相邻元素之间的Numpy差异

Question

我有计算纯python中相邻元素之间差异的算法:

    a = range(1000000) #it's numpy array in my case
    prev = a[0]
    b = [0, ]
    for i in a[1:]:
        b.append(i - prev)
        prev = i

有没有办法用Numpy重写这个功能？

Answer 1

有diff方法:

a = range(5) # python list of numpy array
np.diff(a)

回报

array([1, 1, 1, 1])