Iterators.product

New to Julia
1

Hello everyone. Can anyone help me see why result 1 and 2 are different. Thank you.

function test()
	u = [1,0]
	d = [0,1]
	N = 2
	base = ntuple(i->[u,d],N)
	# result 1
	for q in Iterators.product(base)
		println(q)
	end
	println("--------------")
	# result 2 <-- correct
	for q in Iterators.product([u,d],[u,d])
		println(q)
	end
end
2

It’s a different thing to pass one argument which is a 2-tuple of arrays, or to pass two arguments which are both arrays. You can splat the first tuple into multiple arguments, then it does the same thing as the other version

for q in Iterators.product(base...)
4 Likes
3

I was already rephrasing the question, when I decided to test your suggestion. I thought the “…” was just a ellipsis sign. What is the meaning of “…” after the arguments?

4

it’s the splatting operation.

3 Likes
5

Thank you.

6

Thanks.