finalBearing {geosphere}

Final direction

Description

Get the final direction (bearing) when arriving at p2 after starting from p1 and following the shortest path on an ellipsoid (following a geodetic) or on a sphere (following a great circle).

Usage

finalBearing(p1, p2, a=6378137, f=1/298.257223563, sphere=FALSE)

Arguments

p1

longitude/latitude of point(s). Can be a vector of two numbers, a matrix of 2 columns (first column is longitude, second column is latitude) or a SpatialPoints* object

p2

as above

a

major (equatorial) radius of the ellipsoid. The default value is for WGS84

f

ellipsoid flattening. The default value is for WGS84

sphere

logical. If TRUE, the bearing is computed for a sphere, instead of for an ellipsoid

Value

A vector of directions (bearings) in degrees

Author(s)

This function calls GeographicLib code by C.F.F. Karney

References

C.F.F. Karney, 2013. Algorithms for geodesics, J. Geodesy 87: 43-55. doi:10.1007/s00190-012-0578-z. Addenda: https://geographiclib.sourceforge.io/geod-addenda.html. Also see https://geographiclib.sourceforge.io/

See Also

bearing

Examples

bearing(c(10,10),c(20,20))
finalBearing(c(10,10),c(20,20))