On Oct 2, 2011, at 3:56 AM, Gianks wrote: > i'm trying to learn how to use mapnik from a demo file ( still searching for > something like documentation ) but i've not been able to understand how this > group of numbers has to be interpreted: > > > m.zoom_to_box(box2d<double>(1405120.04127408,-247003.813399447, > > 1706357.31328276,-25098.593149577)); > > The area shown in the result map is in Quebec, Canada. The Coordinates are > about 45° North, 73° West > How can i obtain these from those numbers? Which coord system is it?
Hi Gianks, Those look like coordinates in the Spherical Mercator[1] projection. You can use Proj4 to convert from WGS84 (lat: 45, lon: -73) to Spherical Mercator (1405120.04127408,-247003.813399447). This is usually done by some tool that calls mapnik, for example TileStache[2], if you're planning on rendering tiles. [1] http://spatialreference.org/ref/sr-org/6627/ [2] http://tilestache.org/ Cheers, -- Alex _______________________________________________ Mapnik-users mailing list [email protected] https://lists.berlios.de/mailman/listinfo/mapnik-users
