onGreatCircle: Is a point on a given great circle?
Description
Test if a point is on a great circle defined by two other points.
Usage
onGreatCircle(p1, p2, p3)
Arguments
p1
Longitude/latitude of the first point definging a great circle, in degrees; 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 for the second point
p3
the point(s) to be tested if they are on the great circle or not