NAME¶
r.circle - Creates a raster map containing concentric rings around
a given point.
KEYWORDS¶
raster, geometry
SYNOPSIS¶
r.circle
r.circle help
r.circle [-
b]
output=
name
coordinate=
x,y [
min=
float]
[
max=
float] [
mult=
float] [--
overwrite]
[--
verbose] [--
quiet]
Flags:¶
- -b
-
Generate binary raster map
- --overwrite
-
Allow output files to overwrite existing files
- --verbose
-
Verbose module output
- --quiet
-
Quiet module output
Parameters:¶
- output=name
-
Name for output raster map
- coordinate=x,y
-
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)
- mult=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: 2009-01-05 23:08:26 +0100 (Mon, 05 Jan 2009) $
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