r.li.mps(1)

✨ r.li.mps 💖

okay bestie, gather round, because this is the GRASS GIS User's Manual entry for r.li.mps and it's lowkey iconic 🎀

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🌸 NAME 🌸

r.li.mps — it calculates the mean patch size index on a raster map, and it does it using a 4 neighbour algorithm. no cap. that's the whole job. 💅

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🦋 KEYWORDS 🦋

raster, landscape structure analysis, patch index

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✨ SYNOPSIS ✨

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

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🎀 Flags 🎀

• --overwrite — lets your output files just go ahead and overwrite files that already exist. chaos mode, but consensual.
• --help — prints the usage summary. the classic "what does this do again" move.
• --verbose — verbose module output. it will simply tell you more. 🗣️
• --quiet — quiet module output. shhh. 🤫
• --ui — forces the GUI dialog to launch. main character energy, but graphical.

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🍓 Parameters 🍓

• input=name [required] — name of the input raster map.
• config=name [required] — the configuration file.
• output=name [required] — the name for the output raster map.

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💜 DESCRIPTION 💜

so r.li.mps — that's mean patch size — figures out the mean size of the patches inside your sampling area, like this:

MPS = A / Npatch

where, bestie:

• A: the sampling area size, without the null cells.
• Npatch: the number of patches.

and the unit of that mean size? hectare. that's the vibe. 🌾

also important: this index is calculated using a 4 neighbour algorithm, which means diagonal cells are ignored when it's tracing a patch. diagonals simply don't get a say. periodt. 💅

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🌈 NOTES 🌈

do NOT use absolute path names for the config and output file/map parameters. i'm serious. 🙈

if you picked the "moving window" method back in g.gui.rlisetup, then your output is gonna be a raster map. otherwise you get an ASCII file generated in this folder:

• C:\Users\userxy\AppData\Roaming\GRASS8\r.li\output\ on MS-Windows
• $HOME/.grass8/r.li/output/ on GNU/Linux

and one more thing — if the sample area contains only NULL value cells, then r.li.mps returns 0 (zero). it's not being rude, it's just the rules. 😭

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🧚 EXAMPLES 🧚

wanna calculate the mean path size index on map my_map, using the my_conf configuration file (which you already defined earlier with g.gui.rlisetup), and save the results in my_out? run this:

r.li.mps input=my_map conf=my_conf output=my_out

Forest map (Spearfish sample dataset) example — slay:

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 — also slay:

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

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👑 SEE ALSO 👑

• r.li — package overview
• g.gui.rlisetup

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📚 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)

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🫶 AUTHORS 🫶

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

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⭐ SOURCE CODE ⭐

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

Accessed: Saturday Jan 17 05:40:53 2026

Main index | Raster index | Topics index | Keywords index | Graphical index | Full index

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and that's the whole page, bestie 💖 this was GRASS GIS 8.4.2 Reference Manual, © 2003-2025 GRASS Development Team, running on GRASS 8.4.2 — go forth and calculate those patches, you absolute legend 🌸✨💅