How does one add rows to a Julia array?

[Martin_Florek]

Concatenation need to create new a array and it’s very inefficiently! because the vcat function is used

julia> @which [A;m']
vcat(A::Union{Array{T,1}, ...

Multidimensional arrays in Julia are stored in column-major order. A good discussion is

Silly question. How to add a row to array?

A 2d Array is inherently a bad data structure if you want to add rows dynamically. Julia arrays are stored column-major (contiguous columns), which means that even if you resized the memory to accommodate a new row, you would need to insert a new element into each column by moving every column in memory. One possibility here is to use an vector of arrays, e.g. julia> a = [[2,3], [5,6]] 2-element Array{Array{Int64,1},1}: [2, 3] [5, 6] julia> push!(a, [1,2]) 3-element Array{Array{Int64,1},1…