coyote: CGSHADE_SURF

Description
The purpose of cgShade_Surf is simply to make it easier for people to remember
how to create a shaded surface with cgSurf. See the documentation for cgSurf to
learn more about surface rendering. All this program does is make sure the SHADED
keyword to cgSurf is set.
.. image:: cgshade_surf.png
Categories
Graphics
Author
FANNING SOFTWARE CONSULTING::
    David W. Fanning 
    1645 Sheely Drive
    Fort Collins, CO 80526 USA
    Phone: 970-221-0438
    E-mail: david@idlcoyote.com
    Coyote's Guide to IDL Programming: http://www.idlcoyote.com
Params
data: in, required, type=any
     A two-dimensional array of data to be displayed.
x: in, optional, type=any
     A vector or two-dimensional array specifying the X coordinates of the
     surface grid.
y: in, optional, type=any
     A vector or two-dimensional array specifying the Y coordinates of the
     surface grid.
Keywords
addcmd: in, optional, type=boolean, default=0
   Set this keyword to add the command to an cgWindow. Setting this keyword
   automatically sets the WINDOW keyword, but the command does not erase the
   graphics window as it would normally.
axiscolor: in, optional, type=string/integer, default='black'
   If this keyword is a string, the name of the axis color. By default, 'black'.
   Otherwise, the keyword is assumed to be a color index into the current color table.
axescolor: in, hidden, type=string/integer
   Provisions for bad spellers.
background: in, optional, type=string/integer, default='white'
   If this keyword is a string, the name of the background color. By default, 'white'.
   Otherwise, the keyword is assumed to be a color index into the current color table.
bottom: in, optional, type=string/integer, default='black'
   If this keyword is a string, the name of the bottom color. By default, same as COLOR.
   Otherwise, the keyword is assumed to be a color index into the current color table.
charsize: in, optional, type=float, default=cgDefCharSize*1.25
   The character size for axes annotations. Uses cgDefCharSize()*1.25 to select default
   character size, unless !P.Charsize is set, in which case !P.Charsize*1.25 is always used.
color: in, optional, type=string/integer, default='blu6'
   If this keyword is a string, the name of the data color. By default, "BLU6".
   Otherwise, the keyword is assumed to be a color index into the current color table.
elevation_shading: in, optional, type=boolean, default=0
   Set this keyword to put elevation shading into effect for the surface.
font: in, optional, type=integer, default=-1
   The type of font desired. If undefined, and the current graphics device is PostScript,
   the FONT keyword will be set to 1, indicating true-type fonts. The FONT keyword must
   be set to -1 (Hershey fonts) or 1 (true-type fonts) for surface annotations to be
   rotated correctly in PostScript output.
layout: in, optional, type=intarr(3)
    This keyword specifies a grid with a graphics window and determines where the
    graphic should appear. The syntax of LAYOUT is three numbers: [ncolumns, nrows, location].
    The grid is determined by the number of columns (ncolumns) by the number of 
    rows (nrows). The location of the graphic is determined by the third number. The
    grid numbering starts in the upper left (1) and goes sequentually by column and then
    by row.
noerase: in, optional, type=boolean, default=0
   Set this keyword to prevent the window from erasing the contents before displaying
   the surface plot.
outfilename: in, optional, type=string
   If the `Output` keyword is set, the user will be asked to supply an output
   filename, unless this keyword is set to a non-null string. In that case, the
   value of this keyword will be used as the filename and there will be no dialog
   presented to the user.
output: in, optional, type=string, default=""
   Set this keyword to the type of output desired. Possible values are these::
       'PS'   - PostScript file
       'EPS'  - Encapsulated PostScript file
       'PDF'  - PDF file
       'BMP'  - BMP raster file
       'GIF'  - GIF raster file
       'JPEG' - JPEG raster file
       'PNG'  - PNG raster file
       'TIFF' - TIFF raster file
   Or, you can simply set this keyword to the name of the output file, and the type of
   file desired will be determined by the file extension. If you use this option, the
   user will not be prompted to supply the name of the output file.
   All raster file output is created through PostScript intermediate files (the
   PostScript files will be deleted), so ImageMagick and Ghostview MUST be installed 
   to produce anything other than PostScript output. (See cgPS2PDF and cgPS_Close for 
   details.) And also note that you should NOT use this keyword when doing multiple 
   plots. The keyword is to be used as a convenient way to get PostScript or raster 
   output for a single graphics command.
palette: in, optional, type=byte
    Set this keyword to a 3 x N or N x 3 byte array containing the RGB color vectors 
    to be loaded before the surface is displayed. Such vectors can be obtained, for 
    example, from cgLoadCT with the RGB_TABLE keyword:
        cgLoadCT, 33, RGB_TABLE=palette
        cgSurf, cgDemoData(2), PALETTE=palette, /Elevation
rotx: in, optional, type=float, default=30
   The rotation about the X axis.
rotz: in, optional, type=float, default=30
   The rotation about the Z axis.
shaded: in, optional, type=boolean, default=1
   Set this keyword if you wish to display a shaded surface. To display shaded surfaces
   in a device-independent way, the shading values are confined to indices 0 to 253 with
   SET_SHADING, and the background color is placed in color index 254. The color table vectors
   are reduced to 254 elements when this happens. This all happens behind the stage, 
   and the original color table is restore upon exit. Because I can't tell how many values
   SET_SHADING is using on entering the program, I just set it back to its default 256 values
   on exiting the program.
shades: in, optional, type=byte
   Set this keyword to a byte scaled 2D array of the same size as data to shade the surface
   with these color indices.
skirt: in, optional, type=any
   Set this keyword to a Z value where a skirt will be drawn for the surface.
title: in, optional, type=string
   The title of the plot. It will be written "flat to the screen", rather than rotated.
traditional: in, optional, type=boolean, default=0
    If this keyword is set, the traditional color scheme of a black background for
    graphics windows on the display is used and PostScript files always use a white background.
tsize: in, optional, type=float
   The character size for the title. Normally, the title character size is 1.1 times
   the character size of the surface annotation.
tspace: in, optional, type=float
   The title Y spacing. This should be a number, between 0 and 1 that is the fraction 
   of the distance between !Y.Window[1] and !Y.Window[0] to locate the title above 
   !Y.Window[1]. When Total(!P.MULTI) EQ 0, the default is 0.005, and it is 0.0025 otherwise.
window: in, optional, type=boolean, default=0
    Set this keyword if you want to display the plot in a resizable graphics window.
xstyle: in, hidden
    The normal XSTYLE keyword.
xtitle: in, optional, type=string
    The X title of the plot.
ystyle: in, hidden
    The normal YSTYLE keyword.
ytitle: in, optional, type=string
    The Y title of the plot.
zstyle: in, hidden
    The normal ZSTYLE keyword.
ztitle: in, optional, type=string
    The Z title of the plot.
_ref_extra: in, optional, type=any
   Any keyword appropriate for the IDL Surface command is allowed in the program.
History
Change History::
   Written, 1 February 2011. DWF.
Copyright
Copyright (c) 2011, Fanning Software Consulting, Inc.