[Proj] Finally: geodesic-1.0 is available

strebe strebe at aol.com
Fri Jan 9 16:08:49 EST 2009


On Jan 9, 2009, at 8:52:48 AM, OvV_HN <ovv at hetnet.nl> wrote:
> On the subject of the transverse Mercator projection, I'm about 2 weeks
> away from posting a new version of my "exact" TM program with much more
> exhaustive testing (see above), a more careful treatment of singular
> points, etc. Stay tuned.

Nice!
I've already resolved the lat=90d problem in the inverse (calculation of 
zeta where snv==0 and (cnu==0 or dnv==0) ), but there are probably some more 
problems? I'll stay tuned!

Oscar van Vlijmen

I find the regions from the cusps to a short way along the outer boundary, just inside the boundary, to be most computationally problematic. However, I am not using Thompson/Lee's development through Jacobian elliptic functions, so possibly your difficult terrain differs. I do not use Jacobian elliptic functions at all; only an elliptic integral of the second kind. I am satisfied with my results throughout the rest of the map, so I am keen to compare notes in case it makes sense to bring both methods to bear, depending on the region.

Regards,
— daan Strebe
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