DIGITIZE Name
      
       DIGITIZE Purpose
      
       Digitize a plot in an image using the mouse cursor.
Category
Calling Sequence
      
       digitize, x, y Inputs
Keyword Parameters
Keywords
        
         MAG=mag  Cursor mag factor (def=5). 
        
         /NOAUTOCENTER Do not try to automatically center the
          
           current point when entering them.  Autocentering is
          
           useful for large scrolling windows, but does not allow
          
           tracing the curve while keeping the left button pressed.
Outputs
      
       x,y = Output points along the curve.  out
Common Blocks
      
       digitize_com Notes
      
       Notes: For an XY plot in an image this routine
      
       can be used to trace along the points in the curve.
      
       Only linear plots are handled.  The plot need not be
              perfectly straight, it can be at an angle.
      
       The data coordinates where the axes cross may not be known
      
       so to calibrate the plot 5 points are entered:
        
         The point where the x and y axes cross,
        
         a point about halfway out the x axis,
        
         the last labeled point on the x axis,
        
         a point about halfway out the y axis,
        
         and the last labeled point on the y axis. 
      
       The known data coordinates of each point are also entered.
      
       The accuracy is limited by the pixel resolution of the plot.
               
      
       Make sure to carefully follow the directions that come up.
              Make sure to click exactly on the axes.
Modification History
      
       R. Sterner, 2005 Sep 01 
      
       R. Sterner, 2005 Sep 06 --- Allowed positioning and added autocenter.
      
       R. Sterner, 2010 Jan 08 --- Added /XLOG and /YLOG.
      
       R. Sterner, 2010 May 04 --- Converted arrays from () to []. 
  
 Copyright (C) 2005, Johns Hopkins University/Applied Physics Laboratory
  
 This software may be used, copied, or redistributed as long as it is not
  
 sold and this copyright notice is reproduced on each copy made.  This
  
 routine is provided as is without any express or implied warranties
  
 whatsoever.  Other limitations apply as described in the file disclaimer.txt.