r.li.simpson - GRASS GIS manual

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 input=name config=name output=name [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

--overwrite: Allow output files to overwrite existing files
--help: Print usage summary
--verbose: Verbose module output
--quiet: Quiet module output
--ui: Force launching GUI dialog

Parameters:

input=name [required]: Name of input raster map
config=name [required]: Configuration file
output=name [required]: Name for output raster map

DESCRIPTION
NOTES
EXAMPLES
SEE ALSO
REFERENCES
AUTHORS

DESCRIPTION

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

with:

i: patch type
m: number of different patch types
pi: proportional abundance of patch type i

Do not use absolute path names for the config and output file/map parameters. If the "moving window" method was selected in g.gui.rlisetup, then the output will be a raster map, otherwise an ASCII file will be generated in the folder C:\Users\userxy\AppData\Roaming\GRASS8\r.li\output\ (MS-Windows) or $HOME/.grass8/r.li/output/ (GNU/Linux).

If the input raster map contains only NULL values then r.li.simpson returns NULL.

EXAMPLES

To calculate Simpson's diversity index on map my_map, using my_conf configuration file (previously defined with g.gui.rlisetup) and saving results in my_out, run:

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

Forest map (Spearfish sample dataset) example:

g.region raster=landcover.30m -p
r.mapcalc "forests = if(landcover.30m >= 41 && landcover.30m <= 43,1,null())"
r.li.simpson input=forests conf=movwindow7 out=forests_simpson_mov7
r.univar forests_simpson_mov7

Forest map (North Carolina sample dataset) example:

g.region raster=landclass96 -p
r.mapcalc "forests = if(landclass96 == 5, 1, null() )"
r.li.simpson input=forests conf=movwindow7 out=forests_simpson_mov7

# verify
r.univar forests_simpson_mov7
r.to.vect input=forests output=forests type=area
d.mon wx0
d.rast forests_simpson_mov7
d.vect forests type=boundary

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. (PDF)

AUTHORS

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

SOURCE CODE

Available at: r.li.simpson source code (history)

Latest change: Sunday Feb 12 15:51:56 2023 in commit: 7d6ff54e985c1579e11b74c230cb8fa68a9aa928