zogy.py 文件源码

def get_optflux_Eran (P, P_noshift, D, S, V):

    """Function that calculates optimal flux and corresponding error based
    on the PSF [P], the PSF shifted by the fractional pixel shift
    [P_shift], data [D], sky [S] and variance [V].  All are assumed to
    be in electrons rather than counts. These can be 1- or
    2-dimensional arrays with the same shape, while the sky can also
    be a scalar. See Eqs. 36 and 37 of Zackay & Ofek 2017, ApJ, 836,
    187.

    """

    # and optimal flux and its error
    denominator = np.sum((P_noshift*P)/V)
    optflux = np.sum((P_noshift*(D-S)/V)) / denominator
    optfluxerr = 1./np.sqrt(denominator)
    return optflux, optfluxerr

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