[postgis-users] Does ST_AsText truncate or round

[Havard Tveite]

Sorry, for not making much sense here.  What I wanted to
say was that ST_AsText(geom) should be equivalent to geom,
meaning that if you go from the database/binary
representation of the geometry to the text representation
of the geometry (using ST_AsText) and then back to the
database/binary representation (using ST_GeomFromText),
you should end up with the same geometry that you
started out with.  This is important for applications
that use when WKT when talking to PostGIS.

Håvard


Mark Cave-Ayland wrote:
> Håvard Tveite wrote:
>> ST_GeomFromText(ST_AsText(geom)) != geom
>>
>> sounds like a bug to me (ignoring the SRS).
>>
>> Håvard
> 
> No, since the SFS 1.1 specification supports only 2 dimensions with no
> SRS (and ST_AsText() is spec compliant). If you need the SRS then you
> should use the PostGIS-enhanced ST_EWKT() function which will output the
> extra information, but is not spec-compliant.
> 
> 
> ATB,
> 
> Mark.
> 
> --
> Mark Cave-Ayland
> Sirius Corporation - The Open Source Experts
> http://www.siriusit.co.uk
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