[petsc-users] Question about rank of matrix

[Stefano Zampini]

On Fri, Feb 17, 2023, 10:43 user_gong Kim <ksi2443 at gmail.com> wrote:

> Hello,
>
> I have a question about rank of matrix.
> At the problem
> Au = b,
>
> In my case, sometimes global matrix A is not full rank.
> In this case, the global matrix A is more likely to be singular, and if it
> becomes singular, the problem cannot be solved even in the case of the
> direct solver.
> I haven't solved the problem with an iterative solver yet, but I would
> like to ask someone who has experienced this kind of problem.
>
> 1. If it is not full rank, is there a numerical technique to solve it by
> catching rows and columns with empty ranks in advance?
>
> 2.If anyone has solved it in a different way than the above numerical
> analysis method, please tell me your experience.
>
> Thanks,
> Hyung Kim
>

My experience with this is usually associated to reading a book and find
the solution I'm looking for.

>
>
>
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