[Gnuplot-info] how to make contour plot in 2d with other 2d lines

[Michael C. <van...@gm...>]

Hi, it is pretty common to see such a graph in nonlinear optimization
book: on xy plane, contour of objective function, and lines or curves
of constraints.

I tried to make contour using splot, but then I can not add 2d plots
onto it. Any suggestions?

--=20
Michael Chen