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r.li.mpa

Calculates mean pixel attribute index on a raster map

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

Example:

r.li.mpa input=name config=name output=name

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

Example:

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

Parameters

input=name [required]
    Name of input raster map
config=name [required]
    Configuration file
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
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.mpa (mean pixel attribute) calculates the average value of the attribute of all the non-null cells in the sampling area as:
rlimpa formula
with:

  • i: attribute
  • m: number of non-null attributes in the sampling area
  • w_i: 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 ()
Markus Metz

SOURCE CODE

Available at: r.li.mpa source code (history)
Latest change: Wednesday Feb 19 22:09:55 2025 in commit 5f4fa06