orthodrom.dist {birdring}R Documentation

orthodromic distance and direction

Description

calculates the orthodromic (great circle, shortest distance) distance between two points on the earth

Usage


orthodrom.dist(x1, y1, x2, y2)

Arguments

x1

x-coordinate/longitude of the first point (in decimal coordinates), can be a scalar or a vector

y1

y-coordinate/latitude of the first point (in decimal coordinates), can be a scalar or a vector

x2

x-coordinate/longitude of the second point (in decimal coordinates), can be a scalar or a vector

y2

y-coordinate/latitude of the second point (in decimal coordinates), can be a scalar or a vector

Details

The function is a wrapper of the distMeeus function of the geosphere package.

Value

gives back a number or a vector with the distances in km between the two points on earth.

Warning

see details

Author(s)

Fraenzi Korner-Nievergelt

References

Imboden, C., Imboden D. (1972) Orthodromic and loxodromic formula for the calculation of distance and direction between ringing and finding place. Vogelwarte 26: 336-346.

See Also

decimal.coord

Examples


ringingx<-7.30
ringingy<-47.41
findingx<-5.1
findingy<-32.01
rxdec<-decimal.coord(ringingx)
rydec<-decimal.coord(ringingy)
fxdec<-decimal.coord(findingx)
fydec<-decimal.coord(findingy)     

orthodrom.dist(rxdec, rydec, fxdec, fydec) 

[Package birdring version 1.4 Index]