Reverse Geocode Coordinates to City

geocode-to-cities.rb

# get the geocoder gem by doing 'gem install geocoder' or adding 'gem geocoder' to your Gemfile
require 'geocoder' 

# configure geocoder service -- I'm using bing because it gives more API calls per day
Geocoder.configure(
	# geocoding service (see below for supported options):
	:lookup => :bing,
	# IP address geocoding service (see below for supported options):
	:ip_lookup => :maxmind,
	# to use an API key:
	:api_key => "YOUR_API_KEY",
	# geocoding service request timeout, in seconds (default 3):
	:timeout => 10,
	# set default units to kilometers:
	:units => :km,
)


# get all the location co-ordinates
locations = LocationData.all 
# create a new array to store all the cities you get from reverse geocoding
cities = Array.new 
 
locations.each do |location|
    # create the query string in the format "49.277826,-123.125227"
    query = location.latitude.to_s + "," + location.longitude.to_s 
    # Geocoder returns an array, just take the first object
    result = Geocoder.search(query).first 
    # check for null, get the city, and put it in the array
    if (result) 
        city = result.city
        cities.push(city)
    end
end

# count the number for each city
counts = Hash.new(0)
cities.each { |c| counts[c] += 1 }
counts