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v.voronoi
Langue: en
Version: 371856 (fedora - 01/12/10)
Section: 1 (Commandes utilisateur)
NAME
v.voronoi - Creates a Voronoi diagram from an input vector map containing points or centroids.KEYWORDS
vectorSYNOPSIS
v.voronoiv.voronoi help
v.voronoi [-lt] input=name output=name [--overwrite] [--verbose] [--quiet]
Flags:
- -l
Output tessellation as a graph (lines), not areas- -t
Do not create attribute table- --overwrite
Allow output files to overwrite existing files- --verbose
Verbose module output- --quiet
Quiet module output
Parameters:
- input=name
Name of input vector map- output=name
Name for output vector map
DESCRIPTION
v.voronoi uses an existing vector points map (input) to create a Voronoi diagram (Thiessen polygons) in a new vector map (output).The bounds of the output map are limited by the current region. (see g.region)
Voronoi diagram and Delaunay triangulation example:
|
Delaunay Triangulation (left pane), Voronoi diagram (center pane), and both (right pane)
NOTES
Voronoi diagrams may be used for nearest-neighbor flood filling. Give the centroids attributes (start with v.db.addcol), then optionally convert to a raster map with v.to.rast.EXAMPLE
Commands used with the Spearfish dataset to create the above figure.g.region n=4927250 s=4919400 w=588650 e=594850
d.frame -c fr=one at=0,100,0,33.3333
d.frame -c fr=two at=0,100,33.3333,66.6667
d.frame -c fr=three at=0,100,66.6667,100
v.delaunay -lr in=archsites out=arch_delaunay
d.frame -s one
d.vect arch_delaunay
d.vect archsites color=red fcolor=red size=5 icon=basic/circle
v.voronoi -l in=archsites out=arch_voronoi
d.frame -s two
d.vect arch_voronoi type=line
d.vect archsites color=red fcolor=red size=5 icon=basic/circle
d.frame -s three
d.vect arch_voronoi type=line
d.vect arch_delaunay color=blue
d.vect archsites color=red fcolor=red size=5 icon=basic/circle
BUGS
Only attribute table of field 1 is copied.REFERENCES
Steve J. Fortune, (1987). A Sweepline Algorithm for Voronoi Diagrams, Algorithmica 2, 153-174.SEE ALSO
g.region, v.delaunay, v.hullAUTHORS
James Darrell McCauley, Purdue UniversityGRASS 5 update, improvements: Andrea Aime, Modena, Italy
GRASS 5.7 update: Radim Blazek
Last changed: $Date: 2007-11-15 02:55:18 +0100 (Thu, 15 Nov 2007) $
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