ray/rllib/examples/env/transformed_action_space_env.py

73 lines
2.6 KiB
Python

import gym
from ray.rllib.utils.annotations import override
class ActionTransform(gym.ActionWrapper):
def __init__(self, env, low, high):
super().__init__(env)
self._low = low
self._high = high
self.action_space = type(env.action_space)(self._low, self._high,
env.action_space.shape,
env.action_space.dtype)
def action(self, action):
return (action - self._low) / (self._high - self._low) * (
self.env.action_space.high -
self.env.action_space.low) + self.env.action_space.low
def transform_action_space(env_name_or_creator):
"""Wrapper for gym.Envs to have their action space transformed.
Args:
env_name_or_creator (Union[str, Callable[]]: String specifier or
env_maker function.
Returns:
Type[TransformedActionSpaceEnv]: New TransformedActionSpaceEnv class
to be used as env. The constructor takes a config dict with `_low`
and `_high` keys specifying the new action range
(default -1.0 to 1.0). The reset of the config dict will be
passed on to the underlying env's constructor.
Examples:
>>> # By gym string:
>>> pendulum_300_to_500_cls = transform_action_space("Pendulum-v0")
>>> # Create a transformed pendulum env.
>>> pendulum_300_to_500 = pendulum_300_to_500_cls({"_low": -15.0})
>>> pendulum_300_to_500.action_space
... gym.spaces.Box(-15.0, 1.0, (1, ), "float32")
"""
class TransformedActionSpaceEnv(gym.Env):
"""PendulumEnv w/ an action space of range 300.0 to 500.0."""
def __init__(self, config):
self._low = config.pop("low", -1.0)
self._high = config.pop("high", 1.0)
if isinstance(env_name_or_creator, str):
self.env = gym.make(env_name_or_creator)
else:
self.env = env_name_or_creator(config)
self.env = ActionTransform(self.env, self._low, self._high)
self.observation_space = self.env.observation_space
self.action_space = self.env.action_space
@override(gym.Env)
def reset(self):
return self.env.reset()
@override(gym.Env)
def step(self, actions):
return self.env.step(actions)
@override(gym.Env)
def render(self, mode=None):
return self.env.render(mode)
return TransformedActionSpaceEnv
TransformedActionPendulum = transform_action_space("Pendulum-v0")