Class: Clusto::Distance

Inherits:
Object
  • Object
show all
Defined in:
lib/clusto/distance.rb

Class Method Summary collapse

Class Method Details

.euclidian(pa, pb) ⇒ Object 



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# File 'lib/clusto/distance.rb', line 3

def self.euclidian(pa, pb)
  Math::sqrt((pa.x - pb.x) ** 2 + (pa.y - pb.y) ** 2)
end

.haversine(pa, pb) ⇒ Object 



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# File 'lib/clusto/distance.rb', line 7

def self.haversine(pa, pb)
  x = (pb.x - pa.x) * RADIANS_PER_DEGREES
  y = (pb.y - pa.y) * RADIANS_PER_DEGREES
  
  ar = pa.x * RADIANS_PER_DEGREES
  br = pb.x * RADIANS_PER_DEGREES
  
  a = Math.sin(x / 2) ** 2 + Math.cos(ar) * Math.cos(br) * Math.sin(y / 2) ** 2
  c = 2 * Math.atan2(Math::sqrt(a), Math::sqrt(1 - a))
  GREAT_CIRCLE_RADIUS * c;
end