Class: GeoDistance::NVector

Inherits:
DistanceFormula show all
Defined in:
lib/geo-distance/formula/n_vector.rb

Class Method Summary collapse

Methods inherited from DistanceFormula

geo_distance, get_points, get_units, #initialize

Constructor Details

This class inherits a constructor from GeoDistance::DistanceFormula

Class Method Details

.distance(*args) ⇒ Object 



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# File 'lib/geo-distance/formula/n_vector.rb', line 3

def self.distance *args
  from, to, units = get_points(args)
  lat1, lon1, lat2, lon2 = [from.lat, from.lng, to.lat, to.lng]
  
  sin_x1 = Math.sin(lon1)
  cos_x1 = Math.cos(lon1)

  sin_y1 = Math.sin(lat1)
  cos_y1 = Math.cos(lat1)

  sin_x2 = Math.sin(lon2)
  cos_x2 = Math.cos(lon2)

  sin_y2 = Math.sin(lat2)
  cos_y2 = Math.cos(lat2)

  cross_prod =  (cos_y1*cos_x1 * cos_y2*cos_x2) + (cos_y1*sin_x1 * cos_y2*sin_x2) + (sin_y1 * sin_y2)
    
  c = Math.acos(cross_prod)
  
  # puts "c: #{c}"
  # radians_per_degree                          
  c = (c * 0.0201324).to_deg      
  
  units ? c.radians_to(units) : c
end