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**NAME**

v.net.spanningtree- Computes minimum spanning tree for the network.

**KEYWORDS**

vector, network, spanning tree

**SYNOPSIS**

v.net.spanningtreev.net.spanningtreehelpv.net.spanningtree[-g]input=nameoutput=name[layer=integer] [accol=name] [--overwrite] [--verbose] [--quiet]Flags:-gUse geodesic calculation for longitude-latitude locations--overwriteAllow output files to overwrite existing files--verboseVerbose module output--quietQuiet module outputParameters:input=nameName of input vector mapoutput=nameName for output vector maplayer=integerLayer number A single vector map can be connected to multiple database tables. This number determines which table to use. Default:1accol=nameName of Arc cost column

**DESCRIPTION**

v.net.spanningtreefinds 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.spanningtreedoes 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.Accolis used to specify the costs of the edges. Theoutputconsists 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, MentorLastchanged:$Date:2013-05-2313:01:55-0700(Thu,23May2013)$Full index © 2003-2013 GRASS Development Team