v.net.spanningtree.1grass man page

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  [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 locations

--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

Last changed: $Date: 2016-03-08 22:04:56 +0100 (Tue, 08 Mar 2016) $

Source Code

Available at: v.net.spanningtree source code (history)

Main index | Vector index | Topics index | Keywords index | Graphical index | Full index

© 2003-2017 GRASS Development Team, GRASS GIS 7.2.1 Reference Manual

Info

GRASS 7.2.1 Grass User's Manual