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coach/exploration_policies/e_greedy.py
Gal Leibovich 1d4c3455e7 coach v0.8.0
2017-10-19 13:10:15 +03:00

71 lines
3.1 KiB
Python

#
# Copyright (c) 2017 Intel Corporation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
from exploration_policies.exploration_policy import *
class EGreedy(ExplorationPolicy):
def __init__(self, tuning_parameters):
"""
:param tuning_parameters: A Preset class instance with all the running paramaters
:type tuning_parameters: Preset
"""
ExplorationPolicy.__init__(self, tuning_parameters)
self.epsilon = tuning_parameters.exploration.initial_epsilon
self.final_epsilon = tuning_parameters.exploration.final_epsilon
self.epsilon_decay_delta = (
tuning_parameters.exploration.initial_epsilon - tuning_parameters.exploration.final_epsilon) \
/ float(tuning_parameters.exploration.epsilon_decay_steps)
self.evaluation_epsilon = tuning_parameters.exploration.evaluation_epsilon
# for continuous e-greedy (see http://www.cs.ubc.ca/~van/papers/2017-TOG-deepLoco/2017-TOG-deepLoco.pdf)
self.variance = tuning_parameters.exploration.initial_noise_variance_percentage
self.final_variance = tuning_parameters.exploration.final_noise_variance_percentage
self.decay_steps = tuning_parameters.exploration.noise_variance_decay_steps
self.variance_decay_delta = (self.variance - self.final_variance) / float(self.decay_steps)
def decay_exploration(self):
# decay epsilon
if self.epsilon > self.final_epsilon:
self.epsilon -= self.epsilon_decay_delta
elif self.epsilon < self.final_epsilon:
self.epsilon = self.final_epsilon
# decay noise variance
if not self.discrete_controls:
if self.variance > self.final_variance:
self.variance -= self.variance_decay_delta
elif self.variance < self.final_variance:
self.variance = self.final_variance
def get_action(self, action_values):
if self.phase == RunPhase.TRAIN:
self.decay_exploration()
epsilon = self.evaluation_epsilon if self.phase == RunPhase.TEST else self.epsilon
if self.discrete_controls:
top_action = np.argmax(action_values)
if np.random.rand() < epsilon:
return np.random.randint(self.action_space_size)
else:
return top_action
else:
noise = np.random.randn(1, self.action_space_size) * self.variance * self.action_abs_range
return np.squeeze(action_values + (np.random.rand() < epsilon) * noise)
def get_control_param(self):
return self.epsilon