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)

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) $

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