I started to use Julia a week ago, by porting one of my existing computational fluid dynamics solvers to Julia. A subroutine I am currently working on is creating a 3x6 matrix of Float64s. In Fortran or C++ I would send a reference to the matrix to a subroutine or function, it would work on its contents and results would be available in the body of the code which called it.
I am not quite sure how to approach it in Julia. I understand that Julia is all about returning values from function calls, but I somehow feel that forming a 3x6 matrix inside a function and returning it as a result would create an overhead in terms of memory allocation/deallocation and copying. Shall I put it inside a container (struct) and send that to the function instead? Would that be in line with Julia’s best practices? I don’t know.
inbuilt functions in general are fine. But cell is a much more versatile datatype than matrix. As such it should not be a surprise that usually it is more efficient to operate on the matrix, rather than converting it to a cell, operating on the cell, and converting it to a matrix. – For small problems efficiency may not be a concern, but in that case I would still argue that it is best practice for code clarity, to stick to matrices unless there is a compelling reason not to.