<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>GRASS GIS: v.net.iso</title> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <link rel="stylesheet" href="grassdocs.css" type="text/css"> </head> <body bgcolor="white"> <img src="grass_logo.png" alt="GRASS logo"><hr align=center size=6 noshade> <h2>NAME</h2> <em><b>v.net.iso</b></em> - Split net by cost isolines<BR> 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. <h2>KEYWORDS</h2> vector, networking <h2>SYNOPSIS</h2> <b>v.net.iso</b><br> <b>v.net.iso help</b><br> <b>v.net.iso</b> [-<b>g</b>] <b>input</b>=<em>name</em> <b>output</b>=<em>name</em> [<b>type</b>=<em>string</em>[,<i>string</i>,...]] [<b>alayer</b>=<em>integer</em>] [<b>nlayer</b>=<em>integer</em>] [<b>afcolumn</b>=<em>string</em>] [<b>abcolumn</b>=<em>string</em>] [<b>ncolumn</b>=<em>string</em>] <b>ccats</b>=<em>range</em> <b>costs</b>=<em>integer</em>[,<i>integer</i>,...] [--<b>overwrite</b>] [--<b>verbose</b>] [--<b>quiet</b>] <h3>Flags:</h3> <DL> <DT><b>-g</b></DT> <DD>Use geodesic calculation for longitude-latitude locations</DD> <DT><b>--overwrite</b></DT> <DD>Allow output files to overwrite existing files</DD> <DT><b>--verbose</b></DT> <DD>Verbose module output</DD> <DT><b>--quiet</b></DT> <DD>Quiet module output</DD> </DL> <h3>Parameters:</h3> <DL> <DT><b>input</b>=<em>name</em></DT> <DD>Name of input vector map</DD> <DT><b>output</b>=<em>name</em></DT> <DD>Name for output vector map</DD> <DT><b>type</b>=<em>string[,<i>string</i>,...]</em></DT> <DD>Type</DD> <DD>Arc type</DD> <DD>Options: <em>line,boundary</em></DD> <DD>Default: <em>line,boundary</em></DD> <DT><b>alayer</b>=<em>integer</em></DT> <DD>Layer number</DD> <DD>Arc layer</DD> <DD>Default: <em>1</em></DD> <DT><b>nlayer</b>=<em>integer</em></DT> <DD>Layer number</DD> <DD>Node layer</DD> <DD>Default: <em>2</em></DD> <DT><b>afcolumn</b>=<em>string</em></DT> <DD>Arc forward/both direction(s) cost column (number)</DD> <DT><b>abcolumn</b>=<em>string</em></DT> <DD>Arc backward direction cost column (number)</DD> <DT><b>ncolumn</b>=<em>string</em></DT> <DD>Node cost column (number)</DD> <DT><b>ccats</b>=<em>range</em></DT> <DD>Category values</DD> <DD>Categories of centres (points on nodes) to which net will be allocated. Layer for this categories is given by nlayer option.</DD> <DT><b>costs</b>=<em>integer[,<i>integer</i>,...]</em></DT> <DD>Costs for isolines</DD> </DL> <h2>DESCRIPTION</h2> <em>v.net.iso</em> 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. <h2>NOTES</h2> Nodes must be on the isolines.<P> Center nodes have to be assigned to vector nodes. Nodes and arcs can be closed using cost = -1. <h2>EXAMPLE</h2> Subdivision of a network into areas:<br> The map must contain at least one center (point) on the vector network which can be patched into with <a HREF="v.patch.html">v.patch</a>. <div class="code"><pre> # 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: </pre></div> The network is 4 categories: <div class="code"><pre> cat | distance from point 1 0 - 1000 2 1000 - 2000 3 2000 - 5000 4 > 5000 </pre></div> To see the result, run for example: <div class="code"><pre> 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 </pre></div> <img src="vnetiso.png" alt="v.net.iso example" border="1"> <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.alloc.html">v.net.alloc</a></em>, <em><a HREF="v.net.path.html">v.net.path</a></em>, <em><a HREF="v.net.salesman.html">v.net.salesman</a></em>, <em><a HREF="v.net.steiner.html">v.net.steiner</a></em>, <em><a HREF="v.patch.html">v.patch</a></em> <h2>AUTHOR</h2> Radim Blazek, ITC-Irst, Trento, Italy<br> Documentation: Markus Neteler <p><i>Last changed: $Date: 2007-08-03 14:33:14 +0200 (Fri, 03 Aug 2007) $</i> <HR> <P><a href="index.html">Main index</a> - <a href="vector.html">vector index</a> - <a href="full_index.html">Full index</a></P> <P>© 2003-2008 <a href="http://grass.osgeo.org">GRASS Development Team</a></p> </body> </html>
