QR factorization

[Marco Caliari]

>> Observing Marco's posts from the past, I think he understands that there is no unique solution.
> I think the question was rather given that Octave and Matlab both claim 
> to use the same LAPACK routines they come up with different (though 
> equally valid) solutions. Matlab uses the Intel Blas/Lapack libraries 
> and Octave is probably using Atlas so the difference is probably in the details of the implementations of these libraries.
>>
>> D.
>
> In fact, Octave built using Apple's vecLib gives the same result as "the other program" ;-)

I confirm. "The other program" behaves like my Octave on a Athlon 
(with ACML libraries, I suppose).
By the way, there is a small misprint in qr documentation: in the last 
example spqr should be replaced by qr.

Best regards,

Marco