lsst.synpipe.matchFakeStars Namespace Reference

Functions
def	getFakeSources (rootdir, dataId, tol=0.1)
def	main ()

Detailed Description

matchFakes.py
matches fakes based on position stored in the calibrated exposure image header

Function Documentation

getFakeSources()

def lsst.synpipe.matchFakeStars.getFakeSources	(		rootdir,
			dataId,
			tol = 0.1
	)

Get list of sources which agree in position with fake ones with tol

Definition at line 15 of file matchFakeStars.py.

def getFakeSources(rootdir, dataId, tol=0.1):
    """Get list of sources which agree in position with fake ones with tol
    """
    butler = dafPersist.Butler(rootdir)

    sources = butler.get('src', dataId)
    cal_md = butler.get('calexp_md', dataId)

    # Get the X, Y locations of objects on the CCD
    srcX, srcY = sources.getX(), sources.getY()
    # Get the zeropoint
    zeropoint = 2.5*np.log10(cal_md.getScalar("FLUXMAG0"))
    # Get the PSF flux and its error
    flux, ferr = sources.getPsfFlux(), sources.getPsfFluxErr()
    # Convert them into magnitude and its error
    mag, merr = 2.5*np.log10(flux), 2.5/np.log(10)*(ferr/flux)
    mag = zeropoint - mag

    # X, Y locations of the fake stars
    fakeXY = collections.defaultdict(tuple)
    # Regular Expression
    fakename = re.compile('FAKE([0-9]+)')
    for card in cal_md.names():
        m = fakename.match(card)
        if m is not None:
            x, y = list(map(float, (cal_md.getScalar(card)).split(',')))
            fakeXY[int(m.group(1))] = (x, y)

    srcIndex = collections.defaultdict(list)
    for fid, fcoord in fakeXY.items():
        matched = ((np.abs(srcX-fcoord[0]) < tol) &
                   (np.abs(srcY-fcoord[1]) < tol))
        srcIndex[fid] = np.where(matched)[0]

    srcPsfMag = []
    srcPsfMerr = []
    matchX = []
    matchY = []
    for s in srcIndex.values():
        if len(s) > 0:
            ss = s[0]
            srcPsfMag.append(mag[ss])
            srcPsfMerr.append(merr[ss])
            matchX.append(srcX[ss])
            matchY.append(srcY[ss])
        else:
            srcPsfMag.append(0)
            srcPsfMerr.append(0)
            matchX.append(0)
            matchY.append(0)

    return srcIndex, fakeXY, matchX, matchY, srcPsfMag, srcPsfMerr

main()

def lsst.synpipe.matchFakeStars.main

(

)

Definition at line 69 of file matchFakeStars.py.

def main():

    # TODO: this should use the LSST/HSC conventions
    parser = argparse.ArgumentParser()
    parser.add_argument('rootDir', help='root dir of data repo')
    parser.add_argument('visit', help='id of visit', type=int)
    parser.add_argument('ccd', help='id of ccd', type=int)
    args = parser.parse_args()

    starIndex, fakeXY, matchX, matchY, starPsfMag, starPsfMerr = getFakeSources(args.rootDir,
                                                                                {'visit': args.visit,
                                                                                 'ccd': args.ccd})

    nInject = len(fakeXY)
    nMatch = len(np.argwhere(starPsfMag))
    print("# Number of Injected Stars : %d" % nInject)
    print("# Number of Matched  Stars : %d" % nMatch)
    print("# Visit = %d   CCD = %d" % (args.visit, args.ccd))
    print("# FakeX  FakeY  PSFMag  PSFMagErr  Deblend ")

    for i in range(nInject):
        if len(starIndex[i]) > 1:
            deblend = "blended"
        elif starPsfMag[i] > 0:
            deblend = "isolate"
        else:
            deblend = "nomatch"

        injectXY = fakeXY[i]

        print("%6.1d   %6.1d   %7.3f  %6.3f  %s" % (injectXY[0], injectXY[1],
                                                    starPsfMag[i], starPsfMerr[i], deblend))