Re: Interpolation on scattered data

[Nicholas Jankowski]

On Thu, Mar 12, 2020, 10:49 AM Nicklas Karlsson <address@hidden> wrote:

I have some problem with interpolation on scattered data. griddata(...) or interp2(...) functions do not work well. Delaunay function could triangulate data but maybe not well in all cases.

I have function to find nearest points. Interpolate between the three nearest point should if I think correct be equal to interpolation on delaunay triangulation but me a little bit stupid and can't immidiately figure out the equation. Anyone have it at hand?

I however found two other very interesting functions here http://fourier.eng.hmc.edu/e176/lectures/ch7/node7.html called "Radial Basis Function Method" and "Shepard method". I am however a little bit uncertain what happen then density vary for example then many points are tightly spaced as I expect them to pile up. Anyone used any of these?

I'm not familiar with those algorithms, but what difficulty are you having with a griddata method? What have you tried? Matlab has created a scatteredInterpolant function that works well for the whole process but but it is not yet implemented in octave.

I found a workaround for one of my data sets (a non uniform triangular mesh) following the example from:

https://stackoverflow.com/a/27987120/4598449

they provide an example for whether you do or do not have the scatteredInterpolant function. perhaps some of the suggestions there will be of use.