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NAME - Calculates Shannon's diversity index on a raster map


raster, landscape structure analysis, diversity index

SYNOPSIS help map=name conf=name output=name [--overwrite] [--verbose] [--quiet]


Allow output files to overwrite existing files
Verbose module output
Quiet module output


Name of input raster map
Configuration file
Name for output raster map

DESCRIPTION calculates the "Shannon's diversity index" as: formula


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

If the input raster map contains only NULL values then returns -1.
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.


To calculate Shannon's diversity index on map my_map, using my_conf configuration file (previously defined with and saving results in my_out, run: 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())" map=forests conf=movwindow7 out=forests_shannon_mov7
r.univar forests_shannon_mov7

Forest map (North Carolina sample dataset) example:

g.region rast=landclass96 -p
r.mapcalc "forests = if(landclass96 == 5, 1, null() )" map=forests conf=movwindow7 out=forests_shannon_mov7

# verify
r.univar forests_shannon_mov7 input=forests output=forests feature=area
d.mon x0
d.rast forests_shannon_mov7
d.vect forests type=boundary

SEE ALSO - package overview


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)


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

Last changed: $Date: 2014-10-19 14:32:22 -0700 (Sun, 19 Oct 2014) $

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