Looking for triangulator/interpolator
Travis E. Oliphant
oliphant.travis at ieee.org
Sat May 27 23:29:05 EDT 2006
Grant Edwards wrote:
> On 2006-05-27, Travis E. Oliphant <oliphant.travis at ieee.org> wrote:
>
>> Not that you made a bad choice. I do wonder, how much of your
>> difficulty was with the interface to the underlying fitpack
>> routines.
>
> I've no idea. I had never done anything with splines before,
> so it's quite possible I just wasn't doing things right. I
> never got it to work at all for non-gridded data (which is what
> I needed). Since it wasn't stable even for gridded data, I
> more or less gave up.
>
>> The interface is pretty involved as there are lots of
>> parameter choices to the underlying routine. It's very
>> possible the interface is broken in some strange way.
>
> I took a look at underlying Fortran code, but that made my
> dizzy.
Just to finish this thread, I should mention I spent some time yesterday
looking into the details of the underlying surfit fucntion used by
bisplrep. It appears to have difficulties when s=0 is used. It seems
to be geared toward smoothing applications where you are trying to fit
"noisy" scattered data to a smooth function. There are many warnings
about choosing s to be too low.
Thus, trying to use bisplrep for interpolation (instead of data
smoothing) is probably going to be difficult with bisplrep.
We still need a good N-d re-gridding algorithm in SciPy.
-Travis
More information about the Python-list
mailing list