Thread Subject: multivariate spline approximation

Thank to the replies to my previous message, I now know how to do optimization over spline approximation function for univariate problem. But when it comes to multivariate spline approximation, I still have problems that I can't solve.

In exploring it, I first tried to use csapi. It seems that it can work with multivariates, but it has to be gridded data. But that will require too many computational efforts, which is not feasible in my case.

In the help file, the only other relevant command to do multivariate spline is "stform", but I don't quite understand how this works even after I read the help file. Also it is said in the help file that: "At present, the toolbox works with just one kind of stform, namely a bivariate thin-plate spline and its first partial derivatives. ". Does this mean that it won't work if my function is determined by more than two variables?

Are there other functions/commands that can do multivariate spline approximation that I missed?


Thanks for any help!