[postgis-users] (no subject)

[Nicolas Ribot]

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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