MATLAB: Generating Block Matrix Dynamically

arraysMATLABmatricesmatrixmatrix array

Hello,
I am generating this matrix in 2d:
0.7071    0.7071
0.7071    0.7071
But for even number (and of course greater than 2) I need to generate that:
0.7071    0.7071  0        0
0.7071    0.7071  0        0
0         0       0.7071   0.7071
0         0       0.7071   0.7071
But I can not handle with my size problem. Here is my code:
function [A,B] = CHSH2d(d)
    A=zeros(d,d,2,d);
    B=A;
    projectors_of_sigma_x = [1/sqrt(2)*[1;1],1/sqrt(2)*[1;-1]];
    for k = 1:d
        for l =1:d 
           A(:,:,1,k)=repmat(projectors_of_sigma_x(:,k),1,d);
           if d > 2 
              A(:,:,1,k) = blkdiag(A(:,:,1,k));
           end   
        end
    end
end

Best Answer

This example show how to use blkdiag to create such a matrix
M = [0.7071    0.7071
     0.7071    0.7071];
 
n = 4;
M_cell = repmat({M}, 1, n/2);
M_out = blkdiag(M_cell{:})
Result
M_out =
    0.7071    0.7071         0         0
    0.7071    0.7071         0         0
         0         0    0.7071    0.7071
         0         0    0.7071    0.7071
You can avoid for-loop in your code.
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