import math.*

def haversin( theta ) = (1 - cos( theta ))/2

def radians( deg ) = deg Pi/180

def haversine( (lat1, lon1), (lat2, lon2) ) =
  R = 6372.8
  h = haversin( radians(lat2 - lat1) ) + cos( radians(lat1) ) cos( radians(lat2) ) haversin( radians(lon2 - lon1) )
  2R asin( sqrt(h) )

println( haversine((36.12, -86.67), (33.94, -118.40)) )