How to draw curves in a contour plot

I currently have a contour plot, just like this one here Plot example, now I want to add some simple plots of functions in the length width plane, like f(width) = width^n and so on, but I don't know how to overlap these two plots.

Answer 1

[Mischa Kim]

Simon, use

 hold on

before the second plot command. E.g.

 x = 0:0.1:2*pi;
 y = sin(x);
 z = cos(x);
 plot(x,y)    % corresponds to your existing plot
 hold on
 plot(x,z)    % additional plots...
 plot(x,z.^3) % ...you want to add