How do I divide one column in gnuplot?

Question

I have gnuplot data file. I would like to plot it, but divide every value in the x-axis by n.

Can I do this from within gnuplot, or do I have to rewrite the data file?

Answer 1

Supposing that the x values are in the first column of the file 'test.dat' and the y values are in the second column of the same file, than you can operate on the values in the following way:

plot 'test.dat' using ($1/n):($2)

see the manual for more information and examples on the 'using' keyword.

Note that this will not change the values of your data file 'test.dat'. Instead, if you prefer to rewrite the data file, you can do it automatically through awk. For example:

awk '{print $1/n,$2}' test.dat > testnew.dat

will substitute the x values in the first column of test.dat with x/n and will generate a new file called testnew.dat.