Matt is right. I had completely forgotten about this option and gave you an overly complicated solution.
Barry > On Sep 28, 2019, at 12:11 AM, Matthew Knepley <knep...@gmail.com> wrote: > > On Fri, Sep 27, 2019 at 9:19 AM Li Luo via petsc-users > <petsc-users@mcs.anl.gov> wrote: > Thank you for the suggestions, I'll try it. > > I think an easier way to do what you want is > > -snes_max_linear_solve_fail 10 > > from > > > https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/SNES/SNESSetMaxLinearSolveFailures.html > > Thanks, > > Matt > > Best, > Li > > On Fri, Sep 27, 2019 at 5:27 AM Smith, Barry F. <bsm...@mcs.anl.gov> wrote: > > Li, > > It is possible, but as Hong said probably never appropriate. Especially if > KSP has iterated for 10,000 iterations. If you want SNES to "try" the > direction given by a failed solve you should use a much smaller maximum > number of iterations for KSP. > > Anways, to do what you desire > > #include <petsc/private/kspimpl.h> > > call KSPSetPostSolve() and in your post solve() function simply do > ksp->reason = KSP_CONVERGED_ITS. > > Barry > > > > > > On Sep 26, 2019, at 10:58 AM, Zhang, Hong via petsc-users > > <petsc-users@mcs.anl.gov> wrote: > > > > Li : > > You can use '-ksp_max_it 20000' to change maximum iteration count. However, > > it does not make sense to continue after it fails at 10000 iterations. You > > should figure out why linear solver diverges. Run your code with > > '-ksp_monitor' or '-ksp_monitor_true_residual'. > > Hong > > > > Dear developer, > > > > I am using SNES for solving a nonlinear system. For some cases, SNES > > diverged -3 with "DIVERGED_LINEAR_SOLVE" when the linear solver reached its > > maximum iteration count (i.e -ksp_max_it 10000). > > Is that possible to let SNES continue even though the linear solver reaches > > the maximum number of iterations? Just take the result at 10000 for the > > Jacobian solution and then update the Newton step? > > > > Best, > > Li > > > > > > > > This message and its contents, including attachments are intended solely > > for the original recipient. If you are not the intended recipient or have > > received this message in error, please notify me immediately and delete > > this message from your computer system. Any unauthorized use or > > distribution is prohibited. Please consider the environment before printing > > this email. > > > > -- > Postdoctoral Fellow > Extreme Computing Research Center > King Abdullah University of Science & Technology > https://sites.google.com/site/rolyliluo/ > > This message and its contents, including attachments are intended solely for > the original recipient. If you are not the intended recipient or have > received this message in error, please notify me immediately and delete this > message from your computer system. Any unauthorized use or distribution is > prohibited. Please consider the environment before printing this email. > > > -- > 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 > > https://www.cse.buffalo.edu/~knepley/
