Dear Dr. Bangerth, Thank you very much! I found step-62 yesterday and I have compared the difference between them. I want to write two versions and compare their CPU time to get an exact result. Best regards, Yuesu
On Sun, Aug 16, 2020 at 7:19 PM Wolfgang Bangerth <bange...@colostate.edu> wrote: > Yuesu, > > > I am adding an absorbing boundary condition like step-24 did in the > > frequency domain, in which the time derivative gives a complex term. I > also > > found the complex acoustic wave problem step-29 which splits the complex > wave > > function into two real parts. > > What I want to know is what if I directly set up the matrix and rhs > vector > > as complex<double> ? Why does step-29 says "/it is often more convenient > to > > split complex valued functions into their real and imaginary parts and > use > > separate scalar finite element fields for discretizing each one of > them/" ? > > The problem is that we don't have iterative solvers for problems in which > the > matrix and vectors store complex values. We can, however, use PETSc's > complex-valued solvers as well as the SparseDirectUMFPACK solver. I think > you > probably want to look at step-62 and step-58 for other options. > > Best > W. > > > -- > ------------------------------------------------------------------------ > Wolfgang Bangerth email: bange...@colostate.edu > 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 dealii+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/dealii/168267e0-9fbd-fc96-e780-f697856b5572%40colostate.edu > . > -- Yuesu Jin, Ph.D student, University of Houston, College of Natural Sciences and Mathematics, Department of Earth and Atmospheric Sciences, Houston, Texas 77204-5008 346-404-2062 -- 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. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/CA%2B25a%3DKSeg%2B%2BE4GODU9hf1kqiKbB8s5aDjingWQHk4MpYeY1OQ%40mail.gmail.com.