r.describe(1)

📦
version 8.4.2 · 8 versions
, in fedora 44

💖 r.describe — the GRASS GIS manual, but make it group chat 💖

ok so bestie, you know how you have a raster map and you're like "what values are even IN here??" — that's this. r.describe is a GRASS GIS tool (from the GRASS GIS User's Manual, module name r.describe) that prints a terse list of category values found in a raster map layer. Terse! She does not ramble. She gives you the values and she moves on. 💅

Keywords, for the search bar: raster, metadata. iykyk.

✨ SYNOPSIS ✨

Like, the whole shape of her:

r.describe
r.describe --help
r.describe [-1rndi] map=name  [null_value=string]   [nsteps=integer]
[--help]  [--verbose]  [--quiet]  [--ui]

🎀 FLAGS 🎀

  • -1 — prints the output one value per line. one. per. line. no crowding, no chaos, just vibes. 🌸
  • -r — only prints the range of the data. she's giving summary. she's giving minimalism.
  • -n — suppresses reporting of any NULLs. not today, nulls. 🚫
  • -d — use the current region. yes queen, respect the region for once.
  • -i — read floating-point map as integer. she's rounding. she's deciding.
  • --help — print usage summary. your little cheat sheet 🫶
  • --verbose — verbose module output. she will over-share. iconic.
  • --quiet — quiet module output. she will not.
  • --ui — force launching GUI dialog. for the girlies who love a window ✨

🌈 PARAMETERS 🌈

  • map=name [required] — Name of raster map. mandatory bestie, you HAVE to tell her which one.
  • null_value=string — String representing NULL value. Default: *
  • nsteps=integer — Number of quantization steps. Default: 255

💜 DESCRIPTION 💜

So. r.describe prints a terse listing of category values found in a user-specified raster map layer. that's the whole job. she's focused. she's booked and busy.

here's the part you gotta remember: r.describe ignores the current geographic region and mask, and reads the full extent of the input raster map. no cap. and like — that's actually a feature, because if you're planning to reclassify or rescale your data, those functions (r.reclass and r.rescale) also ignore the current geographic region and mask. so she's matching their energy. consistent queen. 👑

The nv parameter sets the string to be used to represent NULL values in the module output; the default is '*'.

The nsteps parameter sets the number of quantisation steps to divide into the input raster map.

📝 NOTES 📝

FLAGS 🚩

If you pick the -r flag, a range of category values found in the raster map layer gets printed. and the range gets split into three groups: negative, positive, and zero. If negative values occur, the minimum and maximum negative values get printed. If positive values occur, the minimum and maximum positive values get printed. If zero occurs, this will be indicated. The range report will generally run faster than the full list (which is the default output). so if you're in a hurry — -r. periodt.

The -d flag can be used to force r.describe to respect the current region extents when repoting raster map categories. (yes, "repoting", that's what the original says, we keep the typos, we respect the lore 🙈). The default behavior is to read the full extent of the input raster map.

If the -1 flag is specified, the output appears with one category value/range per line.

The -n flag suppresses the reporting of NULL values.

🦋 EXAMPLES 🦋

these ones are from the Spearfish60 sample dataset, so you can literally go try them yourself. slay.

r.describe landcover.30m
* 11 21-23 31 32 41-43 51 71 81-83 85 91 92
r.describe -r landcover.30m
11 thru 92
*
r.describe -n landcover.30m
11 21-23 31 32 41-43 51 71 81-83 85 91 92
r.describe -1 geology
*
1
2
3
4
5
6
7
8
9

👀 SEE ALSO 👀

go read these next, bestie, they're all in the family:

g.region, r.mask, r.reclass, r.report, r.rescale, r.stats, r.univar

👑 AUTHOR 👑

Michael Shapiro, U.S. Army Construction Engineering Research Laboratory

the blueprint. the moment. we love him.

💻 SOURCE CODE 💻

Available at: r.describe source code (history)

Accessed: Saturday Jan 17 05:40:45 2026

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

and that's the whole page, bestie 💖 go describe some rasters. you got this. fr fr. 🫶✨

© 2003-2025 GRASS Development Team, GRASS GIS 8.4.2 Reference Manual — yes, the copyright goes to the GRASS Development Team, and this whole thing is from the GRASS 8.4.2 Reference Manual, r.describe(1), accessed Saturday Jan 17 05:40:45 2026. mwah. 💅🎀

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