help-gsl
[Top][All Lists]

## Re: [Help-gsl] multidim interpolation

 From: jeremy theler Subject: Re: [Help-gsl] multidim interpolation Date: Wed, 8 May 2013 22:35:49 -0300 User-agent: KMail/1.13.7 (Linux/3.2.0-4-amd64; KDE/4.8.4; x86_64; ; )

```David,

already visited by my browser :)

Even though I found your code very attractive, what I want to do is to
interpolate arbritarily-scattered data, not only points located in a
rectangular grid. I managed to perform that task by using the idea behind the
shape functions in the finite element method, which gives pretty good results.

As a matter of fact, today I took a look at a recommendation of one of my
colleagues, that is to arrange the arbitrarily-scattered data into k-
dimensional trees to efficiently perform the nearest-neighbor interpolation. I
think tha an n-nearest-neighbor or a range-based nearest-neighbor search may
also be used to compute some inverse-square weighted sum of individual points
or to use some other scheme that provides continuous outputs.

I think, at least taking into account only my personal experience with the
subject, that multidimensional interpolation has too many caveats and that
there may be other aspects that may have more importance to be discussed
and/or implemented in GSL. However, it may be handy to have a look at this
issue, or even at k-dimensional trees as these artifacts may have other
applications as well.

--
jeremy

On Sunday 05 May 2013 01:42:55 David Zaslavsky wrote:
> I have a library that performs 2D interpolation on Github:
>  https://github.com/diazona/interp2d
> It's not ready to be fully released, primarily because there is little
> to no documentation or test cases, but I have used the bilinear and
> bicubic interpolation routines in a real-world application or two and
> they seem to give accurate results. So if you need 2D interpolation, you
> could clone the repository and take your chances with it.
>
> :) David

```