r3.gradient(1)

📦
version 8.4.2 · 8 versions
, in fedora 44

✨ r3.gradient ✨

okay bestie, welcome to the GRASS GIS User's Manual 💖 this one's all about r3.gradient, and no cap, it's a bop.

🌸 NAME 🌸

r3.gradient — it computes the gradient of a 3D raster map and outputs the gradient components as three 3D raster maps. literally that's the whole gig 🫶

🎀 KEYWORDS 🎀

raster3d, gradient, voxel

✨ SYNOPSIS ✨

r3.gradient
r3.gradient --help
r3.gradient input=name
output=grad_x,grad_y,grad_z[,grad_x,grad_y,grad_z,...]
[blocksize=size_x,size_y,size_z[,size_x,size_y,size_z,...]]
[--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]

🦋 Flags 🦋

  • --overwrite — lets your output files just bulldoze over existing files. iconic but also, be careful bestie 💅
  • --help — prints the usage summary so you're not out here guessing
  • --verbose — verbose module output, aka it tells you everything
  • --quiet — quiet module output, aka it tells you nothing (respect)
  • --ui — forces the GUI dialog to launch. main character energy, go off 🪟

💜 Parameters 💜

  • input=name [required] — the name of your input 3D raster map
  • output=grad_x,grad_y,grad_z[,grad_x,grad_y,grad_z,...] [required] — name(s) for your output 3D raster map(s)
  • blocksize=size_x,size_y,size_z[,size_x,size_y,size_z,...] — the size of blocks
    • Default: 30,30,20

🌈 DESCRIPTION 🌈

so what does r3.gradient actually do, you ask? it computes the gradient from a 3D raster map, periodt. the results? three whole 3D raster maps, and they describe the x, y, z components of the computed gradient field. three maps. three axes. it's giving coordinate slay 💅✨

🍓 EXAMPLES 🍓

first up, create a 3D raster:

# create a 3D raster
g.region s=0 n=100 w=0 e=100 b=0 t=100 -p
r3.mapcalc "test_gradient = sqrt(row()*row() +col()*col()+ depth()*depth())"
# compute gradient
r3.gradient input=test_gradient output=grad_x,grad_y,grad_z

and that's it. you just did that. ate and left no crumbs 🔥

🧚 SEE ALSO 🧚

r3.flow, r.flow

👑 AUTHOR 👑

Anna Petrasova, NCSU GeoForAll Lab, developed during GSoC 2014. periodt, we stan 💖

⭐ SOURCE CODE ⭐

Available at: r3.gradient source code (history)

Accessed: Saturday Jan 17 05:41:14 2026

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

and that's the whole page bestie 🫶 this was r3.gradient, running under GRASS 8.4.2, and you understood every word of it. no cap, obsessed 💜🌸✨

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