Geografic-Information-System/vector/v.net.spanningtree/v.net.spanningtree.html

<h2>DESCRIPTION</h2>

<em>v.net.spanningtree</em> finds the minimum spanning tree in a 
network. 

<h2>NOTES</h2>
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, 
<em>v.net.spanningtree</em> 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. <b>Accol</b> is used to specify the 
costs of the edges. The <b>output</b> consists of the edges in the 
spanning tree.

<h2>EXAMPLES</h2>

Find cheapest set of pipelines connecting all nodes.
<div class="code"><pre>
v.net.spanningtree input=projected_pipelines output=spanningtree accol=cost 
</pre></div>

<h2>SEE ALSO</h2>

<em>
<a href="v.net.html">v.net</a>,
<a href="v.net.steiner.html">v.net.steiner</a>
</em>

<h2>AUTHORS</h2>

Daniel Bundala, Google Summer of Code 2009, Student<br>
Wolf Bergenheim, Mentor

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