[OSM-talk] Increase download limit near the poles?

Petter Reinholdtsen pere at hungry.com
Sun Aug 12 08:56:57 BST 2007


[Tom Hughes]
> Well if you can come up with a good algorithm then maybe we can
> consider it ;-) For what it's worth the current test is:
>
>   (max_lat - min_lat) * (max_lon - min_lon) < 0.25

What about something like this:

    (max_lat - min_lat) * (max_lon - min_lon) < 
        0.1 + 0.2*sin( | max_lat - min_lat | )

The 0.1 is the minimum value used on equator, and 0.2 is a scaling
factor that is zero on equator and 0.2 on the poles, so in this case
it would scale between 0.1 and 0.3 from equator to the poles.  I'm not
sure if 0.1 and 0.2 are the best values to use, but the structure of
the formula should be clear.  I assume we want to tune it based on
what make most sense around the globe.

Happy hacking,
-- 
Petter Reinholdtsen





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