Thanks Johann, this sounds like quite a reasonable approach too. It shouldn't be too hard to add in to the splitter (eg by tacking the info on to the density map, or by holding on to the is_in data until the areas are known then calculating the names as a separate step). Looking at a few osm files the is_in tags and their values seem inconsistent at best though so I don't know how easy it would be to get sensible/consistent data from them. Another possible issue is that osm files without the tags wouldn't work at all. If you do have some code that deals with filtering/sanitising the is_in data I'd be interested to see it however as it sounds like it would be worth investigating further.
The approach I'm currently looking at is using a geonames file (eg cities15000.zip) from http://download.geonames.org/export/dump/ to decide which country and city is the most predominant one in each tile. The advantage is it should be very fast and accurate, won't require an internet connection (aside from the initial download of the file), and can be tailored by people if they use custom input files. The downside is the minor hassle involved in dealing with that extra file. Depending on how well this approach works in practice and what feedback I get, I might look at making the automatic tile naming more configurable/plugable at a later date. Chris JG> I played with an similar thing some time ago, a year or so. My JG> algorithm was not searching for the biggest city, but counted the JG> 'is_in' tags of the osm data. The idea behind it was that should JG> scale with different resolutions. With big tiles it should name the JG> tiles with the names of boundaries, if I break it down into small JG> tiles it should take the names of the cities and villages. With JG> statistical probability in a big city exists much more is_in tags as JG> in a small village. JG> JG> This was inedependent of the geonames service and fully based on the JG> osm data. JG> JG> As far as I can remind, the results worked in general, but the code JG> does not fit well into the splitter. I would have to search on my JG> harddrive, if the code lays around somewhere. JG> JG> Regards, JG> Johann JG> Clinton Gladstone schrieb: _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev