From: Josselin <josselin@...>
Date: 2007-05-03T21:10:05+09:00
Subject: array slicing

given an array

anArray = [["a", 1, 1], ["b", 1, 2], ["c", 1, 5], ["z", 1, 1], ["e", 1, 
5], ["f", 1, 6], ["g", 1, 1], ["h", 1, 3], ["i", 1, 1], ["j", 1, 2], 
["k", 1, 1], ["y", 1, 6], ["m", 1, 1], ["u", 1, 2], ["v", 1, 1], ["p", 
1, 4], ["q", 1, 5], ["r", 1, 1], ["n", 1, 1], ["t", 2, 3], ["s", 2, 2], 
["o", 2, 1], ["w", 2, 1], ["x", 2, 1], ["l", 2, 1], ["d", 2, 1]]

I would like to get it  sliced in groups of element having the same 2nd 
and 3rd values

sliced_array = [
[ ["a", 1, 1],["g", 1, 1], ["i", 1, 1], ["k", 1, 1], ["m", 1, 1], ["n", 
1, 1],["r", 1, 1],["v", 1, 1],["z", 1, 1] ],
 [ ["b", 1, 2],["j", 1, 2], ["u", 1, 2] ],
[ ["c", 1, 5],["e", 1, 5],["q", 1, 5] ],
[ ["d", 2, 1],["l", 2, 1], ["l", 2, 1], ["o", 2, 1],["w", 2, 1],["x", 2, 1] ],
[ ["f", 1, 6],["y", 1, 6] ],
[ ["h", 1, 3] ],
[ ["p", 1, 4] ],
[ ["s", 2, 2] ],
[ ["t", 2, 3] ]
 ]

I believe teh first step is to sort anArray.... then slicing similar 
groups, but writing
 anArray.sort {|a,b| a[1] <=> b[1]}
sorts only on first value... how can I sort on both.. ?

thansk

joss