r.li.cwed(1)

📦
version 8.4.2 · 8 versions
, in fedora 44

💖 r.li.cwed 💖

okay so bestie, welcome to r.li.cwed — that's a lil module from the GRASS GIS User's Manual (yes, the actual manual, we're fancy here) 🎀 and it Calculates contrast weighted edge density index on a raster map. no cap. that's the whole vibe.

KEYWORDS (aka the tags so you can find her again): raster, landscape structure analysis, patch index 🦋

✨ SYNOPSIS ✨

she's giving very "type it exactly like this" energy:

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

🎀 Flags

  • --overwrite — let the output files just bulldoze over existing files. overwrite era 💅
  • --help — prints the usage summary, for when you're lost (real)
  • --verbose — verbose module output, she will NOT stop talking
  • --quiet — quiet module output, the silent treatment
  • --ui — force launches the GUI dialog, for the visual girlies 🖥️✨

🌸 Parameters

  • input=name [required] — Name of input raster map
  • config=name [required] — Configuration file
  • path=name [required] — Name of file that contains the weight to calculate the index
  • output=name [required] — Name for output raster map

🌈 DESCRIPTION 🌈

ok so r.li.cwed (contrast weighted edge density) calculates the edge density between patch types specified:

with:

  • k: attribute
  • m: number of non-null attributes in the sampling area
  • eik: total length of edge in landscape between patch types i and k
  • dik: dissimilarity (edge contrast weight) between patch types i and k
  • Area: total landscape area

The input file contains a row for each couple of patch type that we want to consider in the calculation. Each row must be saved using this syntax:

patchType1,patchType2,dissimilarityBetweenPatchType1andPatchType2

like, one row per couple, comma-separated, no drama 🍓

⭐ NOTES ⭐

Do not use absolute path names for the config and output file/map parameters. bestie I am BEGGING you 🙈

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).

If the sample area contains only NULL values it is considered to have 0 patch and CWED=0. If Area is 0 r.li.cwed returns -1. This is only possible if the map 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. (yes, after — order matters, don't skip steps 💀)

🔥 EXAMPLES 🔥

To calculate the contrast weighted edge density 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.cwed input=my_map conf=my_conf output=my_out \
          path=/path/to/weights.csv

Example for input "weights.csv" file:

12,16,0.65
44,123,0.32
56,12,0.54
23,66,0.99

literally four lines and you're iconic 👑

🦋 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 👑

  • 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.cwed source code (history)

Accessed: Saturday Jan 17 05:40:51 2026

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

© 2003-2025 GRASS Development Team, GRASS GIS 8.4.2 Reference Manual

and that's the whole page bestie 💖 she's running on GRASS 8.4.2, page r.li.cwed(1), and the source code was last accessed on that very date up there — slay, go calculate some edge density, you got this ✨💅🫶

📦 where this page comes from