2009/5/21 Ævar Arnfjörð Bjarmason <ava...@gmail.com>: > On Wed, May 20, 2009 at 6:53 PM, Sebastian Spaeth <sebast...@sspaeth.de> > wrote: >> Ævar Arnfjörð Bjarmason wrote: >>> I want to play with producing a heat map of the globe where "heat" is >>> determined by the relative size of t...@h tilesets at z12. >>> >>> I could also use the tiles themselves, but I suppose the tilesets will >>> be a better indicator of complexity. But whatever's easy. >>> >>> Could someone with access to the t...@h servers pretty please generate >>> this for me? :) >> >> 20:51 < spaetz> http://tah.openstreetmap.org/media/filesizes.bz2 >> 20:52 < spaetz> result of ls --file-type -l -R > filesizes >> 20:52 < spaetz> takes some grepping, and cutting to get the raw sizes, >> but the >> info is in there. > > I converted it to something better using a hacky ad-hoc script (attached): > > http://u.nix.is/~avar/tile-sizes.txt.bz2
I went ahead and created a renderer so it now makes a heat map, it's under applications/rendering/tah-heatmap in svn: http://trac.openstreetmap.org/changeset/15441 Example output here: http://u.nix.is/~avar/osm-heatmap.png And how to run it: http://trac.openstreetmap.org/browser/applications/rendering/tah-heatmap/README Ideally this map would be mostly red around large capital areas and blue along most of the coastline and other sparsely mapped areas. But the heatmap() function I ripped from ViewCVS takes values between 0 and < 1 (which I normalize to with $tile_size/$max_tile_size) and since most tiles fall towards the lower end of the size spectrum the map ends up being mostly blue. I've been trying to find an algorithm which would intelligently distribute these values so I'd get the blue/yellow/green/red colors which compose the canonical heat map, but such numeric crunching isn't my strongest side. Help would be appreciated. These are the min/max/average/median t...@h tile sizes, for reference: Min = 5472 Max = 38211510 Average = 551490 Median = 227879 Number of tiles = 937254 _______________________________________________ dev mailing list dev@openstreetmap.org http://lists.openstreetmap.org/listinfo/dev
