PPO playing LunarLander-v2 from https://github.com/sgoodfriend/rl-algo-impls/tree/0511de345b17175b7cf1ea706c3e05981f11761c
8310b64
import gym | |
import numpy as np | |
from gym import ObservationWrapper | |
from gym.spaces import Box | |
class HwcToChwObservation(ObservationWrapper): | |
def __init__(self, env: gym.Env) -> None: | |
super().__init__(env) | |
assert isinstance(env.observation_space, Box) | |
obs_space = env.observation_space | |
axes = tuple(i for i in range(len(obs_space.shape))) | |
self._transpose_axes = axes[:-3] + (axes[-1],) + axes[-3:-1] | |
self.observation_space = Box( | |
low=np.transpose(obs_space.low, axes=self._transpose_axes), | |
high=np.transpose(obs_space.high, axes=self._transpose_axes), | |
shape=[obs_space.shape[idx] for idx in self._transpose_axes], | |
dtype=obs_space.dtype, | |
) | |
def observation(self, obs: np.ndarray) -> np.ndarray: | |
full_shape = obs.shape | |
obs_shape = self.observation_space.shape | |
addl_dims = len(full_shape) - len(obs_shape) | |
if addl_dims > 0: | |
transpose_axes = list(range(addl_dims)) | |
transpose_axes.extend(a + addl_dims for a in self._transpose_axes) | |
else: | |
transpose_axes = self._transpose_axes | |
return np.transpose(obs, axes=transpose_axes) | |