I want to plot the contour of the following function: f(x,y)=y³*b(x) My data-file looks something like this: x b(x) -1 10.123 -0.995 10.112 -0.99 10.100 I am not sure how to make the right splot command or how to solve this problem at all as my datafile does not look like (x y z). Thats my script so far: reset f(x,y)=y³*b(x) set xrange [-6:6] set yrange [-5:5] set isosamples 50 set table 'test.dat' splot 'Data.dat' u 1:(b(x)=$2, f(x,y)) -------------------------? unset table set contour base set...