[petsc-users] Solving only for certain rows

[Sanjay Govindjee]

Alternately, assemble zeros in the corresponding rows and columns with a 
1 on the diagonal.
-sg

On 2/2/16 6:58 AM, Matthew Knepley wrote:
> On Tue, Feb 2, 2016 at 8:35 AM, Orxan Shibliyev 
> <orxan.shibli at gmail.com <mailto:orxan.shibli at gmail.com>> wrote:
>
>     After hole cutting my unstructured mesh has some active and
>     inactive/fringe cells. I solve equations on
>     active/computational/field cells only. Some of the active cells
>     are neighbors of inactive cells. If I prepare petsc matrix
>     including all cells then the solver does not converge due
>     unchanging values of inactive cells. How can I tell Petsc not to
>     solve for certain rows? If I make all cells active then the solver
>     converge so I am sure that there is no problem related to solver.
>
>
> Leave them out of the matrix?
>
>   Matt
>
> -- 
> 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

-- 
-----------------------------------------------
Sanjay Govindjee, PhD, PE
Professor of Civil Engineering

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Books:

Engineering Mechanics of Deformable
Solids: A Presentation with Exercises
http://www.oup.com/us/catalog/general/subject/Physics/MaterialsScience/?view=usa&ci=9780199651641
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http://amzn.com/0199651647

Engineering Mechanics 3 (Dynamics) 2nd Edition
http://www.springer.com/978-3-642-53711-0
http://amzn.com/3642537111

Engineering Mechanics 3, Supplementary Problems: Dynamics
http://www.amzn.com/B00SOXN8JU

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