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

<h2>DESCRIPTION</h2>
<em>r.li.shannon</em> 
calculates the "shannon's diversity index" as: <br>
<img src="rliShannon_formula.png"><br>
with:<br>
<ul>
  <li><b>i</b>: patch type<br></li>
  <li><b>m</b>: number of patch type<br></li>
  <li><b>p<small><small>i</small></small></b>: proportion of the landscape occupied by patch type i<br></li>
</ul>

<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.

<h2>EXAMPLES</h2>
To calculate shannon's diversity index on map my_map, using
my_conf configuration file and saving results in my_out file run:<br>
<div class="code"><pre>
r.li.shannon input=my_map conf=my_conf output=my_out
</pre></div>

<h2>NOTES</h2>
Do not use absolute path names for output files. They are raster if
moving window disposition was selected, otherwise they are in
~/.r.li/output folder. <br>
If input raster is full of null values r.li.shannon returns -1. <br>
<!-- does that mean the program exit code or raster values?? -->
If you want to have null values instead run <br>
<div class="code"><pre>
r.null setnull=-1 map=my_map
</pre></div>
after index calculation.

<h2>SEE ALSO</h2>
<em>
<a href="r.li.html">r.li</a>
</em>

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

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