oldperiodbase.py 文件源码

def get_frequency_grid(times,
                       samplesperpeak=5,
                       nyquistfactor=5,
                       minfreq=None,
                       maxfreq=None,
                       returnf0dfnf=False):
    '''This calculates a frequency grid for the period finding functions in this
    module.

    Based on the autofrequency function in astropy.stats.lombscargle.

    http://docs.astropy.org/en/stable/_modules/astropy/stats/lombscargle/core.html#LombScargle.autofrequency

    '''

    baseline = times.max() - times.min()
    nsamples = times.size

    df = 1. / baseline / samplesperpeak

    if minfreq is not None:
        f0 = minfreq
    else:
        f0 = 0.5 * df

    if maxfreq is not None:
        Nf = int(npceil((maxfreq - f0) / df))
    else:
        Nf = int(0.5 * samplesperpeak * nyquistfactor * nsamples)


    if returnf0dfnf:
        return f0, df, Nf, f0 + df * nparange(Nf)
    else:
        return f0 + df * nparange(Nf)


###############################################
## DWORETSKY STRING LENGTH (Dworetsky+ 1983) ##
##     (don't use this -- it's very slow)    ##
###############################################