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From: "David Doria" <daviddoria@gmail.com>
Newsgroups: comp.soft-sys.matlab
Subject: Re: RQ decomposition
Date: Sun, 5 Oct 2008 13:36:02 +0000 (UTC)
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Hmm I guess what I am wondering is the following question:

Q and R in the QR decomposition of A are the same Q and R in the RQ decomposition of which matrix?

For square 3x3 matices, I got it down to this:

ReverseRows = [0 0 1; 0 1 0 ; 1 0 0]; %right multiply by ReverseRows reverses columns
[Q R] = qr((ReverseRows * A)');
R = ReverseRows * R' * ReverseRows;
Q = ReverseRows * Q';

but I don't know how to put the last two lines INSIDE the rq operator? I guess I'm completely missing the intuition?

Dave