Finding all possible ways of adding array elements?

A longer code I am writing is extremely time expensive, hopefully this approach will save a lot of time. The idea is to begin with, say, [1 1 1 1 1] And from left to right, find all the ways you can add the elements, ensuring that sum(V)=5 the whole while. The result is something like [0 1 1 1 2]; [0 1 1 2 1]; [0 1 2 1 1]; [0 2 1 1 1]; [0 0 1 1 3]; [0 0 1 2 1]; .... The idea is to create all possible combinations that have sum(row)=5, whilst cutting out repetitions as much as possible. I can filter out the remaining repetitions that will undoubtedly still come as an output using unique(V,'rows').

Anyone have any ideas? Kinda stuck right now.

Answer 1

[the cyclist]

Download this FEX submission and type

partitions(5,[1 1 1 1 1])

[Daniel Derrick]

It's a bit slow- it creates many, many repetitions that are still slow to delete.