Provided by: grass-doc_6.4.3-3_all
v.centroids - Adds missing centroids to closed boundaries.
vector, centroid, area
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
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.
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) $ Full index © 2003-2013 GRASS Development Team