Contour plot when X and Y values are not on a grid

Question

Possible Duplicate:
Generate Contour Given X, Y and Z vectors

I three vectors X, Y, and Z. Currently, I plot them in a scatter plot, but I want to create a contour plot with them. Can I still do this if X and Y do not form a grid?

Answer 1

Some resources about this topic:

http://blogs.mathworks.com/videos/2009/09/18/revisited-integrating-to-find-the-volume-underneath-a-set-of-non-uniformly-spaced-data/

http://www.mathworks.com/matlabcentral/fileexchange/5105