I'm trying to get the outputs for a QR factorization

The for loop only displays one iteration of B and i need many iterations.

A=[8, -3, 0, 2; -9, 4, 5, -7; 6, -2, 2, 4; 5, -1, 7, 10];

for n = 5:1

[Q,R]=qr(A);

B=R*Q;

end

disp(B);

[Walter Roberson]

Duplicated by later https://www.mathworks.com/matlabcentral/answers/338276-how-do-i-make-the-loop-run-more-than-once which also has answers.

Answer 1

[Walter Roberson]

5:1 is the empty vector. Remember, 5:1 is the abbreviation for 5:1:1 which requests the vector starting at 5 and counting upwards to 1, which is not possible.

If you need to loop in reverse use 5:-1:1

[kevin]

I meant to write 1:5 but it still only iterates 1 time and I'm trying to run this code numerouse times to estimate the eigen values.

[Walter Roberson]

You are overwriting the same variable each time, so you would not be able to tell it ran the loop multiple times, except by the timing.