%% Block Diagonal Matrix
% Create a block diagonal matrix.
% Create a 4-by-4 identity matrix and a 2-by-2 matrix that you want to be repeated along the diagonal.

A = eye(4);
B = [1 -1;-1 1];

%
% Use kron to find the Kronecker tensor product.

K = kron(A,B)

% The result is an 8-by-8 block diagonal matrix.
% Copyright 2012 The MathWorks, Inc.