util.py 文件源码

def asinhmag(flux, fluxerr,  m0 = 22.5, f0=1.0, b=0.01):
    """
    Implements
    http://ssg.astro.washington.edu/elsst/opsim.shtml?lightcurve_mags
    """

    mag = m0 -(2.5/np.log(10.)) * ( np.arcsinh( flux / (f0 * 2.0 * b)) + np.log(b) )

    magplu = m0 -(2.5/np.log(10.)) * ( np.arcsinh( (flux+fluxerr) / (f0 * 2.0 * b)) + np.log(b) )
    magmin = m0 -(2.5/np.log(10.)) * ( np.arcsinh( (flux-fluxerr) / (f0 * 2.0 * b)) + np.log(b) )
    magerr = 0.5*(magmin - magplu)

    return (mag, magerr)