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r.li.pielou(1grass) Grass User's Manual r.li.pielou(1grass)

NAME

r.li.pielou - Calculates Pielou's diversity index on a raster map

KEYWORDS

raster, landscape structure analysis, diversity index

SYNOPSIS

r.li.pielou
 
r.li.pielou help
 
r.li.pielou map=name conf=name 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=name
 
Configuration file
output=name
 
Name for output raster map

DESCRIPTION

r.li.pielou calculates the "Pielou's diversity index" as:
 
with:
J: Pielou eveness index
H': Shannon index
S: number of classes

NOTES

Do not use absolute path names for the output map/file. If the "moving window" method was selected in r.li.setup, then the output will be a raster map, otherwise an ASCII file will be generated in the $HOME/.r.li/output/ folder.
If the input raster contains NULL value cells, r.li.pielou returns -1 for these cells.
 
If you want to change these -1 values to NULL, run subsequently on the resulting map:
 
r.null setnull=-1 map=my_map
 
after index calculation.

EXAMPLES

To calculate Pielou's diversity index on map my_map, using my_conf configuration file (previously defined with r.li.setup) and saving results in my_out, run:
 
r.li.pielou map=my_map conf=my_conf output=my_out
 
Forest map (Spearfish sample dataset) example:
 
g.region rast=landcover.30m -p
 
r.mapcalc "forests = if(landcover.30m >= 41 && landcover.30m <= 43,1,null())"
 
r.li.pielou map=forests conf=movwindow7 out=forests_pielou_mov7
 
r.univar forests_pielou_mov7
 

SEE ALSO

r.li - package overview
 
r.li.setup

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).
 
Last changed: $Date: 2014-02-19 01:26:04 +0100 (Wed, 19 Feb 2014) $
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