idlastro / Astronomical Utilities: QDCB_GRID

[Source code]

NAME
QDCB_GRID
PURPOSE
Produce an overlay of latitude and longitude lines over a plot or image
EXPLANATION
Grid is plotted on the current graphics device assuming that the 
current plot is a map  in the so called quad cube projection. The 
output plot range is assumed to go from 7.0 to -1.0 on the X axis and 
-3.0 to 3.0 on the Y axis. Within this plotting space, the quad cube 
faces are laid out as follows (X=Empty, Astronomical Layout shown - 
X axis can be swapped for geographic maps):
    3.0_
        XXX0
        4321
   -3.0_XXX5
        |  |
      7.0  -1.0
CATEGORY
Mapping Support Routine
CALLING SEQUENCE
QDCB_GRID,[,DLONG,DLAT,[LINESTYLE=N,/LABELS]
INPUT PARAMETERS
DLONG   = Optional input longitude line spacing in degrees. If left
          out, defaults to 30.
DLAT    = Optional input lattitude line spacing in degrees. If left
          out, defaults to 30.
OPTIONAL KEYWORD PARAMETERS
LINESTYLE       = Optional input integer specifying the linestyle to
                  use for drawing the grid lines.
LABELS          = Optional keyword specifying that the lattitude and
                  longitude lines on the prime meridian and the
                  equator should be labeled in degrees. If LABELS is
                  given a value of 2, i.e. LABELS=2, then the longitude
                  labels will be in hours and minutes instead of
                  degrees.
OUTPUT PARAMETERS
NONE
PROCEDURE
Uses WCSSPH2XY.PRO with projection 23 ("QSC" - COBE Quadrilatieralized
Spherical Cube) to compute positions of grid lines and labels.
COPYRIGHT NOTICE
This software has been authored by an employee or employees of Los Alamos 
National Security, LLC, operator of the Los Alamos National Laboratory (LANL) 
under Contract No. DE-AC52-06NA25396 with the U.S. Department of Energy.  The U.S.
Government has rights to use, reproduce, and distribute this software.  The public
may copy, distribute, prepare derivative works and publicly display this software 
without charge, provided that this Notice and any statement of authorship are 
reproduced on all copies.  Neither the Government nor LANS makes any warranty, 
express or implied, or assumes any liability or responsibility for the use of this
software.  If software is modified to produce derivative works, such modified 
software should be clearly marked, so as not to confuse it with the version 
available from LANL.
AUTHOR
Jeff Bloch
MODIFICATIONS/REVISION LEVEL
%I%     %G%
Use WCSSPH2XY instead of QDCB   Wayne Landsman   December 1994
Converted to IDL V5.0   W. Landsman   September 1997