Someone posed a question to me about delineating polygons around
points (sites), sort of splitting the distance between points to create
a "polygon of influence" of each site. The sites are unequally distributed.
Would this best be done by converting the sites to a raster and using
r.neighbors or an r.mapcalc statement to "grow" the site cells?
Advice would be appreciated--- thanks in advance
stewalt@ncrds.er.usgs.gov
Sue Tewalt (tewalt@ncrds.er.usgs.gov) writes on 27 September 1995:
Someone posed a question to me about delineating polygons around
points (sites), sort of splitting the distance between points to create
a "polygon of influence" of each site. The sites are unequally distributed.
I believe that the term that you are looking for is "voronoi diagram."
This may be found using the GEOM package:
ftp://moon.cecer.army.mil/grass/incoming/geom.tar.Z
Darrell
P.S. avoid temptation and do not use s.voronoi in src.contrib.
It has a bug which I do not care to fix (GEOM is much
more extensive).
--
James Darrell McCauley, PhD http://www.mcs.com/~mccauley/
16W518 Honeysuckle Rose Lane #214 mccauley@mcs.com
Hinsdale, Illinois 60521 USA tel: 708.655.0643
It sounds like you want to do Thiessen polygons.
I know they can be done with Arc/Info, but I'm new to GRASS.
On Wed, 27 Sep 1995, Sue Tewalt x6437 wrote:
Someone posed a question to me about delineating polygons around
points (sites), sort of splitting the distance between points to create
a "polygon of influence" of each site. The sites are unequally distributed.Would this best be done by converting the sites to a raster and using
r.neighbors or an r.mapcalc statement to "grow" the site cells?Advice would be appreciated--- thanks in advance
stewalt@ncrds.er.usgs.gov