Loop does not save intermediary steps

I have a huge matrix A(1540,1540)

I am trying to get all its diagonals under the main one at 3n+1 steps in separate vectors x or strings using the following loop. They all get displayed in my command window but in the Workspace at x I get only the last one(it overwrites the intermediary steps) I am doing something silly

the code

for i = 4:3:size( A,2 )
    x=diag(A,-i)' 
    fprintf('%d', x);
end

Answer 1

[Stephen23]

"Loop does not save intermediary steps"

because nothing in your code makes any attempt to save them. Because each diagonal has a different number of elements, probably the simplest storage is to use a cell array:

A = rand(1540,1540);
V = 4:3:size(A,2);
N = numel(V);
C = cell(1,N);
for k = 1:N
    C{k} = diag(A,-V(k));
end

All of the diagonals will be in the cell array C:

https://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-cell-array.html

For example, the 512th diagonal:

V(512)

ans = 1537

C{512}

ans = 3×1

0.5061 0.4939 0.9809

Basic concepts, like how to save data during a loop, are explained in the starting tutorials:

https://www.mathworks.com/help/matlab/getting-started-with-matlab.html

[Radu Mihail]

No words to thank you Stephen! Happy New Year