[GRASS-user] vectors: how to find the gravitation centre of point data ?

[Moritz Lennert]

On 04/12/08 11:02, peter.loewe at gmx.de wrote:
> Hi list,
> 
> is there an easy way to derive the centre of a cloud of points ?
> 
> I am aware that the set of vector points ("cloud of points") could be
> used to stake out a polygon/boundary and use v.centroid etc etc to
> derive in turn its' centroid, but I am hoping for an easier solution
> .. ?
> 
> This issue stems from working with v.to.db: currently it is not
> possible to upload xy coordinates for "multiploygons" into a
> database, i.e: Within a vector layer, there might be several
> boundaries which all share the same category value. If the
> "gravitational centre/ super-centroid" for these boundaries could be
> (conveniently) calculated, the v.to.db issue could be taken care of.


Why not use v.dissolve on these polygons and then get the centroids of 
the result ?

Another (very wild) guess: what about the mean of the coordinates of the 
individual polygons' centroids ?

Moritz