How to use a matrix of 12*12 to form a matrix of 96*96?

If B is a 12*12 matrix, and I want to place this B matrix as diagonal matrix of 96*96, How to form this 96*96 diagonal matrix?

[Stephen23]

How do you expect 144 elements from B to be distributed along the 96 diagonal elements?

[S Priya]

Lg=12*12 matrix

gLg=[Lg 0 0 0 0 0 0 0 0 0 0 0

0 Lg 0 0 0 0 0 0 0 0 0 0

0 0 Lg 0 0 0 0 0 0 0 0 0

0 0 0 Lg 0 0 ..........

Lg ..]

gLg is 96*96

[S Priya]

Sorry, its not a diagonal matrix.

[Stephen23]

https://www.mathworks.com/help/matlab/ref/blkdiag.html

Answer 1

[Jan]

gLg = kron(eye(8), Lg)

% A small example:
X = [1,2; 3,4];
kron(eye(3), X)

ans = 6×6

1 2 0 0 0 0 3 4 0 0 0 0 0 0 1 2 0 0 0 0 3 4 0 0 0 0 0 0 1 2 0 0 0 0 3 4

Answer 2

[Paul]

It's too bad we can't do something like this:

B = [1 2;3 4]; repeats = 2; % use a smaller example
% R = blkdiag(repmat({B},1,repeats){:})  % throws error

and instead have to do this

R = blkdiag(struct('temp',repmat({B},1,repeats)).temp)

R = 4×4

1 2 0 0 3 4 0 0 0 0 1 2 0 0 3 4

[Stephen23]

Simpler:

B = {[1,2;3,4]};
R = 2; % use a smaller example
M = blkdiag(B{ones(1,R)})

M = 4×4

1 2 0 0 3 4 0 0 0 0 1 2 0 0 3 4