1v.voronoi(1)                  Grass User's Manual                 v.voronoi(1)
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NAME

6       v.voronoi   -  Creates  a Voronoi diagram from an input vector map con‐
7       taining points or centroids.
8

KEYWORDS

10       vector
11

SYNOPSIS

13       v.voronoi
14       v.voronoi help
15       v.voronoi  [-lt]  input=name  output=name   [--overwrite]   [--verbose]
16       [--quiet]
17
18   Flags:
19       -l
20           Output tessellation as a graph (lines), not areas
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22       -t
23           Do not create attribute table
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25       --overwrite
26           Allow output files to overwrite existing files
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28       --verbose
29           Verbose module output
30
31       --quiet
32           Quiet module output
33
34   Parameters:
35       input=name
36           Name of input vector map
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38       output=name
39           Name for output vector map
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DESCRIPTION

42       v.voronoi  uses  an  existing  vector  points  map  (input) to create a
43       Voronoi diagram (Thiessen polygons) in a new vector map (output).
44
45       The bounds of the output map are limited by the current  region.   (see
46       g.region)
47
48       Voronoi diagram and Delaunay triangulation example:
49            |  Delaunay  Triangulation  (left  pane),  Voronoi diagram (center
50       pane), and both (right pane)
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NOTES

53       Voronoi diagrams may be used for nearest-neighbor flood filling.   Give
54       the centroids attributes (start with v.db.addcol), then optionally con‐
55       vert to a raster map with v.to.rast.
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EXAMPLE

58       Commands used with the Spearfish dataset to create the above figure.
59         g.region n=4927250 s=4919400 w=588650 e=594850
60         d.frame -c fr=one at=0,100,0,33.3333
61         d.frame -c fr=two at=0,100,33.3333,66.6667
62         d.frame -c fr=three at=0,100,66.6667,100
63         v.delaunay -lr in=archsites out=arch_delaunay
64         d.frame -s one
65         d.vect arch_delaunay
66         d.vect archsites color=red fcolor=red size=5 icon=basic/circle
67         v.voronoi -l in=archsites out=arch_voronoi
68         d.frame -s two
69         d.vect arch_voronoi type=line
70         d.vect archsites color=red fcolor=red size=5 icon=basic/circle
71         d.frame -s three
72         d.vect arch_voronoi type=line
73         d.vect arch_delaunay color=blue
74         d.vect archsites color=red fcolor=red size=5 icon=basic/circle
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76

BUGS

78       Only attribute table of field 1 is copied.
79

REFERENCES

81       Steve J. Fortune,  (1987).  A Sweepline Algorithm for Voronoi Diagrams,
82       Algorithmica 2, 153-174.
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SEE ALSO

85        g.region, v.delaunay, v.hull
86

AUTHORS

88       James Darrell McCauley, Purdue University
89       GRASS 5 update, improvements: Andrea Aime, Modena, Italy
90       GRASS 5.7 update: Radim Blazek
91
92       Last changed: $Date: 2007-11-15 02:55:18 +0100 (Thu, 15 Nov 2007) $
93
94       Full index
95
96       © 2003-2008 GRASS Development Team
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100GRASS 6.3.0                                                       v.voronoi(1)
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