Forming a block diagonal matrix of one certain matrix?

1 view (last 30 days)
I have a matrix A which is m*n. I want to create a block tridiagonal matrices of size n*m whose diagonals elements are the matrix A.
B=eye(3);
C=ones(2);
S=ones(2);
for i=1:numel(A)
A(i,i) =repmat(B,i,1)
A(i,i+1)=repmat(C,i,1)
A(i,i-1)=repmat(S,i,1)
end
can anyone help me to find the error
  3 Comments
Adam Danz
Adam Danz on 13 Jan 2020
If that's the example of A, then A cannot be a matrix. Is it a cell array or is the example misleading?

Sign in to comment.

Answers (1)

Matt J
Matt J on 13 Jan 2020
Edited: Matt J on 13 Jan 2020
using interpMatrix (Download)
S=1*ones(2);
B=2*ones(2);
C=3*ones(2);
copies=4; %number of repetitions
L=flip( {S,B,C, zeros(size(B)) } );
idx=full(interpMatrix([1,2,3],2,copies,1))+1;
A=cell2mat(L(idx))
A =
2 2 3 3 0 0 0 0
2 2 3 3 0 0 0 0
1 1 2 2 3 3 0 0
1 1 2 2 3 3 0 0
0 0 1 1 2 2 3 3
0 0 1 1 2 2 3 3
0 0 0 0 1 1 2 2
0 0 0 0 1 1 2 2

Categories

Find more on Creating and Concatenating Matrices in Help Center and File Exchange

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by