set terminal png set size 0.8,0.8 set output "rk.png" set title "Runge-Kutta method" plot "points_rk.dat" using 1:2 title "y(1)", \ "points_rk.dat" using 1:3 title "y(2)" set output "pc.png" set title "Predictor-Corrector method" plot "points_pc.dat" using 1:2 title "y(1)", \ "points_pc.dat" using 1:3 title "y(2)"