Block diagonal change the first and last blocks with some other matrices

N=5;
C=sparse(zeros(N-1));
C([1 end])=C([1 end])+1;
B=speye(N-1);
B([1 end])=B([1 end])-1/2;

I have B and C matrices. I can form a blockdiagonal matrix such that C on the diagonal. As follows;

E0=speye(N);
E0=E0(1:end-1,1:end-1);
T2=kron(E0,C);

But I want to change the first and the last blocks with the matrix B.( In the first block and last block instead of C there should be B matrix.)

How can I do that? (N will be a variable so the size of the matrix will change according to the written N value.)

Answer 1

[David Hill]

Why not use blkdiag() function?

T=blkdiag(B,C,B);

[Mücahit Özalp]

N will be a variable so the size of the matrix will change.

[Mücahit Özalp]

@David Hill could you please delete your answer so that I can delete this topic the answer is not what I need?