r.circle(1grass)

✨ r.circle — the GRASS User's Manual glow-up ✨

okay bestie, welcome to r.circle from the GRASS User's Manual, aka the girl who draws perfect lil concentric rings on your raster and never misses 💅

💖 NAME 💖

r.circle — she creates a raster map with concentric rings around a given point. that's it, that's the whole personality, and it ate. 🎀

🔑 KEYWORDS 🔑

raster, buffer, geometry, circle

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🦋 SYNOPSIS 🦋

r.circle
r.circle --help
r.circle [-b] output=name coordinates=east,north  [min=float]
[max=float]   [multiplier=float]   [--overwrite]  [--help]  [--verbose]
[--quiet]  [--ui]

🎀 Flags:

• -b — generate a binary raster map. like, binary pattern only (super useful for making a mask, iykyk).
• --overwrite — allow output files to overwrite existing files. yes ma'am, permission granted.
• --help — print usage summary. the "wait what do i type" button 🫶
• --verbose — verbose module output. she will not stop talking.
• --quiet — quiet module output. she will say nothing. iconic.
• --ui — force launching GUI dialog. for the visual girlies ✨

🌸 Parameters:

• output=name [required] — name for output raster map. you gotta name her, she's your baby.
• coordinates=east,north [required] — the coordinate of the center (east,north). where the magic happens.
• min=float — minimum radius for ring/circle map (in meters).
• max=float — maximum radius for ring/circle map (in meters).
• multiplier=float — data value multiplier. multiply those z-values, go off.

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💜 DESCRIPTION 💜

so r.circle creates an output raster map centered on the x,y values you gave with the coordinate parameter, and it goes all the way out to the edge of the current region. the output cell values increase linearly from the specified center. the min and max parameters control the inner and outer output raster map radii, respectively. no cap. 🌈

the mult parameter can be used to multiply the output raster cells by a common factor. heads up though: this parameter does not affect the output raster position or size — only the z-values get changed with this parameter. she's just changing the vibe of your numbers, not the geometry, fr fr.

binary-output raster maps (solid circles of one value) can be created with the -b flag. raster maps so created can be used to create binary filters for use in i.ifft (inverse Fourier transformations; apply filter with r.mask). fancy science bestie behavior 🧚

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🔥 EXAMPLES 🔥

generate a raster circle at current map center with a radius of 300m and outwardly increasing raster values:

EASTCENTER=`g.region -c |  awk ’ /center easting:/ { print $3 }’`
NORTHCENTER=`g.region -c | awk ’ /center northing:/ { print $3 }’`
r.circle output=circle coordinate=${EASTCENTER},${NORTHCENTER} max=300

generate a binary raster ring around current map center with an inner radius of 500m and an outer radius of 1000m:

EASTCENTER=`g.region -c |  awk ’ /center easting:/ { print $3 }’`
NORTHCENTER=`g.region -c | awk ’ /center northing:/ { print $3 }’`
r.circle -b output=circle coordinate=${EASTCENTER},${NORTHCENTER} min=500 max=1000

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👀 SEE ALSO 👀

g.region, g.remove, g.rename, i.fft, i.ifft, r.mask

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👑 AUTHORS 👑

Bill Brown, U.S. Army Construction Engineering Research Laboratory

Additional flag/min/max parameter by Markus Neteler, University of Hannover

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💀 SOURCE CODE 💀

Available at: r.circle source code (history)

Latest change: Friday Feb 07 19:16:09 2025 in commit: a82a39f673b97fafcfce1604dc3e6015cb96487a

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

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ok that's the whole page, you're fully caught up bestie 💖 this was GRASS 8.5.0 from the GRASS 8.5.0 Reference Manual, © 2003-2026 GRASS Development Team — and the manual name was published under r.circle(1grass), grandmother of the whole thing 🫶 slay, go draw some circles, periodt ✨🌸