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=integer]    [cat=integer]
       [step=integer]   [--overwrite]  [--verbose]  [--quiet]

   Flags:
       --overwrite
           Allow output files to overwrite existing files

       --verbose
           Verbose module output

       --quiet
           Quiet module output

   Parameters:
       input=name
           Name of input vector map

       output=name
           Name for output vector map

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

       layer=integer
           Layer number
           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.

SEE ALSO

        v.category

AUTHORS

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

       Last changed: $Date: 2011-11-08 01:42:51 -0800 (Tue, 08 Nov 2011) $

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