""" pixtosky - A module to perform coordinate transformation from pixel to sky coordinates.
:Authors: Warren Hack
:License: :doc:`/LICENSE`
"""
import warnings
import numpy as np
from . import util
from . import wcs_functions
from stwcs import wcsutil
from . import __version__
from astropy.utils.decorators import deprecated_renamed_argument
__all__ = ['xy2rd']
blank_list = [None, '', ' ']
[docs]
@deprecated_renamed_argument('coords', 'coordfile', '2.1.3')
def xy2rd(input,x=None,y=None,coords=None, coordfile=None,colnames=None,separator=None,
hms=True, precision=6,output=None,verbose=True):
"""Primary interface to perform coordinate transformations from
pixel to sky coordinates using STWCS and full distortion models
read from the input image header.
Parameters
----------
input : str
Full filename with path of input image, an extension name ['sci',1] should be
provided if input is a multi-extension FITS file
x : float or list or array, optional
X position from input image for a single or multiple sources
y : float or list or array, optional
Y position from input image for a single or multiple sources
coords : str, deprecated
[DEPRECATED] full filename with path of file with x,y coordinates
Filename given here will be *ignored* if a file has been specified
in ``coordfile`` parameter.
coordfile : str, optional
Full filename with path of file with x,y coordinates
colnames : str, optional
Comma separated list of column names or list of column name strings
from 'coordfile' files containing x,y coordinates, respectively.
This parameter will default to first two columns if None are specified.
Column names for ASCII files will use 'c1','c2',... convention.
Valid syntax: ['c1','c3'] or 'c1,c3'
separator : str, optional
Non-blank separator used as the column delimiter in the coordfile file
hms : bool, optional
Produce output in HH:MM:SS.S format instead of decimal degrees? (default: False)
precision : int, optional
Number of floating-point digits in output values
output : str, optional
Name of output file with results, if desired
verbose : bool
Print out full list of transformation results (default: False)
Returns
-------
ra : float or array
Right Ascension of pixel. If more than 1 input value, then it will be a
numpy array.
dec : float or array
Declination of pixel. If more than 1 input value, then it will be a
numpy array.
Notes
-----
This task performs a full distortion-correction coordinate transformation
based on all WCS keywords and any recognized distortion keywords from the
input image header. The transformation recognizes the conventions for
describing distortion implemented as part of the SIP and Paper IV
conventions used with ``AstroDrizzle``. Input images can be updated to use
these conventions through the updatewcs module in the STWCS package. Refer
to the STWCS documentation (https://stwcs.readthedocs.io/en/latest/) for an
overview of the WCS-based transformation utilities relied upon here.
Examples
--------
1. The following command will transform the position 256,256 into a
position on the sky for the image 'input_flt.fits[sci,1]' using::
>>> from drizzlepac import pixtosky
>>> r,d = pixtosky.xy2rd("input_file_flt.fits[sci,1]", 256,256)
2. The set of X,Y positions from 'input_flt.fits[sci,1]' stored as
the 3rd and 4th columns from the ASCII file 'xy_sci1.dat'
will be transformed and written out to 'radec_sci1.dat' using::
>>> from drizzlepac import pixtosky
>>> r,d = pixtosky.xy2rd("input_flt.fits[sci,1]", coordfile='xy_sci1.dat',
... colnames=['c3','c4'], output="radec_sci1.dat")
"""
single_coord = False
# Only use value provided in `coords` if nothing has been specified for coordfile
if coords is not None and coordfile is None:
coordfile = coords
warnings.simplefilter('always',DeprecationWarning)
warnings.warn("Please update calling code to pass in ``coordfile`` instead of ``coords``.",
category=DeprecationWarning)
warnings.simplefilter('default',DeprecationWarning)
if coordfile is not None:
if colnames in blank_list:
colnames = ['c1','c2']
# Determine columns which contain pixel positions
cols = util.parse_colnames(colnames,coordfile)
# read in columns from input coordinates file
xyvals = np.loadtxt(coordfile,usecols=cols,delimiter=separator)
if xyvals.ndim == 1: # only 1 entry in coordfile
xlist = [xyvals[0].copy()]
ylist = [xyvals[1].copy()]
else:
xlist = xyvals[:,0].copy()
ylist = xyvals[:,1].copy()
del xyvals
else:
if isinstance(x, np.ndarray):
xlist = x.tolist()
ylist = y.tolist()
elif not isinstance(x,list):
xlist = [x]
ylist = [y]
single_coord = True
else:
xlist = x
ylist = y
# start by reading in WCS+distortion info for input image
inwcs = wcsutil.HSTWCS(input)
if inwcs.wcs.is_unity():
print("####\nNo valid WCS found in {}.\n Results may be invalid.\n####\n".format(input))
# Now, convert pixel coordinates into sky coordinates
dra,ddec = inwcs.all_pix2world(xlist,ylist,1)
# convert to HH:MM:SS.S format, if specified
if hms:
ra,dec = wcs_functions.ddtohms(dra,ddec,precision=precision)
rastr = ra
decstr = dec
else:
# add formatting based on precision here...
rastr = []
decstr = []
fmt = "%."+repr(precision)+"f"
for r,d in zip(dra,ddec):
rastr.append(fmt%r)
decstr.append(fmt%d)
ra = dra
dec = ddec
if verbose or (not verbose and util.is_blank(output)):
print('# Coordinate transformations for ',input)
print('# X Y RA Dec\n')
for x,y,r,d in zip(xlist,ylist,rastr,decstr):
print("%.4f %.4f %s %s"%(x,y,r,d))
# Create output file, if specified
if output:
f = open(output,mode='w')
f.write("# Coordinates converted from %s\n"%input)
for r,d in zip(rastr,decstr):
f.write('%s %s\n'%(r,d))
f.close()
print('Wrote out results to: ',output)
if single_coord:
ra = ra[0]
dec = dec[0]
return ra,dec
#--------------------------------
# TEAL Interface functions
# (these functions are deprecated)
#---------------------------------
def run(configObj):
if 'coords' in configObj:
coords = util.check_blank(configObj['coords'])
else:
coords = None
coordfile = util.check_blank(configObj['coordfile'])
colnames = util.check_blank(configObj['colnames'])
sep = util.check_blank(configObj['separator'])
outfile = util.check_blank(configObj['output'])
xy2rd(configObj['input'],
x = configObj['x'], y = configObj['y'], coords=coords,
coordfile = coordfile, colnames = colnames,
separator= sep, hms = configObj['hms'], precision= configObj['precision'],
output= outfile, verbose = configObj['verbose'])