Any ideas to generate all possible subarrays from an array?

New to Julia
1

RT. There is an array, like [1, 2, 3]. What’s a proper way to have all subarrays from the array as below?

julia> [1, 2, 3];

julia> [1, 2];

julia> [1, 3];

julia> [2, 3];

julia> [1];

julia> [2];

julia> [3];

Thank you!

2 
julia> using Combinatorics

julia> collect(combinations([1,2,3]))
7-element Vector{Vector{Int64}}:
 [1]
 [2]
 [3]
 [1, 2]
 [1, 3]
 [2, 3]
 [1, 2, 3]
1 Like
3

This may or may not be what the original poster wants. It returns all possible subsets of the array. But it’s not clear if that’s what @Xiao means by “subarray”. (e.g. do you only want consecutive subarrays, or …?)

1 Like
4

Thanks @stevengj ! That’s what I want. I should use " subsets of the array" in my question, because there’re already something like “Julia’s SubArray” …

5

How is this remark helpful? Is it meant for me (should I improve my answering techniques?) or is it meant for OP to clarify the question?

6

It’s meant for the OP to clarify the question. In particular, the [1,2,3] example is too small to distinguish between different colloquial meanings of “subarray”.

2 Likes
7

That clarifies my confusion.

8

It is not that small. The first example does not have [1, 3], so I would assume consecutive. Alas, the post marked as a solution has [1, 3] in the output, so I am not sure what OP really wants.

9

Perhaps it is enough to point to package Combinatorics.

In general I would suppose that you stop talking with others about OPs intentions. Ask him directly. For me as non native english this sounds a bit weird and creates some confusion for me. Just a friendly (with quite some uncertainty) meant remark.