[postgis-users] TRANSFORM failures with some multiploygons - data sample attached

[cyw at dls.net]

Hi All,

In debugging the problem below, I found that TRANSFORM would fail with some 
of my city multipolygons.

I would think that the TRANSFORM function should be independent of the shape 
or complexity of the polygons or lines.

Attached is one of the city multipolygons that failed the TRANSFORM 
function.

Thanks,
CYW


----- Original Message ----- 
From: <cyw at dls.net>
To: "PostGIS Users Discussion" <postgis-users at postgis.refractions.net>
Sent: Thursday, October 09, 2008 8:13 PM
Subject: [postgis-users] transform - update lake 
setthe_geom=transform(the_geom, 26971)


>I have a table city which contains Multipolygons (SRID=4326) in latitude 
>and longitude. To project it to  a plane coordinate (SRID=26971), I did:
>
>    update lake set the_geom=transform(the_geom, 26971);
>
> It ran without any error. But some of the resulted values in the_geom 
> column became null or empty.
>
> Any hitnts why it did this?
>
> Before the transformation, I viewed the table with QuantumGIS, it looked 
> OK. Afterwards, QuantumGIS showed nothing.
>
> Thanks,
> CYW
>
>
>
>
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