This may already be implemented, but I’ve failed to find it in the documentation.
If I have a two dimensional array, for which I know the index, is there a way to get the same information but in a tuple of position?
So for example index 4 in a 2x2 matrix would be (2,2).
Its either ind2sub or sub2ind. Never know which is which… 
I also had to try…
julia> ind2sub(rand(2,2), 4)
(2, 2)
Yes, but be cautious.
According to https://github.com/JuliaLang/julia/blob/master/NEWS.md
sub2ind and ind2sub are deprecated in favor of using CartesianIndices and LinearIndices (#24715).
Good to know. IMO CartesianIndices and LinearIndices are much better names.