Question about concatenation in for-loop

Hello,

I am trying to concatenate a 2D matrix into a 3D matrix where the length of the 3rd dimension is dependent on length of a vector previously asigned. For example, given

A = [1,2,3,4,5];
B = [1,2;3,4];

I would like creat marix C with size 2x2x5. I can do this easily by doing

C = cat(3,B,B,B,B,B);

However if I change the length of A, I want to write my code so that I don't have to update then number of times "B" repeats itself inside the cat function. I tried using the folowing for-loop but it didn't work. Any advice would be appreciated.

for i=1:length(A)
C = cat(3,B,B)
end

[Patrick Keiffer]

So I figured it out. The folowing code works.

A = [1,2,3,4,5];
B = [1,2;3,4];
C = B;

for i=1:length(A)
C = cat(3,C,B);
end

Answer 1

[OCDER]

Instead of cat, use repmat for your case, as you're repeatedly stacking a matrix in a dimension.

B = rand(2, 5)
C = repmat(B, 1, 1, 5) %stacks B in the 3rd dimension 5 times

[Patrick Keiffer]

Oh, thats a great solution. Thanks!