gcIntersectBearing {geosphere}

Intersections of two great circles

Description

Get the two points where two great cricles cross each other. In this function, great circles are defined by a points and an initial bearing. In function gcIntersect they are defined by two sets of points.

Usage

gcIntersectBearing(p1, brng1, p2, brng2) 

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

brng1

Bearing from p1

p2

As above. Should have same length as p1, or a single point (or vice versa when p1 is a single point

brng2

Bearing from p2

Value

a matrix with four columns (two points)

Author(s)

Chris Veness and Robert Hijmans based on code by Ed Williams

References

https://www.edwilliams.org/avform147.htm#Intersection

https://www.movable-type.co.uk/scripts/latlong.html

See Also

gcIntersect

Examples

gcIntersectBearing(c(10,0), 10, c(-10,0), 10)