Bearing (direction of travel; true course) along a rhumb line (loxodrome) between two points.
1.1
bearingRhumb(p1, p2)
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
Chris Veness and Robert Hijmans, based on formulae by Ed Williams
Note
Unlike most great circles, a rhumb line is a line of constant bearing (direction), i.e. tracks of constant true course. The meridians and the equator are both rhumb lines and great circles. Rhumb lines approaching a pole become a tightly wound spiral.