Dear Barry and Matt, Thanks for the help, Indeed, the monitor starts to work with "richardson".
Yan On Tue, Apr 5, 2011 at 11:06 PM, Barry Smith <bsmith at mcs.anl.gov> wrote: > > On Apr 5, 2011, at 9:52 PM, Ryan Yan wrote: > > > Hi, > > I am wondering is there a way of checking the residual of a direct > solver. It should > > be one shot and very small. I tried -ksp_monitor_true_residual, but no > thing shows up. I guess a piece of code > > $Ax-b$ will do the trick? > > The reason that the monitor doesn't display anything is not the direct > solver but because you are using LU with KSPType of KSPPREONLY if you run > with -ksp_type richardson or -ksp_type gmres then -ksp_monitor_true_residual > will print the residual as you want. > > Barry > > > > > Thanks, > > > > Yan > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20110405/bbbd6483/attachment.htm>
