r.li.padsd(1)

r.li.padsd 💅✨

okay bestie, this is r.li.padsd from the GRASS GIS User's Manual — a lil module that does landscape structure analysis and is lowkey obsessed with patch index stuff. it lives in the raster world. let's go 🦋

---

✨ NAME ✨

r.li.padsd — calculates standard deviation of patch area for a raster map 🎀

---

🌸 KEYWORDS 🌸

raster, landscape structure analysis, patch index

---

🫶 SYNOPSIS 🫶

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

🎀 Flags:

• --overwrite — allow output files to overwrite existing files (yes it will actually do that, be brave)
• --help — print usage summary
• --verbose — verbose module output (it talks more, we love a chatty king)
• --quiet — quiet module output (shhh era)
• --ui — force launching GUI dialog

🦋 Parameters:

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

---

💖 DESCRIPTION 💖

so r.li.padsd calculates the standard deviation of patch area sizes in hectares, and it does it like this:

with:

• MPS: mean patch area size
• ai: area of patch i
• Npatch: number of patches

ngl the actual formula is not spelled out in this manual page — the text literally just says "as:" and then "with:" and then these definitions, so that's exactly what you're getting. no cap, no guessing, we don't invent math here 🙈

this index gets calculated using a 4 neighbour algorithm — meaning diagonal cells are ignored when tracing a patch. periodt. 💅

---

🧚 NOTES 🧚

do NOT use absolute path names for the config and output file/map parameters. like, seriously. it's giving chaos.

if the "moving window" method was selected in g.gui.rlisetup, then the 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)

the result is NULL if the sample area contains only NULL values. empty is empty, bestie 😭

---

🌈 EXAMPLES 🌈

wanna calculate the patch area distribution standard deviation index on map my_map, using my_conf configuration file (which you already defined with g.gui.rlisetup) and save the results in my_out? say less, run this:

r.li.padsd 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.padsd input=forests conf=movwindow7 out=forests_padsd_mov7
r.univar forests_padsd_mov7

🍓 Forest map (North Carolina sample dataset) example:

g.region raster=landclass96 -p
r.mapcalc "forests = if(landclass96 == 5, 1, null() )"
r.li.padsd input=forests conf=movwindow7 out=forests_padsd_mov7
# verify
r.univar forests_padsd_mov7
r.to.vect input=forests output=forests type=area
d.mon wx0
d.rast forests_padsd_mov7
d.vect forests type=boundary

---

👑 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 💜

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

---

⭐ SOURCE CODE ⭐

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

Accessed: Saturday Jan 17 05:40:54 2026

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

---

okay that's the whole thing bestie, you ate 💅✨ this was brought to you by GRASS GIS 8.4.2 (that's the version in the footer, fr fr), the GRASS GIS 8.4.2 Reference Manual, and © 2003-2025 GRASS Development Team. mwah, go map something iconic 🦋🌸🎀