r.li.mpa(1)

📦
version 8.4.2 · 8 versions
, in fedora 44

💖 r.li.mpa 💖

okay bestie, welcome to the GRASS GIS User's Manual page for r.li.mpa(1) — yes that's the manual name, and yes we're gonna read it together, it's fine, it's fun, I promise 🫶

✨ NAME ✨

r.li.mpa — it calculates the mean pixel attribute index on a raster map. that's the whole job. she's a specialist. she does one thing and she does it gorgeously 💅

🌸 KEYWORDS 🌸

raster, landscape structure analysis, patch index

iykyk 🧚

🌈 SYNOPSIS 🌈

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

🎀 Flags 🎀

  • --overwrite — lets output files overwrite files that already exist. yes she will absolutely bulldoze your old file, no cap 💀
  • --help — prints the usage summary. the classic "what does this do again" button 🥺
  • --verbose — verbose module output. she talks more. love that for her 💬
  • --quiet — quiet module output. she talks less. also love that for her 🤫
  • --ui — forces the GUI dialog to launch. point-and-click era ✨

💜 Parameters 💜

  • input=name [required] — name of input raster map. mandatory bestie, no skipping 📌
  • config=name [required] — configuration file. also mandatory 📌
  • output=name [required] — name for output raster map. still mandatory 📌

🦋 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)

the way the manpage just says "as:" and then "with:" and moves on… iconic honestly, she said figure it out 🫠 (that's literally how it's written, we're keeping it exactly as-is)

💅 NOTES 💅

  • Do not use absolute path names for the config and output file/map parameters. like, don't. just don't 🙈
  • 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). two totally different vibes depending on your OS, slay 💻
  • 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. ⭐

ngl that last one is a whole two-step routine, don't skip the second step or your map is gonna have weird -1s in it 😭

🔥 EXAMPLES 🔥

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

bestie look at those workflows, she ATE and left no crumbs 👑

👑 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)

academic queen behavior fr fr 🎓

💖 AUTHORS 💖

  • Serena Pallecchi, student of Computer Science University of Pisa (Italy).
  • Commission from Faunalia Pontedera (PI), Italy (www.faunalia.it)
  • Markus Metz

⭐ SOURCE CODE ⭐

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

Accessed: Saturday Jan 17 05:40:52 2026

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

and that's the whole page, babe 💜 this manual is from GRASS GIS 8.4.2 and it's dated Saturday Jan 17 05:40:52 2026 (that's the footer energy right there), copyright © 2003-2025 GRASS Development Team — go forth and calculate those mean pixel attributes, you absolute icon 🌈🦋✨

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