Simple question

[Matthew Knepley]

On 9/28/07, Toby D. Young <tyoung at ippt.gov.pl> wrote:
> Hello,
>
> For the function MatIsSymmetric(),
> is it correct to state that PetscTruth returns:
> 1 - true (symmetric)
> 0 - false (nonsymmetric)

Technically, PETSC_TRUE and PETSC_FALSE.

> This is the output I get from test on an Identity matrix.
>
> A simple question perhaps, but I have really confusing results for other
> matrices which are needed to be symmetry verified.

I assume that you have (supposedly) symmetric matrices that are coming
up nonsymmetric? You could put a break point in MatIsTranspose_SeqAIJ()
and see which row is disputed. Alternatively, you could use MatTranspose()
and then output them both with the ASCII viewer and diff. Perhaps your
tolerance is too low.

  Matt

> Thanks!
>
> Best,
>         Toby
>
> --
>
> Toby D. Young ( Adiunkt )
> Department of Computational Science
> Institute of Fundamental Technological Research, Polish Academy of
> Sciences, Room 206, Swietokrzyska 21, 00-049 Warsaw, POLAND
>
>


-- 
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