[GRASS-user] Buffered categories

Markus Metz markus.metz.giswork at googlemail.com
Thu Feb 23 15:40:23 EST 2012


On Thu, Feb 23, 2012 at 8:14 PM, Hamish <hamish_b at yahoo.com> wrote:
> Moritz wrote:
>> If you create buffers around points which have category
>> values and you would like to assign those values to the buffers,
>> you can then (after v.category) do something like this:
>>
>> v.db.addtable yourbuffers
>> v.db.addcol yourbuffers col="pointcat int"
>> v.distance from=yourbuffers to=yourpoints  dmax=0
>> upload=cat column=pointcat
>
> except of course if two of those buffers overlap, in which case it is
> ambiguous as to which starting category the merged buffer area should
> take. (which is why v.buffer just assigns everything to category 1 instead
> of preserving seed categories in the first place)

Preserving seed categories is in theory easy, no need to assign new
category 1 to all new areas. In ambiguous cases, you could assign all
seed categories to the merged buffer area.

Markus M


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