Module: Mongoid::Spacial::Formulas

Defined in:
lib/mongoid_spacial/spacial/formulas.rb

Class Method Summary collapse

Class Method Details

.haversine(point1, point2) ⇒ Object 



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# File 'lib/mongoid_spacial/spacial/formulas.rb', line 32

def haversine(point1,point2)
  p1 = point1.map{|deg| deg * RAD_PER_DEG}
  p2 = point2.map{|deg| deg * RAD_PER_DEG}

  dlon = p2[0] - p1[0]
  dlat = p2[1] - p1[1]

  a = (Math.sin(dlat/2))**2 + Math.cos(p1[1]) * Math.cos(p2[1]) * (Math.sin(dlon/2))**2

  d = 2 * Math.atan2( Math.sqrt(a), Math.sqrt(1-a))
  d.instance_variable_set("@radian", true)
  d
end

.n_vector(point1, point2) ⇒ Object 



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# File 'lib/mongoid_spacial/spacial/formulas.rb', line 5

def n_vector(point1,point2)
  p1 = point1.map{|deg| deg * RAD_PER_DEG}
  p2 = point2.map{|deg| deg * RAD_PER_DEG}

  sin_x1 = Math.sin(p1[0])
  cos_x1 = Math.cos(p1[0])

  sin_y1 = Math.sin(p1[1])
  cos_y1 = Math.cos(p1[1])

  sin_x2 = Math.sin(p2[0])
  cos_x2 = Math.cos(p2[0])

  sin_y2 = Math.sin(p2[1])
  cos_y2 = Math.cos(p2[1])

  cross_prod =  (cos_y1*cos_x1 * cos_y2*cos_x2) +
    (cos_y1*sin_x1 * cos_y2*sin_x2) +
    (sin_y1        * sin_y2)

  return cross_prod > 0 ? 0 : Math::PI if (cross_prod >= 1 || cross_prod <= -1)

  d = Math.acos(cross_prod)
  d.instance_variable_set("@radian", true)
  d
end

.pythagorean_theorem(p1, p2) ⇒ Object 



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# File 'lib/mongoid_spacial/spacial/formulas.rb', line 46

def pythagorean_theorem(p1, p2)
  Math.sqrt(((p2[0] - p1[0]) ** 2) + ((p2[1] - p1[1]) ** 2))
end