readme.md

Executing the code:

ruby distance_calculator.rb

To edit the points, modify the array location_points

distance_calculator.rb

location_points = [
  [-29.640088, -50.764216],
  [-29.637486, -50.770814],
  [-29.633196, -50.773013]
]

# using Harvesine  formula to calculate the distance
# based on https://github.com/alexreisner/geocoder/blob/master/lib/geocoder/calculations.rb#L72
def distance(location_one, location_two)
  rad_per_deg = Math::PI/180
  radius_in_kilometers = 6371
  radius_in_meters = radius_in_kilometers * 1000

  dlat_rad = (location_two[0]-location_one[0]) * rad_per_deg
  dlon_rad = (location_two[1]-location_one[1]) * rad_per_deg

  latitude_one_rad, lon1_rad = location_one.map {|i| i * rad_per_deg }
  latitude_two_rad, lon2_rad = location_two.map {|i| i * rad_per_deg }

  a = Math.sin(dlat_rad/2)**2 + Math.cos(latitude_one_rad) * Math.cos(latitude_two_rad) * Math.sin(dlon_rad/2)**2
  c = 2 * Math::atan2(Math::sqrt(a), Math::sqrt(1-a))

  radius_in_meters * c # Delta in meters
end

location_points.each_with_index do |initial_point, initial_index|
  puts "Distance from the point #{initial_index} to \n"
  location_points.each_with_index do |point, index|
    if index != initial_index
      puts "point #{index} is #{distance(initial_point, point).to_i} meters"
    end
  end
end