For plotting, Matlab displays everything according to data points, i.e. it doesn't anything about the underlying function. It you want to change the underlying function, the only way I can think of (except changing the Ticks for simple scaling), is the following:
1. extract data
2. perform operation
3. update, e.g. either create a new plot, or update the existing data as
xdata = set(dataObjs, 'XData');
ydata = set(dataObjs, 'YData');
zdata = set(dataObjs, 'ZData');
Cheers
