# File lib/core/facets/numeric/approx.rb, line 24
  def close?(number, epsilon=0.01)
    return(self == number) if epsilon.zero?

    a, b = self.to_f, number.to_f
    if a.zero? or b.zero?
      ## There's no scale, so we can only go on difference.
      (a - b).abs < epsilon
    else
      ## We go by ratio. The ratio of two equal numbers is one, so the ratio
      ## of two practically-equal floats will be very nearly one.
      (a/b - 1).abs < epsilon
    end
  end