geosphere (version 1.5-10)

distCosine: 'Law of cosines' great circle distance

Description

The shortest distance between two points (i.e., the 'great-circle-distance' or 'as the crow flies'), according to the 'law of the cosines'. This method assumes a spherical earth, ignoring ellipsoidal effects.

Usage

distCosine(p1, p2, r=6378137)

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

r

radius of the earth; default = 6378137 m

Value

Vector of distances in the same unit as r (default is meters)

References

http://en.wikipedia.org/wiki/Great_circle_distance

See Also

distGeo, distHaversine, distVincentySphere, distVincentyEllipsoid, distMeeus

Examples

# NOT RUN {
distCosine(c(0,0),c(90,90))
# }