-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi all. Is this of some interest for us too? All the best.
- -------- Messaggio originale -------- Oggetto: [GRASS-dev] [Proj] Improvements to geod and invgeod Data: Sun, 26 May 2013 01:00:16 -0700 (PDT) Mittente: Helmut Kudrnovsky <[email protected]> A: [email protected] fyi taken from http://lists.maptools.org/pipermail/proj/2013-May/006602.html - --------------------------------------------------------------------------------------------- geod and invgeod, programs for performing geodesic calculations, have been part of proj.4 since at least 1995. There are several problems with them: * the overall accuracy is limited; * the results of inverse calculations are sometimes wildly wrong; * there's no documented API for the geodesic capabilities; * there's no provision from computing various quantities associated with geodesics (in particular the area of a geodesic polygon). These problems will be addressed in the next release of proj.4 with the inclusion of the algorithms for geodesics from GeographicLib. These are documented in C. F. F. Karney, Algorithms for geodesics, J. Geodesy 87(1), 43-55 (Jan. 2013) http://dx.doi.org/10.1007/s00190-012-0578-z Addenda: http://geographiclib.sf.net/geod-addenda.html Points to note: [...] * Several libraries that depend on proj.4, e.g., GRASS, use approximate methods for computing polygonal areas. They can now use proj.4 to compute areas accurately. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAlGiEm0ACgkQ/NedwLUzIr7RTwCgronEzHfRhY3LXuQcDASGhorX u20AniV9i5qYQI2aZswpB38ZCabaH2fk =+9c6 -----END PGP SIGNATURE----- _______________________________________________ Qgis-developer mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-developer
