DESCRIPTION
r.li.padsd calculates the standard deviation of patch
area sizes in hectares as:
with:
- MPS: mean patch area size
- ai: area of patch i
- Npatch: number of patches
This index is calculated using a 4 neighbour algorithm, diagonal cells
are ignored when tracing a patch.
NOTES
Do not use absolute path names for the output map/file.
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 $HOME/.grass7/r.li/output/ folder.
The result is NULL if the sample area contains only NULL values.
EXAMPLES
To calculate patch area distribution standard deviation 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.padsd input=my_map conf=my_conf output=my_out
Forest map (Spearfish sample dataset) example:
g.region rast=landcover.30m -p
r.mapcalc "forests = if(landcover.30m >= 41 && landcover.30m <= 43,1,null())"
r.li.padsd input=forests conf=movwindow7 out=forests_padsd_mov7
r.univar forests_padsd_mov7
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
Michael Shapiro - CERL (patch identification)
Markus Metz (statistics)
Last changed: $Date$