Hi, One funny alternative would be to compute not the size of the data (nodes and tags) but the size of the tiles in a compressed format (PNG or JPG or compressed BMP). An empty tile can be compressed to a few bytes, but a dense tile with a lot of ways and place-names cannot be compressed so much. In this way, we would compute the amount of "graphic information" available for each country/zone, and this would not be influenced by uploads of tracks with too many nodes or untagged, disconnected nodes. On the other hand, one very visible difference between Mediterranean cities and, for example, English cities is the population density of the urban areas. For example, a medium-size English city like Liverpool is probably almost as big as Barcelona, even though their population is much smaller, so the ratio kms of streets divided by number of people will be very different in the South and in the North of Europe... not to mention those endless suburbs in the United States, for example... so yes, it's very complicated to compute a map quality index properly. Regards, Lucas ________________________________
De: [EMAIL PROTECTED] en nombre de Frederik Ramm Enviado el: mié 30/04/2008 1:45 Para: talk@openstreetmap.org Asunto: [OSM-talk] OSM in Europe Statistics Hi, a very crude statistic: Country osm.bz2 size population ratio (bytes per capita) -------------------------------------------------------------------- UK 73M 60M 1.2 Germany 110M 82M 1.3 Netherlands 51M 16M 3.2 France 29M 60M 0.5 Finland 20M 5M 4.0 Italy 14M 58M 0.2 Norway 21M 5M 4.2 Sweden 24M 9M 2.6 Spain 17M 40M 0.4 I suspect that disregarding the coastline (which is included in my figures) would probably cost the Scandinavian countries a few ranks in this league. Coastline factor doesn't affect larger countries that much (but still strange that Italy should have so little - must investigate quality of border polygon). It is probably not unreasonable that once the road network is complete in a European country, we'll look at a ratio not unlike the NL figure. This would suggest that both the UK and Germany are about 1/3 there. Of course this is very simplistic and I believe you will come up with much better measures of progress. Let's hear your numbers ;-) (Among other things, NL is known as a very densely populated place - UK has 9 times the area of NL but only 3 times the population -, so those map features that tend to fill the available land even if sparsely populated will mean that the "destination bytes per capita" ratio for places like UK or DE will be higher than 3.) Bye Frederik -- Frederik Ramm ## eMail [EMAIL PROTECTED] ## N49°00'09" E008°23'33" _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
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