Pit Capitain wrote: > On 1 Aug 2002, at 1:47, Daniel Bretoi wrote: > > >>Sorry all, I actually checked for a matrix class, but I must have >>missed it (. Anyway, what I would be interested in is how you would >>approach the problem WITHOUT using the matrix class. > > > I guess using one of my own libraries doesn't qualify either, but > here it goes: Ditto, but anyway, using Enumerable Tools on RAA: require 'enum/op' a = [[1,2],[1,3],[2,4]] aT = EnumerableOperator::diagonal(*[[1,2],[1,3],[2,4]]).to_a p aT