On 13 Nov 2009, at 12:00, Florian Lohoff wrote: > On Fri, Nov 13, 2009 at 07:43:20AM +0000, Peter Childs wrote: >> However in OSM places are points not area's and the areas we do have >> are either to do with admin (ie Counties, Borough's etc) and hence >> are >> rather less than helpful. >> >> The is_in tag is not a lot of use either due to it being >> inconsistent. >> >> I could do it with some kind of nearest function but I don't think >> this is going to give me the right answer either. >> >> What is in a place, is often to do with other geographic features, >> like gaps in housing, majro roads etc, and also to do with history, >> >> What I would like to do is write a script that takes the planet and >> gives a list of the places (towns, villages etc) and a polygon/area >> for each place. >> >> While I don't think this list would be worth piping back in to the >> database, it might be useful for knowing what were missing..... >> >> Maybe Places should be area's rather than points anyway. > > This is a quite complicated thing to do - Some parts of the world > fill very quickly with admin boundaries and using them for searching > in the garmins would definitly give them a strong boost which i'd like > to see.
We already have data for all 50K places in Britain available for import into OSM as part of the NaPTAN dataset. [1] All of the 50K places in this dataset have a boundary (which is approximate) which is based only on whether a bus stop is in a place or not. Each place also has a geocode for its 'centre. Places can have parents and children so one can model suburbs, Here are some examples of the data that is available: http://www.itoworld.com/static/screenshots?product=NAPTAN&id=3 http://www.itoworld.com/static/screenshots?product=NAPTAN&id=1 Of course there is always 'creep' of desirable and undesirable places (where people say they live in the posh bit, not the non-posh bit next door - lots of room for negotiation of boundaries, but highly valuable and useful data all the same). I was also talking just this morning about the value of this data and if such a boundary-of-places dataset could be produced for Northern Ireland within OSM (Northern Ireland is part of the UK but this data is not yet available within NaPTAN). ITO has a new product for directing people by public transport and we need to know whether a bus stop is within a place or not - we can guess, but it would be much better not to guess and this is what we need to do that. In short, I and my company and indeed Travline/DfT would strongly support to option to include boundary polygons for places within OSM together with a relation and a point geocode for the place. Yahoo is also collecting useful data of this sort which I understand they are planning to release for reuse. [1] http://wiki.openstreetmap.org/wiki/NaPTAN Regards, Peter > > The other point is that people are used to fuzzy or non exact > search. For > example i am living in a Town called Rietberg which has a large area > it covers. > There are multiple suburbs which are very distinct from Rietberg the > town > itself. People are used to be able to search for either Rietberg or > even the suburbs names e.g. "Mastholte" or "Varensell" - So in google > ou can search for > > Alt Hammoor 38, Rietberg, Germany > Alt Hammoor 38, Mastholte, Germany > > which is the same place - Postal wise the address is 33397 Rietberg > but all in car navigations are happy to accept Mastholte aswell. > > This gets more complicated taking large citys like Berlin - where the > individual districts are their own administration and therefor have > their > own admin_level 8 boundary. People on the other hand are used to > search > for Gorßbeerenstraßen, Berlin to work - e.g. spit out all the > Großbeerenstraße > Berlin has (Mentioning the District - TomTom does this). > > So - it comes down that people are used to search for admin_level=10 > names > and content and for admin_level=6 Content which will then look for all > content in admin_level=6+ .. > > So - i'd vote for strictly using admin boundarys and invent some tags > for giving some hints - It does not make sense to include > admin_level=4 > or most of the time it does not make sense to include admin_level=6 > for > searching (Kreis Gütersloh for example makes no sense) - But sometimes > it should be included that you look for > > Großebeerenstraße, Berlin > > and get > > Großebeerenstraße, Kreuzberg, Berlin > Großebeerenstraße, Lichterfeld, Berlin > > aswell as beeing able to search for > > Großebeerenstraße, Kreuzberg > > Searching for place nodes and guessing is prone to errors and > hinting will be > on a per street level which will be very hard to maintain and > include so ... > Admin boundarys are there for a reason ... > > Flo > -- > Florian Lohoff [email protected] > "Es ist ein grobes Missverständnis und eine Fehlwahrnehmung, dem Staat > im Internet Zensur- und Überwachungsabsichten zu unterstellen." > - - Bundesminister Dr. Wolfgang Schäuble -- 10. Juli in Berlin > _______________________________________________ > talk mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/talk _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
