Files
Gymnasium/gym/vector/sync_vector_env.py
Tristan Deleu c6a97e17ee Vectorized environments (#1513)
* Initial version of vectorized environments

* Raise an exception in the main process if child process raises an exception

* Add list of exposed functions in vector module

* Use deepcopy instead of np.copy

* Add documentation for vector utils

* Add tests for copy in AsyncVectorEnv

* Add example in documentation for batch_space

* Add cloudpickle dependency in setup.py

* Fix __del__ in VectorEnv

* Check if all observation spaces are equal in AsyncVectorEnv

* Check if all observation spaces are equal in SyncVectorEnv

* Fix spaces non equality in SyncVectorEnv for Python 2

* Handle None parameter in create_empty_array

* Fix check_observation_space with spaces equality

* Raise an exception when operations are out of order in AsyncVectorEnv

* Add version requirement for cloudpickle

* Use a state instead of binary flags in AsyncVectorEnv

* Use numpy.zeros when initializing observations in vectorized environments

* Remove poll from public API in AsyncVectorEnv

* Remove close_extras from VectorEnv

* Add test between AsyncVectorEnv and SyncVectorEnv

* Remove close in check_observation_space

* Add documentation for seed and close

* Refactor exceptions for AsyncVectorEnv

* Close pipes if the environment raises an error

* Add tests for out of order operations

* Change default argument in create_empty_array to np.zeros

* Add get_attr and set_attr methods to VectorEnv

* Improve consistency in SyncVectorEnv
2019-06-21 14:29:44 -07:00

138 lines
5.0 KiB
Python

import numpy as np
from gym import logger
from gym.vector.vector_env import VectorEnv
from gym.vector.utils import concatenate, create_empty_array
__all__ = ['SyncVectorEnv']
class SyncVectorEnv(VectorEnv):
"""Vectorized environment that serially runs multiple environments.
Parameters
----------
env_fns : iterable of callable
Functions that create the environments.
observation_space : `gym.spaces.Space` instance, optional
Observation space of a single environment. If `None`, then the
observation space of the first environment is taken.
action_space : `gym.spaces.Space` instance, optional
Action space of a single environment. If `None`, then the action space
of the first environment is taken.
copy : bool (default: `True`)
If `True`, then the `reset` and `step` methods return a copy of the
observations.
"""
def __init__(self, env_fns, observation_space=None, action_space=None,
copy=True):
self.env_fns = env_fns
self.envs = [env_fn() for env_fn in env_fns]
self.copy = copy
if (observation_space is None) or (action_space is None):
observation_space = observation_space or self.envs[0].observation_space
action_space = action_space or self.envs[0].action_space
super(SyncVectorEnv, self).__init__(num_envs=len(env_fns),
observation_space=observation_space, action_space=action_space)
self._check_observation_spaces()
self.observations = create_empty_array(self.single_observation_space,
n=self.num_envs, fn=np.zeros)
self._rewards = np.zeros((self.num_envs,), dtype=np.float64)
self._dones = np.zeros((self.num_envs,), dtype=np.bool_)
def seed(self, seeds=None):
"""
Parameters
----------
seeds : list of int, or int, optional
Random seed for each individual environment. If `seeds` is a list of
length `num_envs`, then the items of the list are chosen as random
seeds. If `seeds` is an int, then each environment uses the random
seed `seeds + n`, where `n` is the index of the environment (between
`0` and `num_envs - 1`).
"""
if seeds is None:
seeds = [None for _ in range(self.num_envs)]
if isinstance(seeds, int):
seeds = [seeds + i for i in range(self.num_envs)]
assert len(seeds) == self.num_envs
for env, seed in zip(self.envs, seeds):
env.seed(seed)
def reset(self):
"""
Returns
-------
observations : sample from `observation_space`
A batch of observations from the vectorized environment.
"""
self._dones[:] = False
observations = []
for env in self.envs:
observation = env.reset()
observations.append(observation)
concatenate(observations, self.observations, self.single_observation_space)
return np.copy(self.observations) if self.copy else self.observations
def step(self, actions):
"""
Parameters
----------
actions : iterable of samples from `action_space`
List of actions.
Returns
-------
observations : sample from `observation_space`
A batch of observations from the vectorized environment.
rewards : `np.ndarray` instance (dtype `np.float_`)
A vector of rewards from the vectorized environment.
dones : `np.ndarray` instance (dtype `np.bool_`)
A vector whose entries indicate whether the episode has ended.
infos : list of dict
A list of auxiliary diagnostic informations.
"""
observations, infos = [], []
for i, (env, action) in enumerate(zip(self.envs, actions)):
observation, self._rewards[i], self._dones[i], info = env.step(action)
if self._dones[i]:
observation = env.reset()
observations.append(observation)
infos.append(info)
concatenate(observations, self.observations, self.single_observation_space)
return (np.copy(self.observations) if self.copy else self.observations,
np.copy(self._rewards), np.copy(self._dones), infos)
def close(self):
if self.closed:
return
if self.viewer is not None:
self.viewer.close()
for env in self.envs:
env.close()
self.closed = True
def _check_observation_spaces(self):
for env in self.envs:
if not (env.observation_space == self.single_observation_space):
break
else:
return True
raise RuntimeError('Some environments have an observation space '
'different from `{0}`. In order to batch observations, the '
'observation spaces from all environments must be '
'equal.'.format(self.single_observation_space))