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     [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

SOURCE CODE

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

       Accessed: unknown

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