r.li.edgedensity(1grass) GRASS GIS User's Manual r.li.edgedensity(1grass)
NAME
r.li.edgedensity - Calculates edge density index on a raster map, us-
ing a 4 neighbour algorithm
KEYWORDS
raster, landscape structure analysis, patch index
SYNOPSIS
r.li.edgedensity
r.li.edgedensity --help
r.li.edgedensity [-b] input=name config=name output=name
[patch_type=string] [--overwrite] [--help] [--verbose] [--quiet]
[--ui]
Flags:
-b
Exclude border edges
--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=name [required]
Name of input raster map
config=name [required]
Configuration file
output=name [required]
Name for output raster map
patch_type=string
The value of the patch type
It can be integer, double or float; it will be changed in function
of map type
DESCRIPTION
r.li.edgedensity calculates:
• the density of all edges of patch type k , or
• the density of all edges in the sampling area if k is not spec-
ified,
with:
• k: patch type
• m: number of patch types
• n: number of edge segments of patch type k
• eik :total edge length in the landscape involving patch type k
• Area: total landscape area
The unit is meters per hectare.
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).
If the input raster map contains only NULL values then r.li.edgedensity
consider to have 0 patches.
If area is 0 r.li.edgedensity returns NULL; this is only possible if
input raster is masked.
EXAMPLES
To calculate the edge density index on map my_map, using my_conf con-
figuration file (previously defined with g.gui.rlisetup) and saving re-
sults in my_out, run:
r.li.edgedensity input=my_map conf=my_conf output=my_out
To calculate edge density index of patch_type 34, using "my_conf" con-
figuration file and on map "my_map", saving results in "my_out" file
run:
r.li.edgedensity input=my_map conf=my_conf output=my_out patch_type=34
Forest map (Spearfish sample dataset) example:
g.region raster=landcover.30m -p
r.mapcalc "forests = if(landcover.30m >= 41 && landcover.30m <= 43,1,null())"
r.li.edgedensity input=forests conf=movwindow7 out=forests_edgedens_mov7
r.univar forests_edgedens_mov7
Forest map (North Carolina sample dataset) example:
g.region raster=landclass96 -p
r.mapcalc "forests = if(landclass96 == 5, 1, null() )"
r.li.edgedensity input=forests conf=movwindow7 out=forests_edgedensity_mov7
# verify
r.univar forests_edgedensity_mov7
r.to.vect input=forests output=forests type=area
d.mon wx0
d.rast forests_edgedensity_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
Serena Pallecchi student of Computer Science University of Pisa
(Italy).
Commission from Faunalia Pontedera (PI), Italy (www.faunalia.it)
Markus Metz
SOURCE CODE
Available at: r.li.edgedensity source code (history)
Accessed: unknown
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GRASS 7.8.7 r.li.edgedensity(1grass)
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