[postgis-users] GeomUnion problem

[Paul Ramsey]

On 3-May-07, at 6:36 PM, Brent Wood wrote:

> Is GEOS v3RC going to be reliable enough for a mission critical  
> production job
> with several million polygons to be manipulated?

Probably.

> What is entailed in upgrading GEOS?

./configure ; make ; make install

> Do I need to rebuild & reinstall PostGIS?

No, you can drop the new GEOS in behind.  Re-connect to the database  
and the new library will be loaded.

> Will the current DB/data still be accessible?

Yes.

> Or is there some way of tweaking the underlying polygons to be  
> combined to
> address the problem?

Martin gave that recipe:  buffer(geomunion(buffer(a,0.1),buffer(b, 
0.1)),-0.1)

P

>
>
> Appreciated,
>
>    Brent
>
>
>>
>> Brent Wood wrote:
>>> Hi,
>>>
>>> I'm not sure what the problem is here, hopefully someone can help.
>>>
>>> I have some polygons cropped to cell boundaries. (select  
>>> intersection...)
>>> I want to generate the geomunion of these for each cell, which seems
>>> straightforward, but GEOS is throwing an error...
>>>
>>>    select astext(geomunion(track_cell_geom)) from effort_cells3  
>>> where
>> cell_id =
>>> 73721;
>>> NOTICE:  TopologyException: no outgoing dirEdge found
>>> (168.077,-40.1961,-40.1961)
>>> ERROR:  GEOS union() threw an error!
>>>
>>>
>>>
>>> Can anyone say what this means & what I need to do to work around  
>>> it?
>>>
>>> Thanks,
>>>
>>>   Brent Wood
>>> _______________________________________________
>>> postgis-users mailing list
>>> postgis-users at postgis.refractions.net
>>> http://postgis.refractions.net/mailman/listinfo/postgis-users
>>>
>>
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