python - 乘以Python中的上一个和下一个元素

我一直在尝试在Python中乘以上一个和下一个数字，但是我总是遇到不同的错误。这就是我一直在做的：

u=[1, 41, 56, 80]

def Filter(vel):
    global firstDerivative
    firstDerivative = np.repeat(None, len(vel))
    for index, obj in enumerate(vel):
       if index !=0 & index !=len(vel-1):
           firstDerivative = (vel[index-1]*vel[index+1])/2

Filter(u)

出现以下错误：

TypeError: unsupported operand type(s) for -: 'list' and 'int'

我实际上也尝试过地图，但id无效。

最佳答案

您需要从1迭代到-1，并在进行时填充firstDerivative数组：

def Filter(vel):
    global firstDerivative    # you are probably better advised to return firstDerivative instead
    firstDerivative = [0] * (len(vel) - 2)
    for ndx in range(1, len(vel) - 1):
        firstDerivative[ndx-1] = vel[ndx-1] * vel[ndx+1] / 2

firstDerivative = []
u = [1, 2, 3, 4, 5, 6]
Filter(u)
firstDerivative

输出：

对于一阶导数：

[1.5, 4.0, 7.5, 12.0]

关于python - 乘以Python中的上一个和下一个元素，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/47505522/