Dmitry, On Aug 12, 2012, at 3:13 AM, Dmitry Karpeev <karpeev at mcs.anl.gov> wrote:
> On Sat, Aug 11, 2012 at 6:36 PM, Subramanya Gautam Sadasiva <ssadasiv at > purdue.edu> wrote: > Hi, > I was trying the snes solver on the obstacle problem by modifying > miscellaneous ex 7 and I get only linear convergence times.Is this what is > expected from the virs solver? > Yes, in the sense that you can't expect Newton's typical quadratic > convergence: you are not using Newton's method in the usual sense, > since the linear (and, in a sense, the nonlinear) problem you are solving > changes every time the coincidence set changes. You see this is really bad for a case like mine where essentially I am solving a quadratic problem with box constraints (Jac and Constraints are constant during each solve). Is there anything we can do to use this structure shouldn't we be able to get a quadratic convergence ? Thanks, Ata > > Dmitry. > THanks, > Subramanya > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Libmesh-users mailing list > Libmesh-users at lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/libmesh-users > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120813/15db578d/attachment.html>
