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 map=
name conf=
name
output=
name [--
overwrite] [--
verbose]
[--
quiet]
Flags:¶
- --overwrite
-
Allow output files to overwrite existing files
- --verbose
-
Verbose module output
- --quiet
-
Quiet module output
Parameters:¶
- map=name
-
Name of input raster map
- conf=name
-
Configuration file
- output=name
-
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
output map/file. 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
$HOME/.r.li/output/ folder.
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 map=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
r.li.setup)
and saving results in
my_out, run:
r.li.mpa map=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.mpa map=forests conf=movwindow7 out=forests_mpa_mov7
r.univar forests_mpa_mov7
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)
Last changed: $Date: 2014-02-19 01:26:04 +0100 (Wed, 19 Feb 2014) $
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