docs for MINRES, only for positive definite?

[Matthew Knepley]

On Thu, Feb 28, 2008 at 10:56 AM, Barry Smith <bsmith at mcs.anl.gov> wrote:
>
>     But does it require a positive definite preconditioner?

You mean so I can play the trick with M^1/2 A M^1/2 to maintain symmetry? I
think you may be right.

  Matt

>     Barry
>
>
>
>  On Feb 28, 2008, at 9:32 AM, Matthew Knepley wrote:
>
>  > Docs are wrong.
>  >
>  >  Matt
>  >
>  > 2008/2/28 Lisandro Dalcin <dalcinl at gmail.com>:
>  >> I've noticed that the docs for MINRES say that the operator and the
>  >> preconditioner must be POSITIVE DEFINITE. But I understand MINRES is
>  >> tailored for the symmetric/hermitian-indefinite case.
>  >>
>  >> Are the docs wrong? Or the actual code is a (very peculiar) MINRES
>  >> variant?
>  >>
>  >>
>  >> --
>  >> Lisandro Dalcín
>  >> ---------------
>  >> Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
>  >> Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
>  >> Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
>  >> PTLC - Güemes 3450, (3000) Santa Fe, Argentina
>  >> Tel/Fax: +54-(0)342-451.1594
>  >>
>  >>
>  >
>  >
>  >
>  > --
>  > 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
>  >
>
>



-- 
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