Hmmmm..sorry guys - the entire thread got put away in a folder by my mail reader and I just discovered all your emails :-)
SNESVI looks interesting but as someone pointed out I am using matrix free. And as I understand from Barry a matrix free version of SNESVI is not implemented. The idea of flipping the sign seems to be a poor mans approach that might work for me though I would still need some mechanisms in SNES to put the hooks in. Bobby On Dec 14, 2011, at 10:45 PM, Jed Brown wrote: > On Wed, Dec 14, 2011 at 19:40, Dmitry Karpeev <karpeev at mcs.anl.gov> wrote: > The trouble is that the constraints can get "eliminated" only when they > become active. > > That's not what I meant. I meant to transform the algebraic system so that > those extra variables were eliminated. The point is that we tend to put a lot > of effort into designing effective preconditioners for a standard formulation > (e.g. conservative variables), and that is partly lost of we have this other > system in which the evaluations of constitutive relations are added > explicitly. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20111215/b544fe88/attachment.html>
