Mapping resultant velocity on to grid points with MATLAB
 

Greeting fellow CFD users.

I have created an algorithm to determine POD velocity basis vector for x and y components at each node point for a 2d mesh for 9 observations with Matlab.
I have a column vector x denoting the x co-ordinates at each node and a column vector y for the y co-ordinates.
plot(x,y) gives me the 2d domain.
I have a column vector r denoting the resulting velocity of x and y at each node.
Now all I need to do is map the resultant velocity vector at each node onto the back onto the 2d grid.
What is the command to do this?
I have tried meshgrid, and ndgrid but have no success as of yet.
kind regards
gowain