different results with griddata in Matlab2011b vs Matlab2008a

I am using the griddata function with exactly the same variables in Matlab2008a and Matlab2011b, but I get different results. The result from 2011b does not seem correct to me.

The command I'm using is:

[V1 V2 V3] = griddata(A(:,1),A(:,2),A(:,3),B(:,1),B(:,2));

And I check the number of NANs:

S=sum(isnan(V3))

In Matlab2008a I get 6 NANs, in Matlab2011b I get 20.

The A and B matrices I use can be downloaded from here: A_B_matrices

(I give you the exact matrices because I can not reproduce the problem with any numbers. However, they are small: 21x3 and 27x3)

Can someone tell me what has changed between the two Matlab versions I'm using and how can I get the same results in both of them?

Answer 1

[Shashank Prasanna]

Take a look at the release notes. There have been few changes in:

R2009b > Mathematics > Computational Geometry Functions Being Changed

2- and 3-D computational geometry functions (delaunay, convhull, griddata, voronoi, delaunay3, griddata3) no longer use QHULL or the QHULL options arguments. The N-D functions gridatan, delaunayn, convhulln, and voronoin still use QHULL. Compatibility Considerations

The QHULL options arguments to delaunay, convhull, griddata, and voronoi are no longer required and are currently ignored. Support for these options will be removed in a future release.

http://www.mathworks.com/help/matlab/release-notes.html

[DF]

Yes, but I don't use any QHULL options when calling the griddata. So, I don't think this is the root cause.