[postgis-users] navigation trough topology graph

[Sandro Santilli]

There's an example of navigating it with recursive CTE
in the implementation of GetRingEdges:

https://github.com/postgis/postgis/blob/2.1.0/topology/sql/query/GetRingEdges.sql.in#L50

Have fun!

--strk;

On Mon, Oct 21, 2013 at 11:19:05AM -0200, George Silva wrote:
> I kinda need something similar. My objective was to calculate strahler
> stream order and horton's stream order.
> 
> I was feeling that the topology graph next_edge could give me the data that
> I need, but I haven't really tried. I also would like to hear if someone
> else has the same or something that could be done.
> 
> Any thoughts?
> 
> 
> On Mon, Oct 21, 2013 at 11:10 AM, Rémi Cura <remi.cura at gmail.com> wrote:
> 
> > Hey dear list,
> >
> > Anybody has some advices about navigating trough topology graph (ie given
> > a node, find list of next, etc).
> >
> > I was thinking of using directly the table "edge_data", but it feels like
> > a lots of self join.
> >
> >
> > Cheers,
> > Rémi-C