How can I make a variant submatrix?

Hello everybody,

Does anyone know how I can make a variant submatrix, for example, if I have a matrix A (100,100) use a submatrix B (10,10) to get the first 10 rows and 10 columns, then the next 10 columns so on until all elements of the columns and rows have been taken.

Answer 1

[Vijay]

You could try below

(1) If you are just aiming to the get the submatrices in the diagonal of A...

I = length(A);
n = 10; % size of the desired squared submatrix
i= I/n;
% s1 = 'B';
% s2 =[1:i];
for j=1:i
% s3=num2str(s2(j));
eval(sprintf('B%d = A((j-1)*n+1:n*j,(j-1)*n+1:n*j)', j));
end

(2) If you are aiming to cover all the rows and columns...

I = length(A);
n = 10; % size of the desired squared submatrix
i= I/n;
for j=1:i
    for k=1:i
    eval(sprintf('B%d = A((j-1)*n+1:n*j,(k-1)*n+1:n*k)', (j-1)*i+k));
    end
end

[Vijay]

*Note: This code works only if your reference matrix is a square matrix

Answer 2

[Asad (Mehrzad) Khoddam]

You can use vectors to point to the indices of matrix A,

For example:

A(1:10, 1:10); % the first one
A(11:20, 1:10) % second submatrix
A(21:30, 1:10)
%...
A(91:100, 1:10);
A(1:10, 11:20 ...
% ...
A(91:100, 91:100);

% you need to have a loop to go through all sub matrices