[SciPy-dev] interp2d and sandbox/delaunay

[John Travers]

Hi all,

As you may have guessed from my noise (tell me to shut up if i'm
irritating), i'm taking a serious look at the state of
scipy.interpolate

As previously stated, I think it needs to be reorganised/split into
several parts, but I'll leave that to other threads.

In this post I'm wondering about the status of interp2d.

At the moment it is based on netlib->dierckx->surfit. This is bad as
this routine should not be used for interpolation. I think others have
had problems with this code (reading about a year ago on scipy-user) -
it segfaults mine.

I have recently implemented netlib->dierckx->regrid. Which
interpolates nicely for regular rectangular grids -> this could be
used in interp2d, except that it doesn't work on scattered data (is
this required? I think so yes).

The solution would be to call regrid for regular data and
<some_other_method> for scattered data.

The best <some_other_method> appears to be delaunay triangulation
followed by natural neighbour interpolation or regrid. (this is what
MATLAB does).

So my questions are:

1. can I fiddle with interp2d and the other scipy.interpolate stuff?
2. what is the status of the sanbox/delaunay stuff (why is it not in
the main scipy) if there is a problem with it, can I package a
different package that does this?

Regards,
John