NAME¶
r.li.cwed - Calculates contrast weighted edge density index on a
raster map
KEYWORDS¶
raster, landscape structure analysis, patch index
SYNOPSIS¶
r.li.cwed
r.li.cwed help
r.li.cwed map=
name conf=
string
path=
string output=
name [--
overwrite]
[--
verbose] [--
quiet]
Flags:¶
- --overwrite
-
Allow output files to overwrite existing files
- --verbose
-
Verbose module output
- --quiet
-
Quiet module output
Parameters:¶
- map=name
-
Name of input raster map
- conf=string
-
Configuration file
- path=string
-
Input file that contains the weight to calculate the index
- output=name
-
Name for output raster map
DESCRIPTION¶
r.li.cwed (contrast weighted edge density) calculates the edge density
between patch types specified:
with:
-
k: attribute
-
m: number of non-null attributes in the sampling area
-
eik: total length of edge in landscape between patch types i and k
- dik: dissimilarity (edge contrast weight) between
patch types i and k
-
Area: total landscape area
The input file have a row for each couple of patch type that we want to consider
in the calculation. Each row must to have this syntax:
patchType1,patchType2,dissimilarityBetweenPatchType1andPatchType2
EXAMPLES¶
To calculate mean pixel attribute index on map my_map, using my_conf
configuration file and saving results in my_out file run:
r.li.cwed map=my_map conf=my_conf path=my_file output=my_out
Example of input file: 12,16,0.65
44,123,0.32
56,12,0.54
23,66,0.99
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.
If the raster is full of null value it is considered to have 0 patch and CWED=0.
If Area is 0 r.li.cwed returns -1. This is possible only if the map is masked.
If you want to have null values instead run
r.null setnull=-1 map=my_map
after index calculation.
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.
SEE ALSO¶
r.li package overview
r.li.daemon
r.li.setup
AUTHORS¶
Serena Pallecchi student of Computer Science University of Pisa (Italy).
Commission from Faunalia Pontedera (PI), Italy (www.faunalia.it)
Last changed: $Date: 2011-08-16 11:13:05 +0200 (Tue, 16 Aug 2011) $
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