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:
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