ray/rllib/examples/env/mbmpo_env.py
Balaji Veeramani 7f1bacc7dc
[CI] Format Python code with Black (#21975)
See #21316 and #21311 for the motivation behind these changes.
2022-01-29 18:41:57 -08:00

104 lines
3.3 KiB
Python

from gym.envs.classic_control import PendulumEnv, CartPoleEnv
import numpy as np
# MuJoCo may not be installed.
HalfCheetahEnv = HopperEnv = None
try:
from gym.envs.mujoco import HalfCheetahEnv, HopperEnv
except Exception:
pass
class CartPoleWrapper(CartPoleEnv):
"""Wrapper for the Cartpole-v0 environment.
Adds an additional `reward` method for some model-based RL algos (e.g.
MB-MPO).
"""
def reward(self, obs, action, obs_next):
# obs = batch * [pos, vel, angle, rotation_rate]
x = obs_next[:, 0]
theta = obs_next[:, 2]
# 1.0 if we are still on, 0.0 if we are terminated due to bounds
# (angular or x-axis) being breached.
rew = 1.0 - (
(x < -self.x_threshold)
| (x > self.x_threshold)
| (theta < -self.theta_threshold_radians)
| (theta > self.theta_threshold_radians)
).astype(np.float32)
return rew
class PendulumWrapper(PendulumEnv):
"""Wrapper for the Pendulum-v1 environment.
Adds an additional `reward` method for some model-based RL algos (e.g.
MB-MPO).
"""
def reward(self, obs, action, obs_next):
# obs = [cos(theta), sin(theta), dtheta/dt]
# To get the angle back from obs: atan2(sin(theta), cos(theta)).
theta = np.arctan2(np.clip(obs[:, 1], -1.0, 1.0), np.clip(obs[:, 0], -1.0, 1.0))
# Do everything in (B,) space (single theta-, action- and
# reward values).
a = np.clip(action, -self.max_torque, self.max_torque)[0]
costs = (
self.angle_normalize(theta) ** 2 + 0.1 * obs[:, 2] ** 2 + 0.001 * (a ** 2)
)
return -costs
@staticmethod
def angle_normalize(x):
return ((x + np.pi) % (2 * np.pi)) - np.pi
class HalfCheetahWrapper(HalfCheetahEnv or object):
"""Wrapper for the MuJoCo HalfCheetah-v2 environment.
Adds an additional `reward` method for some model-based RL algos (e.g.
MB-MPO).
"""
def reward(self, obs, action, obs_next):
if obs.ndim == 2 and action.ndim == 2:
assert obs.shape == obs_next.shape
forward_vel = obs_next[:, 8]
ctrl_cost = 0.1 * np.sum(np.square(action), axis=1)
reward = forward_vel - ctrl_cost
return np.minimum(np.maximum(-1000.0, reward), 1000.0)
else:
forward_vel = obs_next[8]
ctrl_cost = 0.1 * np.square(action).sum()
reward = forward_vel - ctrl_cost
return np.minimum(np.maximum(-1000.0, reward), 1000.0)
class HopperWrapper(HopperEnv or object):
"""Wrapper for the MuJoCo Hopper-v2 environment.
Adds an additional `reward` method for some model-based RL algos (e.g.
MB-MPO).
"""
def reward(self, obs, action, obs_next):
alive_bonus = 1.0
assert obs.ndim == 2 and action.ndim == 2
assert obs.shape == obs_next.shape and action.shape[0] == obs.shape[0]
vel = obs_next[:, 5]
ctrl_cost = 1e-3 * np.sum(np.square(action), axis=1)
reward = vel + alive_bonus - ctrl_cost
return np.minimum(np.maximum(-1000.0, reward), 1000.0)
if __name__ == "__main__":
env = PendulumWrapper()
env.reset()
for _ in range(100):
env.step(env.action_space.sample())
env.render()