lol.rb

  def self.combined_average_grade_level corpus
    scores = [
      automated_readability_index(corpus),
      coleman_liau_index(corpus),
      FleschKincaidService.grade_level(corpus),
      forcast_grade_level(corpus),
      gunning_fog_index(corpus),
      smog_grade(corpus)
    ]
    scores.reject! &:nan?
    scores.reject! { |hasselhoff| hasselhoff.abs == Float::INFINITY }

    return unless scores.length > 2

    scores.sort.slice(1..-2).sum.to_f / 4
  end