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

<h2>DESCRIPTION</h2>

<em>v.net.alloc</em> allocates subnets for nearest centres (direction from 
centre). Centre node must be opened (costs &gt;= 0). Costs of centre node are 
used in calculation. Supported are cost assignments for both arcs and nodes, 
and also different in both directions of a vector line. For areas cost will 
be calculated along boundary lines.

<h2>NOTES</h2>

Center nodes have to be assigned to vector nodes
using <em><a href="wxGUI.Vector_Digitizing_Tool.html">wxGUI vector
digitizer</a></em>. Nodes and arcs can be closed using cost = -1. 

<h2>EXAMPLES</h2>

Example 1: <em>Calculating subnets for 3 centre nodes using distances</em>
<div class="code"><pre>
#Spearfish

# centre nodes:
echo "591235.5|4926306.62|1
596591.8|4917042.5|2
602722.9|4923544.2|3" | v.in.ascii out=centrenodes

g.copy vect=roads,myroads

#connect points to network
v.net myroads points=centrenodes out=myroads_net op=connect thresh=200

# view map
g.region vect=myroads_net
d.mon x0
d.vect myroads_net
d.vect myroads_net col=red icon=basic/triangle fcol=green size=12 layer=2

# allocate, specifying range of center cats (easier to catch all):
v.net.alloc myroads_net out=myroads_net_alloc ccats=1-100000 nlayer=2

# report categories
v.category myroads_net_alloc option=report

# the result has to be selected by category number of the relevant node:
d.vect myroads_net_alloc cat=1 col=red
d.vect myroads_net_alloc cat=2 col=green
d.vect myroads_net_alloc cat=3 col=yellow
d.vect myroads_net col=red icon=basic/triangle fcol=green size=12 layer=2
</pre></div>
<p>

<img src="v_net_alloc.png" alt="v.net.alloc example" border="1">


<p>
Example 2: <em>Calculating subnets for 7 centre nodes using cost assigned to vector length
</em><br>
<div class="code"><pre>
v.net.alloc in=vectmap out=vectmap.alloc ccats=1-7
</pre></div>

<p>

Example 3: <em>Calculating subnets for 7 centre nodes using cost assignments in both 
directions</em><br>
<div class="code"><pre>
v.net.alloc in=vectmap afcol=INDEX abcol=INDEXBACK out=vectmap.alloc ccats=1-7
</pre></div>

<h2>SEE ALSO</h2>

<em><a HREF="d.path.html">d.path</a></em>,
<em><a HREF="v.net.html">v.net</a></em>,
<em><a HREF="v.net.iso.html">v.net.iso</a></em>,
<em><a HREF="v.net.path.html">v.net.path</a></em>,
<em><a HREF="v.net.steiner.html">v.net.steiner</a></em>,
<em><a HREF="v.net.salesman.html">v.net.salesman</a></em>

<h2>AUTHOR</h2>

Radim Blazek, ITC-Irst, Trento, Italy


<p><i>Last changed: $Date$</i>