Function _check_box_obs

stable_baselines3/common/env_checker.py:311–328

Check that the observation space is correctly formatted when dealing with a ``Box()`` space. In particular, it checks: - that the dimensions are big enough when it is an image, and that the type matches - that the observation has an expected shape (warn the user if not)

(observation_space: spaces.Box, key: str = "")

def _check_box_obs(observation_space: spaces.Box, key: str = "") -> None:
    """
    Check that the observation space is correctly formatted
    when dealing with a ``Box()`` space. In particular, it checks:
    - that the dimensions are big enough when it is an image, and that the type matches
    - that the observation has an expected shape (warn the user if not)
    """
    # If image, check the low and high values, the type and the number of channels
    # and the shape (minimal value)
    if len(observation_space.shape) == 3:
        _check_image_input(observation_space, key)

    if len(observation_space.shape) not in [1, 3]:
        warnings.warn(
            f"Your observation {key} has an unconventional shape (neither an image, nor a 1D vector). "
            "We recommend you to flatten the observation "
            "to have only a 1D vector or use a custom policy to properly process the data."
        )


def _check_returned_values(env: gym.Env, observation_space: spaces.Space, action_space: spaces.Space) -> None: