fejer.py 文件源码

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

        self.points = -numpy.cos(numpy.pi * (numpy.arange(n) + 0.5) / n)

        # n -= 1
        N = numpy.arange(1, n, 2)
        length = len(N)
        m = n - length
        K = numpy.arange(m)

        v0 = numpy.concatenate([
            2 * numpy.exp(1j*numpy.pi*K/n) / (1 - 4*K**2),
            numpy.zeros(length+1)
            ])
        v1 = v0[:-1] + numpy.conjugate(v0[:0:-1])

        w = numpy.fft.ifft(v1)
        assert max(w.imag) < 1.0e-15
        self.weights = w.real

        return