Lets consider an arbitrary spherical function which has no practical meaning at all but serves as a prototype for pole figures, inverse pole figures, Schmidt or Taylor factor maps, etc.
Passing the option contour to the plot command we may add contours at specific levels on top of the smooth plot
The plotting command return a handle h to the plotted contours. This handle can be used to customize the contour lines. In particular, one can use the Matlab command clabel to add labels to specific contour levels.
A practical example
The situation becomes a little bit more involved if contour lines should be added to multiple plot. Let us consider the pole figures of the following ODF
Then we may use the option 'ShowText','on' to display contour labels.