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Float To HTML Fraction Entity

07.24.2006

| 4883 views |

        Uses HTML entities to display pretty fractional values for applicable floating point numbers.

class Float
  def to_html_fraction
    fraction = case self.abs % 1.0
    when 1.0 / 2 then '½'  # One half
      
    when 1.0 / 4 then '¼'  # One quarter
    when 3.0 / 4 then '¾'  # Three quarters
    
    when 1.0 / 3 then '⅓'  # One third
    when 2.0 / 3 then '⅔'  # Two thirds
      
    when 1.0 / 5 then '⅕'  # One fifth
    when 2.0 / 5 then '⅖'  # Two fifths
    when 3.0 / 5 then '⅗'  # Three fifths
    when 4.0 / 5 then '⅘'  # Four fifths

    when 1.0 / 6 then '⅙'  # One sixth
    when 5.0 / 6 then '⅚'  # Five sixths

    when 1.0 / 8 then '⅛'  # One eighth
    when 3.0 / 8 then '⅜'  # Three eighths
    when 5.0 / 8 then '⅝'  # Five eighths
    when 7.0 / 8 then '⅞'  # Seven eighths
    end
    if fraction
      body = case self.floor
      when -1 then '-'
      when  0 then ''
      else self.to_i.to_s
      end
      body + fraction
    else
      self.to_s
    end
  end
end


And it works something like this:

>> (0.1).html_fraction
=> 0.1
>> (0.25).html_fraction
=> ¼
>> (0.50).html_fraction
=> ½
>> (0.75).html_fraction
=> ¾
>> (1.0).html_fraction
=> 1.0
>> (2.25).html_fraction
=> 2¼
>> (3.5).html_fraction
=> 3½
>> (4.75).html_fraction
=> 4¾
>> (5.85).html_fraction
=> 5.85
>> (-1.5).html_fraction
=> -1½
>> (-1.6).html_fraction
=> -1.6;
>> (-0.25).html_fraction
=> -¼

Tags:

Comments

Snippets Manager replied on Mon, 2012/05/07 - 2:25pm

Yeah, I'm definately no mathematician. That's one of the reasons I switched from a mathematical approach to a regular expressions based method. It also was only 1 line. I just love solving things in only 1 line. This is for a personal project, a comic book database. I've been reimplementing it for years in Access, ASP, JSP, PHP, ColdFusion and now Ruby On Rails. (I think of it as my own little personal Pet Store application.) I have issues numbered with negative numbers and issues with fractions, but no issues with negative fractions. Since you brought it up now, I figure it's just a matter of time, though. Thanks for the addition.

Snippets Manager replied on Thu, 2006/08/03 - 8:35pm

Using the modulo operator (%) you can do it like this:


class Float
    def html_fraction
        fraction = case self.abs%1.0
                   when 0.25 : '¼'
                   when 0.5  : '½'
                   when 0.75 : '¾'
                   end
        if fraction
            body = case self.floor
                   when -1 : '-'
                   when  0 : ''
                   else self.to_i.to_s
                   end
            body + fraction
        else
            self.to_s
        end
    end
end

Then it works also for 2.50 and negative numbers. But it might be less readable for non mathematicians...