小编lpl*_*lpl的帖子

假设我有:

test = numpy.array([[1, 2], [3, 4], [5, 6]])

test[i]让我第i个阵列(例如线[1, 2]).我怎样才能访问第i列？(例如[1, 3, 5]).这也是一项昂贵的操作吗？

目前我有:

def func(points): #Input is a matrix with n lines and 2 columns.
    centroid = numpy.mean(points, axis=0)
    sum = 0
    for point in points:
        x = point[0] - centroid[0]
        y = point[1] - centorid[1]
        sum += x**2 + y**2
    return math.sqrt(sum)