> On Dec 12, 2017, at 12:04 PM, Hao Zhang <[email protected]> wrote: > > hi, > > before I introduce HYPRE with BOOMERAMG to my CFD code, I will have output > with good convergence rate. with BOOMERAMG, the same code will take longer > time to run and there's a good chance that no output will be produced > whatsoever.
Are you running with -ksp_monitor -ksp_view_pre -ksp_converged_reason ? If you are using -ksp_monitor and getting no output it could be that hypre is taking a very long time to form the AMG preconditioner, but I won't expect to see this unless the problem is very very big. You can always run with -start_in_debugger and then type cont in the debugger wait a couple minutes and then use control C in the debugger and type where to determine what it is doing at the time (you can email the output to [email protected]). Boomeramg is not good for all classes of matrices, it is fine for elliptic/parabolic generally but if you hand it something that is hyperbolically dominated it will not work well. Barry > > what happened? thanks! > > -- > Hao Zhang > Dept. of Applid Mathematics and Statistics, > Stony Brook University, > Stony Brook, New York, 11790
