# File lib/ruby_units/ruby-units.rb, line 930
  def unit_signature_vector
      return self.to_base.unit_signature_vector unless self.is_base?
      result = self
      vector = Array.new(SIGNATURE_VECTOR.size,0)
      for element in @numerator
        if r=@@ALL_UNIT_DEFINITIONS[element]
            n = SIGNATURE_VECTOR.index(r[2])
           vector[n] = vector[n] + 1 if n
        end
      end
      for element in @denominator
        if r=@@ALL_UNIT_DEFINITIONS[element]
          n = SIGNATURE_VECTOR.index(r[2])
          vector[n] = vector[n] - 1 if n
        end
      end
      vector
  end