Dear Bangerth, When you mention
In general, using MatrixTools::apply_boundary_values() is not the way to go > with MPI programs. Rather, use a ConstraintMatrix and incorporate the > boundary > values into the same object as you do with hanging node constraints. This is the way to go due to correctness, or in the sense of scalability? Bests, Lucas On Tuesday, 10 October 2017 17:48:57 UTC+2, Wolfgang Bangerth wrote: > > On 10/10/2017 08:40 AM, Mark Ma wrote: > > > > I want to solve a heat equation in the time domain with distributed > memory > > using MPI, but the results are incorrect. In order to do so, I reference > > tutorial step-23 for time updating method and step-40 for implementing > MPI. > > May I ask whether my boundary condition is right or not? Should we do > > compress() after apply_boundary_values()? Thanks in advance! > > Jack -- how exactly is your solution wrong when you look at it? Do the > boundary values look wrong? Are they correct if you run your MPI program > with > just one MPI process? > > In general, using MatrixTools::apply_boundary_values() is not the way to > go > with MPI programs. Rather, use a ConstraintMatrix and incorporate the > boundary > values into the same object as you do with hanging node constraints. > That's > what all of the parallel programs do, if I recall correctly. > > Best > W. > > -- > ------------------------------------------------------------------------ > Wolfgang Bangerth email: [email protected] > <javascript:> > www: http://www.math.colostate.edu/~bangerth/ > > -- 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 [email protected]. For more options, visit https://groups.google.com/d/optout.
