diff --git a/fancy_gym/utils/time_aware_observation.py b/fancy_gym/utils/time_aware_observation.py index 192138d..c6b16f1 100644 --- a/fancy_gym/utils/time_aware_observation.py +++ b/fancy_gym/utils/time_aware_observation.py @@ -1,20 +1,65 @@ +from gymnasium.spaces import Box import gymnasium as gym import numpy as np -class TimeAwareObservation(gym.wrappers.TimeAwareObservation): +class TimeAwareObservation(gym.ObservationWrapper, gym.utils.RecordConstructorArgs): + """Augment the observation with the current time step in the episode. - def __init__(self, env: gym.Env): - super().__init__(env) - self._max_episode_steps = env.spec.max_episode_steps + The observation space of the wrapped environment is assumed to be a flat :class:`Box`. + In particular, pixel observations are not supported. This wrapper will append the current timestep within the current episode to the observation. + The timestep will be indicated as a number between 0 and 1. + """ + + def __init__(self, env: gym.Env, enforce_dtype_float32=False): + """Initialize :class:`TimeAwareObservation` that requires an environment with a flat :class:`Box` observation space. + + Args: + env: The environment to apply the wrapper + """ + gym.utils.RecordConstructorArgs.__init__(self) + gym.ObservationWrapper.__init__(self, env) + assert isinstance(env.observation_space, Box) + if enforce_dtype_float32: + assert env.observation_space.dtype == np.float32, + 'TimeAwareObservation was given an environment with a dtype!=np.float32 ('+str(env.observation_space.dtype)+'). This requirement can be removed by setting enforce_dtype_float32=False.' + dtype = env.observation_space.dtype + low = np.append(self.observation_space.low, 0.0) + high = np.append(self.observation_space.high, np.inf) + self.observation_space = Box(low, high, dtype=dtype) + self.is_vector_env = getattr(env, "is_vector_env", False) def observation(self, observation): - """Adds to the observation with the current time step normalized with max steps. + """Adds to the observation with the current time step. Args: observation: The observation to add the time step to Returns: - The observation with the time step appended to + The observation with the time step appended to (relative to total number of steps) """ - return np.append(observation, self.t / self._max_episode_steps) + return np.append(observation, self.t / getattr(self.env, '_max_episode_steps') + + def step(self, action): + """Steps through the environment, incrementing the time step. + + Args: + action: The action to take + + Returns: + The environment's step using the action. + """ + self.t += 1 + return super().step(action) + + def reset(self, **kwargs): + """Reset the environment setting the time to zero. + + Args: + **kwargs: Kwargs to apply to env.reset() + + Returns: + The reset environment + """ + self.t=0 + return super().reset(**kwargs)