On Thu, Dec 17, 2009 at 5:40 PM, Anthony <o...@inbox.org> wrote: > > >> Spherical geometry allows you to calculate _directly_ on the sphere >> >> without using a projection ... you simple use LatLon in radian >> >> degrees. >> > >> > True, but it's not really trivial. >> >> A rectangle with 89.55°, 90.1°, 89.89°, 90,01° is no rectangle. >> > > What's the definition of "rectangle" in non-euclidean geometry anyway? >
Here we go: http://www.math.ucdavis.edu/~xqwang/math141/hw7.pdf Turns out Wyoming isn't even a polygon (*), let alone a rectangle. In fact, there apparently are no rectangles on spheres (which probably holds for bumpy oblate spheroids aside from some small exceptions due to the "bumpy" part). http://www.math.washington.edu/~king/coursedir/m444a04/notes/10-11-Def-of-Rectangle.html (*) In reality. In some projections it is, of course, a polygon. _______________________________________________ josm-dev mailing list josm-dev@openstreetmap.org http://lists.openstreetmap.org/listinfo/josm-dev
