spheredist: Distance on sphere.
In rubak/spatstatsphere: Point patterns on the sphere for spatstat package

Low-level function to calculate distance on the sphere. No checking of arguments is done.

1	spheredist(lat1, long1, lat2, long2, domain = sphere(1))

`lat1, lat2`	Numeric of length 1. Latitude in radians between -pi/2 and pi/2.
`long1, long2`	Numeric of length 1. Longitude in radians between -pi and pi (or between 0 and 2*pi).
`domain`	Sphere object of class `"sphericaldomain"` specifying radius of sphere and type of coordinates. Defaults to `sphere(1)`.