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r.li.cwed

Calculates contrast weighted edge density index on a raster map

r.li.cwed input=name config=name path=name output=name [--overwrite] [--verbose] [--quiet] [--qq] [--ui]

Example:

r.li.cwed input=name config=name path=name output=name

grass.script.run_command("r.li.cwed", input, config, path, output, overwrite=False, verbose=False, quiet=False, superquiet=False)

Example:

gs.run_command("r.li.cwed", input="name", config="name", path="name", output="name")

Parameters

input=name [required]
    Name of input raster map
config=name [required]
    Configuration file
path=name [required]
    Name of file that contains the weight to calculate the index
output=name [required]
    Name for output raster map
--overwrite
    Allow output files to overwrite existing files
--help
    Print usage summary
--verbose
    Verbose module output
--quiet
    Quiet module output
--qq
    Very quiet module output
--ui
    Force launching GUI dialog

input : str, required
    Name of input raster map
    Used as: input, raster, name
config : str, required
    Configuration file
    Used as: input, file, name
path : str, required
    Name of file that contains the weight to calculate the index
    Used as: input, file, name
output : str, required
    Name for output raster map
    Used as: output, raster, name
overwrite: bool, optional
    Allow output files to overwrite existing files
    Default: False
verbose: bool, optional
    Verbose module output
    Default: False
quiet: bool, optional
    Quiet module output
    Default: False
superquiet: bool, optional
    Very quiet module output
    Default: False

DESCRIPTION

r.li.cwed (contrast weighted edge density) calculates the edge density between patch types specified:

rlicwed formula

with:

  • k: attribute
  • m: number of non-null attributes in the sampling area
  • e_ik: total length of edge in landscape between patch types i and k
  • d_ik: dissimilarity (edge contrast weight) between patch types i and k
  • Area: total landscape area

The input file contains a row for each couple of patch type that we want to consider in the calculation. Each row must be saved using this syntax:

patchType1,patchType2,dissimilarityBetweenPatchType1andPatchType2

NOTES

Do not use absolute path names for the config and output file/map parameters. If the "moving window" method was selected in g.gui.rlisetup, then the output will be a raster map, otherwise an ASCII file will be generated in the folder C:\Users\userxy\AppData\Roaming\GRASS8\r.li\output\ (MS-Windows) or $HOME/.grass8/r.li/output/ (GNU/Linux).

If the sample area contains only NULL values it is considered to have 0 patch and CWED=0. If Area is 0 r.li.cwed returns -1. This is only possible if the map is masked.
If you want to change these -1 values to NULL, run subsequently on the resulting map:

r.null setnull=-1 input=my_map

after index calculation.

EXAMPLES

To calculate the contrast weighted edge density index on map my_map, using my_conf configuration file (previously defined with g.gui.rlisetup) and saving results in my_out, run:

r.li.cwed input=my_map conf=my_conf output=my_out \
          path=/path/to/weights.csv

Example for input "weights.csv" file:

12,16,0.65
44,123,0.32
56,12,0.54
23,66,0.99

SEE ALSO

r.li (package overview), g.gui.rlisetup

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. (PDF)

AUTHORS

Serena Pallecchi, student of Computer Science University of Pisa (Italy).
Commission from Faunalia Pontedera (PI), Italy ()
Markus Metz

SOURCE CODE

Available at: r.li.cwed source code (history)
Latest change: Tuesday Apr 29 06:19:47 2025 in commit 12f893b