[postgis-users] PostGIS 2.0 - network topology - crosses edges (SQL/MM: Topo-Net: NEDNODE, NEDLINK)

[Sandro Santilli]

On Tue, Jan 24, 2012 at 08:52:54AM +0100, willi8345 at web.de wrote:
>    Hi,
> 
>    I'm trying to build a linear application (topology network) with PostGIS
>    2.0.0SVN.
> 
>    My real world situation has crosses edges with no nodes (water lines or
>    hiqh voltage power lines in different heights or levels, where both edges
>    have nothing to do with each other).
> 
>    Topo-Geo assumes full planar topology and gives me an error on this
>    crossing edges.
>    (SQL/MM Spatial exception - egometry crosses an edge)
> 
>    The only possiblity I see at the moment to build it up in different
>    topology schemas, which would be ok for example between water lines and
>    low voltage cables, but not between high voltage power lines themselves.
> 
>    Is it possible with PostGIS 2.0 (at the moment) to build up this situation
>    within on topology schema?
> 
>    If yes - how?
>    If no - will it come up in future versions?

Not possible with Topo-Geo. As you point out SQL/MM Topo-Geo assumes planar
topology. But SQL/MM Network-Topology will let you model your network.

Network-topology is not available in 2.0, but could surely come up in
future versions if anyone will be investing time / money on it.

--strk; 

  ()   Free GIS & Flash consultant/developer
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