You donâ€™t seem to only have two arrays, but two more complicated objects that seem to be a solution to some problem. What do you mean when you describe these as â€śarrayâ€ť?

Also, when asking questions, it is generally a good idea to give a concrete example of what you want. That avoids the difficulty in describing the operation in natural language. For example, if you have the two arrays [1,2,3] and [4,5,6], what does â€śmergingâ€ť them mean? What is the final result you want?

You are right, this is the solution of a differential equation. I gather that it is an array because Julia tells that it is a 5-element Array{Float64,1} and 5-element Array{Array{Float64,1},1}. I understand there is a first element that is a vector (t) and a second element (u) that is a vector of vectors (each element is an array of three values).
I simply wanted to concatenate the t vectors of the two arrays together, and the u arrays togetherâ€¦