# Copyright (c) 2020, Fabio Muratore, Honda Research Institute Europe GmbH, and
# Technical University of Darmstadt.
# All rights reserved.
#
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# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
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# documentation and/or other materials provided with the distribution.
# 3. Neither the name of Fabio Muratore, Honda Research Institute Europe GmbH,
# or Technical University of Darmstadt, nor the names of its contributors may
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from typing import Union
import numpy as np
from init_args_serializer import Serializable
import pyrado
from pyrado.environment_wrappers.base import EnvWrapperAct
from pyrado.environments.base import Env
[docs]class GaussianActNoiseWrapper(EnvWrapperAct, Serializable):
"""
Environment wrapper which adds normally distributed i.i.d. noise to all action.
This noise is independent for the potentially applied action-based exploration strategy.
"""
def __init__(
self, wrapped_env: Env, noise_mean: Union[float, np.ndarray] = None, noise_std: Union[float, np.ndarray] = None
):
"""
Constructor
:param wrapped_env: environment to wrap around (only makes sense for simulations)
:param noise_mean: mean of the noise distribution
:param noise_std: standard deviation of the noise distribution
"""
Serializable._init(self, locals())
# Invoke base constructor
super().__init__(wrapped_env)
# Parse noise specification
if noise_mean is not None:
self._mean = np.array(noise_mean)
if not self._mean.shape == self.act_space.shape:
raise pyrado.ShapeErr(given=self._mean, expected_match=self.act_space)
else:
self._mean = np.zeros(self.act_space.shape)
if noise_std is not None:
self._std = np.array(noise_std)
if not self._std.shape == self.act_space.shape:
raise pyrado.ShapeErr(given=self._noise_std, expected_match=self.act_space)
else:
self._std = np.zeros(self.act_space.shape)
def _process_act(self, act: np.ndarray) -> np.ndarray:
# Generate gaussian noise values
noise = np.random.randn(*self.act_space.shape) * self._std + self._mean # * to unsqueeze the tuple
# Add it to the action
return act + noise
def _set_wrapper_domain_param(self, domain_param: dict):
"""
Store the action noise parameters in the domain parameter dict
:param domain_param: domain parameter dict
"""
domain_param["act_noise_mean"] = self._mean
domain_param["act_noise_std"] = self._std
def _get_wrapper_domain_param(self, domain_param: dict):
"""
Load the action noise parameters from the domain parameter dict
:param domain_param: domain parameter dict
"""
if "act_noise_mean" in domain_param:
self._noise_mean = np.array(domain_param["act_noise_mean"])
if not self._noise_mean.shape == self.act_space.shape:
raise pyrado.ShapeErr(given=self._noise_mean, expected_match=self.act_space)
if "act_noise_std" in domain_param:
self._noise_std = np.array(domain_param["act_noise_std"])
if not self._noise_std.shape == self.act_space.shape:
raise pyrado.ShapeErr(given=self._noise_std, expected_match=self.act_space)