interp2 - misuse or bug?

[Kyle Altendorf]

I am running the v3.0.1 MSVC2008 build.  The basic problem is that
even if I pass interp2() a point to interpolate which actually exists
in the x/y parameters  I don't get the same value back as was
contained in the x/y matrices.  Example code and data are both
attached.

I see in the documentation that x and y must be monotonic.  For 1D
interpolation this would be perfectly clear.  Since I am passing
matrices, must both x and y be monotonic in both columns and rows?
Must all rows (or columns) be monotonically increasing in the same
direction?  In my case, columns of x and rows of y are not necessarily
monotonic in either direction.  If I am correct that I am misusing
this function by way of passing not completely monotonic matrices for
x and y, perhaps there should be an error message?

Thanks for any help or clarification,
-kyle

ex.m
Description: Binary data

ex.mat
Description: Binary data