1v.net.spanningtree(1)         Grass User's Manual        v.net.spanningtree(1)
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NAME

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

9       vector, network, spanning tree
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SYNOPSIS

12       v.net.spanningtree
13       v.net.spanningtree --help
14       v.net.spanningtree   [-g]  input=name  output=name   [arc_layer=string]
15       [node_layer=string]   [arc_column=name]   [node_column=name]   [--over‐
16       write]  [--help]  [--verbose]  [--quiet]  [--ui]
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18   Flags:
19       -g
20           Use geodesic calculation for longitude-latitude locations
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22       --overwrite
23           Allow output files to overwrite existing files
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25       --help
26           Print usage summary
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28       --verbose
29           Verbose module output
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31       --quiet
32           Quiet module output
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34       --ui
35           Force launching GUI dialog
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37   Parameters:
38       input=name [required]
39           Name of input vector map
40           Or data source for direct OGR access
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42       output=name [required]
43           Name for output vector map
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45       arc_layer=string
46           Arc layer
47           Vector  features can have category values in different layers. This
48           number determines which layer to use. When  used  with  direct  OGR
49           access this is the layer name.
50           Default: 1
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52       node_layer=string
53           Node layer
54           Vector  features can have category values in different layers. This
55           number determines which layer to use. When  used  with  direct  OGR
56           access this is the layer name.
57           Default: 2
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59       arc_column=name
60           Arc forward/both direction(s) cost column (number)
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62       node_column=name
63           Node cost column (number)
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DESCRIPTION

66       v.net.spanningtree finds the minimum spanning tree in a network.
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NOTES

69       A spanning tree is a minimum cost subnetwork connecting all nodes in an
70       undirected network (same forward and backward costs). If a  network  is
71       disconnected  then  the  module  computes the minimum spanning tree for
72       each (weakly) connected component. So, strictly  speaking,  v.net.span‐
73       ningtree  does  not compute spanning tree but a spanning forest. As the
74       name suggests, a spanning tree is a  tree.  That  is,  it  contains  no
75       cycles  and if a component has N nodes then the tree has N-1 edges con‐
76       necting all nodes. Accol is used to specify the costs of the edges. The
77       output consists of the edges in the spanning tree.
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EXAMPLES

80       Find cheapest set of pipelines connecting all nodes.
81       v.net.spanningtree input=projected_pipelines output=spanningtree accol=cost
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SEE ALSO

84        v.net, v.net.steiner
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AUTHORS

87       Daniel Bundala, Google Summer of Code 2009, Student
88       Wolf Bergenheim, Mentor
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90       Last changed: $Date: 2016-03-08 22:04:56 +0100 (Tue, 08 Mar 2016) $
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SOURCE CODE

93       Available at: v.net.spanningtree source code (history)
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95       Main  index  | Vector index | Topics index | Keywords index | Graphical
96       index | Full index
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98       © 2003-2019 GRASS Development Team, GRASS GIS 7.6.0 Reference Manual
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102GRASS 7.6.0                                              v.net.spanningtree(1)
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