From: "(r.*n){2}" <perl2ruby@...>
Date: 2010-09-23T12:10:13+09:00
Subject: Re: Sorting problem with an Array of Arrays

On Sep 22, 6:54 pm, Jeremy Bopp <jer...@bopp.net> wrote:
> On 9/22/2010 5:43 PM, Jeremy Bopp wrote:
>
>
>
>
>
> > On 9/22/2010 5:35 PM, Paul wrote:
> >> Hi there, I have an array of arrays that looks like the following:
>
> >> arr1 = [["ABC-1", 1271768400, 2],  ["ABC-2", 1271773800, 1],
> >>  ["ABC-3", 1271863200, 2],  ["ABC-4", 1271869200, 2],
> >>  ["AAA-1", 1271862000, 2],  ["DEF-1", 1271772000, 1]]
>
> >> Desired sort order:
> >> (1) label (1st element = all unique)
> >> (2) different labels (e.g. AAA, DEF) need to be inserted according to
> >> timestamp (2nd element), but maintain (1) label sort order; so AAA-2
> >> can't come before AAA-1. (I don't have that data point here but it
> >> happens)
>
> >> => I don't know how to do (2), so I just have the AoA sorted by (1)
> >> right now.
>
> >> Is there a way to do this?  I'm trying to find duplicate and
> >> overlapping timestamps but my current method for checking this is
> >> getting complicated, so I thought I'd check to see if there's a good
> >> way to sort the data properly in the first place.
>
> > You could define a class to represent each of your inner array elements.
> >  That class could then define the <=> method in which you could compare
> > each item in the order you desire.  Then your outer array, consisting of
> > instances of your class, could be trivially sorted with Array#sort.
>
> Silly me.  You can also pass a block to the Array#sort method.  That
> block will receive 2 arguments which you may then compare as you wish,
> returning -1 if the first argument sorts before the last, 0 if they are
> equal, and 1 if the last argument sorts before the first.
>
> -Jeremy

arr2 = arr1.sort { |x,y| (x[0] <=> y[0]) * 10 + (x[1] <=> y[1]) }

or

arr1.sort! { |x,y| (x[0] <=> y[0]) * 10 + (x[1] <=> y[1]) }