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NAME - Calculates range of patch area size on a raster map


raster, landscape structure analysis, patch index

SYNOPSIS --help input=name config=name output=name [--overwrite] [--help] [--verbose] [--quiet] [--ui]


Allow output files to overwrite existing files

Print usage summary

Verbose module output

Quiet module output

Force launching GUI dialog


Name of input raster map

Configuration file

Name for output raster map

DESCRIPTION calculates the range of patch area sizes in hectares as:

  • amax: max patch area size
  • amin: min patch area size

This index is calculated using a 4 neighbour algorithm, diagonal cells are ignored when tracing a patch.


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\\output\ (MS-Windows) or $HOME/.grass7/ (GNU/Linux).

If the sample area contains only NULL values then returns NULL.


To calculate range of patch area size index on map my_map, using my_conf configuration file (previously defined with g.gui.rlisetup) and saving results in my_out, run: 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())" input=forests conf=movwindow7 out=forests_padrange_mov7
r.univar forests_padrange_mov7

Forest map (North Carolina sample dataset) example:

g.region raster=landclass96 -p
r.mapcalc "forests = if(landclass96 == 5, 1, null() )" input=forests conf=movwindow7 out=forests_padrange_mov7
# verify
r.univar forests_padrange_mov7 input=forests output=forests type=area
d.mon wx0
d.rast forests_padrange_mov7
d.vect forests type=boundary

SEE ALSO - package overview


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)


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


Available at: source code (history)

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© 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual

GRASS 7.8.5