Re: [boost] geodetic library

Subject: Re: [boost] geodetic library
From: DE (satan66613_at_[hidden])
Date: 2009-08-28 11:39:10

on 28.08.2009 at 19:17
 Michael Fawcett wrote :
> Well, I'm certainly interested.  Can you prove yours is more accurate?
well, will you believe my word?

i don't know about other implementations but the implementation
(vincenty) that i saw truncates the series to the order 6 say (don't
remeber exactly)
while i save some extra terms (say of order 8)
i also compared this solution to a higher order solution (which
provides ~12 significant digits but which is overweighted with coeffs)
if you are interested i can post a paper of formulas' derivation

also there is another approach (to direct problem at least)
whole thing is to evaluate an elliptic integral
while i do the series expansion (to build inverse routine later) one
can directly evaluate the integral with one of special function evaluation
techniques (which are widely available, e.g. in numeric recipies)
i didn't try this (no time) and can not say if it is more accurate or
faster (however it might be)

-- 
Pavel