R: 'Law of cosines' great circle distance

distCosine {geosphere} | R Documentation

## '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)

### Author(s)

Robert Hijmans

### References

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

### See Also

`distHaversine, distVincentySphere, distVincentyEllipsoid, distMeeus`

### Examples

    distCosine(c(0,0),c(90,90))

[Package geosphere version 1.5-5 Index]