[petsc-users] about Singular value

[Matthew Knepley]

On Mon, Nov 7, 2011 at 9:06 AM, behzad baghapour <behzad.baghapour at gmail.com
> wrote:

> Is there any link with "Incremental Condition Estimation" (ICE) developed
> by Bischof in LAPACK with Petsc to evaluate Extremal singular values?
>

We do not use this (it is intended for triangular matrices). It may be
tenuously connected. He says he is
approximating the secular equation with rational functions, in some sense
we are approximating the
characteristic equation with polynomials (Krylov).

    Matt


> Thanks,
> B.B.
>
>
>
>
> On Sun, Oct 30, 2011 at 6:49 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
>
>> On Sun, Oct 30, 2011 at 05:17, Matthew Knepley <knepley at gmail.com> wrote:
>>
>>> We call LAPACK SVD on the Hermitian matrix made by the Krylov method.
>>
>>
>> GMRES builds a Hessenberg matrix.
>>
>
>
>


-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
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