Re: improving speed of mysql distance filter
Less than about 20 km, the diff between answers given by Pythagorean & great circle distance formulas is very small, so as a first approximation, at least away from the poles, you could look for small values of sqrt((lat2 - lat11)^2 + (lon2 - lon1)^2).
Google for great circle distance,approximation for more ideas.
PB
Edited 1 time(s). Last edit at 06/29/2006 07:55PM by Peter Brawley.
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Re: improving speed of mysql distance filter
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