Re: [JPP-Devel] Metric distances for lat long coordinates
No problem Nicolas, There are still so many features I discover on OJ. Sorry for my short sintetic answer due to lack of PC in this moment. Not sure if I already integrated the source code of measure plugin into OJ svn. When I worked on that plugin I tried to detailed the origin of the algorithms, I revisited Vincenty's algorithms. I will be glad if you want to reuse the code for other purpose. Best Giuseppe Il gio 21 feb 2019, 17:53 Nicolas Ribot ha scritto: > Hi Giuseppe, > > Yes exactly what I needed ! > Thanks, I was about reinventing the wheel ;) > (so many features I don't know of in OJ...) > > Nicolas > > On Thu, 21 Feb 2019 at 17:42, Giuseppe Aruta > wrote: > >> 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 ha scritto: >> >>> On Wed, 20 Feb 2019 10:20:14 +0100 >>> Nicolas Ribot 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 >>> >> ___ >> Jump-pilot-devel mailing list >> Jump-pilot-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel >> > ___ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > ___ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
Re: [JPP-Devel] Metric distances for lat long coordinates
Hi Giuseppe, Yes exactly what I needed ! Thanks, I was about reinventing the wheel ;) (so many features I don't know of in OJ...) Nicolas On Thu, 21 Feb 2019 at 17:42, Giuseppe Aruta wrote: > 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 ha scritto: > >> On Wed, 20 Feb 2019 10:20:14 +0100 >> Nicolas Ribot 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 >> > ___ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > ___ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
Re: [JPP-Devel] Metric distances for lat long coordinates
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 ha scritto: > On Wed, 20 Feb 2019 10:20:14 +0100 > Nicolas Ribot 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 > ___ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
Re: [JPP-Devel] Metric distances for lat long coordinates
On Wed, 20 Feb 2019 10:20:14 +0100 Nicolas Ribot 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
Re: [JPP-Devel] Metric distances for lat long coordinates
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 ___ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
Re: [JPP-Devel] Metric distances for lat long coordinates
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 On Tue, Feb 19, 2019, 15:49 Nicolas Ribot Hi, > > I was thinking about adding an option when measuring distance, to compute > distance in meters (or km) if map units are latitude/longitude. > > For instance, here: a distance measure along a 1 degree segment: > > [image: Screenshot 2019-02-19 at 19.45.41.png] > > Option in Measurement would allow to activate this feature and choose > between m and km (other units too ?) > > Do you think this feature would be useful ? > > Cheers > Nicolas > ___ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > ___ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
[JPP-Devel] Metric distances for lat long coordinates
Hi, I was thinking about adding an option when measuring distance, to compute distance in meters (or km) if map units are latitude/longitude. For instance, here: a distance measure along a 1 degree segment: [image: Screenshot 2019-02-19 at 19.45.41.png] Option in Measurement would allow to activate this feature and choose between m and km (other units too ?) Do you think this feature would be useful ? Cheers Nicolas ___ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
