.TH v.net.spanningtree 1grass "" "GRASS 6.4.4" "Grass User's Manual"
.SH NAME
\fI\fBv.net.spanningtree\fR\fR  - Computes minimum spanning tree for the network.
.SH KEYWORDS
vector, network, spanning tree
.SH SYNOPSIS
\fBv.net.spanningtree\fR
.br
\fBv.net.spanningtree help\fR
.br
\fBv.net.spanningtree\fR [\-\fBg\fR] \fBinput\fR=\fIname\fR \fBoutput\fR=\fIname\fR  [\fBlayer\fR=\fIinteger\fR]   [\fBaccol\fR=\fIname\fR]   [\-\-\fBoverwrite\fR]  [\-\-\fBverbose\fR]  [\-\-\fBquiet\fR] 
.SS Flags:
.IP "\fB\-g\fR" 4m
.br
Use geodesic calculation for longitude-latitude locations
.IP "\fB\-\-overwrite\fR" 4m
.br
Allow output files to overwrite existing files
.IP "\fB\-\-verbose\fR" 4m
.br
Verbose module output
.IP "\fB\-\-quiet\fR" 4m
.br
Quiet module output
.PP
.SS Parameters:
.IP "\fBinput\fR=\fIname\fR" 4m
.br
Name of input vector map
.IP "\fBoutput\fR=\fIname\fR" 4m
.br
Name for output vector map
.IP "\fBlayer\fR=\fIinteger\fR" 4m
.br
Layer number
.br
A single vector map can be connected to multiple database tables. This number determines which table to use.
.br
Default: \fI1\fR
.IP "\fBaccol\fR=\fIname\fR" 4m
.br
Name of Arc cost column
.PP
.SH DESCRIPTION
\fIv.net.spanningtree\fR finds the minimum spanning tree in a 
network. 
.SH 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, \fIv.net.spanningtree\fR 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. \fBAccol\fR is used to 
specify the costs of the edges. The \fBoutput\fR consists of the 
edges in the spanning tree.
.SH EXAMPLES
Find cheapest set of pipelines connecting all nodes.
\fC
.DS
.br
v.net.spanningtree input=projected_pipelines output=spanningtree accol=cost 
.br
.DE
\fR
.SH SEE ALSO
\fI
v.net,
v.net.steiner
\fR
.SH AUTHORS
Daniel Bundala, Google Summer of Code 2009, Student
.br
Wolf Bergenheim, Mentor
.PP
\fILast changed: $Date: 2013-05-23 22:01:55 +0200 (Thu, 23 May 2013) $\fR
.PP
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.PP
© 2003-2014 GRASS Development Team