for extracting all nonzero elemnts of an one dimentional array, we do the following:
One_D = [1,4,5,0,0,4,7,0,2,6]
One_D[One_D .> 0]
How to do a similar thing for a two or more than 2 dimentinal vectore array?
two_D = [[1,0,2,3,0],[4,0,5,0,6]]
this two_D[two_D .> 0] obviously is incorrect. So, what esle we can try?
Your two_D is not 2 dimensional, but it is a vector of vectors. You can use then broadcasted filter:
julia> filter.(>(0), two_D)
2-element Vector{Vector{Int64}}:
[1, 2, 3]
[4, 5, 6]
If instead your two_D were a matrix like this:
julia> mat = [[1,0,2,3,0] [4,0,5,0,6]]
5×2 Matrix{Int64}:
1 4
0 0
2 5
3 0
0 6
You can still use filter but without broadcasting. In this case you will get a flat vector of found elements:
julia> filter(>(0), mat)
6-element Vector{Int64}:
1
2
3
4
5
6