From: Cai Li <caili@...>
Date: 2004-06-28T01:04:15+09:00
Subject: Re: rounding to n decimal digits

David Garamond wrote:

> 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?
>
What I'm looking for in Ruby is a command causing all arithmetic to be 
rounded to special digits.
Like we do in  Matlab:
 >Digits:=t;