stroud1957.py 文件源码

def __init__(self, n):
        self.degree = 2
        self.dim = n

        n2 = fr(n, 2) if n % 2 == 0 else fr(n-1, 2)
        pts = [[
            [sqrt(fr(2, n+2)) * cos(2*k*i*pi / (n+1)) for i in range(n+1)],
            [sqrt(fr(2, n+2)) * sin(2*k*i*pi / (n+1)) for i in range(n+1)],
            ] for k in range(1, n2+1)]
        if n % 2 == 1:
            sqrt3pm = numpy.full(n+1, 1/sqrt(n+2))
            sqrt3pm[1::2] *= -1
            pts.append(sqrt3pm)
        pts = numpy.vstack(pts).T

        data = [(fr(1, n+1), pts)]

        self.points, self.weights = untangle(data)
        self.weights *= volume_unit_ball(n)
        return