r.li.cwed.1grass

Langue: en

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Version: 335161 (ubuntu - 24/10/10)

Section: 1 (Commandes utilisateur)

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)

BUGS

Please send bugs reports to pallecch@cli.di.unipi.it

Last changed: $Date: 2007-02-08 17:33:52 +0100 (gio, 08 feb 2007) $

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