Re: Interpolation on scattered data

[Francesco Potortì]

>linear, cubic, and natural methods are all triangulation based.  they take
>the scattered points, use octave's delauney triangulation, then calculate
>local interpolants within the triangles. linear (actually bilinear i guess)
>is simply a weighted some of triangle areas (the interpolation point
>creates three sub-triangles within the mesh triangle, and value is a
>weighted projection inversely proportional to sub-triangle size, where a
>big sub-triangle has you more strongly weighted toward the point not
>associated with that sub-triangle).  the v4 method does not triangulate,
>and does a weighted interpolation over the entire mesh. that can get slow
>and memory intensive, but it's currently the only 'smooth' interpolation
>function Octave has implemented (sort of).

Have you considered Kriging?  I have used the stk package from
Octave-forge with profit.

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