1r.circle(1)                   Grass User's Manual                  r.circle(1)
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NAME

6       r.circle   -  Creates a raster map containing concentric rings around a
7       given point.
8

KEYWORDS

10       raster
11

SYNOPSIS

13       r.circle
14       r.circle help
15       r.circle [-b]  output=name  coordinate=x,y   [min=float]    [max=float]
16       [mult=float]   [--overwrite]  [--verbose]  [--quiet]
17
18   Flags:
19       -b
20           Generate binary raster map
21
22       --overwrite
23           Allow output files to overwrite existing files
24
25       --verbose
26           Verbose module output
27
28       --quiet
29           Quiet module output
30
31   Parameters:
32       output=name
33           Name for output raster map
34
35       coordinate=x,y
36           The coordinate of the center (east,north)
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38       min=float
39           Minimum radius for ring/circle map (in meters)
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41       max=float
42           Maximum radius for ring/circle map (in meters)
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44       mult=float
45           Multiplier
46

DESCRIPTION

48       This  module  creates  an  output raster map centered on the x,y values
49       specified with the coordinate parameter, out to the edge of the current
50       region.   The  output  cell values increase linearly from the specified
51       center. The min and max parameters control the inner and  outer  output
52       raster map radii, respectively.
53
54       The mult parameter can be used to multiply the output raster cells by a
55       common factor.  Note that this parameter does  not  affect  the  output
56       raster position or size; only the z-values are changed with this param‐
57       eter.
58
59       Binary-output raster maps (solid circles of one value) can  be  created
60       with  the  -b flag. Raster maps so created can be used to create binary
61       filters for use in i.ifft (inverse Fourier transformations; apply  fil‐
62       ter with r.mask).
63

EXAMPLES

65       Generate  a  raster  circle at current map center with a radius of 300m
66       and outwardly increasing raster values:
67       EASTCENTER=`g.region -c |  awk ' /center easting:/ { print $3 }'`
68       NORTHCENTER=`g.region -c | awk ' /center northing:/ { print $3 }'`
69       r.circle output=circle coordinate=${EASTCENTER},${NORTHCENTER} max=300
70        Generate a binary raster ring around current map center with an  inner
71       radius of 500m and an outer radius of 1000m:
72       EASTCENTER=`g.region -c |  awk ' /center easting:/ { print $3 }'`
73       NORTHCENTER=`g.region -c | awk ' /center northing:/ { print $3 }'`
74       r.circle   -b   output=circle   coordinate=${EASTCENTER},${NORTHCENTER}
75       min=500 max=1000
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77

SEE ALSO

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

82       Bill Brown, U.S. Army Construction Engineering Research Laboratory
83       Additional flag/min/max parameter by Markus Neteler, University of Han‐
84       nover
85
86       Last changed: $Date: 2008-01-22 15:21:36 +0100 (Tue, 22 Jan 2008) $
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88       Full index
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90       © 2003-2008 GRASS Development Team
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94GRASS 6.3.0                                                        r.circle(1)