Fitting 3d data

I have a nonlinear 3D data. Can someone help in providing me a function that fits my data? I would like to use that function for interpolation/extrapolation. Appreciate your help.

Answer 1

[Torsten]

I suggest you interpolate directly from the data:

https://de.mathworks.com/help/matlab/ref/scatteredinterpolant.html

Best wishes

Torsten.

[Bhar_tex]

I am confused how to use function, F (= scatteredInterpolant(x,y,z)) for interpolation. i.e., if I have xnew,ynew and how can I predict corresponding znew using this F?

[Torsten]

Put your first column in vector x, your second column in vector y and your third column in vector z.

Then call

F = scatteredInterpolant(x,y,z);

For a query point (xq,yq)

zq = F(xq,yq)

gives you the interpolated z-value.

Best wishes

Torsten.