## NAME

r.li.simpson

## DESCRIPTION

r.li.simpson calculates the "simpson's diversity index" as:
with:

- i: patch type
- m: number of patch type
- pi: proportion of the landscape occupied by patch type i

## REFERENCES

McGarigal, K., and B. J. Marks. 1995. FRAGSTATS: spatial pattern analysis program for quantifying landscape structure. USDA For. Serv. Gen. Tech. Rep. PNW-351.

## EXAMPLES

To calculate simpson's diversity index on map my_map, using my_conf configuration file and saving results in my_out file run:

    r.li.simpson map=my_map conf=my_conf output=my_out

## NOTES

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.
If input raster is full of null values r.li.simpson returns -1.
If you want to have null values instead run

    r.null setnull=-1 map=my_map

after index calculation.

## SEE ALSO

r.li

## AUTHORS

Serena Pallecchi student of Computer Science University of Pisa (Italy).
Commission from Faunalia Pontedera (PI), Italy (www.faunalia.it)

Last changed: $Date: 2011-08-16 11:13:05 +0200 (Tue, 16 Aug 2011) $

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