
NAME
r.li.cwed
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)
BUGS
Please send bugs reports to
pallecch@cli.di.unipi.it
Last changed: $Date: 2007-02-08 17:33:52 +0100 (Thu, 08 Feb 2007) $
Main index - raster index - Full index
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