From: Rob Biedenharn <Rob@...>
Date: 2009-03-20T20:17:51+09:00
Subject: Re: Complex sort of matrix possible, e.g. like Excel?

On Mar 20, 2009, at 3:27 AM, Ryan Davis wrote:
> On Mar 19, 2009, at 20:01 , Rob Biedenharn wrote:
>> On Mar 19, 2009, at 10:44 PM, Ryan Davis wrote:
>>> I'm kinda surprised nobody has said this:
>>>
>>>  sorted = matrix.sort_by { |row| [row[0], -row[1]] }
>>>
>>> P.S. PLEASE trim to the relevant parts when you reply. In some of  
>>> your email on this thread you have two whole copies of nearly the  
>>> whole thread.
>>
>> Actually, it was suggested, but it assumes that row[1] has a -@  
>> method.  The OP confirmed later that the columns are text, not  
>> numbers.
>
> kk. sorry. I made assumptions based on him using Matrix. I couldn't  
> see that someone suggested this already through all the noise. :)
>
> umm....
>
> class String
>  def -@
>    self.gsub(/./) { |s| (?z - s[0] + ?a).chr }
>  end
> end
>
> >> %w(abc def ghi jhk).sort_by { |s| -s }
> => ["jhk", "ghi", "def", "abc"]
>
> horrible, no?
>
> :D

Only if you have any characters that aren't lowercase letters.

class String
  def -@
    self.gsub(/./) {|s| (255 - s[0]).chr }
  end
end

Well, still pretty horrible, though.

irb> - "Ryan Davis"
=> "\255\206\236\221\337\273\236\211\226\214"

If you ever meet someone with that name, don't shake hands; the  
universe could come to an end!

-Rob

Rob Biedenharn		http://agileconsultingllc.com
Rob@AgileConsultingLLC.com