r.li.cwed(1)

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)

Last changed: $Date: 2011-08-16 11:13:05 +0200 (Tue, 16 Aug 2011) $

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