The shortest distance between two points (i.e., the 'great-circle-distance' or 'as the crow flies'),
according to the 'haversine method'. This method assumes a spherical earth, ignoring ellipsoidal effects. Note
that this version is implemented in C++. A quick benchmark to the version of geosphere showed it to be a non-insignificant speed enhancement.
The algorithm converges in one-twentieth of the original time.
Usage
haversine(lat_from, lon_from, lat_to, lon_to, r = 6378137)
Arguments
lat_from
Latitude of point.
lon_from
Longitude of point.
lat_to
Latitude of point.
lon_to
Longitude of point.
r
Radius of the earth; default = 6378137m
Value
Vector of distances in the same unit as r (default in meters).
Details
The Haversine ('half-versed-sine') formula was published by R.W. Sinnott in 1984, although it has been known for much longer.
References
Sinnott, R.W, 1984. Virtues of the Haversine. Sky and Telescope 68(2): 159.