How to use the aotools.functions.circle function in aotools

Zs = numpy.empty((maxJ, N, N))

        for j in xrange(1, maxJ+1):
            Zs[j-1] = zernike_noll(j, N)


    if norm=="p2v":
        for z in xrange(len(Zs)):
            Zs[z] /= (Zs[z].max()-Zs[z].min())

    elif norm=="rms":
        for z in xrange(len(Zs)):
            # Norm by RMS. Remember only to include circle elements in mean
            Zs[z] /= numpy.sqrt(
                    numpy.sum(Zs[z]**2)/numpy.sum(circle(N/2., N)))



    return Zs

R = numpy.sqrt(X**2 + Y**2)
    theta = numpy.arctan2(Y, X)

    if m==0:
        Z = numpy.sqrt(n+1)*zernikeRadialFunc(n, 0, R)
    else:
        if m > 0: # j is even
            Z = numpy.sqrt(2*(n+1)) * zernikeRadialFunc(n, m, R) * numpy.cos(m*theta)
        else:   #i is odd
            m = abs(m)
            Z = numpy.sqrt(2*(n+1)) * zernikeRadialFunc(n, m, R) * numpy.sin(m * theta)

    # clip
    Z = Z*numpy.less_equal(R, 1.0)

    return Z*circle(N/2., N)