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

Daniel Calvelo Aros dcalvelo at minag.gob.pe
Wed Aug 10 14:15:54 EDT 2005

Hi, Markus.

If your points have the exact same coordinate, you might v.out.ascii then stg
like 'awk -F"|" {print $1 " " $2} | sort -n | uniq -c' on the output file,
then v.in.ascii back. If you have a tolerance radius for "same location", some
rounding tweaking might be needed.


---------- Original Message -----------
From: Markus Neteler <neteler at itc.it>
To: grass5 developers list <grass5 at grass.itc.it>
Sent: Wed, 10 Aug 2005 18:35:51 +0200
Subject: [GRASS5] counting number of vector points in same position?

> 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
> _______________________________________________
> grass5 mailing list
> grass5 at grass.itc.it
> http://grass.itc.it/mailman/listinfo/grass5
------- End of Original Message -------

More information about the grass-dev mailing list