From: Ryan Davis <ryand-ruby@...>
Date: 2009-03-20T11:44:20+09:00
Subject: Re: Complex sort of matrix possible, e.g. like Excel?


On Mar 17, 2009, at 22:02 , RichardOnRails wrote:

> I've got an array of rows (and thus a matrix) created user FasterCSV
> to extract data from a CSV file.  I'd like to sort the matrix on
> column A ascending and, within that, column B descending.  I looked at
> Matrix,  but it doesn't seem to address that functionality.  Is there
> a package that does, or do I have to write my own SuperMatrix
> inherited from Matrix?

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.