[Q]:Nature Neighbor Interpolation

[James Darrell McCauley]

tyshih at cc.nctu.edu.tw (tyshih at cc.nctu.edu.tw) writes on 28 July 1995:
>Greetings.  Is the a nature neighbor interpolation scheme implemented
>with TIN in GRASS?  And, is there a constrainted TIN implementation in 
>GRASS?  Any information will be highly appreciated.  Cheers.

no, natural neighbor is not implemented in grass.
If David Watson wants to release his code in electronic
format, I'd be glad to put a GRASS wrapper around it 
(I have it in printed form but I'm not much for OCR;
I also have a binary, but I'm not much into reverse engineering).

For triangulation, see the GEOM package.
  ftp://moon.cecer.army.mil/grass/incoming/geom.tar.Z

For what it's worth, my tests have shown that the regularized spline
in s.surf.tps does a better job at interpolation than natural neighbor
(with gradient estimation). See the article on "Bivariate
Interpolation" on my homepage (be sure to get the submission to
*Transactions of ASAE* for details).

>Shih, Peter (tyshih at cc.nctu.edu.tw)

Darrell
-- 
James Darrell McCauley, PhD           http://soils.ecn.purdue.edu/~mccauley/
Agricultural & Biological Engineering mccauley at ecn.purdue.edu
Purdue University                     tel: 317.494.1198 fax: 317.496.1115