#Plot Data File set title "Interpolatory Polynomials\nLagrange" plot [0:100] [0:100] "data.dat" with points #Now plot fit on top of points. Assumes fit values are in separate file replot "fit.dat" with lines #Now change graphics device to be a PostScript file set output "plot.ps" set terminal postscript enhanced color landscape replot #Now you should be able to send the plot.ps file to a PostScript printer