Frank Steggink wrote: > Frank Steggink wrote: > >> Hi, >> >> As a bit of a challenge I've looked at the administrative data pointed >> out by Nicolas Gignac: [1]. I know there are some doubts about the >> accuracy, but this was also meant as an exercise to deal with this kind >> of data. Maybe it can be reused for other purposes, although I haven't >> written the tool I used in a generic way. I also hope that the more >> accurate (1:20k) data uses the same structure. >> >> First I converted this data to SHP (with an ESRI tool called Import71, >> and then ogr2ogr). Then it was converted to OSM with shp-to-osm.jar. >> However, the data has a topological structure, so it has not much value >> if it would be imported into OSM directly. >> >> The set of administrative boundaries contains municipalities, MRCs, >> administrative regions (17) and urban agglomerates. The municipal data >> contains also information about MRC, admin. regions and agglomerates, so >> I decided to examine this further. Now the topological structure was a >> benefit, because this is how administrative boundaries should also be >> entered in OSM. The boundaries only contain attributes like from-node, >> to-node, left-poly and right-poly. However, this is enough to compose >> relationships (type=multipolygon/boundary, boundary=administrative, >> etc.) out of them. Because I ended with an ArcInfo coverage as a result >> of the conversion by Import71, I decided to extract data from the file >> pat.adf to get the municipality and other relevant names, codes, etc. >> >> So far I have only created relationships, including the municipality >> name. I would like to share it with you, in order to gather feedback. >> The result can be found here: [2]. PLEASE do NOT upload this data to >> OSM! The ways are sorted in the relationship, so they form closed >> chains. Also the nodes where multiple ways meet have been deduplicated, >> otherwise JOSM (and also OSM itself) won't recognize the ways as being >> connected. The deduplication was based on the actual coordinates, not >> the node IDs used in the topology. >> >> Things to do: >> * Detect which boundary is the outer boundary, and which ones are the >> inner boundaries. Obviously, the ring with the biggest surface area is >> the outer boundary, and the rest are inner boundaries. >> * Add multiple municipalities in the same relationship. >> * Create MRCs, administrative regions, and urban agglomerates. >> >> More information about administrative boundaries can be found in [3]. >> For Canadian provinces admin_level=4 should be used, for regional >> municipalities (MRCs in Quebec) admin_level=6, and actual municipalities >> admin_level=8. I would like to propose to use admin_level=5 for the >> regions. They have at least a semi-offical status. Others might be able >> to elaborate on it more. This leaves the urban agglomerates (Montreal >> and Quebec only), for which admin_level=7 would be a natural choice, >> although I'm not sure if they have any official status. What do you guys >> think? >> >> Regards, >> >> Frank >> >> [1] >> http://www.mrnf.gouv.qc.ca/territoire/portrait/portrait-donnees-mille.jsp >> [2] http://www.steggink.org/osm/Quebec/quebec_munic.zip >> [3] http://wiki.openstreetmap.org/wiki/Tag:boundary%3Dadministrative >> >> >> _______________________________________________ >> Talk-ca mailing list >> Talk-ca@openstreetmap.org >> http://lists.openstreetmap.org/listinfo/talk-ca >> >> >> > A clarification on this: "Add multiple municipalities in the same > relationship." Several municipalities have exclaves, like outlying > islands. They are divided over multiple polygons, so I created multiple > relations for them. > > For the higher-level administrative boundaries, I intend to use > information from the AAT file which was generated by Import71. This file > contains records describing the boundary type. Although there is > specific data for each level, in OSM it would be best to reuse the same > set of nodes and ways, and that can best be done by using the same > source data. > > Frank > > > _______________________________________________ > Talk-ca mailing list > Talk-ca@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk-ca > >
Hi all, The last days I've flexed my Mapnik / osm2pgsql skills, and was able to put a visualization of the tiles online. They can be found here: [1]. The tiles themselves are generated as transparent PNGs, so they didn't have to be integrated into the data. Note that I also adjusted the zoomlevels, so they are visible earlier than they would be normally. Levels 6 - 13 are available, but the last level is still rendering as I write this. I haven't take care of any labeling yet, although it is present in the DB. Cheers, Frank [1] http://mijndev.openstreetmap.nl/~fsteggink/quebec_admin.html _______________________________________________ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca