The "clabel" function allows you to create contour labels and partially customize their appearance.
One approach could be to label the contour plot manually. The following command allows you to click on the plot and MATLAB creates labels at the selected position for the contour line under the mouse:
>> clabel(C,h,'manual')
Click the mouse or press the space bar to label the contour closest to the center of the crosshair. Press the Return key while the cursor is within the figure window to terminate labeling.
There are two possibilities to adjust the density of labels in the entire contour plot when using automatic labelling: 1) Label only a subset of the displayed contour lines:
>> [x,y,z] = peaks;
>> [C,h] = contour(x,y,z);
>> v = [-2 0 6 8]; %Label only the contours with contour levels -2, 0, 6 or 8
>> clabel(C,h,v)
2) Change the spacing between labels on one contour line:
>> [x,y,z] = peaks;
>> [C,h] = contour(x,y,z);
>> clabel(C,h,'LabelSpacing',100) % define space between labels, specified as a scalar value in point units
