Help! 3D plot of z-values over a set of (x,y) coordinates--surf plot or plot3?

Hi,

I have a 20x8 matrix of z-values that I'm trying to plot over a set of
corresponding x-y coordinates with regular intervals. I checked that
the values and the dimensions all matched. Using surf(x,y,z) gave me
interpolated 3-D graph of only 19x7 map. Whereas plot3 has all 20x8
coordinate points plotted, but does not show the 3rd dimension (i.e.,
the topdown view are only 8 vertical lines, each with a different
color).

Is there a way of getting a 3D mapping at each of the 160 points
(20x8)? I thought matlab could do this. Plese advice!

Thanks in advance.

Cheng

 

Note: In my case, z is not a function of (x,y).