[postgis-users] Determining clusters of points

[Sébastien Lorion]

Err, it is ok starting with 55, not 50, sorry. So to be clear, even tho the
points "interact" with a range of 40, they are not clustered together with
the function you sent.

Sébastien

On Wed, Dec 8, 2010 at 18:49, Sébastien Lorion <sl at thestrangefactory.com>wrote:

> Hello Kevin,
>
> I am still testing/trying stuff .. One strange thing I saw is that if I set
> the range to 40 instead of 80, then there are more clusters than there
> should be, but at 50 it is ok. Using the buffer/merge method, it works
> correctly. I did not investigate further into that.
>
> Sébastien
>
>
> On Wed, Dec 8, 2010 at 11:24, Kevin Neufeld <kneufeld.ca at gmail.com> wrote:
>
>> On 12/8/2010 7:38 AM, Sébastien Lorion wrote:
>>
>>>
>>> The points are not static, they will potentially be in a different
>>> position each time the query is run.
>>>
>>
>> Ah, I was going to ask about that.  It might be possible to create a
>> recursive query to maintain a very large point table as new records are
>> added (add them to existing clusters and / or merge clusters), but according
>> to my initial findings, there is no way a recursive query approach is going
>> to be able to scale well enough for your million points, esp. if you need to
>> be able to run such a query every 30 min.  But I'd be curious to hear what
>> your findings are as well.
>>
>> -- Kevin
>>
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>>
>
>
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