Op 17 apr 2008, om 14:00 heeft Frederik Ramm het volgende geschreven: > Hi, > >> As you can see, I employ four tags to indicate house number ranges: >> * houseno:left-min >> * houseno:left-max >> * houseno:left-scheme >> * houseno:right-min >> * houseno:right-max >> * houseno:right-scheme >> Left and right are relative to the direction if the way. >> Min is the first house number on either side, again looking in the >> direction of the way. >> Max is the last house number on either side, looking in the >> direction of the way. >> Scheme can be one of 'even', 'odd' or 'mixed'. > > Pitfalls include: > > * what if way direction is reversed? > * what if way is extended, merged, split?
That will be a problem indeed. Could theoretically be solved with strong editor support, but that does not fix the intrinsic flaw. You never know when a script comes around that reverses direction for some valid reason, outside the editors. Someone on talk-nl suggested using a NSEW-based tagging scheme, but this is not unambiguous either. > > * what if way provides access to houses with the address of another > way (corner buildings typically - house is on A street but entry is > from B street) > * what do you do with letters? At least in Germany they sometimes > have 2, 4, 6a, 6b, 6c, 6d, 6e, 8... You could override the ranges with individual tags on the buildings, but I guess the buildings would have to have a relation to the way then. > > * what if there are gaps in numbering? split the way? Either that, or accept that there may be nonexistant numbers in the range > > > Some of this may not seem to important but I would really like to > have house numbers on the map, and if at all possible I'd like to > avoid printing a number that doesn't even exist. I'm hadn't even thought of actually having house numbers on the map, but for routing / geocoding they can be extremely useful. > [...] > A completely different (and quite OSM-like!) option is dropping all > this complex logic, left-right-blah tagging, number schemes, > relations and all, and just put simple nodes: "This is B street > number 25". This brings redundancy, typos, and all - but we're used > to that. It would be *extremely* easy to edit, and renderers or > routers would have to do a little bit of processing to work with the > data. Not too hard probably. I like it for its obvious OSMity. The schemes could co-exist I guess. > > I'm not saying either of these is best. We'll have a little "house > number hacking workshop" here in Karlsruhe where some of us will try > and decide on a working scheme and implement this in a renderer/ > editor if possible, and enter a few house numbers for the local > area, just to see if it works. Interesting. Keep us informed! -- martijn van exel -+- [EMAIL PROTECTED] -+- http://www.schaaltreinen.nl/ _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
