[OSM-dev] Polygons in OSM don't necessarily comply to simple?feature specification

Christopher Schmidt crschmidt at metacarta.com
Wed Apr 16 23:55:15 BST 2008


On Thu, Apr 17, 2008 at 12:43:06AM +0200, Iván Sánchez Ortega wrote:
> El Jueves, 17 de Abril de 2008, Christopher Schmidt escribió:
> 
> > "Geometry in a 2 dimensional plane." In a 2 dimensional plane, all
> > geometries are 2d, because you specify their coordinates in two
> > dimensions.
> 
> Nope.
> 
> A point is a 0-dimensional entity, because you cannot move along it.
> 
> A line is a 1-dimensional entity, because you can move along it with one 
> degree of freedom.
> 
> A surface (i.e. a closed polygon) is a 2-dimensional entity, because you can 
> move inside along it with two degrees of freedom.
> 
> 
> Now, in a 2-dimensional realm (i.e. a plane), you can have 0-, 1-, and 
> 2-dimensional things. Specified with 2-dimensional coordinates.

Right. Sorry, that's what I meant, but now we're ust as bad as OGC
wankers :)

Regards,
-- 
Christopher Schmidt
MetaCarta




More information about the dev mailing list