r.li.mpa.1grass - Man Page
Calculates mean pixel attribute index on a raster map
Keywords
raster, landscape structure analysis, patch index
Synopsis
r.li.mpa
r.li.mpa --help
r.li.mpa input=name config=name output=name [--overwrite] [--help] [--verbose] [--quiet] [--ui]
Flags
- --overwrite
Allow output files to overwrite existing files
- --help
Print usage summary
- --verbose
Verbose module output
- --quiet
Quiet module output
- --ui
Force launching GUI dialog
Parameters
- input=name [required]
Name of input raster map
- config=name [required]
Configuration file
- output=name [required]
Name for output raster map
Description
r.li.mpa (mean pixel attribute) calculates the average value of the attribute of all the non-null cells in the sampling area as:
with:
- i: attribute
- m: number of non-null attributes in the sampling area
- wi: number of cells of attribute i
- size: size of sampling area (in cells)
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 input raster map contains only NULL values then r.li.mpa considers to have 0 patches.
If area is 0 r.li.mpa returns -1; it is possible only if the raster 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 mean pixel attribute 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.mpa input=my_map conf=my_conf output=my_out
Forest map (Spearfish sample dataset) example:
g.region raster=landcover.30m -p r.mapcalc "forests = if(landcover.30m >= 41 && landcover.30m <= 43,1,null())" r.li.mpa input=forests conf=movwindow7 out=forests_mpa_mov7 r.univar forests_mpa_mov7
Forest map (North Carolina sample dataset) example:
g.region raster=landclass96 -p r.mapcalc "forests = if(landclass96 == 5, 1, null() )" r.li.mpa input=forests conf=movwindow7 out=forests_mpa_mov7 # verify r.univar forests_mpa_mov7 r.to.vect input=forests output=forests type=area d.mon wx0 d.rast forests_mpa_mov7 d.vect forests type=boundary
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 (www.faunalia.it)
Markus Metz
Source Code
Available at: r.li.mpa source code (history)
Accessed: Tuesday Mar 19 11:02:00 2024
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