NAME

r.li.renyi - Calculates Renyi’s diversity index on a raster map

KEYWORDS

raster, landscape structure analysis, diversity index

SYNOPSIS

r.li.renyi
r.li.renyi --help
r.li.renyi input=name config=name alpha=string 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
alpha=string [required]: Alpha value is the order of the generalized entropy
output=name [required]: Name for output raster map

DESCRIPTION

r.li.renyi calculates the "Renyi’s diversity index" as:
with:

H: Renyi entropy
alpha: order of the generalized entropy
i: patch type
S: number of different patch types
pi: proportional abundance of patch type i

NOTES

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\GRASS7\r.li\output\ (MS-Windows) or $HOME/.grass7/r.li/output/ (GNU/Linux).

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

EXAMPLES

To calculate Renyi’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.renyi input=my_map conf=my_conf output=my_out alpha=0.6

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.renyi input=forests conf=movwindow7 out=forests_renyi_mov7_a06 alpha=0.6
r.univar forests_renyi_mov7_a06

Forest map (North Carolina sample dataset) example:


g.region raster=landclass96 -p
r.mapcalc "forests = if(landclass96 == 5, 1, null() )"
r.li.renyi input=forests conf=movwindow7 out=forests_renyi_mov7
# verify
r.univar forests_renyi_mov7
r.to.vect input=forests output=forests type=area
d.mon wx0
d.rast forests_renyi_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

Luca Delucchi and Duccio Rocchini, Fondazione E. Mach (Italy), based on the r.li.shannon code developed by Serena Pallecchi student of Computer Science University of Pisa (Italy).

SOURCE CODE

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