haversine

Build Status

Crystal implementation of the Haversine formula to calculate distances between two points given their latitudes and longitudes.

Installation

  1. Add the dependency to your shard.yml:

    dependencies:
  haversine:
    github: mamantoha/haversine

  2. Run shards install

Usage

require "haversine"

Calling Haversine.distance with four latitude/longitude coordinates returns a Haversine::Distance object which can provide output in kilometers, meters, miles, feet, or nautical miles.

# Tokyo -> Paris
distance = Haversine.distance(35.61488, 139.5813, 48.85341, 2.3488)

distance.to_kilometers     # => 9715.470491159029
distance.to_meters         # => 9715470.491159027
distance.to_miles          # => 6032.710918698025
distance.to_feet           # => 31852713.65072557
distance.to_nautical_miles # => 5242.2799481204265

If you have latitude/longitude pairs stored in an array, you can alternately provide two arrays when calling Haversine.distance:

london = [51.500153, -0.126236]
new_york = [40.714268, -74.005974]

distance = Haversine.distance(new_york, london)
distance.to_kilometers # => 5570.4744596620685

Also you can compare Haversine::Distance objects:

london = [51.500153, -0.126236]
new_york = [40.714268, -74.005974]
shanghai = [31.222220, 121.458060]

distance1 = Haversine.distance(london, new_york)
distance2 = Haversine.distance(london, shanghai)

distance1 < distance2 # => true

Contributing

  1. Fork it (https://github.com/mamantoha/haversine/fork)
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request

Contributors