## NAME

v.net.iso

## DESCRIPTION

v.net.iso splits net to bands between cost isolines (direction from centre). Centre node must be opened (costs >= 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.

## NOTES

Nodes must be on the isolines.

Center nodes have to be assigned to vector nodes. Nodes and arcs can be closed using cost = -1.

## EXAMPLE

Subdivision of a network into areas:
The map must contain at least one center (point) on the vector network which can be patched into with v.patch.

    # Spearfish

    # start node:
    echo "591280.5|4926396.0|1" | v.in.ascii out=startnode
    g.copy vect=roads,myroads

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

    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
    v.category myroads_net layer=2 op=print

    # specify range of center cats (easier to catch all):
    v.net.iso input=myroads_net output=myroads_net_iso ccats=1-100000 costs=1000,2000,5000
    v.category myroads_net_iso option=report
    # ... reports 4 categories:

The network is 4 categories:

    cat | distance from point
    1          0 - 1000
    2       1000 - 2000
    3       2000 - 5000
    4            > 5000

To see the result, run for example:

    g.region n=4928200 s=4922300 w=589200 e=596500
    d.erase
    d.vect myroads_net_iso
    d.vect myroads_net_iso col=blue   cats=1
    d.vect myroads_net_iso col=green  cats=2
    d.vect myroads_net_iso col=orange cats=3
    d.vect myroads_net_iso col=magenta  cats=4
    d.vect myroads_net col=red icon=basic/triangle fcol=green size=12 layer=2

## SEE ALSO

d.path, v.net, v.net.alloc, v.net.path, v.net.salesman, v.net.steiner, v.patch

## AUTHOR

Radim Blazek, ITC-Irst, Trento, Italy
Documentation: Markus Neteler

Last changed: $Date: 2007-08-03 14:33:14 +0200 (Fri, 03 Aug 2007) $

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