windy_gridworld.py 文件源码

def __init__(self):
        self.shape = (7, 10)

        nS = np.prod(self.shape)
        nA = 4

        # Wind strength
        winds = np.zeros(self.shape)
        winds[:,[3,4,5,8]] = 1
        winds[:,[6,7]] = 2

        # Calculate transition probabilities
        P = {}
        for s in range(nS):
            position = np.unravel_index(s, self.shape)
            P[s] = { a : [] for a in range(nA) }
            P[s][UP] = self._calculate_transition_prob(position, [-1, 0], winds)
            P[s][RIGHT] = self._calculate_transition_prob(position, [0, 1], winds)
            P[s][DOWN] = self._calculate_transition_prob(position, [1, 0], winds)
            P[s][LEFT] = self._calculate_transition_prob(position, [0, -1], winds)

        # We always start in state (3, 0)
        isd = np.zeros(nS)
        isd[np.ravel_multi_index((3,0), self.shape)] = 1.0

        super(WindyGridworldEnv, self).__init__(nS, nA, P, isd)