ghostAgents.py 文件源码

def getDistribution( self, state ):
    # Read variables from state
    ghostState = state.getGhostState( self.index )
    legalActions = state.getLegalActions( self.index )
    pos = state.getGhostPosition( self.index )
    isScared = ghostState.scaredTimer > 0

    speed = 1
    if isScared: speed = 0.5

    actionVectors = [Actions.directionToVector( a, speed ) for a in legalActions]
    newPositions = [( pos[0]+a[0], pos[1]+a[1] ) for a in actionVectors]
    pacmanPosition = state.getPacmanPosition()

    # Select best actions given the state
    distancesToPacman = [manhattanDistance( pos, pacmanPosition ) for pos in newPositions]
    if isScared:
      bestScore = max( distancesToPacman )
      bestProb = self.prob_scaredFlee
    else:
      bestScore = min( distancesToPacman )
      bestProb = self.prob_attack
    bestActions = [action for action, distance in zip( legalActions, distancesToPacman ) if distance == bestScore]

    # Construct distribution
    dist = util.Counter()
    for a in bestActions: dist[a] = bestProb / len(bestActions)
    for a in legalActions: dist[a] += ( 1-bestProb ) / len(legalActions)
    dist.normalize()
    return dist