set key graph 0.4,0.95 set label "4E" at graph 0.02,0.95 set xlabel "objective functions" set ylabel "time (seconds) set terminal fig big thickness 1 fontsize 18 set pointsize 1 plot "trial4E.plt" index 0 t "version-3" with linespoints pointtype 1 replot "trial4E.plt" index 1 t "version-5" with linespoints pointtype 5 set output "trial4E.fig" replot