Has QR [Q,R,E]=qr(X,0) changed? licols for extracting lin indep cols is not working

1 view (last 30 days)
I am using the downloaded code licols.m for extracting a lin indep set of columns from a matrix. It is based on the qr algorithm in the form
[q,r,e] = qr(X,0);
The algorithm is based on the diagonal of r dominating the upper triangular parts and the diagonal of r (in abs value) being nonincreasing. But my examples/random problems illustrate that this is not true for r. Has QR changed? If so, then licols.m needs to be modified.
Is there older version of qr around to use with licols?

Answers (1)

Bruno Luong
Bruno Luong on 28 Oct 2021
It seems working fine on random matrix (R2021b online server or my PC)
X=randn(1000);
[q,r,e] = qr(X,0);
issorted(abs(diag(r)),"descend")
ans = logical
1

Categories

Find more on Operating on Diagonal Matrices 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!