Get the initial bearing (direction; azimuth) to go from point p1 to point p2 (in longitude/latitude) following the shortest path on an ellipsoid (geodetic). Note that the bearing of travel changes continuously while going along the path. A route with constant bearing is a rhumb line (see bearingRhumb).
Usage
bearing(p1, p2, a=6378137, f=1/298.257223563)
Arguments
p1
longitude/latitude of point(s). Can be a vector of two numbers, a matrix of 2 columns (first one is longitude, second is latitude) or a SpatialPoints* object
p2
as above. Can also be missing, in which case the bearing is computed going from the first point to the next and continuing along the following points
a
major (equatorial) radius of the ellipsoid. The default value is for WGS84
f
ellipsoid flattening. The default value is for WGS84