Program:       RENZOGRAM

Purpose:       Build and execute a GPLOT input file that plots 
               contours per level for different subsets. The contours
               can be plotted on a set displayed in GIDS.

Category:      DYNAMICS, PLOTTING, UTILITY

File:          renzogram.c

Author:        M.G.R. Vogelaar

Keywords:

   INSET=      Give set and subsets for the colour contours.
               Maximum number of subsets is 1024.
              
               From these subsets, the contours will be plotted in one
               plot. The levels are entered in LEVEL1= etc.
              
             
   BACKSET=    Give set or subset for a background colour map: [no map]
       
               Draw the contours on this image which becomes your
               background.
               Input must be 2-dimensional and the box at BOX= is 
               applied to THIS set. Then the contour map is scaled 
               so that it fits this map. If nothing is entered (default),
               then BOX= applies to INSET=


   BOX=        Give box in .....                        [entire subset]
   
               If BACKSET= has a set name then BOX= applies to this set.
               Else, BOX= applies to the subsets in INSET=


** FILENAME=   Name of GPLOT ascii file:           [GPLOTinputfile.scr]

               This program generates an input file for GPLOT.
               After finishing, it is not erased from disk, so you can
               use it again, or edit it before re-use in GPLOT.
               If you want a hardcopy (COPY=Y) then a second file
               is created with the same name and extra extension '.dump'. 
               This file contains plot commands for a printer or a 
               PostScript file.


    LEVEL1=    Enter contour level:
    LEVEL2=    Enter contour level:                              [skip]
    LEVEL3=    Enter contour level:                              [skip]
    LEVEL4=    Enter contour level:                              [skip]
    LEVEL5=    Enter contour level:                              [skip]
                     
               Enter per LEVELx= keyword ONE contour level in units 
               of the input data at INSET=
               Each level gets its own line style which must be 
               specified with the LTYPE= keyword.
               
               Data is read from each subset and the contour is plotted 
               in a colour depending on the subset number. 
               However, after starting GIDS there are only 16 colours 
               available for the the contours, so some neighbouring 
               subsets get the same colour. The colours are selected
               according the 'Rainbow' colour lookup table. For
               hard copy devices there are 112 colours available.
               
              
    LTYPE=     Enter a line style per contour level:          [1 2 ...]
               The styles are:

               1. full line 
               2. long dashes
               3. dash-dot-dash-dot
               4. dotted
               5. dash-dot-dot-dot
                            
              
** LWIDTH=     Give the line width of the contours:                 [2] 

               This controls how thick your contours will be plotted.
               You can select a number between 1 and 21. 
               

   COPY=       Copy output to hardcopy device?                 Yes/[No]
   
               Send the output to printer or PostScript file.
               Adjust the colours in GIDS if you have a background 
               image. Then use COPY=Y to create a hard copy.
               If COPY=Y , the GRDEVICE= keyword is prompted 
               to specify the device.
  
       
   READY=      You can change the colours for the background set now!
 
               At this point you can adjust the colours of the 
               background set in GIDS. After pressing enter, the
               colours are fixed. If you want to use the generated
               GPLOT file from within GPLOT, then you need to 
               start GIDS also because the GPLOT macro will always
               try to contact GIDS for the colour information.
               
                
   GRDEVICE=   Graphics device           [list of all graphics devices]
              
               Select the device to which you want to send the output.
               This can be a (colour) printer or a (colour) PostScript 
               file. Note that this keyword is also set in hidden mode
               to start VIEW, so for a batch job you have to specify 
               a second device e.g.: GRDEVICE=X11;X11



Description:   RENZOGRAM is a program which displays kinematic and spatial 
               information in a single colour plot. It overlays one 
               (or more) contours per subset over an image (such as an 
               optical image), plotting the contours of each subset with a
               different colour. In this way, the velocity information is 
               color coded and easy to see together with the extension of 
               the features. It is a useful tool to observe changes in 
               inclination of galactic disks (warps). Its most common use is
               to plot a low contour (e.g. 3 sigma), and perhaps a high 
               contour (to see the peak of each channel). The program is an 
               implementation of an old idea of prof. Renzo Sancisi.

Notes:         


Example:       renzogram
               INSET=AURORA freq
               BACKSET=AURORA freq 0 
               BOX=-64 -64 64 64
               CLIP=
               LEVEL1=3
               COPY=y
               GRDEVICE=PCPSFILE/myfile.ps

Updates:       Mar 31, 1998: VOG, Document created.
               Oct 19, 2000: VOG, Add colour coded table with physical 
                                  coordinates.
               Nov 24, 2000: VOG, 'box' in GPLOT file and change of format
                                  in velocity legend.