Get points on a great circle as defined by the shortest distance between two specified points
Usage
greatCircle(p1, p2, n=360, sp=FALSE)
Value
A matrix of points, or a list of such matrices (e.g., if multiple bearings are supplied)
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
p2
as above
n
The requested number of points on the Great Circle
sp
Logical. Return a SpatialLines object?
Author
Robert Hijmans, based on a formula provided by Ed Williams