1v.centroids(1)                Grass User's Manual               v.centroids(1)
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NAME

6       v.centroids  - Adds missing centroids to closed boundaries.
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KEYWORDS

9       vector, centroid, area
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SYNOPSIS

12       v.centroids
13       v.centroids --help
14       v.centroids  input=name  output=name   [option=string]   [layer=string]
15       [cat=integer]   [step=integer]   [--overwrite]   [--help]   [--verbose]
16       [--quiet]  [--ui]
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18   Flags:
19       --overwrite
20           Allow output files to overwrite existing files
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22       --help
23           Print usage summary
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25       --verbose
26           Verbose module output
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28       --quiet
29           Quiet module output
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31       --ui
32           Force launching GUI dialog
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34   Parameters:
35       input=name [required]
36           Name of input vector map
37           Or data source for direct OGR access
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39       output=name [required]
40           Name for output vector map
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42       option=string
43           Action to be taken
44           Options: add
45           Default: add
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47       layer=string
48           Layer number or name
49           Vector  features can have category values in different layers. This
50           number determines which layer to use. When  used  with  direct  OGR
51           access this is the layer name.
52           Default: 1
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54       cat=integer
55           Category number starting value
56           Default: 1
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58       step=integer
59           Category increment
60           Default: 1
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DESCRIPTION

63       GRASS defines vector areas as composite entities consisting of a set of
64       closed boundaries and a centroid. The attribute information  associated
65       with  that  area is linked to the centroid. The v.centroids module adds
66       centroids to closed boundaries in the input file and assigns a category
67       number to them. The starting value as well as the increment size may be
68       set using optional parameters.
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70       Multiple attributes may be linked to a  single  vector  entity  through
71       numbered  fields  referred  to  as layers. Refer to v.category for more
72       details, as v.centroids is simply a frontend to that module.
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74       The boundary itself is often stored without any category  reference  as
75       it  can  mark  the  border between two adjacent areas. Thus it would be
76       ambiguous as to which feature the attribute would belong. In some cases
77       it  may,  for example, represent a road between two parcels of land. In
78       this case it is entirely appropriate for the boundary to contain  cate‐
79       gory information.
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EXAMPLES

82       Create an area from a closed line using North Carolina sample dataset:
83       v.type input=busroute11 output=busroute11_boundary from_type=line to_type=boundary
84       v.centroids input=busroute11_boundary output=busroute11_area
85       Figure: Creating area from closed line
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SEE ALSO

88        v.category
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AUTHORS

91       module:  M.  Hamish Bowman, Dept. Marine Science, Otago University, New
92       Zealand
93       help page: Trevor Wiens
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SOURCE CODE

96       Available at: v.centroids source code (history)
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98       Main index | Vector index | Topics index | Keywords index  |  Graphical
99       index | Full index
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101       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual
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105GRASS 7.8.2                                                     v.centroids(1)