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

Iván Sánchez Ortega ivan at sanchezortega.es
Wed Apr 16 23:43:06 BST 2008


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.


-- 
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Iván Sánchez Ortega <ivan at sanchezortega.es>

No hacer nada es el camino para no ser nadie
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