[petsc-users] symmetric matrix

Matthew Knepley knepley at gmail.com
Thu Aug 9 23:52:26 CDT 2012


On Thu, Aug 9, 2012 at 11:45 PM, Eleni Siampli <siaeleni at hotmail.com> wrote:

>
> What about nz and nnz?
>

These apply only to the upper triangular part.

  Matt


> Thank you for the quick answer
>
> Helen
>
> On Thu, Aug 9, 2012 at 11:36 PM, Eleni Siampli <siaeleni at hotmail.com>wrote:
>
>  Hello all,
>
> Lets say that I have a square Mat A, nxn and is upper triangular. The rest
> elements are 0.
> for example: lets say that I have a matrix 3x3 : [5 7 8;0 9 1;0 0 2]
> What I want is to take the symmetric matrix: [5 7 8;7 9 1;8 1 2]
> I think that I have to use MatCreateSeqSBAIJ(), but I don't understand
> exactly how can I use it.
> What is the block?
>
>
> Set blocksize to 1 and you should have what you want.
>
>    Matt
>
>
> Thank you in advance,
> Helen
>
>
>
>
> --
> 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
>



-- 
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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