refmag = refmag[np.flatnonzero(mag)] refmagerr = refmagerr[np.flatnonzero(mag)] mag = mag[np.flatnonzero(mag)] if(len(mag) == 0): print "No good sources to plot" sys.exit(1) # Now apply the exposure time and nom_at_ext corrections to mag et = float(ad.exposure_time()) if(ad.is_type('GMOS_NODANDSHUFFLE')): print "Imaging Nod-And-Shuffle. Photometry may be dubious" et /= 2.0 etmag = 2.5*math.log10(et) nom_at_ext = float(ad.nominal_atmospheric_extinction()) mag += etmag mag += nom_at_ext # Can now calculate the zp array zp = refmag - mag zperr = np.sqrt(refmagerr*refmagerr + magerr*magerr) # Trim values out of zp where the zeropoint error is > 0.1 zp_trim = np.where((zperr<0.1), zp, None) zperr_trim = zperr[np.flatnonzero(zp_trim)] refmag_trim = refmag[np.flatnonzero(zp_trim)] refmagerr_trim = refmagerr[np.flatnonzero(zp_trim)] zp_trim = zp[np.flatnonzero(zp_trim)]