On Feb 2, 10:52 am, Michael Sc <michael.schat... / gmail.com> wrote:
> Hello,
> I am a newbie with Ruby and I had a couple of questions while
> manipulating csv files.  How would I do a multiple column sort?  I have
> a file that needs to be sorted by the 3rd column, then 1st, then second.
> I understand how to do one sort for the csv file but I was unsure of how
> to do multiple.
>
>  Also,How would I to do a percentage change between two numbers in a
> column?
>
>  Thank you very much.  I know these are easy questions but I am still
> learning how to program in Ruby.
>
> --
> Posted viahttp://www.ruby-forum.com/.


[ [9,'ash','cube'],
  [8,'blue','cube'],
  [3,'mauve','frustrum'],
  [8,'green','cube']
].sort_by{|a| a.values_at( 2,0,1 ) }.
each{|a| p a }

---  output  -----
[8, "blue", "cube"]
[8, "green", "cube"]
[9, "ash", "cube"]
[3, "mauve", "frustrum"]