
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 02:13:05 -0700 (Tue, 16 Aug 2011) $
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