pyraf / iraf tasks can now become obsolete

[sophiathl]

#13.07.23 - Notes
# Pure Python registration using montage & montage-wrapper
# montage-wrapper is an astropy affiliated package, but: 
# montage from IPAC needs be installed separately from here: 
# http://montage.ipac.caltech.edu/
# montage-wrapper needs be installed separately from here: 
# http://www.astropy.org/montage-wrapper/
#
# all the following pyraf tasks (used in the registration & resampling steps) 
# can now become obsolete:
#
# iraf.unlearn()
# artdata.mkpattern()
# iraf.ccsetwcs()
# iraf.wregister()

import astropy
import montage_wrapper as montage

# making a header template - general use
# montage.commands.mHdr(object_or_location, width, out_file, system=None, equinox=None, height=None, pix_size=None, rotation=None)
# the "width" (and "height") is in degrees, and it is the angular size (given by 
# the user, and if in arcsecs then converted) in degrees
# the "pix_size" is the native pixelscale of each image in the registration step,
# while in the resampling step, the "pix_scale" is the same for all images, as before 
# example application of the above general use (with example values)
#
montage.commands.mHdr('67.7044117 64.8479444', 0.071666666666724, 'hdr_registration', system='eq', equinox=2000.0, height=0.071666666666724, pix_size=2., rotation=0.)
#
# note: 
# we can either use the target name, or specify ra-dec - in the former case, the 
# user let us know of the target name, 
# while in the latter case the user let us know of the ra-dec (best in degrees) - in 
# the former case we do as follows:
# montage.commands.mHdr('ngc1569', 0.071666666666724, 'hdr_registration', system='eq', equinox=2000.0, height=0.071666666666724, pix_size=2., rotation=0.)

# registering the images - general use
# montage.wrappers.reproject(in_images, out_images, header=None, bitpix=None, north_aligned=False, system=None, equinox=None, factor=None, common=False, exact_size=False, hdu=None, cleanup=True, silent_cleanup=False)[source]
# the in_images / out_images can be tuples - then, all of them are registered to the 
# header specified in the "hdr_registration"
# the rest of the arguments are either not needed or can be left at the default value
#
montage.wrappers.reproject('I1Jy.fits','I1Jy_pyreg.fits', header='hdr_registration')
#
# note 1:
# the above is equivalent to using the following:
# montage.commands.mProject('I1Jy.fits','I1Jy_pyreg.fits', header='hdr_registration')
# 
# note 2: 
# in the case of an image cube, then the following can be used instead:
# montage.wrappers.reproject_cube('input_cube.fits','output_cube.fits', header='hdr_registration')
# to bear in mind: the images are registered all with the same "pix_scale" -- ideal 
# to use in the resampling step
#
# note 3: selected header keywords are retained - all rest should be added by "hand"

[jeffctaylor]

That looks awesome. I'll start integrating it into the code now, unless there are any other issues that need to be taken care of first.

[jeffctaylor]

This has now been done.