There is also a plugin already integrated into OJ that can measure distance/ area in lat/lon. (Epsg 4326). See Measure toolbox under Plugin menu.
Il mer 20 feb 2019, 15:55 Paul J. Morris <m...@morris.net> ha scritto: > On Wed, 20 Feb 2019 10:20:14 +0100 > Nicolas Ribot <nicolas.ri...@gmail.com> wrote: > > > Hi, > > > > > > > > Sounds useful to me. But i am not sure its so easy given that the > > > length of a degree is changing, but there may be some formulas out > > > there (even web pages) that calculate great circle distances ... > > > mhm... i think somewhere i even used such, once. > > > > > > Cheers, > > > Stefan > > > > > > Yes, it is based on great circles computation. I used formula from > > > this > > rather complete page : > > https://www.movable-type.co.uk/scripts/latlong.html > > > > Nicolas > > That page is a good source. > > Here's a java implementation: > > > https://sourceforge.net/p/sarmanager/code/HEAD/tree/trunk/SMT/src/net/aa3sd/SMT/math/SphericalUtility.java#l486 > > with a very basic unit test: > > > https://sourceforge.net/p/sarmanager/code/HEAD/tree/trunk/SMT/src/net/aa3sd/SMT/test/TestSphericalUtilityMethods.java#l64 > > Derived from the c implementation in xastir > > https://github.com/Xastir/Xastir/blob/master/src/util.c#L2913 > > Key choice is what value to use for the mean radius of the Earth. > > -Paul > -- > Paul J. Morris > Biodiversity Informatics Manager > Museum of Comparative Zoölogy, Harvard University > m...@morris.net AA3SD PGP public key available > > > _______________________________________________ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel >
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