程序不想比较这些值

Question

我第一次把东西放在这里，对不起，如果我有任何错误。

我的程序使用两个边界限制来强制我的程序保持在数组中，但他没有比较限制，我没有发现问题。

限制：     pos_range = [-1.2,0.60]     vel_range = [-0.07,0.07]

速度和位置更新在下面，更新值后我检查结果，因为汽车不能越过pos_range或vel_range，但他总是去。我是否犯了任何错误来比较价值？这种方法错了吗？

感谢。

pos_range = [-1.2, 0.60]
vel_range = [-0.07, 0.07]

def update_position_velocity(a):
    # action 0,1,2,3 0 backward 1 forward 2 coast
    global simulatev
    global simulatep
    global newv
    global newp
    oldv = simulatev  # preserve old values
    oldp = simulatep

    if a == 0:  # backward
        aval = -1
    else:
        aval = a  # coast = 0, forward = +1, backward = -1;

    newv = oldv + (0.001 * aval) + (gravity * cos(3 * oldp))  # update equation for velocity

    newp = simulatep + newv  # update equation for position
    print newp, newv

    if newv < vel_range[0]:  # clip velocity if necessary to keep it within range
        newv = vel_range[0]

    if newv > vel_range[1]:
        newv = vel_range[1]

    if newp < pos_range[0]:  # clip position and velocity if necessary to keep it within range
        newp = pos_range[0]
        newv = 0  # reduce velocity to 0 if position was out of bounds

    if newv > pos_range[1]:
        newp = pos_range[1]
        newv = 0

    print newp, newv
    simulatep = newp
    simulatev = newv  # update state to new values

程序在这里失败：

if newv < vel_range[0]:  # clip velocity if necessary to keep it within range
    newv = vel_range[0]

if newv > vel_range[1]:
    newv = vel_range[1]

if newp < pos_range[0]:  # clip position and velocity if necessary to keep it within range
    newp = pos_range[0]
    newv = 0  # reduce velocity to 0 if position was out of bounds

if newv > pos_range[1]:
    newp = pos_range[1]
    newv = 0