From: Robert Klemme <shortcutter@...>
Date: 2007-07-10T17:16:30+09:00
Subject: Re: Repacking an array of arrays

2007/7/10, Kaps Lok <jocubeit@gmail.com>:
> Is there an elegant (maybe a one-liner) for repacking:
>
> [[1, 4, 7, 10, 13], [2, 5, 8, 11, 14], [3, 6, 9, 12, 15]]
>
> to?
>
> [[1, 4, 7], [10, 13, 2], [5, 8, 11], [14, 3, 6], [9, 12, 15]]
>
> So rather than having 3 arrays each with 5 elements, I get five arrays
> of 3 elements each...
>
> the only way I can see to do this is by looping the array, and creating
> new arrays.

Try this:

require 'enumerator'
p [[1, 4, 7, 10, 13], [2, 5, 8, 11, 14], [3, 6, 9, 12,
15]].flatten.to_enum(:each_slice, 3).to_a

Kind regards

robert