dist_greatcircle function

Distance between points

Returns the great circle distance between a location and all grid point in km

dist_greatcircle(
  lat1,
  lon1,
  lat2,
  lon2,
  r = earth_radius(),
  method = c("haversine", "orthodrome", "vincenty", "euclidean")
)

Arguments

• lat1, lon1: numeric vector. coordinate of point(s) 1 (degrees).

• lat2, lon2: numeric vector. coordinates of point(s) 2 (degrees).

• r: numeric. radius of the sphere (default = 6371.0087714 km, i.e. the radius of the Earth)

• method: Character. Formula for calculating great circle distance, one of:

  • "haversine": great circle distance based on the haversine formula that is optimized for 64-bit floating-point numbers (the default)
  • "orthodrome": great circle distance based on the spherical law of cosines
  • "vincenty": distance based on the Vincenty formula for an ellipsoid with equal major and minor axes
  • "euclidean": Euclidean distance (not great circle distance!)

Returns

numeric vector with length equal to length(lat1)

Examples

dist_greatcircle(lat1 = 20, lon1 = 12, lat2 = c(50, 30), lon2 = c(40, 32))
dist_greatcircle(
  lat1 = 20, lon1 = 12, lat2 = c(50, 30), lon2 = c(40, 32),
  method = "orthodrome"
)
dist_greatcircle(
  lat1 = 20, lon1 = 12, lat2 = c(50, 30), lon2 = c(40, 32),
  method = "vincenty"
)
dist_greatcircle(
  lat1 = 20, lon1 = 12, lat2 = c(50, 30), lon2 = c(40, 32),
  method = "euclidean"
)

See Also

orthodrome(), haversine(), vincenty()