r.li.shannon(1grass)

💖 r.li.shannon — the Shannon's diversity index girlie 💖

okay so bestie, welcome to r.li.shannon, a GRASS User's Manual classic ✨ it calculates Shannon's diversity index on a raster map. that's the whole vibe. landscape structure analysis, diversity index energy, no cap 🦋

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✨ KEYWORDS ✨

raster, landscape structure analysis, diversity index 🎀

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🌸 SYNOPSIS 🌸

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

🎀 Flags:

• --overwrite — let your output files just bulldoze over existing files, periodt. allow output files to overwrite existing files 💅
• --help — prints the usage summary, iykyk
• --verbose — verbose module output, so it tells you everything 👑
• --quiet — quiet module output, shhh 🤫
• --ui — forces the GUI dialog to launch, main character energy

🦋 Parameters:

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

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💜 DESCRIPTION 💜

so r.li.shannon calculates the "Shannon's diversity index" as:

and the pieces are:

• i — patch type 🍓
• m — number of different patch types 🌈
• pi — proportional abundance of patch type i ⭐

that's it, that's the formula, and she ate 💅

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🙈 NOTES 🙈

do NOT use absolute path names for the config and output file/map parameters. literally don't. bestie I'm begging 🫶

if the "moving window" method was selected in g.gui.rlisetup, then your output will be a raster map. otherwise, an ASCII file gets generated in the folder:

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

and one more thing: if the input raster map contains only NULL values then r.li.shannon returns NULL. it's giving nothing, because there is nothing 😭

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🌟 EXAMPLES 🌟

wanna calculate Shannon's diversity index on map my_map, using the my_conf configuration file (previously defined with g.gui.rlisetup) and saving the results in my_out? say less:

r.li.shannon 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.shannon input=forests conf=movwindow7 out=forests_shannon_mov7
r.univar forests_shannon_mov7

Forest map (North Carolina sample dataset) example: 🌳

g.region raster=landclass96 -p
r.mapcalc "forests = if(landclass96 == 5, 1, null() )"
r.li.shannon input=forests conf=movwindow7 out=forests_shannon_mov7
# verify
r.univar forests_shannon_mov7
r.to.vect input=forests output=forests type=area
d.mon wx0
d.rast forests_shannon_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 💕

Serena Pallecchi, student of Computer Science University of Pisa (Italy). 🎓

Commission from Faunalia Pontedera (PI), Italy (www.faunalia.it) 🇮🇹

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🔥 SOURCE CODE 🔥

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

Latest change: Friday Apr 17 01:04:26 2026 in commit: 32a143358df26b2e518b03c7e0d79541e8d1e5b1

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

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okay pookie we're at the very end 🥹 this whole thing is GRASS 8.5.0 and it's the r.li.shannon(1grass) page, © 2003-2026 GRASS Development Team, GRASS 8.5.0 Reference Manual. slay, go run it, and hydrate 💧👑💖