set data style linespoints set grid plot 'saida7.dat' using 1:2 title 'Is (ve) replot 'saida7.dat' using 1:3 title 'Is (pa) replot 'saida7.dat' using 1:4 title 'Is (vácuo) set xlabel 'x / L' set title 'IMPULSO ESPECÍFICO (s)' replot