set key below set pointsize 5.0 set terminal png size 300,300 set xrange [0:500] set yrange [0:400] set output "courbe1.png" plot sin(x)+250 with lines title "sin(x)+250" linewidth 2 set yrange [248:256] set output "courbe2.png" plot sin(x)+250 with lines title "sin(x)+250" linewidth 2 set yrange [1:500] set output "courbe3.png" plot x with lines title "x" lw 2, sqrt(x) with lines title "√x" lw 2 set logscale y set output "courbe4.png" plot x with lines title "x" lw 2, sqrt(x) with lines title "√x" lw 2