Unfortunately, James notified me offline of a breakage in PyTrilinos on Macs. I need to find time to debug.
- Jon > On Jun 1, 2017, at 11:37 AM, Daniel Wheeler <daniel.wheel...@gmail.com> wrote: > > Hi James, > > I don't have any hints for preconditioners, but using Trilinos's GMRES > and then systematically changing the GMRES parameters and > preconditioners might help you find one that works. I have done this > in the past, for example, > > > https://gist.github.com/wd15/c28ab796cb3d9781482b01fb67a7ec2d#file-unsegregatedequation-py-L187 > > You can also get information about how well the solver is converging. > > Cheers, > > Daniel > > On Wed, May 31, 2017 at 3:31 PM, James Pringle <jprin...@unh.edu> wrote: >> >> Dear all -- >> >> I need to solve a second order PDE in 2D of the form >> >> A(x,y)*(eta_xx+eta_yy)+B(x,y)*eta_x+C(x,y)*eta_y = 0 >> >> This is an advective diffusive balance, with B and C representing the >> advective velocities. >> >> >> Over much of the domain the low order terms dominate. For some geometries, >> the default solver I am using (SciPy LinearLUSolver) is having trouble find >> an answer (especially when the characteristics defined by B and C form >> loops. >> >> Does anyone have recommendations for how to choose a better solver? (I have >> blindly tried all the ones in SciPy, the ones besides LinearLUSolver do >> worse). >> >> And are there any hints on how to use preconditioners? There is discussion >> of preconditioners and Trilinnos, but I can't find hints on how one would >> choose to use them and when they might help. >> >> Pointers to the broader literature are welcome! >> >> Thank you, >> Jamie Pringle >> >> _______________________________________________ >> fipy mailing list >> fipy@nist.gov >> http://www.ctcms.nist.gov/fipy >> [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ] >> > > > > -- > Daniel Wheeler > _______________________________________________ > fipy mailing list > fipy@nist.gov > http://www.ctcms.nist.gov/fipy > [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ] _______________________________________________ fipy mailing list fipy@nist.gov http://www.ctcms.nist.gov/fipy [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]
