"You know that yA is just a single number, right? It's the count of the number of non-zeros in A but not the actual non-zero numbers themselves."
Now, what does "collect" mean to you? A game of life will have iterations (generations or days or time periods or whatever) where you change the population. I don't see any loops where you're changing the population in any way. If you did, then you could "collect" or store each population in a 3D array. But first you need some algorithm for how you want to change the population at each iteration. Can you tell us how you plan to do that?
