 
Note: A new GRASS GIS stable version has been released: GRASS GIS 7.6, available here.
 Updated manual page: here
NAME
r.li.mpa  - 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
 
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)
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\GRASS7\r.li\output\
(MS-Windows) or 
$HOME/.grass7/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.
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
g.gui.rlisetup
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)
Serena Pallecchi student of Computer Science University of Pisa (Italy).
Commission from Faunalia Pontedera (PI), Italy (www.faunalia.it)
Markus Metz
Last changed: $Date: 2014-12-19 13:17:36 -0800 (Fri, 19 Dec 2014) $
SOURCE CODE
Available at: r.li.mpa source code (history)
Note: A new GRASS GIS stable version has been released: GRASS GIS 7.6, available here.
 Updated manual page: here
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GRASS Development Team,
GRASS GIS 7.2.4svn Reference Manual