[petsc-users] about Singular value

behzad baghapour behzad.baghapour at gmail.com
Sun Oct 30 08:20:42 CDT 2011


Thanks...

On Sun, Oct 30, 2011 at 3:42 PM, Matthew Knepley <knepley at gmail.com> wrote:

> On Sun, Oct 30, 2011 at 11:24 AM, behzad baghapour <
> behzad.baghapour at gmail.com> wrote:
>
>> Then it would be an approximation to the Preconditioned Matrix (JM^(-1)
>> or M^(-1)J) up to the dimension of the Krylov subspace?
>
>
> Yes.
>
>    Matt
>
>
>> On Sun, Oct 30, 2011 at 2:47 PM, Matthew Knepley <knepley at gmail.com>wrote:
>>
>>> On Sun, Oct 30, 2011 at 7:49 AM, behzad baghapour <
>>> behzad.baghapour at gmail.com> wrote:
>>>
>>>> Dear all,
>>>>
>>>> What is the procedure or method to calculate Extreme Singular Values
>>>> when calling KSPComputeExtremeSingularValues( )?
>>>>
>>>
>>> Are you asking what is done internally? We call LAPACK SVD on the
>>> Hermitian matrix made by the Krylov method.
>>>
>>>    Matt
>>>
>>>
>>>> Thanks, B. B.
>>>>
>>>
>>> --
>>> 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
>>>
>>
>>
>>
>> --
>> ==================================
>> Behzad Baghapour
>> Ph.D. Candidate, Mechecanical Engineering
>> University of Tehran, Tehran, Iran
>> https://sites.google.com/site/behzadbaghapour
>> Fax: 0098-21-88020741
>> ==================================
>>
>>
>
>
> --
> 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
>



-- 
==================================
Behzad Baghapour
Ph.D. Candidate, Mechecanical Engineering
University of Tehran, Tehran, Iran
https://sites.google.com/site/behzadbaghapour
Fax: 0098-21-88020741
==================================
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