midPoint {geosphere}

Mid-point

Description

Find the point half-way between two points along an ellipsoid

Usage

midPoint(p1, p2, a=6378137, f = 1/298.257223563)

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

a

major (equatorial) radius of the ellipsoid

f

ellipsoid flattening. The default value is for WGS84

Value

matrix with coordinate pairs

Author(s)

Elias Pipping and Robert Hijmans

Examples

midPoint(c(0,0),c(90,90))  
midPoint(c(0,0),c(90,90), f=0)