[postgis-users] topology overlapping of edges

Mario Jurcevic mario at geosar.ch
Thu Sep 27 00:11:28 PDT 2012

the cadastre data ( Suisse ) are full of this overlaps, It happens when 
they introduce arc curves ( specially with streets ),
i suppose due to inaccuracy of the computation of  the arc points or for 
historically reason ( digitizing errors ) or simply
because is cheaper to measure.

Attached the image of the overlap.

In addition I have some more questions:

Will topology support edge with arcs and not only linestrings?

I try to insert into an empty topology geometries with functions 
TopoGeo_AddLineString, addEdge, addIsoEdge and is incredibly slow,
it was only a small subset of data ( 20'000 lines ) and  after waiting 
10 minutes I dropped out, why is so slow  or maybe there is another way
to insert data?


Mario Jurcevic


On 09/27/2012 08:00 AM, Christophe Vergon wrote:
> Hi,
> "cadastre" data means that you're french ?
> I do the same, importing french survey data in postgis 2.0 with topology.
> I think that you're not in the right way. Have a look at 
> topogeo_addpolygon function with tolerance=0.
> It's a better way to fix french survey data topology troubles.
> Mario Jurcevic a écrit :
>> Hello,
>> I am testing postgis topology with cadastre data, overlapping of 
>> edges with given tolerance is allowed.
>> How to handle this kind of data: insert,modify,etc?
>> Is possible to temporary disable the validation and  or implement a 
>> custom validation?
>> Thanks in advance
>> Mario Jurcevic
>> _______________________________________________
>> postgis-users mailing list
>> postgis-users at postgis.refractions.net
>> http://postgis.refractions.net/mailman/listinfo/postgis-users
-------------- next part --------------
A non-text attachment was scrubbed...
Name: overlap.png
Type: image/png
Size: 13771 bytes
Desc: not available
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20120927/c351efc7/attachment.png>

More information about the postgis-users mailing list