GNUPLOT

If you have a file which contains the data to plot, example file.dat , type gnuplot to the terminal and press Enter.

On the new line wich appears, type

 p "file.dat" u 1:2 w lp

This p means to plot for the file.dat, u: use, 1:2: plot column 1 vs column 2, w: write, lp: line and points. Then, name the graph for example image01.pngby typing the following comands

set term png

set output "image01.png"

Then, set the y label, x label and title to be for exapmle Energy, Lattice consant, and Optimized lattice constant respectivelly by

set ylabel "energy"

set xlabel "Lattice constant"

set title "Optimized lattice constant"

You can also set the x range, y range and x tics by typing the following comands

set xrange [4.5, 9.5]

set yrange [-260.5, -260.1]

set xtics (4.5,5.0,5.5,6.0,6.5,7.0,7.5,8.0,8.5,9.0,9.5)

After to put the all needed comands, then replot and exit by typing

 replot


 exit

To se the plotted image, type

  gwenview image01.png

  eog image01.png