Generating Postscript files using the x-windows versions________________________________________________________To generate Postscript files directly using the x-windows library (xpltlib.f), set iplot=0 or 2 in the pltpar namelist. The file is a colour Postscript file if iroute=4 in the pltparnamelist, and a black and white plot otherwise. So this means,only the uniras versions of the programs will generate the plot meta-file called p.out used by the program rayplot. The file produced by the x-windows versions will also be called p.out if iplot=0 or 2, but will be a postscript file. The program rayplot will also produce a postscript file if iplot=0 or 2 is used, and the postscript file will be called post.outin this case.Postscript plotting added by D. Demanet (Liege Univ, Belgium)