Scroll to navigation

r.buffer.lowmem(1grass) GRASS GIS User's Manual r.buffer.lowmem(1grass)

NAME

r.buffer.lowmem - Creates a raster map showing buffer zones surrounding cells that contain non-NULL category values.
This is the low-memory alternative to the classic r.buffer module.

KEYWORDS

raster, buffer

SYNOPSIS

r.buffer.lowmem
r.buffer.lowmem --help
r.buffer.lowmem [-z] input=name output=name distances=float[,float,...] [units=string] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:


Ignore zero (0) data cells instead of NULL cells

Allow output files to overwrite existing files

Print usage summary

Verbose module output

Quiet module output

Force launching GUI dialog

Parameters:


Name of input raster map

Name for output raster map

Distance zone(s)

Units of distance
Options: meters, kilometers, feet, miles, nautmiles
Default: meters

DESCRIPTION

r.buffer.lowmem creates a new raster map showing buffer (a.k.a. "distance" or "proximity") zones around all cells that contain non-NULL category values in an existing raster map. The distances of buffer zones from cells with non-zero category values are user-chosen.

This is the low-memory alternative to the classic r.buffer module. It is much slower than the classic version, but will run on massive raster maps without using a lot of RAM. If your raster map is larger than 32000x32000 cells on a system with 1 GB of RAM, or larger than 90000x90000 cells on a system with 8 GB of RAM, consider using this module.

For more info see manual of r.buffer.

EXAMPLE

In the following example, the buffer zones would be (in the default units of meters): 0-100, 101-200, 201-300, 301-400 and 401-500.

r.buffer.lowmem input=roads output=roads.buf distances=100,200,300,400,500

Result:

r.category input=roads.buf

1 distances calculated from these locations
2 0-100 meters
3 100-200 meters
4 200-300 meters
5 300-400 meters
6 400-500 meters

SEE ALSO

g.region, r.buffer, r.cost, r.grow.distance, r.mapcalc, r.reclass, v.buffer

AUTHORS

Michael Shapiro, U.S. Army Construction Engineering Research Laboratory
James Westervelt, U.S. Army Construction Engineering Research Laboratory
Low-memory Python version by Glynn Clements

SOURCE CODE

Available at: r.buffer.lowmem source code (history)

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

© 2003-2021 GRASS Development Team, GRASS GIS 7.8.6 Reference Manual

GRASS 7.8.6