Plotting specific points

Hmmm, does anyone know the best/easiest way to take a file of x and y coordinates of dots, and draw those dots on a .pic?

Chris

Hi Chris,

Unfortunately, there is no program that will do what you want directly, as it would be an easy thing to do. The only way I could figure out to do this without writing a very nasty pcomb script is a hack involving vwrays and glow sources in rpict. For a 1024x768 image, it would go something like this:

% echo void glow sglow 0 0 4 100 0 0 0 > sources.rad
% vwrays -i orig.pic < image.pts | rcalc -o 'sglow source s${recno} 0 0 4 ${$4} ${$5} ${$6} 2' >> sources.rad
% oconv sources.rad | rpict -vf orig.pic -w -x 1024 -y 768 \
  > pcompos orig.pic 0 0 -t 1 - 0 0 > spotty.pic
% rm sources.rad

The file "orig.pic" is your original rendering, and "image.pts" is a set of x and y picture coordinates (x left to right, y bottom to top) giving positions in this image where you want to place red spots. (Change the echo command if you want a different color.) The vwrays then generates rays to each point in the image, which get converted to 2-degree distant sources by the rcalc command. (Again, you may wish to alter this if 2 is too big or too small.) Finally, we render these sources and superimpose them on the original picture using rpict and pcompos (with a threshold), resulting in "spotty.pic".

I haven't tried this, and I probably messed up some bit of it, but hopefully you'll be able to sort it out.

-Greg

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From: Christopher Kings-Lynne <[email protected]>
Date: February 16, 2005 5:59:08 AM PST

Hmmm, does anyone know the best/easiest way to take a file of x and y coordinates of dots, and draw those dots on a .pic?

Chris