make figure contours mor evident

How I can plot the contour lines more evident in fig1 like it in figure 2? what is the command for that?

Answer 1

[Walter Roberson]

When you call contour() you can pass in the number of contour levels to use. Or instead you can pass in a vector of the values of the contour levels. To make the contours more obvious, reduce the number of contour levels.