matrix creation on LAPACK mode

[Zi-Hao Wei]

Hi

I remember that when you use LAPACK as eigensolver the SLEPc will
automatically convert sparse matrix into dense matrix by the function
SlepcMatConvertSeqDense.


On Fri, Jul 3, 2009 at 12:30 PM, Takuya Sekikawa<sekikawa at msi.co.jp> wrote:
> Hello
>
> I made eigenvalue solver program with SLEPc. in my program, to
> setup matrix, I use MatCreateSeqAIJ() function.
>
> void setupMatrix(int m, int n)
> {
>        PetscErrorCode ierr;
>
>        ierr=MatCreateSeqAIJ(PETSC_COMM_WORLD, m, n, nz, PETSC_NULL,
> &g_A);
>        ...
> }
>
> Normally I select solver as KrylovSchur, but sometimes I switched solver
> to LAPACK. with using LAPACK, result seems to be no problem. but I
> suspect calculation time takes longer (because of using MatCreateSeqAIJ)
>
> Does switching matrix create function to MatCreateSeqDense() give any
> effect to speed up on LAPACK mode?
>
> Thanks,
> Takuya
> ---------------------------------------------------------------
>   Takuya Sekikawa
>         Mathematical Systems, Inc
>                   sekikawa at msi.co.jp
> ---------------------------------------------------------------
>
>
>



-- 
Zi-Hao Wei
Department of Mathematics
National Central University, Taiwan
Adrienne Gusoff  - "Opportunity knocked. My doorman threw him out." -
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