Gnuplot 2

# gráfico do potencial elétrico
set xlabel 'x'
set ylabel 'y'
set zlabel 'V'
set xrange [-1:1]
set yrange [-1:1]
set zrange [0:1]
set grid
set title 'Potencial elétrico'
splot 'potencial_laplace_jacob2.dat' every 5:5 using 1:2:3 lt 7 lc 1 title 'jacobi'
replot 'potencial_laplace_gauss2.dat' every 5:5 using 1:2:3 lt 7 lc 2  title 'gauss-siedel'
set term png 
set out 'potencial_laplace2.png'
replot
reset

# gráfico das equipotenciais
set xlabel 'x'
set ylabel 'y'
set xrange [-1:1]
set yrange [-1:1]
set grid
set title 'Equipotenciais'
plot 'equipotencial_laplace_jacob2.dat' using 1:2 with points lt 7 lc 1 title 'jacobi'
replot 'equipotencial_laplace_gauss2.dat' using 1:2 with points lt 7 lc 2 title 'gauss-siedel'
set term png 
set out 'equipotencial_laplace2.png'
replot
reset

# gráfico do campo elétrico
set xlabel 'x'
set ylabel 'y'
set xrange [-1:1]
set yrange [-1:1]
set grid
set title 'Campo elétrico'
plot 'electric_laplace_jacob2.dat' every 5:5 using 1:2:($3*3):($4*3) with vectors lc 1 title 'jacobi'
replot 'electric_laplace_gauss2.dat' every 5:5 using 1:2:($3*3):($4*3) with vectors lc 2 title 'gauss-siedel'
set term png 
set output 'electric_laplace2.png'
replot