.TH r.buffer.lowmem 1grass "" "GRASS 8.3.1" "GRASS GIS User's Manual" .SH NAME \fI\fBr.buffer.lowmem\fR\fR \- Creates a raster map showing buffer zones surrounding cells that contain non\-NULL category values. .br This is the low\-memory alternative to the classic r.buffer module. .SH KEYWORDS raster, buffer .SH SYNOPSIS \fBr.buffer.lowmem\fR .br \fBr.buffer.lowmem \-\-help\fR .br \fBr.buffer.lowmem\fR [\-\fBz\fR] \fBinput\fR=\fIname\fR \fBoutput\fR=\fIname\fR \fBdistances\fR=\fIfloat\fR[,\fIfloat\fR,...] [\fBunits\fR=\fIstring\fR] [\-\-\fBoverwrite\fR] [\-\-\fBhelp\fR] [\-\-\fBverbose\fR] [\-\-\fBquiet\fR] [\-\-\fBui\fR] .SS Flags: .IP "\fB\-z\fR" 4m .br Ignore zero (0) data cells instead of NULL cells .IP "\fB\-\-overwrite\fR" 4m .br Allow output files to overwrite existing files .IP "\fB\-\-help\fR" 4m .br Print usage summary .IP "\fB\-\-verbose\fR" 4m .br Verbose module output .IP "\fB\-\-quiet\fR" 4m .br Quiet module output .IP "\fB\-\-ui\fR" 4m .br Force launching GUI dialog .SS Parameters: .IP "\fBinput\fR=\fIname\fR \fB[required]\fR" 4m .br Name of input raster map .IP "\fBoutput\fR=\fIname\fR \fB[required]\fR" 4m .br Name for output raster map .IP "\fBdistances\fR=\fIfloat[,\fIfloat\fR,...]\fR \fB[required]\fR" 4m .br Distance zone(s) .IP "\fBunits\fR=\fIstring\fR" 4m .br Units of distance .br Options: \fImeters, kilometers, feet, miles, nautmiles\fR .br Default: \fImeters\fR .SH DESCRIPTION \fIr.buffer.lowmem\fR creates a new raster map showing buffer (a.k.a. \(dqdistance\(dq or \(dqproximity\(dq) 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. .PP This is the low\-memory alternative to the classic \fIr.buffer\fR 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. .PP For more info see manual of \fIr.buffer\fR. .SH 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. .br .nf \fC r.buffer.lowmem input=roads output=roads.buf distances=100,200,300,400,500 \fR .fi Result: .br .nf \fC 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 \fR .fi .SH SEE ALSO \fI g.region, r.buffer, r.cost, r.grow.distance, r.mapcalc, r.reclass, v.buffer \fR .SH AUTHORS Michael Shapiro, U.S. Army Construction Engineering Research Laboratory .br James Westervelt, U.S. Army Construction Engineering Research Laboratory .br Low\-memory Python version by Glynn Clements .SH SOURCE CODE .PP Available at: r.buffer.lowmem source code (history) .PP Accessed: Sunday Dec 17 17:22:50 2023 .PP Main index | Raster index | Topics index | Keywords index | Graphical index | Full index .PP © 2003\-2023 GRASS Development Team, GRASS GIS 8.3.1 Reference Manual