I am calculating the azimuth between two points whose position is defined in WGS84 coordinates. If I Open Attribute Table -> Open Field Calculator and ask for
I get 95.885 degrees which is inconsistent with the manual calculation
atan2(sin(delta_lon)*cos(lat2),cos(lat1)*sin(lat2)-sin(lat1)*cos(lat2)*cos(delta_lon)), or with the result provided by the French Geographic Institute (geoportail) web site.
However, if following Azimuth calculation, extending lines I run in the Python Console
p1 = QgsPointXY(6.020323,47.248690) p2 = QgsPointXY(6.083703,47.242157) d = QgsDistanceArea() d.setEllipsoid('WGS84') d.bearing(p1,p2)*180/3.1415926535
then I get the correct result of 98.584. Could someone enlighten me as to why the first method provides an erroneous result?