lsst.synpipe.makeBlendedCat Namespace Reference

Functions
def	disturbRaDec (num, mu=0.6, sigma=0.6)
def	makeBlendedCat (fakeCat, realCat, raCol='ra', decCol='dec', sigma=0.6, mu=0.6)

Variables
	parser
	args

Detailed Description

Make a catalog of fakes that are highly blended.

Function Documentation

disturbRaDec()

def lsst.synpipe.makeBlendedCat.disturbRaDec	(		num,
			mu = 0.6,
			sigma = 0.6
	)

Disturb the coordinate a little bit.

Definition at line 11 of file makeBlendedCat.py.

def disturbRaDec(num, mu=0.6, sigma=0.6):
    """Disturb the coordinate a little bit."""
    return (np.random.normal(mu, sigma, num) / 3600.0)
 
 

makeBlendedCat()

def lsst.synpipe.makeBlendedCat.makeBlendedCat	(		fakeCat,
			realCat,
			raCol = 'ra',
			decCol = 'dec',
			sigma = 0.6,
			mu = 0.6
	)

Make a highly blended version of fake catalog.

Definition at line 16 of file makeBlendedCat.py.

def makeBlendedCat(fakeCat, realCat, raCol='ra', decCol='dec',
                   sigma=0.6, mu=0.6):
    """Make a highly blended version of fake catalog."""
    # Fake catalog
    if not os.path.isfile(fakeCat):
        raise Exception('# Can not find input fake catalog : %s' % fakeCat)
    else:
        fakeTab = Table.read(fakeCat, format='fits')
        nFake = len(fakeTab)
        print("# There are %d fake galaxies in the catalog" % nFake)
    # Name of the output catalog
    blendTab = fakeCat.replace('.fits', '_highb.fits')
 
    # Real catalog
    if not os.path.isfile(realCat):
        raise Exception('# Can not find input real catalog : %s' % realCat)
    else:
        realTab = Table.read(realCat, format='fits')
        nReal = len(realTab)
        print("# There are %d real galaxies in the catalog" % nReal)
 
    # Randomly select nFake galaxies from the realCat
    indices = random.sample(list(range(nReal)), nFake)
 
    # Replace the RA, DEC with a small shift
    fakeTab.add_column(Column(realTab[indices][raCol], name='RA_ori'))
    fakeTab.add_column(Column(realTab[indices][decCol], name='Dec_ori'))
 
    fakeTab['RA'] = (realTab[indices][raCol] + disturbRaDec(nFake,
                                                            mu=mu,
                                                            sigma=sigma))
    fakeTab['Dec'] = (realTab[indices][decCol] + disturbRaDec(nFake,
                                                              mu=mu,
                                                              sigma=sigma))
 
    # Save the new catalog
    fakeTab.write(blendTab, format='fits', overwrite=True)
 
    return fakeTab
 
 

Variable Documentation

args

lsst.synpipe.makeBlendedCat.args

Definition at line 75 of file makeBlendedCat.py.

parser

lsst.synpipe.makeBlendedCat.parser

Definition at line 59 of file makeBlendedCat.py.