On Thu, Feb 21, 2013 at 5:19 PM, Amneet Bhalla <mail2amneet at gmail.com>wrote:
> Can you guys comment on what example case would be best to start off for > shell > operators with FieldSplit? The examples I am looking into all start with > creating native > PETSc matrices and vectors. > > If possible could you write down steps that would be needed in setting > such system... > > a) Create matrices using XXXX (?) b) Create vectors using YYYY .... > 1) Solve your system with a standard KSP solver, like GMRES 2) Tell PCFIELDSPLIT about your fields using PCFieldSplitSetIS(), http://www.mcs.anl.gov/petsc/petsc-dev/docs/manualpages/PC/PCFieldSplitSetIS.html Now you are ready. Matt > On Thu, Feb 21, 2013 at 3:24 PM, Matthew Knepley <knepley at gmail.com>wrote: > >> On Thu, Feb 21, 2013 at 4:20 PM, Amneet Bhalla <mail2amneet at >> gmail.com>wrote: >> >>> >>> On Thu, Feb 21, 2013 at 2:57 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote: >>> >>>> that you're happy with and that performs well with fieldsplit or custom >>>> preconditioning that will be amenable to your MatShells >>> >>> >>> Is fieldsplit an alternative approach to MatNest and VecNest? The >>> problem is that I am working on nonnative PETSc >>> data; so I am not sure which recent methods would support shell >>> approach. All I want is to use PETSc's algorithm >>> for solving multicomponent system of equation. I am not bothering about >>> preconditioning yet, as I will be trying >>> a custom preconditioner down the road. >>> >> >> MatNest is just an optimization matrix format. Get your stuff working >> with FieldSplit and then think about optimization. >> >> Matt >> >> >>> >>> -- >>> Amneet >>> >>> >>> >>> >> >> >> -- >> 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 >> > > > > -- > Amneet > > > > -- 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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20130221/736d358e/attachment.html>
