On Mon, Jul 30, 2012 at 5:40 PM, Todd Munson <tmunson at mcs.anl.gov> wrote:
> > 1. change SNESVI to support general complementarity constraints because > only doing box constraints on state variables is lame > > Okay; and how do you want to do this? You need to write out the > corresponding KT system > and then you just have a box constrained problem. One can make it easier > to write the > KT system, but then you have to precondition the KT system. > Yes, but if the user created the augmented system, they have to inform the linear solver of that structure. I think it is much more convenient for the user to not have to manage those things. > > There are some reformulations for polyhedral constraints, but they are, in > my opinion, > a bit unwieldy. > Why unwieldy? Note that changing the size of the constrained size is also important, and box constraints strike me as even more confusing in that context. > > > 2. have a mode to solve the system in the full space, instead of > eliminating the semi-smooth variables (which produces the bad conditioning) > > There are all these options in the TAO methods. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20120731/0eb70fac/attachment.html>
