Hi Jérôme, As you said the idea would be to add a function that calculates a skeleton from a polygon.
Currently pgRouting contains a couple of functions ( http://www.pgrouting.org/docs/1.x/index.html), but all of them require network data with at least information about "start" and "end" ID of a linestring. If the information about "start" and "end" ID doesn't exist yet, you can run a function called "assign_vertex_id". But what you need is network data. Your skeleton function now would allow users to add one more step before and retrieve a network from polygon data. So one could first run the skeleton function, then the "assign_vertex_id" function and finally have all the routing functions available even if the original data was of polygon shape. pgRouting has it's source code on GitHub (https://github.com/pgRouting/). The "assign_vertex_id" function is here: https://github.com/pgRouting/pgrouting/blob/master/core/sql/routing_topology.sql. Though I'm not sure it wouldn't be a good idea to reorganize this a bit. Well, I think we might better discuss details on the pgRouting list: http://lists.osgeo.org/mailman/listinfo/pgrouting-dev Best regards, Daniel 2010/12/11 j.rolland <jrmroll...@aol.com> > > Hi Daniel, > > Of course that I am interested, say me how I can contribute my share. > As I indicate it in my blog, I can develop a function which turns over the > skeleton from a polygon. Give me your specifications and I would study > them. > > > cordially, > Jérôme > > > Daniel Kastl-3 wrote: > > > > Salut Jérôme, > > > > Thank you for sharing your blog article! > > I tried to recall my French from high school and thanks to nice > > screenshots > > and code samples I think I could mostly understand. > > > > Well, I thought your functions might be an interesting contribution to > > pgRouting project (http://www.pgrouting.org). > > We're trying to collect various routing and network analysis related > > functionality. Some voronoi and skeleton addition would for sure suite > > well. > > That way users could build some routable network out of river polygons > for > > example. It might also help to build a routable graph for maritime > > navigation. Probably there are a lot more use cases. > > > > Let me know if you're interested. > > > > Daniel > > > > > > 2010/12/9 j.rolland <jrmroll...@aol.com> > > > >> > >> hi, > >> > >> I have just set up on my blog at the following address > >> http://ageoguy.blogspot.com/2010/12/squ… ation.html > >> http://ageoguy.blogspot.com/2010/12/squ… ation.html a tutorial (in > >> french) > >> which presents an algorithm of surface squelettisation of waterway > >> (POLYGON). > >> I provide an example like all the necessary functions and requests which > >> will enable you to obtain the skeleton of the waterway as you can see it > >> in > >> the capture below : > >> > >> http://old.nabble.com/file/p30413623/skeleton5.jpg > >> > >> > >> regards, > >> Jérôme > >> -- > >> View this message in context: > >> > http://old.nabble.com/Diagram-of-Vorono%C3%AF-to-Squelettisation-of-polygon-tp30413623p30413623.html > >> Sent from the PostGIS - User mailing list archive at Nabble.com. > >> > >> _______________________________________________ > >> postgis-users mailing list > >> postgis-users@postgis.refractions.net > >> http://postgis.refractions.net/mailman/listinfo/postgis-users > >> > > > > > > > > -- > > Georepublic UG & Georepublic Japan > > eMail: daniel.ka...@georepublic.de > > Web: http://georepublic.de > > > > _______________________________________________ > > postgis-users mailing list > > postgis-users@postgis.refractions.net > > http://postgis.refractions.net/mailman/listinfo/postgis-users > > > > > > -- > View this message in context: > http://old.nabble.com/Diagram-of-Vorono%C3%AF-to-Squelettisation-of-polygon-tp30413623p30428747.html > Sent from the PostGIS - User mailing list archive at Nabble.com. > > _______________________________________________ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users > -- Georepublic UG & Georepublic Japan eMail: daniel.ka...@georepublic.de Web: http://georepublic.de
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