QR factorization

Matthew Knepley knepley at gmail.com
Thu Dec 14 14:53:39 CST 2006

No, we have no support for QR since sparse QR does not really exist, and
we ignore a lot of dense things since PETSc is not really designed for that.
If you want dense parallel QR, use FLAME from UT Austin, for serial use


On 12/14/06, Arvid Bessen <bessen at cs.columbia.edu> wrote:
> Hi,
> does petsc currently support QR factorization?
> I saw that it is supposedly provided by an interface to the spooles
> package, however the comment in MatQRFactorSymbolic_SeqAIJSpooles
> that says
> SETERRQ(PETSC_ERR_SUP,"QR Factorization is unsupported as the Spooles
> implementation of QR is invalid.");
> seems to imply that it is not working.
> Thanks,
> Arvid

One trouble is that despite this system, anyone who reads journals widely
and critically is forced to realize that there are scarcely any bars to eventual
publication. There seems to be no study too fragmented, no hypothesis too
trivial, no literature citation too biased or too egotistical, no design too
warped, no methodology too bungled, no presentation of results too
inaccurate, too obscure, and too contradictory, no analysis too self-serving,
no argument too circular, no conclusions too trifling or too unjustified, and
no grammar and syntax too offensive for a paper to end up in print. --
Drummond Rennie

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