r.li.patchdensity(1)

1r.li.patchdensity(1)          Grass 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  map=name  conf=string   output=name    [--overwrite]
16       [--verbose]  [--quiet]
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18   Flags:
19       --overwrite
20           Allow output files to overwrite existing files
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22       --verbose
23           Verbose module output
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25       --quiet
26           Quiet module output
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28   Parameters:
29       map=name
30           Name of input raster map
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32       conf=string
33           Configuration file
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35       output=name
36           Name for output raster map
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DESCRIPTION

39       r.li.patchdensity  is  a patch index for r.li suite.  It calculates the
40       function:
41       f(sample_area) = (Patch_Number/Area) * 1000000
42        that is 1000000 by number of patch for area unit.  This index is  cal‐
43       culated using a 4 neighbour algorithm.
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EXAMPLES

46       To  calculate patch density index on map my_map, using my_conf configu‐
47       ration file (previously defined with r.li.setup) and saving results  in
48       the raster map my_out, run:
49       r.li.patchdensity map=my_map conf=my_conf out=my_out
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52       Example for Spearfish forest areas:
53       g.region rast=landcover.30m -p
54       # extract forested areas:
55       r.category landcover.30m
56       r.mapcalc    "forests=if(landcover.30m    >=    41   &&   landcover.30m
57       <=43,1,null())"
58       # patch density (7x7 moving window defined in r.li.setup):
59       r.li.patchdensity forests conf=movwindow7 out=forests_p_dens7
60       d.rast.leg forests_p_dens7
61       r.to.vect forests out=forests feature=area
62       d.vect forests type=boundary
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NOTES

66       A map of NULL values is considered to have zero patches.
67       If you want to have null values instead run
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69       r.null setnull=0 map=my_out
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71       after index calculation.
72       If raster area is 0, r.li.patchdensity returns -1. This is only  possi‐
73       ble
74       if the raster is masked.
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AUTHORS

82       Claudio Porta and Lucio Davide Spano, students of Computer Science
83       University of Pisa (Italy).
84       Commission from Faunalia Pontedera (PI) (www.faunalia.it)
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BUGS

87       Please send bugs reports to
88       spano@cli.di.unipi.it,
89       porta@cli.di.unipi.it
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92       Full index
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94       © 2003-2008 GRASS Development Team
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98GRASS 6.3.0                                               r.li.patchdensity(1)