From b27c2d291ed5b323b99efe766193ba2bc29b2bee Mon Sep 17 00:00:00 2001
From: Alex Reisner <alex@alexreisner.com>
Date: Tue, 5 Apr 2011 13:47:56 -0400
Subject: [PATCH] Change distance/bearing_between argument formats.
---
lib/geocoder/calculations.rb | 63 +++++++++++++++++++++++++++---------
lib/geocoder/orms/base.rb | 36 ++++++++-------------
test/geocoder_test.rb | 15 ++++-----
3 files changed, 67 insertions(+), 47 deletions(-)
diff --git a/lib/geocoder/calculations.rb b/lib/geocoder/calculations.rb
index 418d84d0..292b559b 100644
--- a/lib/geocoder/calculations.rb
+++ b/lib/geocoder/calculations.rb
@@ -38,24 +38,44 @@ module Geocoder
##
# Distance between two points on Earth (Haversine formula).
- # Takes two sets of coordinates and an options hash:
+ # Takes two points and an options hash.
+ # The points are given in the same way that points are given to all
+ # Geocoder methods that accept points as arguments. They can be:
+ #
+ # * an array of coordinates ([lat,lon])
+ # * a geocodable address (string)
+ # * a geocoded object (one which implements a +to_coordinates+ method
+ # which returns a [lat,lon] array
+ #
+ # The options hash supports:
#
# * <tt>:units</tt> - <tt>:mi</tt> (default) or <tt>:km</tt>
#
- def distance_between(lat1, lon1, lat2, lon2, options = {})
+ def distance_between(point1, point2, options = {}, *args)
+ if args.size > 0
+ warn "DEPRECATION WARNING: Instead of passing lat1/lon1/lat2/lon2 as separate arguments to the distance_between method, please pass two two-element arrays: [#{point1},#{point2}], [#{options}, #{args.first}]. The old argument format will not be supported in Geocoder v.1.0."
+ point1 = [point1, point2]
+ point2 = [options, args.shift]
+ options = args.shift || {}
+ end
# set default options
options[:units] ||= :mi
+ # convert to coordinate arrays
+ point1 = extract_coordinates(point1)
+ point2 = extract_coordinates(point2)
+
# convert degrees to radians
- lat1, lon1, lat2, lon2 = to_radians(lat1, lon1, lat2, lon2)
+ point1 = to_radians(point1)
+ point2 = to_radians(point2)
# compute deltas
- dlat = lat2 - lat1
- dlon = lon2 - lon1
+ dlat = point2[0] - point1[0]
+ dlon = point2[1] - point1[1]
- a = (Math.sin(dlat / 2))**2 + Math.cos(lat1) *
- (Math.sin(dlon / 2))**2 * Math.cos(lat2)
+ a = (Math.sin(dlat / 2))**2 + Math.cos(point1[0]) *
+ (Math.sin(dlon / 2))**2 * Math.cos(point2[0])
c = 2 * Math.atan2( Math.sqrt(a), Math.sqrt(1-a))
c * earth_radius(options[:units])
end
@@ -64,7 +84,8 @@ module Geocoder
# Bearing between two points on Earth.
# Returns a number of degrees from due north (clockwise).
#
- # Also accepts an options hash:
+ # See Geocoder::Calculations.distance_between for
+ # ways of specifying the points. Also accepts an options hash:
#
# * <tt>:method</tt> - <tt>:linear</tt> (default) or <tt>:spherical</tt>;
# the spherical method is "correct" in that it returns the shortest path
@@ -74,15 +95,27 @@ module Geocoder
#
# Based on: http://www.movable-type.co.uk/scripts/latlong.html
#
- def bearing_between(lat1, lon1, lat2, lon2, options = {})
+ def bearing_between(point1, point2, options = {}, *args)
+ if args.size > 0
+ warn "DEPRECATION WARNING: Instead of passing lat1/lon1/lat2/lon2 as separate arguments to the bearing_between method, please pass two two-element arrays: [#{point1},#{point2}], [#{options}, #{args.first}]. The old argument format will not be supported in Geocoder v.1.0."
+ point1 = [point1, point2]
+ point2 = [options, args.shift]
+ options = args.shift || {}
+ end
+
options[:method] = :linear unless options[:method] == :spherical
+ # convert to coordinate arrays
+ point1 = extract_coordinates(point1)
+ point2 = extract_coordinates(point2)
+
# convert degrees to radians
- lat1, lon1, lat2, lon2 = to_radians(lat1, lon1, lat2, lon2)
+ point1 = to_radians(point1)
+ point2 = to_radians(point2)
# compute deltas
- dlat = lat2 - lat1
- dlon = lon2 - lon1
+ dlat = point2[0] - point1[0]
+ dlon = point2[1] - point1[1]
case options[:method]
when :linear
@@ -90,9 +123,9 @@ module Geocoder
x = dlat
when :spherical
- y = Math.sin(dlon) * Math.cos(lat2)
- x = Math.cos(lat1) * Math.sin(lat2) -
- Math.sin(lat1) * Math.cos(lat2) * Math.cos(dlon)
+ y = Math.sin(dlon) * Math.cos(point2[0])
+ x = Math.cos(point1[0]) * Math.sin(point2[0]) -
+ Math.sin(point1[0]) * Math.cos(point2[0]) * Math.cos(dlon)
end
bearing = Math.atan2(x,y)
diff --git a/lib/geocoder/orms/base.rb b/lib/geocoder/orms/base.rb
index 17346e68..1b98ae8e 100644
--- a/lib/geocoder/orms/base.rb
+++ b/lib/geocoder/orms/base.rb
@@ -18,52 +18,42 @@ module Geocoder
##
# Calculate the distance from the object to an arbitrary point.
- # The point can be:
- #
- # * an array of coordinates ([lat,lon])
- # * a geocoded object (one which implements a +to_coordinates+ method
- # which returns a [lat,lon] array
- # * a geocodable address (string)
- #
- # Also takes a symbol specifying the units (:mi or :km; default is :mi).
+ # See Geocoder::Calculations.distance_between for ways of specifying
+ # the point. Also takes a symbol specifying the units
+ # (:mi or :km; default is :mi).
#
def distance_to(point, *args)
if point.is_a?(Numeric) and args[0].is_a?(Numeric)
warn "DEPRECATION WARNING: Instead of passing latitude/longitude as separate arguments to the distance_to/from method, please pass an array [#{point},#{args[0]}], a geocoded object, or a geocodable address (string). The old argument format will not be supported in Geocoder v.1.0."
+ point = [point, args.shift]
end
return nil unless geocoded?
- units = args.last.is_a?(Symbol) ? args.pop : :mi
- them = args.size > 0 ? [point, args.first] :
- Geocoder::Calculations.extract_coordinates(point)
- us = to_coordinates
Geocoder::Calculations.distance_between(
- us[0], us[1], them[0], them[1], :units => units)
+ to_coordinates, point, :units => args.pop || :mi)
end
alias_method :distance_from, :distance_to
##
# Calculate the bearing from the object to another point.
- # See distance_to for various ways to specify the point.
+ # See Geocoder::Calculations.distance_between for
+ # ways of specifying the point.
#
def bearing_to(point, options = {})
- return nil unless geocoded? &&
- them = Geocoder::Calculations.extract_coordinates(point)
- us = to_coordinates
+ return nil unless geocoded?
Geocoder::Calculations.bearing_between(
- us[0], us[1], them[0], them[1], options)
+ to_coordinates, point, options)
end
##
# Calculate the bearing from another point to the object.
- # See distance_to for various ways to specify the point.
+ # See Geocoder::Calculations.distance_between for
+ # ways of specifying the point.
#
def bearing_from(point, options = {})
- return nil unless geocoded? &&
- them = Geocoder::Calculations.extract_coordinates(point)
- us = to_coordinates
+ return nil unless geocoded?
Geocoder::Calculations.bearing_between(
- them[0], them[1], us[0], us[1], options)
+ point, to_coordinates, options)
end
##
diff --git a/test/geocoder_test.rb b/test/geocoder_test.rb
index d705810a..3cc67138 100644
--- a/test/geocoder_test.rb
+++ b/test/geocoder_test.rb
@@ -160,14 +160,14 @@ class GeocoderTest < Test::Unit::TestCase
end
def test_distance_between_in_miles
- assert_equal 69, Geocoder::Calculations.distance_between(0,0, 0,1).round
- la_to_ny = Geocoder::Calculations.distance_between(34.05,-118.25, 40.72,-74).round
+ assert_equal 69, Geocoder::Calculations.distance_between([0,0], [0,1]).round
+ la_to_ny = Geocoder::Calculations.distance_between([34.05,-118.25], [40.72,-74]).round
assert (la_to_ny - 2444).abs < 10
end
def test_distance_between_in_kilometers
- assert_equal 111, Geocoder::Calculations.distance_between(0,0, 0,1, :units => :km).round
- la_to_ny = Geocoder::Calculations.distance_between(34.05,-118.25, 40.72,-74, :units => :km).round
+ assert_equal 111, Geocoder::Calculations.distance_between([0,0], [0,1], :units => :km).round
+ la_to_ny = Geocoder::Calculations.distance_between([34.05,-118.25], [40.72,-74], :units => :km).round
assert (la_to_ny - 3942).abs < 10
end
@@ -237,11 +237,8 @@ class GeocoderTest < Test::Unit::TestCase
methods.each do |m|
directions.each_with_index do |d,i|
opp = directions[(i + 2) % 4] # opposite direction
- p1 = points[d]
- p2 = points[opp]
-
- args = p1 + p2 + [:method => m]
- b = Geocoder::Calculations.bearing_between(*args)
+ b = Geocoder::Calculations.bearing_between(
+ points[d], points[opp], :method => m)
assert (b - bearings[opp]).abs < 1,
"Bearing (#{m}) should be close to #{bearings[opp]} but was #{b}."
end
--
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