Dear Netters:
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.
Shih, Peter (tyshih@cc.nctu.edu.tw)
Sorry, there is no TIN implementation in GRASS at all. Virtually all
analysis in GRASS is done with raster data, though there are an
increasing number of programs that make use of GRASS' arc-node vector
format as well.
--
Malcolm D. Williamson - GIS Specialist E-mail: malcolm@cast.uark.edu
Center for Advanced Spatial Technologies Telephone: (501) 575-6159
Ozark Rm. 12 Fax: (501) 575-5218
University of Arkansas
Fayetteville, AR 72701
On 28 Jul 1995 tyshih@cc.nctu.edu.tw wrote:
Dear Netters:
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.Shih, Peter (tyshih@cc.nctu.edu.tw)
tyshih@cc.nctu.edu.tw (tyshih@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@cc.nctu.edu.tw)
Darrell
--
James Darrell McCauley, PhD http://soils.ecn.purdue.edu/~mccauley/
Agricultural & Biological Engineering mccauley@ecn.purdue.edu
Purdue University tel: 317.494.1198 fax: 317.496.1115