set output 'waves_out_phase.ps' set term postscript color enhanced set grid set key top right set size square set xlabel '' set ylabel '' set title 'Two waves moving out of phase ' plot [-5:12][-1.5:2.0] 'wave_phase.dat' using 1:2 with linespoints lt 1 lw 5 t '' , 'wave_phase.dat' using 1:5 with linespoints ps 1 pt 3 lw 3 t '' set output quit