.TH r.li.simpson 1grass "" "GRASS 6.4.2" "Grass User's Manual"
.SH NAME
\fI\fBr.li.simpson\fR\fR  - Calculates Simpson's diversity index on a raster map
.SH KEYWORDS
raster, landscape structure analysis, diversity index
.SH SYNOPSIS
\fBr.li.simpson\fR
.br
\fBr.li.simpson help\fR
.br
\fBr.li.simpson map\fR=\fIname\fR \fBconf\fR=\fIstring\fR \fBoutput\fR=\fIname\fR  [--\fBoverwrite\fR]  [--\fBverbose\fR]  [--\fBquiet\fR] 
.SS Flags:
.IP "\fB--overwrite\fR" 4m
.br
Allow output files to overwrite existing files
.IP "\fB--verbose\fR" 4m
.br
Verbose module output
.IP "\fB--quiet\fR" 4m
.br
Quiet module output
.PP
.SS Parameters:
.IP "\fBmap\fR=\fIname\fR" 4m
.br
Name of input raster map
.IP "\fBconf\fR=\fIstring\fR" 4m
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Configuration file
.IP "\fBoutput\fR=\fIname\fR" 4m
.br
Name for output raster map
.PP
.SH DESCRIPTION
\fIr.li.simpson\fR 
calculates the "simpson's diversity index" as:
.br
with: 
.br
.RS
.IP
\fBi\fR: patch type
.br
 
.IP
\fBm\fR: number of patch type
.br
  
.IP
\fBpi\fR: proportion of the landscape occupied by patch type i
.br
 
.RE
.SH 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.
.SH EXAMPLES
To calculate simpson's diversity index on map my_map, using
my_conf configuration file and saving results in my_out file run:
.br
\fC
.DS
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r.li.simpson map=my_map conf=my_conf output=my_out
.br
.DE
\fR
.SH 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. 
.br
If input raster is full of null values r.li.simpson returns -1.
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If you want to have null values instead run 
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\fC
.DS
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r.null setnull=-1 map=my_map
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.DE
\fR
after index calculation.
.SH SEE ALSO
\fI
r.li
\fR
.SH AUTHORS
Serena Pallecchi student of Computer Science University of Pisa (Italy).
.br
Commission from Faunalia Pontedera (PI), Italy (www.faunalia.it)
.PP
\fILast changed: $Date: 2011-08-16 11:13:05 +0200 (Tue, 16 Aug 2011) $\fR
.PP
Full index
.PP
© 2003-2011 GRASS Development Team