On Jan 9, 2008 8:44 PM, Robin Paulson <[EMAIL PROTECTED]> wrote: > can someone explain a few things about the way boundaries work, and > their relation to the is_in key? > > as far as i can tell, when a location (say the suburb of balham, in > london) is added to the map, the is_in tag needs to be set, multiple > times. in this case, it would be set as follows: > > is_in:Westminster (...i think) > is_in:greater london > is_in:england > is_in:united_kingdom > is_in:British_Isles > is_in:Great_Britain > is_in:Europe > ...etc. > > which seems counter-intuitive, not to mention requiring huge amounts > of work. do we set this for every item - roads, churches, > supermarkets,....thousands of other items? > is there anything underway to enable OSM to calculate where an object > is, based upon knowledge of administrative boundaries - after all, > they are only a polygon-shaped bounding box?
I think it's worth remembering the history of all of this, since it will help explain things. The is_in tag predates the ideas of having wide-spread administrative boundaries (something which I've only seen happening in the UK over the last 5 months or so) and certainly predates relations by a long way. They are probably still useful for some cases, but as you can see other mechanisms for specifying hierarchy and relations may be more appropriate nowadays. Cheers, Andy _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
