[R] Re : how to plot select points in preexisting persp plot

[Preeti Iyer]

Hello,
I have a set of points (x and y coordinates) generated by 
multidimensional scaling function (isoMDS) . The z-axis coordinates 
consists of a set of values for each of these x and y coordinates. I use 
persp function to give a surface. What I would like to know is, how I 
can use the z-coordinates to plot a text label for select points on this 
surface?
Hope it is clearer now.
Regards,
Preeti