Gnuplot

Basic Usage
Create PNG with sine plot: gnuplot> set terminal png small gnuplot> set out 'somefile.png' gnuplot> plot sin(x)+sin(2*x)

3D Plot Data File
Plot set terminal png font "/usr/share/fonts/corefonts/arial.ttf" 12 size 800,600 set out "test.png" set xlabel "x" set ylabel "y" set zlabel "sin(x)+sin(y)" set key below set nogrid set view 45,30,1.0 # view angles (rotation around x, rotation around y, zoom) set xrange [-3:3] set yrange [-3:3] set zrange [-2:2] splot "datafile.dat" with lines Generate test data -3.step(3, 0.1) do |x| -3.step(3, 0.1) do |y| z = Math.sin(x)+Math.sin(y) puts "#{x} #{y} #{z}" end puts # groups points with same x values end The output data looks like this -3.0 -3.0 -0.282240016119734 -3.0 -2.9 -0.38036933727385 -3.0 -2.8 -0.476108158215772 -3.0 -2.7 -0.568499888293697 -3.0 -2.6 -0.656621379881331
 * 1) set terminal PDF output font-size 12

2D Plot Data File
Create data file: $ vim createdata.py import math d = 0 while d < 2 * math.pi: print d,',',sin(d)+sin(2*d) d += 2 * math.pi / 100 $ python createdata.py > datafile The program outputs this: 0, 0.0 0.0628318530718 , 0.00394264934276 0.125663706144 , 0.0157084194357 0.188495559215 , 0.0351117570559 0.251327412287 , 0.0618466599781 Create gnuplot program: $ vim dataplot.gnuplot set terminal png small set out 'somefile.png' plot 'datafile' using '%lf, %lf' |_ plot the second column as a                          function of the first