diff options
Diffstat (limited to 'astro/oskar/fits2skymodel.py')
| -rwxr-xr-x | astro/oskar/fits2skymodel.py | 45 |
1 files changed, 40 insertions, 5 deletions
diff --git a/astro/oskar/fits2skymodel.py b/astro/oskar/fits2skymodel.py index dfd27d3..eefeb1c 100755 --- a/astro/oskar/fits2skymodel.py +++ b/astro/oskar/fits2skymodel.py @@ -56,18 +56,23 @@ class SkyModel: The coordinate of the image center; unit [deg] minvalue : float, optional The minimum threshold for the image values + mask : 2D bool `~numpy.ndarray`, optional + Use this mask to select the sources of the output sky model, + instead of the above ``minvalue``. + NOTE: this overwrite the above ``minvalue`` if provided. projection : str, optional The WCS projection for the image; default "TAN" TODO: support "SIN" etc. """ def __init__(self, image, freq, pixsize, ra0, dec0, - minvalue=1e-4, projection="TAN"): + minvalue=1e-4, mask=None, projection="TAN"): self.image = image # K (brightness temperature) self.freq = freq # MHz self.pixsize = pixsize # arcmin self.ra0 = ra0 # deg self.dec0 = dec0 # deg self.minvalue = minvalue + self.mask = mask self.projection = projection logger.info("SkyModel: Loaded image @ %.2f [MHz]" % freq) @@ -136,7 +141,12 @@ class SkyModel: dec : (J2000) declination (deg) flux : source (Stokes I) flux density (Jy) """ - idx = self.image.flatten() >= self.minvalue + if self.mask is None: + self.mask = self.image >= self.minvalue + logger.info("Use minimum threshold to determine output sky") + else: + logger.info("Use provided mask to determine output sky") + idx = self.mask.flatten() ra, dec = self.ra_dec ra = ra.flatten()[idx] dec = dec.flatten()[idx] @@ -182,6 +192,20 @@ class SkyModel: hdu.writeto(outfile, clobber=True) # old astropy versions logger.info("Wrote FITS image of sky model to file: %s" % outfile) + def write_mask(self, outfile, clobber=False): + if os.path.exists(outfile) and (not clobber): + raise OSError("Sky mask already exists: " % outfile) + header = self.fits_header + header.add_history(datetime.now().isoformat()) + header.add_history(" ".join(sys.argv)) + hdu = fits.PrimaryHDU(data=self.mask.astype(np.int16), + header=header) + try: + hdu.writeto(outfile, overwrite=True) + except TypeError: + hdu.writeto(outfile, clobber=True) # old astropy versions + logger.info("Wrote mask of sky model to file: %s" % outfile) + def main(): parser = argparse.ArgumentParser( @@ -189,9 +213,11 @@ def main(): parser.add_argument("-C", "--clobber", dest="clobber", action="store_true", help="overwrite existing file") - parser.add_argument("-r", "--ra0", dest="ra0", type=float, required=True, + parser.add_argument("-r", "--ra0", dest="ra0", type=float, + default=0.0, help="R.A. of the image center") - parser.add_argument("-d", "--dec0", dest="dec0", type=float, required=True, + parser.add_argument("-d", "--dec0", dest="dec0", type=float, + default=-27.0, help="Dec. of the image center") parser.add_argument("-p", "--pix-size", dest="pixsize", type=float, help="image pixel size [arcmin]; " + @@ -207,12 +233,16 @@ def main(): type=float, help="minimum threshold determined as the fraction " + "the peak value to the output sky model") + exgrp.add_argument("--mask", dest="mask", + help="use a mask to determine the output sky model") # parser.add_argument("-F", "--osm-fits", dest="osmfits", action="store_true", help="save a FITS version of the converted sky model") parser.add_argument("-o", "--outdir", dest="outdir", help="output directory for sky model files") + exgrp.add_argument("--create-mask", dest="create_mask", + help="create a FITS mask for the output sky model") parser.add_argument("infile", help="input FITS image") parser.add_argument("outfile", nargs="?", help="output OSKAR sky model (default: " + @@ -237,18 +267,23 @@ def main(): logger.info("Frequency: %.2f [MHz]" % freq) logger.info("Pixel size: %.2f [arcmin]" % pixsize) minvalue = 1e-4 # i.e., 0.1 [mK] + mask = None if args.minvalue: minvalue = args.minvalue if args.minpfrac: minvalue = args.minpfrac * image.max() + if args.mask: + mask = fits.open(args.mask)[0].data.astype(np.bool) logger.info("Minimum threshold: %g [K]" % minvalue) skymodel = SkyModel(image=image, freq=freq, ra0=args.ra0, dec0=args.dec0, - pixsize=pixsize, minvalue=minvalue) + pixsize=pixsize, minvalue=minvalue, mask=mask) logger.info("Conversion [K] -> [Jy/pixel]: %g" % skymodel.factor_K2JyPixel) skymodel.write_sky_model(outfile, clobber=args.clobber) if args.osmfits: outfits = outfile + ".fits" skymodel.write_fits(outfits, oldheader=header, clobber=args.clobber) + if args.create_mask: + skymodel.write_mask(args.create_mask, clobber=args.clobber) if __name__ == "__main__": |