SignTransform

class torchrl.envs.transforms.SignTransform(in_keys=None, out_keys=None, in_keys_inv=None, out_keys_inv=None)

A transform to compute the signs of TensorDict values.

This transform reads the tensors in in_keys and in_keys_inv, computes the signs of their elements and writes the resulting sign tensors to out_keys and out_keys_inv respectively.

Parameters:

• in_keys (list of NestedKeys) – input entries (read)

• out_keys (list of NestedKeys) – input entries (write)

• in_keys_inv (list of NestedKeys) – input entries (read) during inv() calls.

• out_keys_inv (list of NestedKeys) – input entries (write) during inv() calls.

Examples

>>> from torchrl.envs import GymEnv, TransformedEnv, SignTransform
>>> base_env = GymEnv("Pendulum-v1")
>>> env = TransformedEnv(base_env, SignTransform(in_keys=['observation']))
>>> r = env.rollout(100)
>>> obs = r["observation"]
>>> assert (torch.logical_or(torch.logical_or(obs == -1, obs == 1), obs == 0.0)).all()

transform_observation_spec(observation_spec: TensorSpec) → TensorSpec

Transforms the observation spec such that the resulting spec matches transform mapping.

Parameters:

observation_spec (TensorSpec) – spec before the transform

Returns:

expected spec after the transform

transform_reward_spec(reward_spec: TensorSpec) → TensorSpec

Transforms the reward spec such that the resulting spec matches transform mapping.

Parameters:

reward_spec (TensorSpec) – spec before the transform

Returns:

expected spec after the transform