GRASS GIS manual: r.li.simpson

NAME

r.li.simpson - Calculates Simpson's diversity index on a raster map

KEYWORDS

raster, landscape structure analysis, diversity index

SYNOPSIS

r.li.simpson
r.li.simpson help
r.li.simpson map=name conf=string output=name [--overwrite] [--verbose] [--quiet]

Flags:

--overwrite: Allow output files to overwrite existing files
--verbose: Verbose module output
--quiet: Quiet module output

Parameters:

map=name: Name of input raster map
conf=string: Configuration file
output=name: Name for output raster map

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.

AUTHORS

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

BUGS

Please send bugs reports to pallecch@cli.di.unipi.it

Last changed: $Date: 2007-02-08 08:52:53 -0800 (Thu, 08 Feb 2007) $

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