Fill a matrix with matrix powers
3 views (last 30 days)
Show older comments
Luigi Emanuel di Grazia
on 22 Jul 2021
Answered: Steven Lord
on 22 Jul 2021
Hi to everyone,
I was wondering if anyone knows the fastest way to achieve the following:
Given A [n x n], fill a matrix B such as:
B= [A 0n ... 0n;
0n A^2 ... 0n;
.... ;
0n 0n ... A^n]
where 0n=zeros(n).
Thanks in advance
0 Comments
Accepted Answer
Rik
on 22 Jul 2021
n=3;
A=rand(n,n);
Zero=zeros(size(A));
C=repmat({Zero},n,n);
C(logical(eye(n)))=arrayfun(@(n)A^n,1:n,'uni',false);
C=cell2mat(C)
0 Comments
More Answers (1)
Steven Lord
on 22 Jul 2021
A = magic(3);
AM = {A^0, A^1, A^2};
celldisp(AM)
B = blkdiag(AM{:})
You could create AM automatically rather than hard-coding it if you wanted a larger B.
AM2 = arrayfun(@(x) A^x, 0:2, 'UniformOutput', false);
check = isequal(AM, AM2)
C = blkdiag(AM2{:});
isequal(B, C)
0 Comments
See Also
Categories
Find more on Data Type Conversion in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!