gnuplot generate plot command with sprintf?

Question

I want to generate a gnuplot plot command programmatically, like:

plotline = sprintf(\"\'datafile1.dat\' using %d:3 with points, \'%s\' using %d:3 with point         


        

Answer 1

In order to construct such a plot command from some strings, you can use eval to execute the commands contained in a string:

plotline = 'x title "mytitle"'
eval('plot '.plotline)

Alternatively you can use set macros:

set macros
plotline = 'x title "mytitle"'
plot @plotline

This replaces @plotline with the content of the string variable plotline before executing the command. Using plot plotline interpretes the content of plotline as file name. Note, that as of version 4.6 macros don't work properly in loops, but eval works fine.

BTW: If you don't specify your own title, then the actual plot statement is written in the plot legend. But that can't be written to the terminal output.