Geografic-Information-System/raster/r.li/r.li.edgedensity/r.li.edgedensity.html

<h2>DESCRIPTION</h2>

<em>r.li.edgedensity </em>calculates:<br>
<br>
<ul>
   <li> the density of all edges of patch type <em>k</em>
	<img alt="r.li.edgedensity formula 1" src="r_li_edgedensity_formula_1.png">
	, or
   <li> the density of all edges in the sampling area if <em>k</em> is 
        not specified,
	<img alt="r.li.edgedensity formula 2" src="r_li_edgedensity_formula_2.png">
</ul>
<p>with:
<ul>
<li><b>k</b>: patch type</li>
<li><b>m</b>: number of patch types</li>
<li><b>n</b>: number of edge segments of patch type k</li>
<li><b>e<small><small>ik </small></small></b>:total edge length in 
the landscape involving patch type k</li>
<li> <b>Area</b>: total landscape area</li>
</ul>
<p>
The unit is meters per hectare.

<h2>NOTES</h2>

Do not use absolute path names for the <b>config</b> and <b>output</b>
file/map parameters.

If the "moving window" method was selected in <b>g.gui.rlisetup</b>, then the
output will be a raster map, otherwise an ASCII file will be generated in
the folder <tt>C:\Users\userxy\AppData\Roaming\GRASS7\r.li\output\</tt>
(MS-Windows) or <tt>$HOME/.grass7/r.li/output/</tt> (GNU/Linux).
<p>
<!-- TODO: verify next: -->
If the input raster map contains only NULL values then <em>r.li.edgedensity</em>
consider to have 0 patches.<br>
If area is 0 <em>r.li.edgedensity</em> returns NULL; this is only possible if input
raster is masked.

<h2>EXAMPLES</h2>
To calculate the edge density index on map <em>my_map</em>, using
<em>my_conf</em> configuration file (previously defined with
<em>g.gui.rlisetup</em>) and saving results in <em>my_out</em>, run:
<div class="code"><pre>
r.li.edgedensity input=my_map conf=my_conf output=my_out
</pre></div>

To calculate edge density index of patch_type 34, using
"my_conf" configuration file and on map "my_map", saving results in "my_out"
file run:<br>
<div class="code"><pre>
r.li.edgedensity input=my_map conf=my_conf output=my_out patch_type=34
</pre></div>
<p>

Forest map (Spearfish sample dataset) example:
<div class="code"><pre>
g.region raster=landcover.30m -p
r.mapcalc "forests = if(landcover.30m >= 41 && landcover.30m <= 43,1,null())"
r.li.edgedensity input=forests conf=movwindow7 out=forests_edgedens_mov7
r.univar forests_edgedens_mov7
</pre></div>
<p>

Forest map (North Carolina sample dataset) example:
<div class="code"><pre>
g.region raster=landclass96 -p
r.mapcalc "forests = if(landclass96 == 5, 1, null() )"
r.li.edgedensity input=forests conf=movwindow7 out=forests_edgedensity_mov7

# verify
r.univar forests_edgedensity_mov7
r.to.vect input=forests output=forests type=area
d.mon wx0
d.rast forests_edgedensity_mov7
d.vect forests type=boundary
</pre></div>

<h2>SEE ALSO</h2>
<em>
<a href="r.li.html">r.li</a> - package overview<br>
<a href="g.gui.rlisetup.html">g.gui.rlisetup</a>
</em>

<h2>REFERENCES</h2>
McGarigal, K., and B. J. Marks. 1995. FRAGSTATS: spatial pattern
analysis program for quantifying landscape structure. USDA For. Serv.
Gen. Tech. Rep. PNW-351. (<a href="http://treesearch.fs.fed.us/pubs/3064">PDF</a>)

<h2>AUTHORS</h2>
Serena Pallecchi student of Computer Science University of Pisa (Italy).<br>
Commission from Faunalia Pontedera (PI), Italy (www.faunalia.it)<br>
Markus Metz

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