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

Markus Neteler neteler at itc.it
Wed Aug 10 12:35:51 EDT 2005


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

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).



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