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

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

10       raster, landscape structure analysis, patch index
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SYNOPSIS

13       r.li.patchdensity
14       r.li.patchdensity --help
15       r.li.patchdensity  input=name  config=name  output=name   [--overwrite]
16       [--help]  [--verbose]  [--quiet]  [--ui]
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18   Flags:
19       --overwrite
20           Allow output files to overwrite existing files
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22       --help
23           Print usage summary
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25       --verbose
26           Verbose module output
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28       --quiet
29           Quiet module output
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31       --ui
32           Force launching GUI dialog
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34   Parameters:
35       input=name [required]
36           Name of input raster map
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38       config=name [required]
39           Configuration file
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41       output=name [required]
42           Name for output raster map
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DESCRIPTION

45       r.li.patchdensity  calculates  the "patch density index", the number of
46       patches per square kilometer, as:
47       PD = Npatch / A
48       with:
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50           ·   A:sampling area size
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52           ·   Npatch: number of patches
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54       This index is calculated using a 4 neighbour algorithm, diagonal  cells
55       are ignored when tracing a patch.
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NOTES

58       Do  not  use  absolute  path  names  for the config and output file/map
59       parameters.   If  the  "moving   window"   method   was   selected   in
60       g.gui.rlisetup,  then  the  output  will  be a raster map, otherwise an
61       ASCII  file  will  be  generated  in  the  folder  C:\Users\userxy\App‐
62       Data\Roaming\GRASS7\r.li\output\             (MS-Windows)            or
63       $HOME/.grass7/r.li/output/ (GNU/Linux).
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65       A sample area of only NULL values is considered to have  zero  patches,
66       that is, the result is always ≥ 0.
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EXAMPLES

69       To  calculate patch density index on map my_map, using my_conf configu‐
70       ration file (previously defined with g.gui.rlisetup) and saving results
71       in my_out, run:
72       r.li.patchdensity input=my_map conf=my_conf output=my_out
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74       Example for Spearfish forest areas:
75       g.region raster=landcover.30m -p
76       # extract forested areas:
77       r.category landcover.30m
78       r.mapcalc "forests = if(landcover.30m >= 41 && landcover.30m <= 43, 1, null())"
79       # patch density (7x7 moving window defined in g.gui.rlisetup):
80       r.li.patchdensity forests conf=movwindow7 out=forests_p_dens7
81       r.univar forests_p_dens7
82       d.rast.leg forests_p_dens7
83       r.to.vect forests out=forests feature=area
84       d.vect forests type=boundary
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86       Forest map (North Carolina sample dataset) example:
87       g.region raster=landclass96 -p
88       r.mapcalc "forests = if(landclass96 == 5, 1, null() )"
89       r.li.patchdensity input=forests conf=movwindow7 out=forests_patchdensity_mov7
90       # verify
91       r.univar forests_patchdensity_mov7
92       r.to.vect input=forests output=forests type=area
93       d.mon wx0
94       d.rast forests_patchdensity_mov7
95       d.vect forests type=boundary
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SEE ALSO

98        r.li - package overview
99       g.gui.rlisetup
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REFERENCES

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

107       Michael Shapiro - CERL (patch identification)
108       Markus Metz (statistics)
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SOURCE CODE

111       Available at: r.li.patchdensity source code (history)
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113       Main  index  | Raster index | Topics index | Keywords index | Graphical
114       index | Full index
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116       © 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual
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120GRASS 7.8.5                                               r.li.patchdensity(1)