Thanks for your quick reply! It helps me much. Akihiro
2014/04/26 2:13、Barry Smith <[email protected]> のメール： > > Run with -ksp_view (or -snes_view etc). If that does not provide all > relevant information then tell us what is missing so we can add that to the > output. Defaults etc change over time so you should never rely on what > someone thinks it is or what it “should be”, just run with the viewer. > > barry > > On Apr 25, 2014, at 11:31 AM, Matthew Knepley <[email protected]> wrote: > >> On Fri, Apr 25, 2014 at 11:26 AM, 藤井昭宏 <[email protected]> wrote: >> Hello everybody, >> >> I’d like to compare a solver with PETSc-gamg for Poisson problems. >> I used PETSc version 3.4.3., and the following command line option. >> >> -ksp_type “bcgs” -pc_type “gamg” -ksp_monitor -ksp_rtol 1.0E-7 -log_summary >> -pc_mg_log >> >> >> Would you give me some information on the following questions? >> >> - Does this option correspond to BICGSTAB solver with smoothed aggregation >> algebraic multigrid method? >> >> Yes >> >> - Are coarser level small distributed matrices re-distributed to reduce the >> parallelism, when the number of processes is very large? >> >> Yes >> >> - What kind of smoother will be used for this command line option? >> >> Cheby(2)/Jacobi is the default in GAMG. >> >> - pc_mg_log option shows the MG Apply stage. Does this stage time >> correspond to the solver time except for multi-level setup time? >> Does it include the time for BICGSTAB? >> >> Yes, and no. >> >> Thanks, >> >> Matt >> >> Thanks in advance. >> >> Akihiro Fujii >> >> >> >> >> >> -- >> What most experimenters take for granted before they begin their experiments >> is infinitely more interesting than any results to which their experiments >> lead. >> -- Norbert Wiener > >
