From: David Garamond <lists@...6.isreserved.com>
Date: 2004-06-27T19:09:51+09:00
Subject: rounding to n decimal digits

I often do this:

  class Float
    def round_n(n=0)
      raise FloatDomainError unless self.finite?
      raise ArgumentError unless n.class == Fixnum && n >= 0
      sprintf("%.#{n}f", self).to_f
    end

    def ceil_n(n=0)
      raise FloatDomainError unless self.finite?
      raise ArgumentError unless n.class == Fixnum && n >= 0
      (self*10**n).ceil.to_f / 10**n
    end

    def floor_n(n=0)
      raise FloatDomainError unless self.finite?
      raise ArgumentError unless n.class == Fixnum && n >= 0
      (self*10**n).floor.to_f / 10**n
    end
  end

However I can't help get the feeling that Ruby already has something 
like this. Did I indeed miss it?

-- 
dave