NAME
v.net.spanningtree - Computes minimum spanning tree for the network.
KEYWORDS
vector, network, spanning tree
SYNOPSIS
v.net.spanningtree
v.net.spanningtree help
v.net.spanningtree [-g] input=name output=name alayer=string nlayer=string [afcolumn=name] [ncolumn=name] [--overwrite] [--verbose] [--quiet]
Flags:
- -g
- Use geodesic calculation for longitude-latitude locations
- --overwrite
- Allow output files to overwrite existing files
- --verbose
- Verbose module output
- --quiet
- Quiet module output
Parameters:
- input=name [required]
- Name of input vector map
- Or data source for direct OGR access
- output=name [required]
- Name for output vector map
- alayer=string [required]
- Layer number or name
- Arc layer
- Default: 1
- nlayer=string [required]
- Layer number or name
- Node layer
- Default: 2
- afcolumn=name
- Arc forward/both direction(s) cost column (number)
- ncolumn=name
- Node cost column (number)
DESCRIPTION
v.net.spanningtree finds the minimum spanning tree in a network.
NOTES
A spanning tree is a minimum cost subnetwork connecting all nodes in a
network. Or, if a network is disconnected then the module computes the
minimum spanning tree for each (weakly) connected component. So, strictly
speaking, v.net.spanningtree does not compute spanning tree but
a spanning forest. As the name suggests, a spanning tree is a tree. That
is, it contains no cycles and if a component has N nodes then the tree
has N-1 edges connecting all nodes. Accol is used to specify the
costs of the edges. The output consists of the edges in the
spanning tree.
EXAMPLES
Find cheapest set of pipelines connecting all nodes.
v.net.spanningtree input=projected_pipelines output=spanningtree accol=cost
SEE ALSO
v.net.steiner
AUTHORS
Daniel Bundala, Google Summer of Code 2009, Student
Wolf Bergenheim, Mentor
Last changed: $Date: 2011-11-08 13:24:20 -0800 (Tue, 08 Nov 2011) $
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