Boost logo

Boost :

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)


Boost list run by bdawes at, gregod at, cpdaniel at, john at