r.li.renyi(1)

💖 r.li.renyi 💖

okay bestie, so this is a page from the GRASS GIS User's Manual — section r.li.renyi(1), one of the raster modules — and it's literally about calculating Renyi's diversity index on a raster map. landscape structure analysis girlies rise up 🦋

✨ NAME ✨

r.li.renyi — calculates Renyi's diversity index on a raster map. that's the whole job. she does one thing and she does it 💅

🔑 KEYWORDS 🔑

raster, landscape structure analysis, diversity index

🌸 SYNOPSIS 🌸

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

⭐ Flags ⭐

• --overwrite — lets your output files just overwrite existing files. chaotic but sometimes necessary, no cap 😌
• --help — prints the usage summary. your girl when you're lost fr
• --verbose — verbose module output. she will talk more 💬
• --quiet — quiet module output. she will talk less 🤫
• --ui — force launching the GUI dialog. for when you want the pretty buttons ✨

🎀 Parameters 🎀

• input=name [required] — name of input raster map. the map you're analyzing, your main character 🗺️
• config=name [required] — configuration file. the settings file, she's important
• alpha=string [required] — "Alpha value is the order of the generalized entropy". so alpha is the order, and order is alpha. keep up 🫶
• output=name [required] — name for output raster map. where the results land 🍓

💜 DESCRIPTION 💜

r.li.renyi calculates the "Renyi's diversity index" as:

with:

• H: Renyi entropy
• alpha: order of the generalized entropy
• i: patch type
• S: number of different patch types
• pi: proportional abundance of patch type i

like yes the formula is implied and the variables are all spelled out for you, iconic behavior honestly 👑

📝 NOTES 📝

do NOT use absolute path names for the config and output file/map parameters. just don't, bestie. the module will not be happy 💀

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). so like, know where your stuff is going, mkay 🧚

if the input raster map contains only NULL values then r.li.renyi returns NULL. that's it, that's the whole mood 🌈

🔥 EXAMPLES 🔥

to calculate Renyi's diversity 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.renyi input=my_map conf=my_conf output=my_out alpha=0.6

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.renyi input=forests conf=movwindow7 out=forests_renyi_mov7_a06 alpha=0.6
r.univar forests_renyi_mov7_a06

forest map (North Carolina sample dataset) example:

g.region raster=landclass96 -p
r.mapcalc "forests = if(landclass96 == 5, 1, null() )"
r.li.renyi input=forests conf=movwindow7 out=forests_renyi_mov7
# verify
r.univar forests_renyi_mov7
r.to.vect input=forests output=forests type=area
d.mon wx0
d.rast forests_renyi_mov7
d.vect forests type=boundary

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👀 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 👑

Luca Delucchi and Duccio Rocchini, Fondazione E. Mach (Italy), based on the r.li.shannon code developed by Serena Pallecchi, student of Computer Science University of Pisa (Italy). absolute legends, we stan 💖

💻 SOURCE CODE 💻

available at: r.li.renyi source code (history)

accessed: Saturday Jan 17 05:40:55 2026

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

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and that's a wrap, bestie 🎀 this was r.li.renyi(1) from GRASS GIS 8.4.2, © 2003-2025 GRASS Development Team, straight outta the GRASS GIS 8.4.2 Reference Manual — go forth and compute that entropy, periodt ✨🦋💅