On Sun, Jan 22, 2023 at 1:06 PM Barry Smith <bsm...@petsc.dev> wrote:
> > That makes incrementally adding new options to an existing object > difficult, since each call to setFromOptions() screws up previous calls. > > We already have > > -ksp_monitor_cancel > -ksp_converged_reason_view_cancel > Let me address it another way. If I understand correctly, what happens currently is that at each ViewFromOptions() call, the database is inspected and if a *_view is found, then the view is executed. So when you replace the database, if this option is not found then nothing happens. This seems to satisfy a kind of options locality. If instead we make some options sticky, like -ksp_view, so that once given they never expire, this would make the code exceedingly hard to reason about, especially if options are set deep inside something, before a user is knowingly doing things. This does not sound like the right model to me. Matt > On Jan 22, 2023, at 12:45 PM, Matthew Knepley <knep...@gmail.com> wrote: > > On Sat, Jan 21, 2023 at 4:34 PM Barry Smith <bsm...@petsc.dev> wrote: > >> >> If I run KSPSetFromOptions() on an options database that contains >> -ksp_view and then push another options database that does not contain >> -ksp_view and call KSPSetFromOptions() again it undoes the previous setting >> of that viewer. So -ksp_view is not used. >> >> I think this is the wrong model, it should not turn off the previously >> set view just because it is not being set in the new call, since it was >> previously set in the KSP. I fear some PETSc function will need another >> argument to properly handle this; like another flag to >> PetscOptionsGetViewer(). >> >> Note this is for much more than KSP. >> >> Thoughts? >> > > I think it must get rid of it. Otherwise, it would stay forever since > there would be no way to get rid of it. > > Matt > > > -- > 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/ > <http://www.cse.buffalo.edu/~knepley/> > > > -- 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/ <http://www.cse.buffalo.edu/~knepley/>
