self, action):
"""Step the environment with the given action. Repeat action, sum
reward, and max over last observations.
"""
obs_list, total_reward, done = [], 0., False
for i in range(self._skip):
obs, reward, done, info = self.env.step(action)
obs_list.append(obs)
total_reward += reward
if done:
break
max_frame = np.max(obs_list[-2:], axis=0)
return max_frame, total_reward, done, info
class EpisodicLifeEnv(gym.Wrapper):
"""Make end-of-life == end-of-episode, but only reset on true game over. It
helps the value estimation.
:param gym.Env env: the environment to wrap.
"""
def __init__(self, env):
super().__init__(env)
self.lives = 0
self.was_real_done = True
def step(self, action):
obs, reward, done, info = self.env.step(action)
self.was_real_done = done
# check current lives, make loss of life terminal, then update lives to
# handle bonus lives
lives = self.env.unwrapped.ale.lives()
if 0 < lives < self.lives:
# for Qbert sometimes we stay in lives == 0 condition for a few
# frames, so its important to keep lives > 0, so that we only reset
# once the environment is actually done.
done = True
self.lives = lives
return obs, reward, done, info
def reset(self):
"""Calls the Gym environment reset, only when lives are exhausted. This
way all states are still reachable even though lives are episodic, and
the learner need not know about any of this behind-the-scenes.
"""
if self.was_real_done:
obs = self.env.reset()
else:
# no-op step to advance from terminal/lost life state
obs = self.env.step(0)[0]
self.lives = self.env.unwrapped.ale.lives()
return obs
class FireResetEnv(gym.Wrapper):
"""Take action on reset for environments that are fixed until firing.
Related discussion: https://github.com/openai/baselines/issues/240
:param gym.Env env: the environment to wrap.
"""
def __init__(self, env):
super().__init__(env)
assert env.unwrapped.get_action_meanings()[1] == 'FIRE'
assert len(env.unwrapped.get_action_meanings()) >= 3
def reset(self):
self.env.reset()
return self.env.step(1)[0]
class WarpFrame(gym.ObservationWrapper):
"""Warp frames to 84x84 as done in the Nature paper and later work.
:param gym.Env env: the environment to wrap.
"""
def __init__(self, env):
super().__init__(env)
self.size = 84
self.observation_space = gym.spaces.Box(
low=np.min(env.observation_space.low),
high=np.max(env.observation_space.high),
shape=(self.size, self.size), dtype=env.observation_space.dtype)
def observation(self, frame):
"""returns the current observation from a frame"""
frame = cv2.cvtColor(frame, cv2.COLOR_RGB2GRAY)
return cv2.resize(frame, (self.size, self.size),
interpolation=cv2.INTER_AREA)
class ScaledFloatFrame(gym.ObservationWrapper):
"""Normalize observations to 0~1.
:param gym.Env env: the environment to wrap.
"""
def __init__(self, env):
super().__init__(env)
low = np.min(env.observation_space.low)
high = np.max(env.observation_space.high)
self.bias = low
self.scale = high - low
self.observation_space = gym.spaces.Box(
low=0., high=1., shape=env.observation_space.shape,
dtype=np.float32)
def observation(self, observation):
return (observation - self.bias) / self.scale
class ClipRewardEnv(gym.RewardWrapper):
"""clips the reward to {+1, 0, -1} by its sign.
:param gym.Env env: the environment to wrap.
"""
def __init__(self, env):
super().__init__(env)
self.reward_range = (-1, 1)
def reward(self, reward):
"""Bin reward to {+1, 0, -1} by its sign. Note: np.sign(0) == 0."""
return np.sign(reward)
class FrameStack(gym.Wrapper):
"""Stack n_frames last frames.
:param gym.Env env: the environment to wrap.
:param int n_frames: the number of frames to stack.
"""
def __init__(self, env, n_frames):
super().__init__(env)
self.n_frames = n_frames
self.frames = deque([], maxlen=n_frames)
shape = (n_frames,) + env.observation_space.shape
self.observation_space = gym.spaces.Box(
low=np.min(env.observation_space.low),
high=np.max(env.observation_space.high),
shape=shape, dtype=env.observation_space.dtype)
def reset(self):
obs = self.env.reset()
for _ in range(self.n_frames):
self.frames.append(obs)
return self._get_ob()
def step(self, action):
obs, reward, done, info = self.env.step(action)
self.frames.append(obs)
return self._get_ob(), reward, done, info
def _get_ob(self):
# the original wrapper use `LazyFrames` but since we use np buffer,
# it has no effect
return np.stack(self.frames, axis=0)
def wrap_deepmind(env_id, episode_life=True, clip_rewards=True,
frame_stack=4, scale=False, warp_frame=True):
"""Configure environment for DeepMind-style Atari. The observation is
channel-first: (c, h, w) instead of (h, w, c).
:param str env_id: the atari environment id.
:param bool episode_life: wrap the episode life wrapper.
:param bool clip_rewards: wrap the reward clipping wrapper.
:param int frame_stack: wrap the frame stacking wrapper.
:param bool scale: wrap the scaling observation wrapper.
:param bool warp_frame: wrap the grayscale + resize observation wrapper.
:return: the wrapped atari environment.
"""
assert 'NoFrameskip' in env_id
env = gym.make(env_id)
env = NoopResetEnv(env, noop_max=30)
env = MaxAndSkipEnv(env, skip=4)
if episode_life:
env = EpisodicLifeEnv(env)
if 'FIRE' in env.unwrapped.get_action_meanings():
env = FireResetEnv(env)
if warp_frame:
env = WarpFrame(env)
if scale:
env = ScaledFloatFrame(env)
if clip_rewards:
env = ClipRewardEnv(env)
if frame_stack:
env = FrameStack(env, frame_stack)
return env