[OSM-dev] Projection code

Lars Aronsson lars at aronsson.se
Sun Apr 30 11:18:35 BST 2006

Immanuel Scholz wrote:

> >From Wikipedia:
> x = lon*PI/180,
> y = log(tan(PI/4+lat*PI/360)))

Which Wikipedia page are you quoting?  These equations seem to 
assume the Earth is a sphere, which is wrong by up to 0.3 percent.
The Earth radius is 6372 km, and 0.3 percent of that is 19 km.
If it was all this simple, libraries such as PROJ4 wouldn't exist.

  Lars Aronsson (lars at aronsson.se)
  Aronsson Datateknik - http://aronsson.se

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