[Qgis-user] Isochrones

kirk kirk at nortekresources.com
Wed Mar 25 13:27:01 PDT 2020


Nicolas is right. There is  good chance the topology is a bit messed up. You can spend Lot of time fixing it up so I would suggest downloading the gis basmap layers from the pei government website. There us a large scale database for Charlottetown  (1:2000) that will work better for you. Just search gis database pei.KirkSent from my Samsung Galaxy smartphone.
-------- Original message --------From: Nicolas Cadieux <nicolas.cadieux at archeotec.ca> Date: 2020-03-25  12:35 PM  (GMT-04:00) To: Tyler Veinot <tylerkveinot at gmail.com> Cc: QGIS User List <qgis-user at lists.osgeo.org> Subject: Re: [Qgis-user] Isochrones Hi,The first thing I would do is to check the network integrity.  Perhaps some road are not connected (snapped).  You also need a snap and break at every intersection. You can do some of this by exporting all the end node. Check for multiline vs lines. You can split all of those in the vector menu.  Your problems are likely linked to a bad network topology. Users of that network could perhaps confirm this? I have used it but not for this type of stuff.Nicolas Cadieux> Le 25 mars 2020 à 10:22, Tyler Veinot <tylerkveinot at gmail.com> a écrit :> > > All;> I have a network, Canada National Road Network it is a free download, that I am trying to use for PEI and the City of Charlottetown to find out what area is within X time of various points of interest. I used Here for QGIS to get the initial result but QGIS has a tool built in Network Analyst that has Service Area from Network and from Point, also and QNEAT that has 6 isochrone tools for doing exactly what I am trying to do. For some reason though the results don't seem to match the network. I would expect the from the point of origin the shortest times to be along the lines and radiate out. > What tools are you guys using to do this kind of work? Do my values for forward backward both direction need to be numeric? Any tutorials on using these tools?> Thanks;> Tyler> _______________________________________________> Qgis-user mailing list> Qgis-user at lists.osgeo.org> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user_______________________________________________Qgis-user mailing listQgis-user at lists.osgeo.orgList info: https://lists.osgeo.org/mailman/listinfo/qgis-userUnsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
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