__init__.py 文件源码

def clenshaw_curtis1D(u, quad="GC"):
    assert u.ndim == 1
    N = u.shape[0]
    if quad == 'GL':
        w = np.arange(0, N, 1, dtype=float)
        w[2:] = 2./(1-w[2:]**2)
        w[0] = 1
        w[1::2] = 0
        ak = dct(u, 1)
        ak /= (N-1)
        return np.sqrt(np.sum(ak*w))

    elif quad == 'GC':
        d = np.zeros(N)
        k = 2*(1 + np.arange((N-1)//2))
        d[::2] = (2./N)/np.hstack((1., 1.-k*k))
        w = dct(d, type=3)
        return np.sqrt(np.sum(u*w))