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coach/rl_coach/environments/toy_problems/bit_flip.py
2018-08-27 10:54:11 +03:00

100 lines
3.3 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.
#
import random
import gym
import numpy as np
from gym import spaces
class BitFlip(gym.Env):
metadata = {
'render.modes': ['human', 'rgb_array'], 'video.frames_per_second': 30
}
def __init__(self, bit_length=16, max_steps=None, mean_zero=False):
super(BitFlip, self).__init__()
if bit_length < 1:
raise ValueError('bit_length must be >= 1, found {}'.format(bit_length))
self.bit_length = bit_length
self.mean_zero = mean_zero
if max_steps is None:
# default to bit_length
self.max_steps = bit_length
elif max_steps == 0:
self.max_steps = None
else:
self.max_steps = max_steps
# spaces documentation: https://gym.openai.com/docs/
self.action_space = spaces.Discrete(bit_length)
self.observation_space = spaces.Dict({
'state': spaces.Box(low=0, high=1, shape=(bit_length, )),
'desired_goal': spaces.Box(low=0, high=1, shape=(bit_length, )),
'achieved_goal': spaces.Box(low=0, high=1, shape=(bit_length, ))
})
self.reset()
def _terminate(self):
return (self.state == self.goal).all() or self.steps >= self.max_steps
def _reward(self):
return -1 if (self.state != self.goal).any() else 0
def step(self, action):
# action is an int in the range [0, self.bit_length)
self.state[action] = int(not self.state[action])
self.steps += 1
return (self._get_obs(), self._reward(), self._terminate(), {})
def reset(self):
self.steps = 0
self.state = np.array([random.choice([1, 0]) for _ in range(self.bit_length)])
# make sure goal is not the initial state
self.goal = self.state
while (self.goal == self.state).all():
self.goal = np.array([random.choice([1, 0]) for _ in range(self.bit_length)])
return self._get_obs()
def _mean_zero(self, x):
if self.mean_zero:
return (x - 0.5) / 0.5
else:
return x
def _get_obs(self):
return {
'state': self._mean_zero(self.state),
'desired_goal': self._mean_zero(self.goal),
'achieved_goal': self._mean_zero(self.state)
}
def render(self, mode='human', close=False):
observation = np.zeros((20, 20 * self.bit_length, 3))
for bit_idx, (state_bit, goal_bit) in enumerate(zip(self.state, self.goal)):
# green if the bit matches
observation[:, bit_idx * 20:(bit_idx + 1) * 20, 1] = (state_bit == goal_bit) * 255
# red if the bit doesn't match
observation[:, bit_idx * 20:(bit_idx + 1) * 20, 0] = (state_bit != goal_bit) * 255
return observation