NAME

       v.centroids  - Adds missing centroids to closed boundaries.

KEYWORDS

       vector, centroid, area

SYNOPSIS

       v.centroids
       v.centroids --help
       v.centroids  input=name  output=name   [option=string]    [layer=string]   [cat=integer]   [step=integer]
       [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       --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:
       input=name [required]
           Name of input vector map
           Or data source for direct OGR access

       output=name [required]
           Name for output vector map

       option=string
           Action to be taken
           Options: add
           Default: add

       layer=string
           Layer number or name
           Vector features can have category values in different layers. This number determines which  layer  to
           use. When used with direct OGR access this is the layer name.
           Default: 1

       cat=integer
           Category number starting value
           Default: 1

       step=integer
           Category increment
           Default: 1

DESCRIPTION

       GRASS defines vector areas as composite entities consisting of a set of closed boundaries and a centroid.
       The  attribute  information  associated  with that area is linked to the centroid. The v.centroids module
       adds centroids to closed boundaries in the input file and assigns a category number to them. The starting
       value as well as the increment size may be set using optional parameters.

       Multiple attributes may be linked to a single vector  entity  through  numbered  fields  referred  to  as
       layers. Refer to v.category for more details, as v.centroids is simply a frontend to that module.

       The  boundary itself is often stored without any category reference as it can mark the border between two
       adjacent areas. Thus it would be ambiguous as to which feature the attribute would belong. In some  cases
       it  may,  for  example,  represent  a  road  between  two  parcels  of  land. In this case it is entirely
       appropriate for the boundary to contain category information.

EXAMPLES

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

SEE ALSO

        v.category

AUTHORS

       module: M. Hamish Bowman, Dept. Marine Science, Otago University, New Zealand
       help page: Trevor Wiens

       Last changed: $Date: 2017-11-11 19:59:24 +0100 (Sat, 11 Nov 2017) $

SOURCE CODE

       Available at: v.centroids source code (history)

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       © 2003-2018 GRASS Development Team, GRASS GIS 7.4.0 Reference Manual

GRASS 7.4.0                                                                                  v.centroids(1grass)