Geo Point
Adds the concept of a GeoPoint for geo libraries. A GeoPoint encapsulates latitude and longitude, and:
- a coordinates mode (coord_mode) that can be set to either :lng_lat or :lat_lng
- calculations such as: distance_to, bearing_to, midpoint, intersection and destination point
- parsing from various String, Hash or Array formats, including from DMS string format, such as “58 38 38N, 003 04 12W”
Using GeoPoints makes it much easier and more efficient to transport location point data and various geo libraries adds additional functionality such as
vector operations on top (see fx geo_vectors gem). Enjoy!
Install
Gemfile:
gem 'geo_point'
$ bundle
Status Sept 2012
Currently a few of the specs break. Please help Fix. They might be related to geo_calc and/or geo_units gems.
Quick start (Usage)
First define the points on the globe you want to work with.
The GeoPoint initializer is very flexible with regards to the arguments it can handle.
# factory method on core ruby classes "51 12 03 N, 24 10 02 E".geo_point [51.5136, -0.0983].geo_point {:latitude => 27.3, :longitude => "24 10 02 E"}.geo_point # two arguments p1 = GeoPoint.new 51.5136, -0.0983 p2 = GeoPoint.new "14 11 01 N", "-0.0983" p3 = GeoPoint.new 51.5136, "24 10 02 E" # a String p1 = GeoPoint.new "51.5136, -0.0983" p1 = GeoPoint.new "51.5136, 24 10 02 E" p3 = GeoPoint.new "51.4778, -0.0015" p1 = GeoPoint.new "51 12 03 N, 24 10 02 E" # an Array p2 = GeoPoint.new [51.5136, -0.0983] p2 = GeoPoint.new [51.5136, "24 10 02 E"] p2 = GeoPoint.new [51.5136, {:lon => 27.3}] # a Hash p4 = GeoPoint.new {:lat => 27.3, :lng => "24 10 02 E"} p4 = GeoPoint.new {:latitude => 27.3, :longitude => "24 10 02 E"}
Utility methods
These are some of the utility methods you can use on a GeoPoint object
p1 = GeoPoint.new 5.1, -7 p1.lat # latitude p1.lon # longitude p1.to_lat_lng # Array representation of [lat, lng] p1.to_lng_lat # Array representation of [lng, lat] p1.to_s # String representation (DMS format) p1.to_coords # calls either #to_lat_lng or #to_lng_lat depending on global :coord_mode setting
Global configuration options
GeoPoint.coord_mode = :lat_lng GeoPoint.coord_mode = :lng_lat GeoPoint.earth_radius_km = 6379 GeoPoint.earth_radius_km = 6371
GeoPoint functionality
A GeoPoint always has the following calculation API available:
- bearing_to(point)
- final_bearing_to(point)
- destination_point(brng, dist)
- distance_to(point)
- intersection_point(brng1, p2, brng2)
- midpoint_to(point)
Rhumb: (see Rhumb_line)
- rhumb_distance_to(point)
- rhumb_bearing_to(point)
- rhumb_destination_point(brng, dist)
See the geo_calc gem for details on how to use this Api
Contributing to geo_point
- Check out the latest master to make sure the feature hasn’t been implemented or the bug hasn’t been fixed yet
- Check out the issue tracker to make sure someone already hasn’t requested it and/or contributed it
- Fork the project
- Start a feature/bugfix branch
- Commit and push until you are happy with your contribution
- Make sure to add tests for it. This is important so I don’t break it in a future version unintentionally.
- Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.
Copyright
Copyright © 2011 Kristian Mandrup. See LICENSE.txt for
further details.