symmetric matrices

[Matthew Knepley]

On 5/22/06, Randall Mackie <randy at geosystem.us> wrote:
>
> Hi Matt,
>
> Thanks, that fixed the compilation problem, but then the program just
> seemed to
> hang at the place where it was creating/assembling the matrix.


My guess is that it is not hanging, but rather allocating all over the
place. If you give
-info, it shouldlet you know how manty mallocs were used.

Maybe I do not understand how to set bs, the block size for the call
> to MatCreateMPISBAIJ, any advice?


If you do not know the block size, just use 1 to start.

Are symmetric MPI BAIJ matrices my only choice? Is there not a symmetric
> MPIAIJ
> matrix format?


That is really block size 1.

   Matt

Thanks, Randy
>
>
> Matthew Knepley wrote:
> > The Fortran interface fell behind. I will fix it in dev, but for now you
> can
> > just use the value, 91. You can also use the command line option.
> >
> > Thanks,
> >
> >    Matt
> >
> > On 5/22/06, *Randall Mackie* <randy at geosystem.us
> > <mailto:randy at geosystem.us>> wrote:
> >
> >     I'm trying to modify my code to take advantage of the fact that my
> >     system matrix
> >     is symmetric.
> >
> >     It seemed from reading the manual pages that I could call
> >     MatCreateMPISBAIJ
> >     to create a symmetric data matrix.
> >
> >     However, when I tried this, I got the error:
> >
> >     [1]PETSC ERROR: Lower triangular value cannot be set for sbaij
> >     format. Ignoring these value
> >     s, run with -mat_ignore_lower_triangular or call
> >     MatSetOption(mat,MAT_IGNORE_LOWER_TRIANGUL
> >     AR)!
> >
> >     So I tried including the line:
> >
> >            call MatSetOption(A,MAT_IGNORE_LOWER_TRIANGULAR,ierr)
> >
> >     But when I tried to compile the code, I then got this message:
> >
> >     fortcom: Error: csem3dfwd.F, line 771: This name does not have a
> >     type, and must have an explicit type.
> [MAT_IGNORE_LOWER_TRIANGULAR]
> >            call MatSetOption(A,MAT_IGNORE_LOWER_TRIANGULAR,ierr)
> >     --------------------------^
> >
> >
> >     So, can anyone point me in the right direction for taking advantage
> >     of the fact that
> >     my matrices are symmetric? (they are actually complex symmetric, and
> >     NOT Hermitian).
> >
> >     Thanks, Randy
> >
> >     --
> >     Randall Mackie
> >     GSY-USA, Inc.
> >     PMB# 643
> >     2261 Market St.,
> >     San Francisco, CA 94114-1600
> >     Tel (415) 469-8649
> >     Fax (415) 469-5044
> >
> >     California Registered Geophysicist
> >     License No. GP 1034
> >
> >
> >
> >
> > --
> > "Failure has a thousand explanations. Success doesn't need one" -- Sir
> > Alec Guiness
>
> --
> Randall Mackie
> GSY-USA, Inc.
> PMB# 643
> 2261 Market St.,
> San Francisco, CA 94114-1600
> Tel (415) 469-8649
> Fax (415) 469-5044
>
> California Registered Geophysicist
> License No. GP 1034
>
>


-- 
"Failure has a thousand explanations. Success doesn't need one" -- Sir Alec
Guiness
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