[petsc-users] SLEPc Eigenvalue problem - Zero Pivot

[venkatesh g]

Hi Jose, all,

I tried that too, it is telling the same error of "Detected Zero pivot in
LU factorization".
My matrix B in AX=lambda BX has large no. of zeros and is singular.

Is there another way ?

Venkatesh

On Wed, May 13, 2015 at 9:02 PM, Jose E. Roman <jroman at dsic.upv.es> wrote:

>
> El 13/05/2015, a las 17:28, venkatesh g escribió:
>
> > Dear All,
> >
> > I am having a block matrix Eigenvalue problem AX = lambda BX
> >
> > My B is singular, it is a block matrix and only one block has non-zero
> values.
> >
> > Matlab Eigs is giving the result.
> >
> > I am using option: "./ex7 -f1 A1 -f2 B1 -st_type sinvert"
> >
> > Result is: Detected zero pivot in LU factorization.
> >
> > The ex7 is an example from SLEPc.
> >
> > Pls advice what to do ?
> >
> > cheers,
> > Venkatesh
> >
> >
>
> If you know where your wanted eigenvalues are, set the target value, for
> instance:
> ./ex7 -f1 A1 -f2 B1 -st_type sinvert -eps_target 0.5
>
> Jose
>
>
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