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 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 r.li.setup, then the
output will be a raster map, otherwise an ASCII file will be generated in
the folder C:\Users\userxy\.r.li\output\
(MS-Windows) or $HOME/.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 map=my_map
EXAMPLES
To calculate the contrast weighted edge density index on map my_map, using
my_conf configuration file (previously defined with
r.li.setup) and saving results in my_out, run:
r.li.cwed map=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
r.li.setup
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 (www.faunalia.it)
Markus Metz
Last changed: $Date$