zernike.py 文件源码

def rnm(n,m,rho):
    """
    Return an array with the zernike Rnm polynomial calculated at rho points.
    """
    Rnm=zeros(rho.shape)
    S=(n-abs(m))/2
    for s in range (0,S+1):
        CR=pow(-1,s)*factorial(n-s)/ \
            (factorial(s)*factorial(-s+(n+abs(m))/2)* \
            factorial(-s+(n-abs(m))/2))
        p=CR*pow(rho,n-2*s)
        Rnm=Rnm+p
    Rnm[rho>1.0] = 0
    return Rnm