class GeoDistance::Haversine

Public Class Methods

distance(*args) click to toggle source

given two lat/lon points, compute the distance between the two points using the haversine formula

the result will be a Hash of distances which are key'd by 'mi','km','ft', and 'm'
# File lib/geo-distance/formula/haversine.rb, line 41
def self.distance *args
  begin
    from, to, units = get_points(args)
    
    lat1, lon1, lat2, lon2 = [from.lat, from.lng, to.lat, to.lng]               
    dlon = lon2 - lon1
    dlat = lat2 - lat1

    a = (Math.sin(dlat.rpd/2))**2 + Math.cos(lat1.rpd) * Math.cos((lat2.rpd)) * (Math.sin(dlon.rpd/2))**2
    c = (2 * Math.atan2( Math.sqrt(a), Math.sqrt(1-a)))
    c = c.to_deg
            
    units ? c.radians_to(units) : c
  rescue Errno::EDOM
    0.0        
  end
end