<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div><br></div><div> Working example in </div> <a href="https://gitlab.com/petsc/petsc/-/merge_requests/6430">https://gitlab.com/petsc/petsc/-/merge_requests/6430</a><br><div><br><blockquote type="cite"><div>On May 7, 2023, at 11:47 AM, Barry Smith <bsmith@petsc.dev> wrote:</div><br class="Apple-interchange-newline"><div><meta http-equiv="content-type" content="text/html; charset=utf-8"><div style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div><br></div> Note, you must call the default test on iteration 0. This is how it determines the initial residual for relative residual tests etc. <div><br></div><div> I recommend not having the if () test at all. Instead, always call the default convergence test first and then change the flag value it provides if needed before doing any custom checking.</div><div><div><br><blockquote type="cite"><div>On May 7, 2023, at 11:38 AM, Barry Smith <bsmith@petsc.dev> wrote:</div><br class="Apple-interchange-newline"><div><meta http-equiv="content-type" content="text/html; charset=utf-8"><div style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div><br></div> The code will not work as written because KSPConvergedDefault() requires a context created with KSPConvergedDefaultCreate(). <div><br></div><div> Here is a starting point for what you need, in main</div><div><br></div><div> integer*8 defaultctx</div><div> extern MyKSPConverged, KSPConvergedDefaultDestroy</div><div><br></div><div>KSPDefaultConvergedCreate(defaultctx,ierr)</div><div><pre width="80"><a href="https://petsc.org/main/manualpages/KSP/KSPSetConvergenceTest/">KSPSetConvergenceTest</a>(ksp,MyKSPConverged,defaultctx,KSPConvergedDefaultDestroy, ierr)</pre><pre width="80"><br></pre></div><div><br></div><div><i style="caret-color: rgb(34, 34, 34); color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif;">subroutine MyKSPConverged(ksp,n,rnorm,flag,defaultctx,ierr)<br><br> KSP ksp<br> PetscErrorCode ierr<br> PetscInt n</i></div><div><i style="caret-color: rgb(34, 34, 34); color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif;"> integer*8 defaultctx<br> KSPConvergedReason flag<br> PetscReal rnorm<br><br> if (n>1) then<br> call KSPConvergedDefault(ksp, n, rnorm, flag,defaultctx, ierr)<br> else<br> flag = 0<br> endif<br> ierr = 0<br><br> end subroutine MyKSPConverged</i></div><div><font color="#222222" face="Arial, Helvetica, sans-serif"><span style="caret-color: rgb(34, 34, 34);"><i><br></i></span></font></div><div><font color="#222222" face="Arial, Helvetica, sans-serif"><span style="caret-color: rgb(34, 34, 34);"><i><br></i></span></font><div><br><blockquote type="cite"><div>On May 7, 2023, at 10:09 AM, Matthew Knepley <knepley@gmail.com> wrote:</div><br class="Apple-interchange-newline"><div><div dir="ltr"><div dir="ltr">On Sun, May 7, 2023 at 10:02 AM Edoardo alinovi <<a href="mailto:edoardo.alinovi@gmail.com">edoardo.alinovi@gmail.com</a>> wrote:<br></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Thanks, <div><br></div><div>Is this a reasonable thing to do if I want to replicate what KSP is doing by default?</div></div>
</blockquote></div><br clear="all"><div>Yes. The other option is to pass along 'dummy'</div><div><br></div><div> Thanks,</div><div><br></div><div> Matt</div><div><br></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>-- Norbert Wiener</div><div><br></div><div><a href="http://www.cse.buffalo.edu/~knepley/" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><br></div></div></div></div></div></div></div></div>
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