3D Interpolation - TSpline?

since I have a scalar function f(x,y,z) calculated in a 3D grid, I wonder if interpolation classes are available under ROOT.
I guess I could do the job just mapping my 3D manifold in a TH3 histogram an then TH3::Interpolate(x,y,z).
That’s only tri-linear, however. Any TSpline-3D for that?

I do not understand. If you have a function(x,y,z) why you do not evaluate this function for a given point?
Use a TF3 and you have it.
If instead of a function you have a set of points in a grid, you can fill a TH3 and use TH3::Interpolate.
An alternative solution is to use TMultiDimfit on your data and then procedd as in the case of a TF3.


Because my function can be defined and evaluated only in that discrete set of points: as a matter of fact, my problem belongs to the second case (set of points in a grid).
I am already using the tri-linear method TH3::Interpolate.
I just asked if higher-order interpolation tools are available under root.