math2.py 文件源码

def _cospi_complex(z):
    if z.real < 0:
        z = -z
    n, r = divmod(z.real, 0.5)
    z = pi*complex(r, z.imag)
    n %= 4
    if n == 0: return cmath.cos(z)
    if n == 1: return -cmath.sin(z)
    if n == 2: return -cmath.cos(z)
    if n == 3: return cmath.sin(z)