Module: Locationary

Defined in:
lib/locationary.rb,
lib/locationary/version.rb,
lib/locationary/nearest_neighbour.rb

Constant Summary collapse

VERSION = 
"0.0.2"

Class Method Summary collapse

Class Method Details

.clear_nn_data ⇒ Object 



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# File 'lib/locationary/nearest_neighbour.rb', line 9

def Locationary.clear_nn_data
  @kd = nil
  @kd_lookup = nil
end

.data ⇒ Object 



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# File 'lib/locationary.rb', line 41

def Locationary.data
  @data ||= Locationary.load_data
end

.find(query, options = {:strict => true}) ⇒ Object 



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# File 'lib/locationary.rb', line 10

def Locationary.find(query, options = {:strict => true})
  query.upcase

  result = Locationary.data[query]
  #if the user asked for a fuzzy lookup and we didn't find an exact match above
  if not options[:strict] and not result
    result = Locationary.fuzzy(query)
  end

  result
end

.fuzzy(query) ⇒ Object 



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# File 'lib/locationary.rb', line 22

def Locationary.fuzzy(query)
  best_score = 9999999999
  best_hamming = 9999999999
  best_match = nil
  Locationary.data.keys.each do |key|
    new_score = Levenshtein.distance(key,query)
    if new_score < best_score
      new_hamming = 0
      key.dup.xor!(query).bytes.each { |b| new_hamming += b}
      if new_hamming < best_hamming
        best_score = new_score
        best_match = key
      end
    end
  end

  Locationary.data[best_match]
end

.nearest_neighbour(latitude, longitude, options = {}) ⇒ Object 



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# File 'lib/locationary/nearest_neighbour.rb', line 18

def Locationary.nearest_neighbour(latitude, longitude, options = {})
  num_matches = options[:num_matches] ||= 1

  results = []
  Locationary.nn_data.nearestk(latitude, longitude, num_matches).each do |match|
    results << Locationary.data[Locationary.nn_lookup[match]]
  end
  results
end

.nn_data ⇒ Object 



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# File 'lib/locationary/nearest_neighbour.rb', line 5

def Locationary.nn_data
  @kd ||= Locationary.load_nn_data
end

.nn_lookup ⇒ Object 



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# File 'lib/locationary/nearest_neighbour.rb', line 14

def Locationary.nn_lookup
  @kd_lookup ||= Locationary.load_nn_lookup
end

.persist_nn_structure ⇒ Object 



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# File 'lib/locationary/nearest_neighbour.rb', line 28

def Locationary.persist_nn_structure
  points = []
  lookup = []
  i = 0

  Locationary.data.each do |location|
    lat = location[1]['Latitude']
    lon = location[1]['Longitude']
    if !lat.nil? and !lon.nil?
      points << [Float(location[1]['Latitude']), Float(location[1]['Longitude']), i]
      lookup << location[0]
      i += 1
    end
  end
  kd = Kdtree.new(points)

  File.open(Locationary.nn_data_location,"w") do |file|
    kd.persist(file)
  end

  File.open(Locationary.nn_lookup_location, "w") do |file|
    lookup.each { |l| file.write("#{l}\n") }
  end
end