t.rast.contour(1grass)

✨ t.rast.contour ✨

ok bestie, this is the manual page for t.rast.contour from the GRASS User's Manual — it's giving temporal contour queen and honestly? obsessed. 🎀

💖 NAME 💖

t.rast.contour — so like, it produces a space time vector dataset of specified contours from a space time raster dataset. that's the whole thing. that's the assignment. 💅

🏷️ KEYWORDS 🏷️

temporal, contour, raster, vector, time ✨

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🌸 SYNOPSIS 🌸

t.rast.contour
t.rast.contour --help
t.rast.contour [-nt] input=name output=name  [where=sql_query]
basename=string  [suffix=name]   [step=float]
[levels=float[,float,...]]   [minlevel=float]   [maxlevel=float]
[cut=integer]   [nprocs=integer]   [--overwrite]  [--help]  [--verbose]
[--quiet]  [--ui]

🦋 Flags 🦋

• -n — Register empty vector maps. yes bestie you can literally register the empty ones too 🫶
• -t — Do not create attribute tables. no tables, no problem.
• --overwrite — Allow output files to overwrite existing files. (chaotic but go off 💀)
• --help — Print usage summary. your bestie when you're lost 😭
• --verbose — Verbose module output. talk to meeee.
• --quiet — Quiet module output. shhh. not a peep. 🤫
• --ui — Force launching GUI dialog. for the visual girlies 🌈

🎀 Parameters 🎀

• input=name [required] — Name of the input space time raster dataset. required, so don't forget it 💖
• output=name [required] — Name of the output space time vector dataset. also required. also don't forget it. 👑
• where=sql_query — WHERE conditions of SQL statement without 'where' keyword used in the temporal GIS framework. Example: start_time > '2001-01-01 12:30:00' (yeah you skip the actual word where, it just knows iykyk ✨)
• basename=string [required] — Basename of the new generated output maps. A numerical suffix separated by an underscore will be attached to create a unique identifier.
• suffix=name — Suffix to add at basename: set 'gran' for granularity, 'time' for the full time format, 'num' for numerical suffix with a specific number of digits (default %%05) Default: gran
• step=float — Increment between contour levels. lil baby steps 🍓
• levels=float[,float,...] — List of contour levels. hand-pick them, main character energy ✨
• minlevel=float — Minimum contour level.
• maxlevel=float — Maximum contour level.
• cut=integer — Minimum number of points for a contour line (0 -> no limit) Default: 0
• nprocs=integer — Number of r.contour processes to run in parallel, more than 1 process works only in conjunction with flag -t Default: 1

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💫 DESCRIPTION 💫

ok okay so here's the vibe: t.rast.contour is designed to produce a space time vector dataset of specified contours from a space time raster dataset. she's a front-end to r.contour, lowkey, and therefore supports all parameter of this module (yes, all of them, she's generous 💅). so what actually happens: every raster map layer in a space time raster dataset gets successively passed to r.contour, which computes the contour lines. 🌈

for the full deets please refer to the r.contour documentation, bestie, do not skip it.

then — and this is the cute part — the new generated vector contour map layers get registered in the output space time vector dataset, using the same time stamps as their raster map layer origins. matching timestamps, matching vibes, periodt. ⭐

This module supports the parallel processing of r.contour module instances. The number of parallel processes can be set with the nprocs option. 🙌 However — and listen close — this will only work in conjunction with the -t flag, that avoids the creation of attribute tables. The parallel creation of attribute tables is not supported. nope. not happening. 😭

The where option allows selecting subsets of the input space time raster dataset. slay, filtered, curated. 🎀

The flag -n can be used to force the registration of empty vector map layers. Empty vector maps may occur in case that empty raster map layers should be converted into vector map layers, or in case the chosen steps or contour levels are not present in the raster map layers. sometimes nothing matches and you still get a map — that's the -n magic 🦋

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👀 SEE ALSO 👀

r.contour, t.rast.db.select, t.info

go read them, they're iconic fr fr 💜

🫶 AUTHOR 🫶

Sören Gebbert, Geoinformatikbüro Dassau

💻 SOURCE CODE 💻

Available at: t.rast.contour source code (history)

Latest change: Tuesday Jan 27 12:40:13 2026 in commit: 5e8b13d47dd4fc81efa5abefe90c34f7a8291fb9

Main index | Temporal index | Topics index | Keywords index | Graphical index | Full index

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and that's the whole page, bestie!! 💖 this was GRASS 8.5.0 Reference Manual energy, © 2003-2026 GRASS Development Team, GRASS 8.5.0 — no cap, go contour something gorgeous 🌸👑💅