[GRASS5] counting number of vector points in same position?

[Michael Barton]

If v.neighbors had other statistical functions besides count (e.g., sum,
mean, max, min), you could sum cases for all points within a raster cell.
Then you could transform it back to vector.


Michael



On 8/10/05 9:35 AM, "Markus Neteler" <neteler at itc.it> wrote:

> Hi,
> 
> I have to transform a vector points map of disease reports.
> Often more than one report falls into the same location as
> reports were done/geocoded based on cities. This results into
> a vector map with often several vector falling into the
> same coodinate pair.
> 
> I have to transform this map into a new vector map with
> single point per coordinate pair and number of cases as
> attribute.
> 
> How to do that?
> 
> I was thinking of v.distance -a to calculate zero-distances.
> This requires to exclude that the points "see" themselves.
> But then, I am not sure how to transform this into a map.
> Maybe with some SQL fun (distinct() operator or so)?
> 
> Suggestions welcome. This functionality appears to me to
> be needed for GRASS. I darkly remember that it was asked
> time ago, but cannot find the mail(s).
> 
> Thanks
> 
>  Markus
>