NAME

       r.circle  - Creates a raster map containing concentric rings around a given point.

KEYWORDS

       raster, buffer, geometry, circle

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 binary raster map

       --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:
       output=name [required]
           Name for output raster map

       coordinates=east,north [required]
           The coordinate of the center (east,north)

       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

DESCRIPTION

       This module creates an output raster map centered on the x,y  values  specified  with  the
       coordinate  parameter,  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.

       The  mult  parameter  can  be used to multiply the output raster cells by a common factor.
       Note that this parameter does not affect the output raster  position  or  size;  only  the
       z-values are changed with this parameter.

       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).

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

SEE ALSO

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

AUTHOR

       Bill Brown, U.S. Army Construction Engineering Research Laboratory
       Additional flag/min/max parameter by Markus Neteler, University of Hannover

       Last changed: $Date: 2014-12-12 00:16:30 +0100 (Fri, 12 Dec 2014) $

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       © 2003-2016 GRASS Development Team, GRASS GIS 7.0.3 Reference Manual