[postgis-users] (no subject)

[Pavel Shub]

I also found that the @ operator produced the desired results. But maybe it
will exclude things that are on the border, like && includes them. So I'll
just use ST_Intersects as per Nicolas' suggestion.

Thank you for the help.
Pavel Shub


On Sat, Feb 2, 2013 at 5:54 AM, Nicolas Ribot <nicolas.ribot at gmail.com>wrote:

> Hi,
>
> To complete Hugues' answer, it may be due to the && operator that operates
> on geometry extents, which are an approximation, if I recall correctly.
> But when running a true contains test, the answer is correct:
>
> select
>
>
>
>
>  st_intersects(ST_MakeEnvelope(-105.17353271032549,39.798766541338225,-105.07765728967452,39.83016145866177,4326),
>
>
>
>
> st_setsrid(ST_MakePOint(-105.130637 ,39.830165),4326));
>
>  st_intersects
> ---------------
>  f
>
> The && operator is mainly used to trigger geometric index use.
> Index over estimate the geometry a bit.
>
> Nicolas
>
>
>
> On 2 February 2013 09:14, Francois Hugues <hugues.francois at irstea.fr>wrote:
>
>> **
>> Hi,
>>
>> I think this is a tolerance issue. If you try
>>
>> select
>> st_distance(ST_MakeEnvelope(-105.17353271032549,39.798766541338225,-105.07765728967452,39.83016145866177,4326),
>> st_setsrid(ST_MakePOint(-105.130637 ,39.830165),4326))
>>
>> The distance is very short : 3.54133823066149e-06
>>
>> And i you add the where clause, it is also true that your lat is not <=
>> to the given one, so the single line returned with the simple && query is
>> now excluded.
>>
>> Hugues.
>>
>>  ------------------------------
>> *De :* postgis-users-bounces at lists.osgeo.org [mailto:
>> postgis-users-bounces at lists.osgeo.org] *De la part de* Pavel Shub
>> *Envoyé :* samedi 2 février 2013 07:14
>> *À :* postgis-users at lists.osgeo.org
>> *Objet :* [postgis-users] (no subject)
>>
>>     Hi all,
>>
>> Please tell me if I'm doing something incorrectly, but I seem to be
>> getting wrong results for the following bounding box query:
>>
>> select * from geotest where geom &&
>> ST_MakeEnvelope(-105.17353271032549,39.798766541338225,-105.07765728967452,39.83016145866177,4326)
>>
>> Given table with columns: name (varchar), lat (double), lon (double),
>> geom (geometry). geom having srid 4326 points
>>
>> A row with lat = 39.830165, lon = -105.130637 is returned. I find this
>> very peculiar because the latitude is greater than the maxiumum latitude in
>> the envelope (39.83016145866177). If I then add a 'and lat <=
>> 39.83016145866177' clause, the row is no longer returned.
>> I noticed this on postgres 9.1 with postgis 1.5 then when testing again
>> got the same results on postgres 9.2 and postgis 2.0
>>
>> Is this intended and I missed some documentation somewhere, or is this an
>> issue?
>>
>> Thank you,
>> Pavel Shub
>>
>> _______________________________________________
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>> postgis-users at lists.osgeo.org
>> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
>>
>>
>
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