def xy2sky(self, x, y, usepv=True):
if usepv:
try:
return xy2skypv(x=numpy.array(x), y=numpy.array(y),
crpix1=self.crpix1,
crpix2=self.crpix2,
crval1=self.crval1,
crval2=self.crval2,
cd=self.cd,
pv=self.pv,
nord=self.nord)
except Exception as ex:
logger.warning("Error {} {}".format(type(ex), ex))
logger.warning("Reverted to CD-Matrix WCS.")
print ex
xy = numpy.array([x, y]).transpose()
pos = self.wcs_pix2world(xy, 1).transpose()
return pos[0] * units.degree, pos[1] * units.degree
def sky2xy(self, ra, dec, usepv=True):
if isinstance(ra, Quantity):
ra = ra.to(units.degree).value
if isinstance(dec, Quantity):
dec = dec.to(units.degree).value
try:
if usepv:
return sky2xypv(ra=ra,
dec=dec,
crpix1=self.crpix1,
crpix2=self.crpix2,
crval1=self.crval1,
crval2=self.crval2,
dc=self.dc,
pv=self.pv,
nord=self.nord)
except Exception as ex:
logger.warning("sky2xy raised exception: {0}".format(ex))
logger.warning("Reverted to CD-Matrix WCS to convert: {0} {1} ".format(ra, dec))
print ex
pos = self.wcs_world2pix([[ra, dec], ], 1)
return pos[0][0], pos[0][1]
def phot(fits_filename, x_in, y_in, aperture=15, sky=20, swidth=10, apcor=0.3,
maxcount=30000.0, exptime=1.0, zmag=None, extno=0, centroid=True):
"""
Compute the centroids and magnitudes of a bunch sources on fits image.
:rtype : astropy.table.Table
:param fits_filename: Name of fits image to measure source photometry on.
:type fits_filename: str
:param x_in: x location of source to measure
:type x_in: float, numpy.array
:param y_in: y location of source to measure
:type y_in: float, numpy.array
:param aperture: radius of circular aperture to use.
:type aperture: float
:param sky: radius of inner sky annulus
:type sky: float
:param swidth: width of the sky annulus
:type swidth: float
:param apcor: Aperture correction to take aperture flux to full flux.
:type apcor: float
:param maxcount: maximum linearity in the image.
:type maxcount: float
:param exptime: exposure time, relative to zmag supplied
:type exptime: float
:param zmag: zeropoint magnitude
:param extno: extension of fits_filename the x/y location refers to.
"""
if not hasattr(x_in, '__iter__'):
x_in = [x_in, ]
if not hasattr(y_in, '__iter__'):
y_in = [y_in, ]
if (not os.path.exists(fits_filename) and
not fits_filename.endswith(".fits")):
# For convenience, see if we just forgot to provide the extension
fits_filename += ".fits"
try:
input_hdulist = fits.open(fits_filename)
except Exception as err:
logger.debug(str(err))
raise TaskError("Failed to open input image: %s" % err.message)
# get the filter for this image
filter_name = input_hdulist[extno].header.get('FILTER', 'DEFAULT')
# Some nominal CFHT zeropoints that might be useful
zeropoints = {"I": 25.77,
"R": 26.07,
"V": 26.07,
"B": 25.92,
"DEFAULT": 26.0,
"g.MP9401": 32.0,
'r.MP9601': 31.9,
'gri.MP9603': 33.520}
if zmag is None:
logger.warning("No zmag supplied to daophot, looking for header or default values.")
zmag = input_hdulist[extno].header.get('PHOTZP', zeropoints[filter_name])
logger.warning("Setting zmag to: {}".format(zmag))
# check for magic 'zeropoint.used' files
for zpu_file in ["{}.zeropoint.used".format(os.path.splitext(fits_filename)[0]), "zeropoint.used"]:
if os.access(zpu_file, os.R_OK):
with open(zpu_file) as zpu_fh:
zmag = float(zpu_fh.read())
logger.warning("Using file {} to set zmag to: {}".format(zpu_file, zmag))
break
photzp = input_hdulist[extno].header.get('PHOTZP', zeropoints.get(filter_name, zeropoints["DEFAULT"]))
if zmag != photzp:
logger.warning(("zmag sent to daophot: ({}) "
"doesn't match PHOTZP value in image header: ({})".format(zmag, photzp)))
# setup IRAF to do the magnitude/centroid measurements
iraf.set(uparm="./")
iraf.digiphot()
iraf.apphot()
iraf.daophot(_doprint=0)
iraf.photpars.apertures = aperture
iraf.photpars.zmag = zmag
iraf.datapars.datamin = 0
iraf.datapars.datamax = maxcount
iraf.datapars.exposur = ""
iraf.datapars.itime = exptime
iraf.fitskypars.annulus = sky
iraf.fitskypars.dannulus = swidth
iraf.fitskypars.salgorithm = "mode"
iraf.fitskypars.sloclip = 5.0
iraf.fitskypars.shiclip = 5.0
if centroid:
iraf.centerpars.calgori = "centroid"
iraf.centerpars.cbox = 5.
iraf.centerpars.cthreshold = 0.
iraf.centerpars.maxshift = 2.
iraf.centerpars.clean = 'no'
else:
iraf.centerpars.calgori = "none"
iraf.phot.update = 'no'
iraf.phot.verbose = 'no'
iraf.phot.verify = 'no'
iraf.phot.interactive = 'no'
# Used for passing the input coordinates
coofile = tempfile.NamedTemporaryFile(suffix=".coo", delete=False)
for i in range(len(x_in)):
coofile.write("%f %f \n" % (x_in[i], y_in[i]))
coofile.flush()
# Used for receiving the results of the task
# mag_fd, mag_path = tempfile.mkstemp(suffix=".mag")
magfile = tempfile.NamedTemporaryFile(suffix=".mag", delete=False)
# Close the temp files before sending to IRAF due to docstring:
# "Whether the name can be used to open the file a second time, while
# the named temporary file is still open, varies across platforms"
coofile.close()
magfile.close()
os.remove(magfile.name)
iraf.phot(fits_filename+"[{}]".format(extno), coofile.name, magfile.name)
pdump_out = ascii.read(magfile.name, format='daophot')
logging.debug("PHOT FILE:\n"+str(pdump_out))
if not len(pdump_out) > 0:
mag_content = open(magfile.name).read()
raise TaskError("photometry failed. {}".format(mag_content))
# apply the aperture correction
pdump_out['MAG'] -= apcor
# if pdump_out['PIER'][0] != 0 or pdump_out['SIER'][0] != 0 or pdump_out['CIER'][0] != 0:
# raise ValueError("Photometry failed:\n {}".format(pdump_out))
# Clean up temporary files generated by IRAF
os.remove(coofile.name)
os.remove(magfile.name)
logger.debug("Computed aperture photometry on {} objects in {}".format(len(pdump_out), fits_filename))
del input_hdulist
return pdump_out