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r.li.mps(1grass) GRASS GIS User's Manual r.li.mps(1grass)

NAME

r.li.mps - Calculates mean patch size index on a raster map, using a 4 neighbour algorithm

KEYWORDS

raster, landscape structure analysis, patch index

SYNOPSIS

r.li.mps
r.li.mps --help
r.li.mps input=name config=name output=name [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:


Allow output files to overwrite existing files

Print usage summary

Verbose module output

Quiet module output

Force launching GUI dialog

Parameters:


Name of input raster map

Configuration file

Name for output raster map

DESCRIPTION

r.li.mps (mean patch size) calculates the mean size of the patches in the sampling area as: 

MPS = A / Npatch

with:

  • A:sampling area size without null cells
  • Npatch: number of patches
The unit of the mean size is hectare.

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 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 sample area contains only NULL value cells, r.li.mps returns 0 (zero).

EXAMPLES

To calculate mean path size 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.mps 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.mps input=forests conf=movwindow7 out=forests_mps_mov7
r.univar forests_mps_mov7

Forest map (North Carolina sample dataset) example: 

g.region raster=landclass96 -p
r.mapcalc "forests = if(landclass96 == 5, 1, null() )"
r.li.mps input=forests conf=movwindow7 out=forests_mps_mov7
# verify
r.univar forests_mps_mov7
r.to.vect input=forests output=forests type=area
d.mon wx0
d.rast forests_mps_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

Michael Shapiro - CERL (patch identification)
Markus Metz (statistics)

SOURCE CODE

Available at: r.li.mps source code (history)

Accessed: Sunday Jan 22 07:36:19 2023

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© 2003-2023 GRASS Development Team, GRASS GIS 8.2.1 Reference Manual

GRASS 8.2.1