[petsc-users] Question about eigenvalue and eigenvectors

[Matthew Knepley]

Or just call the LAPACK routine directly.

   Matt

On Sat, Dec 24, 2022 at 7:14 AM Stefano Zampini <stefano.zampini at gmail.com>
wrote:

> For 3x3 matrices you can use explicit formulas
>
> On Sat, Dec 24, 2022, 11:20 김성익 <ksi2443 at gmail.com> wrote:
>
>> Hello,
>>
>>
>> I tried to calculate the eigenvalues and eigenvectors in 3 by 3 matrix
>> (real and nonsymmetric).
>> I already checked the kspcomputeeigenvalues and kspcomputeritz.
>>
>> However, the target matrix is just 3 by 3 matrix.
>> So I need another way to calculate the values and vectors.
>> Can anyone recommend other methods that are efficient for such small size
>> problems??
>>
>> Thanks,
>> Hyung Kim
>>
>

-- 
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

https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
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