Great-Circle Distance — great_circle

Calculates the great-circle distance between two languages as determined by their WALS latitude-longitude coordinates.

great_circle_distance(id1, id2)

Arguments

id1	WALS ID of first language
id2	WALS ID of second language

Details

WALS defines the geographical representation of a language as a point in latitude-longitude space. Calculation of great-circle distance is by the haversine formula assuming a perfectly spherical Earth of radius 6,371 km.

Examples

a <- great_circle_distance("fre", "ger")
b <- great_circle_distance("ger", "rus")
c <- great_circle_distance("fre", "rus")
if (a + b >= c) {
  print("The triangle inequality works!")
}
#> [1] "The triangle inequality works!"