def compute_alignment(self):
        v = Point(0,0)
        if len(self.align_list) == 0:
            return v
        for fish in self.align_list:
            v += fish.velocity
        v /= len(self.align_list)
        v.restrain(0.212)
        return v

    def compute_attraction(self):
        v = Point(0,0)
        if len(self.attract_list) == 0:
            return v
        for fish in self.attract_list:
            v += fish.position - self.position
        v /= len(self.attract_list)
        v.restrain(0.50)
        return v

    def compute_repulsion(self):
        v = Point(0,0)
        if len(self.repulse_list) == 0:
            return v
        for fish in self.repulse_list:
            w = (self.position - fish.position)
            w.normalize(1)
            v += (w/self.distance_from(fish))*28
        v /= len(self.repulse_list)
        return v