たけ(tk)です

　複素数の四捨五入という概念はないのでしょうか？

  ## Complex#to_f should return Float (TypeError)
  ##G:\Apollo\TkUtils\Numeric_round_to.rb:32:in `round'

----
#! ruby -Ks
#-- Complex_round.rb

require "complex"

class Complex
  def round
    Complex(self.real.round,self.image.round)
  end
  def floor
    Complex(self.real.floor,self.image.floor)
  end
  def ceil
    Complex(self.real.ceil,self.image.ceil)
  end

  require "Numeric_bankers_round"
  def bankers_round
    Complex(self.real.bankers_round,self.image.bankers_round)
  end
end

if __FILE__ == $0
  require "Numeric_round_to"

  p Complex(2.200000048,1.799999952).round_to(-4)  #=> Complex(2.2, 1.8)
  p Complex(2.200000048,1.799999952).floor_to(-4)  #=> Complex(2.2, 1.7999)
  p Complex(2.200000048,1.799999952).ceil_to(-4)   #=> Complex(2.2001, 1.8)
  p Complex(2.200000048,1.799999952).bankers_round_to(-4)   #=> Complex(2.2001, 1.8)

end
----

Take_tk = KUMAGAI Hidetake
たけ(tk)＝熊谷秀武