regarding storage issues for mixed-type value matrix

There has a loop in my program, and during each iteration an ID will be generated. I want to store these IDs into a two dimensional array, i.e., A. The first column of A stores the iteration number, i.e., A(1,1) = 1 and A(2,1) = 2. The second column of A stores the ID generated during each iteration, i.e., A(1,2) stores the ID generated during the first iteration. The tricky part is that these IDs can be either a numerical value or a string. For instance, A(1,2) = 12345; A(2,2) = abcde. Which kind of data structure should I use to store this mixed-value matrix?

Answer 1

[Andrei Bobrov]

%                cell array
A = {1 12345;2 'abcde'}
%                structure array
A = struct('iter',{1 2},'ID',{12345,'abcde'})
A.ID
A.iter

e.g.

A = cell(2);
for j1 = 1:2
    A{j1,1} = j1;
    if j1 == 1
        A{j1,2} = 12345; % or other
    else
        A{j1,2} = 'abcde';
    end
end

OR

A = struct('iter',[],'ID',[]);
for j1 = 1:2
    A(j1).iter = j1;
    if j1 == 1
        A(j1).ID = 12345; % or other
    else
        A(j1).ID  = 'abcde';
    end
end

Answer 2

[Image Analyst]

I'd use an array of structures. I think it would be simplest. However you can use a cell array if you want, though figuring out when to use parentheses and when to use braces can be tricky.