do floating point calculation in a script and save to a file

k=$(echo “scale = 10; 2 * ((3.14 – $i) / 3.14)” | bc)






make both point size and point color a function of a variable

This can be useful in plotting the wavefunctions on a bunch of sites. For example say the 1 and 2 column has the x and y coordinates of the sites. The 3 rd column contains the wavefunction amplitude.

pl ‘./fort.80’ u 1:2:($3)*10:3 w p pt 7 ps variable palette

The above command will make both the size of the point and the color bar a function of the wavefunction amplitude.