You need to do Distance Matrix. See https://www.qgistutorials.com/en/docs/3/origin_destination_matrix.html
On Fri, 6 May 2022 at 7:33 PM, Francesca Parente via Qgis-user < [email protected]> wrote: > Thank you very much indeed Nicolas, for your inputs and all the suggested > materials! > I have 50 targets and 532 origins. My goal is to define where is best to > go within the 50 destinations for each starting point - given the actual > range of choices though, so I'm not sure that running a batch one-to-many > would take into account all the variables properly as a many-to-many would > do. In the absence of a specific modelling, also some second best could > work. > > I understand that your upstream-downstream-Dijkstra script is suitable for > layer-to-layer indeed and I'm trying to run it, but at the >>> import > geopandas as gpd<< line I got the following error message: > > > > > > > > *Traceback (most recent call last): File > "C:\OSGEO4~1\apps\Python37\lib\code.py", line 90, in runcode exec(code, > self.locals) File "<input>", line 1, in <module> File > "C:/OSGEO4~1/apps/qgis/./python\qgis\utils.py", line 799, in _import mod > = _builtin_import(name, globals, locals, fromlist, level)* > *ModuleNotFoundError: No module named 'geopandas'* > > I've been following your tutorial, but I admit I'm not quite familiar with > py. I've gone through the remaining import coding and it seems working, but > I'm not sure the "geopandas" module is needed or not to properly complete > the script. > > Thanks again!! > Best, > Francesca > > Il giorno gio 5 mag 2022 alle ore 22:28 Nicolas Cadieux < > [email protected]> ha scritto: > >> Hi, >> >> How many shortest path calculations are you looking at? You could >> probably do a all pairs shortest path dijkstra and filter the results. You >> could batch multiple one to many (point to layers) In QGIS using the >> processing plug-in. >> >> I did create an algorithm using networkX that could be modified to work >> with two input layers. This could be useful if QGIS is not fast enough or >> if you have too many routes to calculate. You will find it in the links >> below. Keep in mind this algorithm was for rivers therefore you have no >> trafic rules. This would need more work. >> >> You will also find an article we wrote in Data that may help. If you >> have trouble with the network, look in the QGIS hub for the models. Look >> for the 3 “fix directional networks models”. >> >> I added a few YouTube videos I made. >> >> https://gitlab.com/njacadieux/upstream_downstream_shortests_path_dijkstra >> <https://www.mdpi.com/2306-5729/5/1/8> >> >> https://www.mdpi.com/2306-5729/5/1/8 >> >> https://plugins.qgis.org/models/ >> >> https://youtu.be/v61PafSByvM >> >> https://youtu.be/qQrHcKtmr3o >> >> >> Nicolas Cadieux >> https://gitlab.com/njacadieux >> >> Le 5 mai 2022 à 10:38, Francesca Parente via Qgis-user < >> [email protected]> a écrit : >> >> >> Hello everyone, >> >> I'd need to identify optimal destinations (within a point layer of >> geolocated facilities) for each territory of a given set of possible >> origins. >> I already calculated a distance matrix between the two point-layers, and >> also applied the distance-to-nearest-hub tool to generate a string layer >> and identify the optimal facilities. >> But I'd like to obtain a more realistic estimate, accounting for the >> roads network (and ideally their travel times). With quite a few issues, I >> finally managed to import an OSM road network from download.geofabrik.de >> (in order to cover my area of interest, I had to merge two different >> vectors fo Center and Southern Italy and then extract a focus spot in >> between the two and save it as a lighter layer, otherwise it also took an >> eternity to run every analysis). >> >> So now my question would be: is there a tool to perform a layer-to-layer >> shortest-path analysis that takes it into account? >> All that I could find was either point-to-point or >> layer-to-point/point-to-layer (I looked also at built-in network analysis >> tool and Qneat3 plugin). >> >> Any kind of inputs and suggestions will be more than welcome! >> Thanks a lot for your support and have a good day, >> Francesca >> >> -- >> ---------------------------- >> Francesca Parente >> >> _ SESS Euro PhD >> <https://phd.uniroma1.it/web/FRANCESCA-PARENTE_nT1602922_IT.aspx> in >> SocioEconomic and Statistical Studies >> _ Luiss SEP <https://sep.luiss.it/> School of European Political Economy >> >> >> email: [email protected] >> [email protected] >> >> _______________________________________________ >> Qgis-user mailing list >> [email protected] >> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user >> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user >> >> > > -- > ---------------------------- > Francesca Parente > > _ SESS Euro PhD > <https://phd.uniroma1.it/web/FRANCESCA-PARENTE_nT1602922_IT.aspx> in > SocioEconomic and Statistical Studies > _ Luiss SEP <https://sep.luiss.it/> School of European Political Economy > > email: [email protected] > [email protected] > > _______________________________________________ > Qgis-user mailing list > [email protected] > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > -- [image: Logo] <https://spatialthoughts.com/> Ujaval Gandhi Spatial Thoughts mobile: +91-8095684687 email: [email protected] [image: LinkedIn icon] <https://www.linkedin.com/in/spatialthoughts/> [image: Twitter icon] <https://twitter.com/spatialthoughts>
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