Kmeans clusterer for hashes

kmeans.rb

require 'kmeans-clusterer'
# move this to Oma::Api::Kmeans when its working and we
# decide to use it


module Maintenance
  class Kmeans
    attr_accessor :profiles

    def initialize(profiles)
      @profiles = profiles
    end

    # define the list of words in their profiles
    # TODO - remove stop words
    def words
      @words ||= begin
        @profiles.map do |p|
          profile_to_string(p).split(/\W+/)
        end.flatten.uniq
      end
    end

    # n dimennsional vector, 1 for each profile
    def vector_index
      @vector_index ||= begin
        indx = {}
        profiles.each_with_index do |p, i|
          vector = words.map do |w|
            profile_to_string(p).include?(w) ? 1 : 0
          end
          indx[i] = vector
        end
        indx
      end
    end

    # used to select the attributes that get merged together
    # for purposes of this calculation
    def profile_to_string(profile)
      "#{profile['username']} #{profile['name']} #{profile['description']}".to_s.downcase
    end

    def target_cluster_count
      @target_cluster_count ||= (profiles.length.to_i.to_f / 3).to_i rescue 3
    end

    # the kmeans calculator
    def kmeans
      @kmeans ||= KMeansClusterer.run target_cluster_count, vector_index.values, labels: vector_index.keys, runs: 5
    end

    def clusters
      kmeans.clusters
    end

  end
end