Hei Giuliano, I would suggest also having a look at the igraph library: http://igraph.org/redirect.html. Very powerful and feature rich and with Python, R, and C interface. I used the library for network analysis in different context and can only recommend it...
Cheers Stefan -----Original Message----- From: Qgis-developer [mailto:[email protected]] On Behalf Of Giuliano Curti Sent: 13. september 2016 12:41 To: qgis-developer <[email protected]> Subject: Re: [Qgis-developer] a graph plugin for QGIS On 8/29/16, Giuliano Curti <[email protected]> wrote: > On 8/29/16, Anita Graser <[email protected]> wrote: >> Dear Giuliano, Hi Anita, Hi Paolo, Hi all I had a look at the available material on the subject of graphs / networks; I saw (very quickly) three products: 1) Library Network Analysis 2) the plugin Road Graph 3) the sDNAV plugin; apart from the third product that seems to be the most complex tool and I have not seen well, the other two seems contain essentially the search for shortest paths by Dijkstra method; confirmed the great importance of the Dijkstra method for the graph theory, we need remember the many faces on the subject; in my (very experimental) plugin I approach: - the vertex and edge inquiry - some (limited) editing (weight of edges) - storage I/O - trees (BFS, DFS) - cycles - minimum spanning tree (Jarnik-Prim and Boruvka-Kruskal) - connectivity (cutpoints, bridges, vertex- and edge- connectivity) - paths (shortest & not shortest, single & all) - visualization with QGIS desktop - (limited) import/export from/to SHP format; I know, that's probably an approach more theoretic than practical oriented, but I think that these topics represents fundamental tools for graph analyzing; I will try to apply them in some actual case (the road graph on my town? :-) and describe it in the last part of the presentation article I uploaded at Slideshare; in the topic of SHP import/export, it's very interesting the ability to build graphs starting from SHP files available in the Library Network Analysis, even though there does not convince me at all, for example, the plethora of generated vertices (suffices imho the end points) and the automatic intersection of linestring with a shared vertex (I think might prevent the processing of not planar graphs); so here's a first report (I took some commitment); I'll look better the classes of the Network Analysis Library and I will try also to take a look at sDNAV plugin although I fear that now it is beyond of my potential; I repeat: I am not a graphs expert but a simple "mathematics" amateur, but if I can do some help to this part of the QGIS would gladly give a contribution; sfmbe, thanks, bye, giuliano _______________________________________________ Qgis-developer mailing list [email protected] List info: http://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-developer _______________________________________________ Qgis-developer mailing list [email protected] List info: http://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-developer
