On Wed, 06 Apr 2011 17:06:40 +0200, Umut Tabak <u.tabak at tudelft.nl> wrote: > On 04/06/2011 04:50 PM, Jed Brown wrote: > > On Wed, 06 Apr 2011 16:37:26 +0200, Umut Tabak <u.tabak at tudelft.nl> > > wrote: > >> Just curious, are not the other negative eigenvalues problematic as > >> well? > > > > Negative eigenvalues do not pose any particular problem to Krylov > > methods like GMRES. Conjugate gradients does require that the matrix > > be SPD, but petsc-dev detects when a matrix is negative definite and > > still does the right thing. > > Also with cg type methods? if yes, how?
http://petsc.cs.iit.edu/petsc/petsc-dev/rev/cae94ca39fcb
