Each subplot defines a context menu that can enable and disable the listeners associated
with that graph. For example, if you disable the listeners on subplot 221 (upper left) and
change the MATLAB expression contained by the fcneval object, only the remaining
three subplots update when the UpdateGraph event is triggered:
feobject.FofXY = @(x,y) x.*exp(-x.^.5-y.^.5);
Techniques for Using Events and Listeners