68 lines
1.9 KiB
Python
68 lines
1.9 KiB
Python
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import numpy as np
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from math import cos
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class MountainCarEnv:
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def __init__(self, max_step):
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self.min_position = -1.2
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self.max_position = 0.6
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self.max_speed = 0.07
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self.goal_position = 0.5
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self.position = 0.0
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self.speed = 0.0
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self.reward = 0.0
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self.step_count = 0
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self.max_step = max_step
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self.distance_penaltiy = 100
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self.reset()
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def reset(self):
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self.position = np.random.uniform(low=-0.6, high=-0.4)
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self.speed = 0.0
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self.reward = 0.0
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self.step_count = 0
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def state(self):
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return self.position, self.speed
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@staticmethod
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def minmax(value, lower, upper):
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return lower if value < lower else upper if value > upper else value
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def termination(self):
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if self.step_count < self.max_step:
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if self.position >= self.goal_position:
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return True
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else:
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self.reward += -1.0
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return False
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else:
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self.reward += -(self.goal_position - self.position) * self.distance_penaltiy
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return True
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def step(self, action):
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position, speed = self.state()
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speed += (action-1)*0.001 + cos(3*position)*(-0.0025)
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speed = self.minmax(speed, -self.max_speed, self.max_speed)
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position += speed
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position = self.minmax(position, self.min_position, self.max_position)
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if (position == self.min_position) and (speed < 0.0):
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speed = 0.0
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self.speed = speed
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self.position = position
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self.step_count += 1
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done = self.termination()
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return done, self.reward, self.step_count
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def runner(self, policy):
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done = False
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self.reset()
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while not done:
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action = policy[self.step_count]
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done, _, _ = self.step(float(action))
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return self.reward, self.step_count
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