GRASS GIS: v.delaunay

NAME

v.delaunay - Creates a Delaunay triangulation from an input vector map containing points or centroids.

KEYWORDS

vector

SYNOPSIS

v.delaunay
v.delaunay help
v.delaunay [-rl] input=name output=name [--overwrite] [--verbose] [--quiet]

Flags:

-r: Use only points in current region
-l: Output triangulation as a graph (lines), not areas
--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.delaunay uses an existing vector points map (input) to create a Delaunay triangulation vector map (output).

Delaunay triangulation and Voronoi diagram example:

Delaunay Triangulation (left pane), Voronoi diagram (center pane), and both (right pane)

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

REFERENCES

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

AUTHORS

James Darrell McCauley, Purdue University
GRASS 5 update, improvements: Andrea Aime, Modena, Italy
GRASS 5.7 update: Radim Blazek

Last changed: $Date: 2007-11-14 17:50:31 -0800 (Wed, 14 Nov 2007) $

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