Files
baselines/baselines/common/vec_env/dummy_vec_env.py
2018-11-05 19:19:39 -08:00

82 lines
2.8 KiB
Python

import numpy as np
from gym import spaces
from . import VecEnv
from .util import copy_obs_dict, dict_to_obs, obs_space_info
class DummyVecEnv(VecEnv):
"""
VecEnv that does runs multiple environments sequentially, that is,
the step and reset commands are send to one environment at a time.
Useful when debugging and when num_env == 1 (in the latter case,
avoids communication overhead)
"""
def __init__(self, env_fns):
"""
Arguments:
env_fns: iterable of callables functions that build environments
"""
self.envs = [fn() for fn in env_fns]
env = self.envs[0]
VecEnv.__init__(self, len(env_fns), env.observation_space, env.action_space)
obs_space = env.observation_space
self.keys, shapes, dtypes = obs_space_info(obs_space)
self.buf_obs = { k: np.zeros((self.num_envs,) + tuple(shapes[k]), dtype=dtypes[k]) for k in self.keys }
self.buf_dones = np.zeros((self.num_envs,), dtype=np.bool)
self.buf_rews = np.zeros((self.num_envs,), dtype=np.float32)
self.buf_infos = [{} for _ in range(self.num_envs)]
self.actions = None
def step_async(self, actions):
listify = True
try:
if len(actions) == self.num_envs:
listify = False
except TypeError:
pass
if not listify:
self.actions = actions
else:
assert self.num_envs == 1, "actions {} is either not a list or has a wrong size - cannot match to {} environments".format(actions, self.num_envs)
self.actions = [actions]
def step_wait(self):
for e in range(self.num_envs):
action = self.actions[e]
if isinstance(self.envs[e].action_space, spaces.Discrete):
action = int(action)
obs, self.buf_rews[e], self.buf_dones[e], self.buf_infos[e] = self.envs[e].step(action)
if self.buf_dones[e]:
obs = self.envs[e].reset()
self._save_obs(e, obs)
return (self._obs_from_buf(), np.copy(self.buf_rews), np.copy(self.buf_dones),
self.buf_infos.copy())
def reset(self):
for e in range(self.num_envs):
obs = self.envs[e].reset()
self._save_obs(e, obs)
return self._obs_from_buf()
def _save_obs(self, e, obs):
for k in self.keys:
if k is None:
self.buf_obs[k][e] = obs
else:
self.buf_obs[k][e] = obs[k]
def _obs_from_buf(self):
return dict_to_obs(copy_obs_dict(self.buf_obs))
def get_images(self):
return [env.render(mode='rgb_array') for env in self.envs]
def render(self, mode='human'):
if self.num_envs == 1:
return self.envs[0].render(mode=mode)
else:
return super().render(mode=mode)