Re: [Qgis-developer] [Qgis-user] ShapeTools XY to Line
Tobias, Thank you for that suggestion. I am now using the geographiclib routines in Shape Tools' XY to Line routine that was released today. I am still including Great Circle as an option and if you zoom in you can see the differences. http://plugins.qgis.org/plugins/shapetools/ All the best, Calvin Wait, it's way better to use this one: > https://geographiclib.sourceforge.io/ > > There's a Python port and it's extreme accurate and quick. > It's under MIT and it works great (just tested it). > > It also works with WGS84 and all other ellipsoids (WGS84 should be > fine for most of the users). > > This might be the easiest and best way for accurate distances and > azimuths. > > > ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] [Qgis-user] ShapeTools XY to Line
I look into that code next week and see about replacing my algorithms with it. I suppose that what one really wants is the most accurate algorithm so perhaps it doesn't make sense to use support multiple algorithms. Thanks for your suggestion!!! On Fri, Mar 17, 2017 at 3:02 PM, Tobias Wendorff < tobias.wendo...@tu-dortmund.de> wrote: > Am Fr, 17.03.2017, 20:00 schrieb C Hamilton: > > I can implement Vincenty as I have some of that code as well - > > at least for WGS84. I am not an expert on projections so I am > > not sure how to change the code to make it work for any ellipsoid. > > Wait, it's way better to use this one: > https://geographiclib.sourceforge.io/ > > There's a Python port and it's extreme accurate and quick. > It's under MIT and it works great (just tested it). > > It also works with WGS84 and all other ellipsoids (WGS84 should be > fine for most of the users). > > This might be the easiest and best way for accurate distances and > azimuths. > > > ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] [Qgis-user] ShapeTools XY to Line
I can implement Vincenty as I have some of that code as well - at least for WGS84. I am not an expert on projections so I am not sure how to change the code to make it work for any ellipsoid. On Fri, Mar 17, 2017 at 2:47 PM, Tobias Wendorff < tobias.wendo...@tu-dortmund.de> wrote: > Am Fr, 17.03.2017, 19:21 schrieb C Hamilton: > > How important would it be to implement other geodetic line types ie > > GEODESIC , RHUMB_LINE, and NORMAL_SECTION. > > I > had the code for Great Circle so it was easy to implement, > > but I don't know how to implement the others. > > Try to implement "Vincenty's formulae". It's very easy and much more > accurate than "Great Circle": > > https://en.wikipedia.org/wiki/Vincenty's_formulae > > Perhaps I can give it a try. Did something equal in the past, but > without a GUI :) > > "Great Circle" and "Vincenty" work with any ellipsoid. Projecting the > current CRS to WGS84 first might be faulty. To get more accurate results, > it might be better to use the current ellipsoid. > > ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
