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From: Randy Yates <yates@ieee.org>
Newsgroups: comp.soft-sys.matlab,comp.dsp
Subject: Re: Is a QR Decomposition Better than B \ A?
Date: Mon, 16 Jul 2007 20:23:26 -0400
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Clay <physics@bellsouth.net> writes:
> [...]
> Sorry  I didn't check it fully before sending
>
> x = (((A^t)A)^-1)(A^t)b
>
> or
>
> x = (R^-1)(Q^t)b
>
> will give LSQR solutions to Ax=b
>
> Clay

As Robert said, that's only good if A is non-singular, and it ain't
necessarily in my application.

I know these are all least-squares solutions. I'm asking which ones are
"better." That is, which one provides a smaller squared-error? 
-- 
%  Randy Yates                  % "She's sweet on Wagner-I think she'd die for Beethoven.
%% Fuquay-Varina, NC            %  She love the way Puccini lays down a tune, and
%%% 919-577-9882                %  Verdi's always creepin' from her room." 
%%%% <yates@ieee.org>           % "Rockaria", *A New World Record*, ELO   
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