Andrew, Glad you got it figured, this is indeed an issue with invalid geometries that Mapnik's proj4 implementation can't cope with:
http://trac.mapnik.org/ticket/308 In the case of the world_borders file try using this one called 'tm_wgs84_sans_antarctica' here: http://mapnik-utils.googlecode.com/svn/data/ Dane On Dec 16, 2009, at 6:46 PM, Andrew Frieze wrote: > Ok, I think I have this figured out. > > Apparently the world_borders file has some trouble projecting. I am > able to successfully render a different shp file. > > > On Wed, Dec 16, 2009 at 11:55 AM, Andrew Frieze <[email protected]> > wrote: > Hi all > > I just discovered Mapnik and am very excited about the potential I > see here. I have run into a problem that I am hoping is easily > solved by this community. > > I followed the HelloWorld XML tutorial using the world_borders file > successfully. I would now like to have my output image rendered to > a Mercator projection(for google). Unfortunately, when I attempt > this I just get a blank tile. > > Here is a summary of my code(some parts removed for readability): > > mapfile = 'world_styles.xml' > m = Map(256, 256,"+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 > +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgri...@null +no_defs") > load_map(m, mapfile) > googleProj = Projection("+proj=merc +a=6378137 +b=6378137 > +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m > +nadgri...@null +no_defs") > > c0 = googleProj.forward(Coord(leftLong, botLat)) > c1 = googleProj.forward(Coord(rightLong, topLat)) > > bbox = Envelope(c0.x,c0.y,c1.x,c1.y) > m.zoom_to_box(bbox) > map_output = 'H:/inetpub/wwwroot/MapDev/images/image.png' > render_to_file(m, map_output) > > > Thanks! > Andrew > > > _______________________________________________ > Mapnik-users mailing list > [email protected] > https://lists.berlios.de/mailman/listinfo/mapnik-users _______________________________________________ Mapnik-users mailing list [email protected] https://lists.berlios.de/mailman/listinfo/mapnik-users
