[Proj] Distance calculation

Hamish hamish_b at yahoo.com
Wed Oct 15 22:30:50 EDT 2008

support.mn at elisanet.fi a écrit:
> > > There is a windows program that can calculate distances on a sphere.
> > > It can be downloaded here
> > > http://www.elisanet.fi/master.navigator/xCalc/
> > > 
> > > It is free and can also calculate other expressions and functions.

Jean-Claude Repetto kirjoitti: 
> > It is not free :

lisanet.fi writes:
> It is practically free. After a while it asks you to order,
> but there is the "Later" button. You can cointinue to push
> "Later" for ever and it does not stop to calculate.

cue libre vs. gratis "debate". I will try to short circuit that with
two lines of code and a small png image...

> > - I couldn't find the source code
> Source code is not free. The executable is.

great circle distance calcs on a sphere is no problem -- I've attached
a small Matlab (or GNU/Octave...) script that I wrote some time ago which
does that (formula gleaned from MathWorld). Adjust +a to taste.

I was more concerned with distance along the WGS84 ellipsoid; a big thanks
to all for the interesting tips & references in that regard.


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