Module: Geokit::Mappable::ClassMethods
- Defined in:
- lib/geokit/mappable.rb
Overview
:nodoc:
Instance Method Summary collapse
-
#distance_between(from, to, options = {}) ⇒ Object
Returns the distance between two points.
-
#endpoint(start, heading, distance, options = {}) ⇒ Object
Given a start point, distance, and heading (in degrees), provides an endpoint.
-
#geocode(location) ⇒ Object
Geocodes a location using the multi geocoder.
-
#heading_between(from, to) ⇒ Object
Returns heading in degrees (0 is north, 90 is east, 180 is south, etc) from the first point to the second point.
-
#midpoint_between(from, to, options = {}) ⇒ Object
Returns the midpoint, given two points.
Instance Method Details
#distance_between(from, to, options = {}) ⇒ Object
Returns the distance between two points. The from and to parameters are required to have lat and lng attributes. Valid options are: :units - valid values are :miles, :kms, :nms (Geokit::default_units is the default) :formula - valid values are :flat or :sphere (Geokit::default_formula is the default)
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# File 'lib/geokit/mappable.rb', line 35 def distance_between(from, to, ={}) from=Geokit::LatLng.normalize(from) to=Geokit::LatLng.normalize(to) return 0.0 if from == to # fixes a "zero-distance" bug units = [:units] || Geokit::default_units formula = [:formula] || Geokit::default_formula case formula when :sphere begin units_sphere_multiplier(units) * Math.acos( Math.sin(deg2rad(from.lat)) * Math.sin(deg2rad(to.lat)) + Math.cos(deg2rad(from.lat)) * Math.cos(deg2rad(to.lat)) * Math.cos(deg2rad(to.lng) - deg2rad(from.lng))) rescue Errno::EDOM 0.0 end when :flat Math.sqrt((units_per_latitude_degree(units)*(from.lat-to.lat))**2 + (units_per_longitude_degree(from.lat, units)*(from.lng-to.lng))**2) end end |
#endpoint(start, heading, distance, options = {}) ⇒ Object
Given a start point, distance, and heading (in degrees), provides an endpoint. Returns a LatLng instance. Typically, the instance method will be used instead of this method.
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# File 'lib/geokit/mappable.rb', line 75 def endpoint(start,heading, distance, ={}) units = [:units] || Geokit::default_units radius = case units when :kms; EARTH_RADIUS_IN_KMS when :nms; EARTH_RADIUS_IN_NMS else EARTH_RADIUS_IN_MILES end start=Geokit::LatLng.normalize(start) lat=deg2rad(start.lat) lng=deg2rad(start.lng) heading=deg2rad(heading) distance=distance.to_f end_lat=Math.asin(Math.sin(lat)*Math.cos(distance/radius) + Math.cos(lat)*Math.sin(distance/radius)*Math.cos(heading)) end_lng=lng+Math.atan2(Math.sin(heading)*Math.sin(distance/radius)*Math.cos(lat), Math.cos(distance/radius)-Math.sin(lat)*Math.sin(end_lat)) LatLng.new(rad2deg(end_lat),rad2deg(end_lng)) end |
#geocode(location) ⇒ Object
Geocodes a location using the multi geocoder.
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# File 'lib/geokit/mappable.rb', line 112 def geocode(location) res = Geocoders::MultiGeocoder.geocode(location) return res if res.success raise Geokit::Geocoders::GeocodeError end |
#heading_between(from, to) ⇒ Object
Returns heading in degrees (0 is north, 90 is east, 180 is south, etc) from the first point to the second point. Typicaly, the instance methods will be used instead of this method.
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# File 'lib/geokit/mappable.rb', line 60 def heading_between(from,to) from=Geokit::LatLng.normalize(from) to=Geokit::LatLng.normalize(to) d_lng=deg2rad(to.lng-from.lng) from_lat=deg2rad(from.lat) to_lat=deg2rad(to.lat) y=Math.sin(d_lng) * Math.cos(to_lat) x=Math.cos(from_lat)*Math.sin(to_lat)-Math.sin(from_lat)*Math.cos(to_lat)*Math.cos(d_lng) heading=to_heading(Math.atan2(y,x)) end |
#midpoint_between(from, to, options = {}) ⇒ Object
Returns the midpoint, given two points. Returns a LatLng. Typically, the instance method will be used instead of this method. Valid option:
:units - valid values are :miles, :kms, or :nms (:miles is the default)
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# File 'lib/geokit/mappable.rb', line 101 def midpoint_between(from,to,={}) from=Geokit::LatLng.normalize(from) units = [:units] || Geokit::default_units heading=from.heading_to(to) distance=from.distance_to(to,) midpoint=from.endpoint(heading,distance/2,) end |