Hamed, On Thursday, October 27, 2016 at 5:40:04 PM UTC-4, Hamed Babaei wrote:
> First: I have parallelized a code in which I use > TrilinosWrappers::SolverDirect > . The problem is that with around 20000 DOFs the code is run on my own > machine and on the cluster as well but when I increase DOF even to 150000 > it get stuck at the first call to direct solver without giving any error > and Direct solver never got done. > 150000 is a lot of unknowns for a direct solver. 100000 unknowns is around the time when you need to switch to an iterative method to get the results quickly enough. Which solver are you using? If you are using Amesos_KLU, the solver is serial so using more processors is pointless. You need to use Amesos_Superludist. > Second: I don't know what solver control do for SolverDirect !! > SolverDirect > <https://www.dealii.org/8.4.1/doxygen/deal.II/classTrilinosWrappers_1_1SolverDirect.html#a5d216dac60a7bdf696c206d926974d1f> > (SolverControl > <https://www.dealii.org/8.4.1/doxygen/deal.II/classSolverControl.html> &cn, > const AdditionalData > <https://www.dealii.org/8.4.1/doxygen/deal.II/structTrilinosWrappers_1_1SolverDirect_1_1AdditionalData.html> > &data=AdditionalData > <https://www.dealii.org/8.4.1/doxygen/deal.II/structTrilinosWrappers_1_1SolverDirect_1_1AdditionalData.html> > ()) > I thought SolverControl has meaning when we have iterative solvers. > You are right. It is use internally to check that the direct solver was able to find the solution but the parameters that you put in SolverControl are not used. > > I was wondering why the code doesn't work with increased DOF and if I can > do something to find out where the problem is and how to solve it. > It probably works but you may need to wait a long time for the direct solver to solve the system. Best, Bruno -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
