# File lib/ai4r/data/data_set.rb, line 255
      def default_data_labels(data_items)
        data_labels = []
        data_items[0][0..-2].each_index do |i|
          data_labels[i] = "attribute_#{i+1}"
        end
        data_labels[data_labels.length]="class_value"
        return data_labels
      end