Generate a normalized Moffat profile from its FWHM and alpha

def generate_moffat_profile(seeing_fwhm, alpha):
    """Generate a normalized Moffat profile from its FWHM and alpha"""

    scale = 2 * math.sqrt(2**(1.0 / alpha) - 1)
    gamma = seeing_fwhm / scale
    amplitude = 1.0 / math.pi * (alpha - 1) / gamma**2
    seeing_model = Moffat2D(amplitude=amplitude,
                            x_mean=0.0,
                            y_mean=0.0,
                            gamma=gamma,
                            alpha=alpha)
    return seeing_model