Demonstrate the basic capabilities of procedures WCSSPH2XY & WCSXY2SPH
Mapping and Auxilary FITS Demo Routine
.run wcs_demo: compiles wcs_demo and the supporting demo routines
wcs_demo: run the demo
This is a demo program which is meant to call the routines
wcssph2xy.pro and wcsxy2sph.pro. Since the purpose of this
routine is both to show what the routines can do and what the
user has to do, a file is created with all of the commands
needed to complete the desired operation. Wcs_demo actually
executes this command file, so the user can exactly duplicate
the results by simply re-executing this file. Also, this
allows a user to edit an already existing file which calls
wcssph2xy.pro and wcsxy2sph.pro properly and extend the file's
usefulness. This demo program allows several possible tests.
The first option is to simply draw a grid of evenly spaced
latitude and longitude lines in a particular map transformation.
Another possibility is to do a full loop, creating a Cartesian
grid of latitude and longitude lines and calling wcssph2xy.pro
to convert them to a particular map. Then, wcsxy2sph.pro is
called to invert the process and the difference between the
original and final latitudes and longitudes can be plotted.
This allows one to assess the level of the numerical errors
introduced by the mapping routines. A third possible option is to
look at some of the map transformations and include rotations of
the reference points so that a different perspective is given.
SPHDIST(), WCSXY2SPH, WCSSPH2XY
Copyright 1991, The Regents of the University of California. This
software was produced under U.S. Government contract (W-7405-ENG-36)
by Los Alamos National Laboratory, which is operated by the
University of California for the U.S. Department of Energy.
The U.S. Government is licensed to use, reproduce, and distribute
this software. Neither the Government nor the University makes
any warranty, express or implied, or assumes any liability or
responsibility for the use of this software.
1.2 3/19/96 - J. Bloch - LANL
- Made compatible with wcslib-2.2 by Calabretta.
Converted to IDL V5.0 W. Landsman September 1997
Updated for conical projections W. Landsman July 2003