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Note: This document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade, and read the current manual page.

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:

-z
Ignore zero (0) data cells instead of NULL cells
--overwrite
Allow output files to overwrite existing files
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--ui
Force launching GUI dialog

Parameters:

input=name [required]
Name of input raster map
output=name [required]
Name for output raster map
distances=float[,float,...] [required]
Distance zone(s)
units=string
Units of distance
Options: meters, kilometers, feet, miles, nautmiles
Default: meters

Table of contents

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)

Latest change: Mon Nov 18 20:15:32 2019 in commit: 1a1d107e4f6e1b846f9841c2c6fabf015c5f720d


Note: This document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade, and read the current manual page.

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