dolfin team mailing list archive

["Evan Lezar" <evanlezar@xxxxxxxxx>]

(Sorry, I keep missing the list)

There are also ways to scale the eigensystem so that the desired eigenvalues
are the largest eigenvalues of the scaled system.  I don't have the
references available at the moment, but I will track some down later this
evening.

Evan


On Mon, Aug 25, 2008 at 2:48 PM, Garth N. Wells <gnw20@xxxxxxxxx> wrote:

> Anders Logg wrote:
> > How should one use the eigenvalue solver to compute the N smallest
> > eigenvalues?
> >
> > There seems to be a parameter "Eigenvalues to compute" that is used
> > internally in SLEPcEigenvalueSolver. Should this be used?
> >
>
>
> I would say with care. You'll probably need to do some work on
> SLEPcEigenSolver and look into the SLEPc manual in you want to compute
> the smallest eigenvalues efficiently. Most algorithms are designed to
> find the largest and won't work for finding the smallest eigenvalues.
>
> If you're interested in small systems, SLEPcEigenSolver can find all
> eigenvalues using a direct method.
>
> Garth
>
> >
> >
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