Re: 3d plotting, griddata and deluanayn

[Paul Kienzle]

João Cardoso wrote:

> On Tuesday 04 February 2003 02:28, Paul Kienzle wrote:
> | If you are on Windows, you will need to first figure out how to
> | compile qhull for Windows.  We haven't done so yet.
I should add that under the most recent cygwin and the next mingw,
there is no reason it shouldn't build and be usable even as a DLL.
If nothing else, static linking should be possible.

> |
> | If you are on unix, follow the octave-forge/main/geometry/readme
> | instructions
> | for installing qhull.  I haven't tried yet with the most recent qhull
> | release.
> |
> | Download the correct version of octave-forge (octave.sf.net) for your
> | particular
> | version of octave (the latest is for octave 2.1.40 I believe --- if
> | you are using
> | something more recent, you will need to get the CVS version).
> |
> |     ./configure
> |     make
> |     make install
> |
> | griddata does not work as quickly as I would like.  Talk to the
> | qhull author about how to improve it if it is not fast enough for
> | you.
>
> I don't think that Qhull is slow, slow is the searching of triangles in 
> tsearch.
Agreed.  Time permitting, I understand the author of qhull is interested 
in having griddata
functionality in qhull.  Please let him know what you are doing.

> I'm using Sakov's "nn" (natural neighbors) library 
> http://www.marine.csiro.au/~sakov/ that uses Lawson's "walking 
> triangle" algorithm to search for a triangle given a point. "nn" uses 
> "triangle", which not free software, but I have adapted it to work with 
> Qhull.
Oops --- Andreas is using triangle in his FEM stuff.  Your are right --- 
the license is not
open source since it does not allow redistribution for commercial 
purposes.  Does
triangle do anything that qhull doesn't?

> plgriddata() will soon be integrated into PLplot.
>  
Any chance you could create 'griddata' which we could include in 
octave-forge
and call that from plgriddata?

Thanks in advance,

Paul Kienzle
address@hidden




-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
Subscription information:  http://www.octave.org/archive.html
-------------------------------------------------------------