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 Dalc?n > >> --------------- > >> Centro Internacional de M?todos Computacionales en Ingenier?a (CIMEC) > >> Instituto de Desarrollo Tecnol?gico para la Industria Qu?mica (INTEC) > >> Consejo Nacional de Investigaciones Cient?ficas y T?cnicas (CONICET) > >> PTLC - G?emes 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
