v.net.spanningtree.1grass - Man Page
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 [arc_layer=string] [node_layer=string] [arc_column=name] [node_column=name] [--overwrite] [--help] [--verbose] [--quiet] [--ui]
Flags
- -g
Use geodesic calculation for longitude-latitude projects
- --overwrite
Allow output files to overwrite existing files
- --help
Print usage summary
- --verbose
Verbose module output
- --quiet
Quiet module output
- --ui
Force launching GUI dialog
Parameters
- input=name [required]
Name of input vector map
Or data source for direct OGR access- output=name [required]
Name for output vector map
- arc_layer=string
Arc layer
Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.
Default: 1- node_layer=string
Node layer
Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.
Default: 2- arc_column=name
Arc forward/both direction(s) cost column (number)
- node_column=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 an undirected network (same forward and backward costs). 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, v.net.steiner
Authors
Daniel Bundala, Google Summer of Code 2009, Student
Wolf Bergenheim, Mentor
Source Code
Available at: v.net.spanningtree source code (history)
Accessed: Saturday Nov 09 07:55:49 2024
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