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r.li.patchdensity(1)	    GRASS GIS User's Manual	  r.li.patchdensity(1)

NAME
       r.li.patchdensity   -  Calculates  patch	density	index on a raster map,
       using a 4 neighbour algorithm

KEYWORDS
       raster, landscape structure analysis, patch index

SYNOPSIS
       r.li.patchdensity
       r.li.patchdensity --help
       r.li.patchdensity  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=nameA [required]
	   Name	of input raster	map

       config=nameA [required]
	   Configuration file

       output=nameA [required]
	   Name	for output raster map

DESCRIPTION
       r.li.patchdensity  calculates  the "patch density index", the number of
       patches per square kilometer, as:
       PD = Npatch / A
       with:

	   o   A:sampling area size

	   o   Npatch: number of patches

       This index is calculated	using a	4 neighbour algorithm, diagonal	 cells
       are ignored when	tracing	a patch.

NOTES
       Do  not	use absolute path names	for the	config and output file/map pa-
       rameters.   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\App-
       Data\Roaming\GRASS7\r.li\output\		    (MS-Windows)	    or
       $HOME/.grass7/r.li/output/ (GNU/Linux).

       A sample	area of	only NULL values is considered to have	zero  patches,
       that is,	the result is always aY	0.

EXAMPLES
       To  calculate patch density index on map	my_map,	using my_conf configu-
       ration file (previously defined with g.gui.rlisetup) and	saving results
       in my_out, run:
       r.li.patchdensity input=my_map conf=my_conf output=my_out

       Example for Spearfish forest areas:
       g.region	raster=landcover.30m -p
       # extract forested areas:
       r.category landcover.30m
       r.mapcalc "forests = if(landcover.30m >=	41 && landcover.30m <= 43, 1, null())"
       # patch density (7x7 moving window defined in g.gui.rlisetup):
       r.li.patchdensity forests conf=movwindow7 out=forests_p_dens7
       r.univar	forests_p_dens7
       d.rast.leg forests_p_dens7
       r.to.vect forests out=forests feature=area
       d.vect forests type=boundary

       Forest map (North Carolina sample dataset) example:
       g.region	raster=landclass96 -p
       r.mapcalc "forests = if(landclass96 == 5, 1, null() )"
       r.li.patchdensity input=forests conf=movwindow7 out=forests_patchdensity_mov7
       # verify
       r.univar	forests_patchdensity_mov7
       r.to.vect input=forests output=forests type=area
       d.mon wx0
       d.rast forests_patchdensity_mov7
       d.vect forests type=boundary

SEE ALSO
	r.li - package overview
       g.gui.rlisetup

REFERENCES
       McGarigal, K., and B. J.	Marks. 1995. FRAGSTATS:	spatial	pattern	analy-
       sis program for quantifying landscape structure.	USDA For. Serv.	  Gen.
       Tech. Rep. PNW-351. (PDF)

AUTHORS
       Michael Shapiro - CERL (patch identification)
       Markus Metz (statistics)

SOURCE CODE
       Available at: r.li.patchdensity source code (history)

       Main  index  | Raster index | Topics index | Keywords index | Graphical
       index | Full index

       A(C) 2003-2020 GRASS Development	Team, GRASS GIS	7.8.3 Reference	Manual

GRASS 7.8.3						  r.li.patchdensity(1)

NAME | KEYWORDS | SYNOPSIS | DESCRIPTION | NOTES | EXAMPLES | SEE ALSO | REFERENCES | AUTHORS | SOURCE CODE

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