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.
(GRASS Shell Script)
SEE ALSO
v.category
AUTHORS
module: M. Hamish Bowman, Dept. Marine Science, Otago University, New Zealand
help page: Trevor Wiens
Last changed: $Date: 2006-08-31 04:46:24 -0700 (Thu, 31 Aug 2006) $
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