<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>GRASS GIS: r.li.patchdensity</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>r.li.patchdensity</b></em> - Calculates patch density index on a raster map, using a 4 neighbour algorithm <h2>KEYWORDS</h2> raster, landscape structure analysis, patch index <h2>SYNOPSIS</h2> <b>r.li.patchdensity</b><br> <b>r.li.patchdensity help</b><br> <b>r.li.patchdensity</b> <b>map</b>=<em>name</em> <b>conf</b>=<em>string</em> <b>output</b>=<em>name</em> [--<b>overwrite</b>] [--<b>verbose</b>] [--<b>quiet</b>] <h3>Flags:</h3> <DL> <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>map</b>=<em>name</em></DT> <DD>Name of input raster map</DD> <DT><b>conf</b>=<em>string</em></DT> <DD>Configuration file</DD> <DT><b>output</b>=<em>name</em></DT> <DD>Name for output raster map</DD> </DL> <H2>DESCRIPTION</H2> <EM>r.li.patchdensity</EM> is a patch index for <em>r.li</em> suite. It calculates the function: <div class="code"><pre> f(sample_area) = (Patch_Number/Area) * 1000000 </pre></div> that is 1000000 by number of patch for area unit. This index is calculated using a 4 neighbour algorithm. <H2>EXAMPLES</H2> To calculate patch density index on map <em>my_map</em>, using <em>my_conf</em> configuration file (previously defined with <em>r.li.setup</em>) and saving results in the raster map <em>my_out</em>, run: <div class="code"><pre> r.li.patchdensity map=my_map conf=my_conf out=my_out </pre></div> <p> Example for Spearfish forest areas: <div class="code"><pre> g.region rast=landcover.30m -p # extract forested areas: r.category landcover.30m r.mapcalc "forests=if(landcover.30m >= 41 && landcover.30m <=43,1,null())" # patch density (7x7 moving window defined in r.li.setup): r.li.patchdensity forests conf=movwindow7 out=forests_p_dens7 d.rast.leg forests_p_dens7 r.to.vect forests out=forests feature=area d.vect forests type=boundary </pre></div> <H2>NOTES</H2> A map of NULL values is considered to have zero patches. <br> If you want to have null values instead run <br> <div class="code"><pre> r.null setnull=0 map=my_out <pre></div> after index calculation.<br> <!-- next ??????: --> If raster area is 0, <em>r.li.patchdensity</em> returns -1. This is only possible if the raster is masked. <H2>SEE ALSO</H2> <EM><A HREF="r.li.html">r.li</A></EM> package overview <BR> <EM><A HREF="r.li.daemon.html">r.li.daemon</A></EM><BR> <EM><A HREF="r.li.setup.html">r.li.setup</A></EM> <H2>AUTHORS</H2> Claudio Porta and Lucio Davide Spano, students of Computer Science University of Pisa (Italy).<br> Commission from Faunalia Pontedera (PI) (www.faunalia.it)<br> <H2>BUGS</h2> Please send bugs reports to <a href="mailto:spano@cli.di.unipi.it">spano@cli.di.unipi.it</a>, <a href="mailto:porta@cli.di.unipi.it">porta@cli.di.unipi.it</a><BR> <p><i>Last changed: $Date: 2008-02-19 21:18:46 +0100 (Tue, 19 Feb 2008) $</i<pre> <HR> <P><a href="index.html">Main index</a> - <a href="raster.html">raster 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>
