<head><!-- BaNnErBlUrFlE-HeAdEr-start -->
<style>
#pfptBanner53sgb83 { all: revert !important; display: block !important;
visibility: visible !important; opacity: 1 !important;
background-color: #D0D8DC !important;
max-width: none !important; max-height: none !important }
.pfptPrimaryButton53sgb83:hover, .pfptPrimaryButton53sgb83:focus {
background-color: #b4c1c7 !important; }
.pfptPrimaryButton53sgb83:active {
background-color: #90a4ae !important; }
</style>
<!-- BaNnErBlUrFlE-HeAdEr-end -->
</head><!-- BaNnErBlUrFlE-BoDy-start -->
<!-- Preheader Text : BEGIN -->
<div style="display:none !important;display:none;visibility:hidden;mso-hide:all;font-size:1px;color:#ffffff;line-height:1px;height:0px;max-height:0px;opacity:0;overflow:hidden;">
On Thu, Aug 1, 2024 at 12: 19 PM Barry Smith <bsmith@ petsc. dev> wrote: The current code is nonsensical. We can "fix" it in a patch to the release branch (but the fix may break some current usage) by changing if (nfields == 1)
</div>
<!-- Preheader Text : END -->
<!-- Email Banner : BEGIN -->
<div style="display:none !important;display:none;visibility:hidden;mso-hide:all;font-size:1px;color:#ffffff;line-height:1px;height:0px;max-height:0px;opacity:0;overflow:hidden;">ZjQcmQRYFpfptBannerStart</div>
<!--[if ((ie)|(mso))]>
<table border="0" cellspacing="0" cellpadding="0" width="100%" style="padding: 16px 0px 16px 0px; direction: ltr" ><tr><td>
<table border="0" cellspacing="0" cellpadding="0" style="padding: 0px 10px 5px 6px; width: 100%; border-radius:4px; border-top:4px solid #90a4ae;background-color:#D0D8DC;"><tr><td valign="top">
<table align="left" border="0" cellspacing="0" cellpadding="0" style="padding: 4px 8px 4px 8px">
<tr><td style="color:#000000; font-family: 'Arial', sans-serif; font-weight:bold; font-size:14px; direction: ltr">
This Message Is From an External Sender
</td></tr>
<tr><td style="color:#000000; font-weight:normal; font-family: 'Arial', sans-serif; font-size:12px; direction: ltr">
This message came from outside your organization.
</td></tr>
</table>
</td></tr></table>
</td></tr></table>
<![endif]-->
<![if !((ie)|(mso))]>
<div dir="ltr" id="pfptBanner53sgb83" style="all: revert !important; display:block !important; text-align: left !important; margin:16px 0px 16px 0px !important; padding:8px 16px 8px 16px !important; border-radius: 4px !important; min-width: 200px !important; background-color: #D0D8DC !important; background-color: #D0D8DC; border-top: 4px solid #90a4ae !important; border-top: 4px solid #90a4ae;">
<div id="pfptBanner53sgb83" style="all: unset !important; float:left !important; display:block !important; margin: 0px 0px 1px 0px !important; max-width: 600px !important;">
<div id="pfptBanner53sgb83" style="all: unset !important; display:block !important; visibility: visible !important; background-color: #D0D8DC !important; color:#000000 !important; color:#000000; font-family: 'Arial', sans-serif !important; font-family: 'Arial', sans-serif; font-weight:bold !important; font-weight:bold; font-size:14px !important; line-height:18px !important; line-height:18px">
This Message Is From an External Sender
</div>
<div id="pfptBanner53sgb83" style="all: unset !important; display:block !important; visibility: visible !important; background-color: #D0D8DC !important; color:#000000 !important; color:#000000; font-weight:normal; font-family: 'Arial', sans-serif !important; font-family: 'Arial', sans-serif; font-size:12px !important; line-height:18px !important; line-height:18px; margin-top:2px !important;">
This message came from outside your organization.
</div>
</div>
<div style="clear: both !important; display: block !important; visibility: hidden !important; line-height: 0 !important; font-size: 0.01px !important; height: 0px"> </div>
</div>
<![endif]>
<div style="display:none !important;display:none;visibility:hidden;mso-hide:all;font-size:1px;color:#ffffff;line-height:1px;height:0px;max-height:0px;opacity:0;overflow:hidden;">ZjQcmQRYFpfptBannerEnd</div>
<!-- Email Banner : END -->
<!-- BaNnErBlUrFlE-BoDy-end -->
<div dir="ltr"><div dir="ltr">On Thu, Aug 1, 2024 at 12:19 PM Barry Smith <<a href="mailto:bsmith@petsc.dev">bsmith@petsc.dev</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><div><br></div> The current code is nonsensical. We can "fix" it in a patch to the release branch (but the fix may break some current usage) by changing<div><br></div><div><div> if (nfields == 1) {</div><div> PetscCall(PCFieldSplitSetIS(pc, fieldNames[ifields[0]], compField));</div><div> } else {</div><div> PetscCall(PetscSNPrintf(splitname, sizeof(splitname), "%" PetscInt_FMT, i));</div><div> PetscCall(PCFieldSplitSetIS(pc, splitname, compField));</div><div> }</div><div><br></div><div>to </div><div><br></div><div><div> PetscCall(PetscSNPrintf(splitname, sizeof(splitname), "%" PetscInt_FMT, i));</div><div> PetscCall(PCFieldSplitSetIS(pc, splitname, compField));</div><div><br></div></div><div><br></div><div>but a "correct" fix will take some thought. The current model using a combination of some "inner" integer fieldnames and some outer fieldnames (which are whatever they are including possible integers) doesn't make any sense.</div></div></div></blockquote><div><br></div><div>My fix was going to be a flag that turns off names altogether. I think this will fix it for Sebastian, and is the only consistent fix I can think of.</div><div><br></div><div> Thanks,</div><div><br></div><div> Matt</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div><div><div><br><blockquote type="cite"><div>On Aug 1, 2024, at 9:19 AM, Blauth, Sebastian <<a href="mailto:sebastian.blauth@itwm.fraunhofer.de" target="_blank">sebastian.blauth@itwm.fraunhofer.de</a>> wrote:</div><br><div><div style="font-family:Helvetica;font-size:18px;font-style:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none"><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span>Hello everyone,<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span><u></u> <u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">I have a follow up on my question. I noticed the following behavior. Let’s assume I have 5 fields which I want to group with the following options:<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"><u></u> <u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-ksp_type fgmres<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-ksp_max_it 1<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-ksp_monitor_true_residual<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-ksp_view<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-pc_type fieldsplit<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-pc_fieldsplit_type multiplicative<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-pc_fieldsplit_0_fields 0,1<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-pc_fieldsplit_1_fields 2<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-pc_fieldsplit_2_fields 3,4<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_ksp_type preonly<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_pc_type jacobi<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_2_ksp_type preonly<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_2_pc_type jacobi<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"><u></u> <u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Then, the first split is fine, but both the second and third splits get the same prefix, i.e., “fieldsplit_2”. This is shown in the output of the ksp_view, which I attach below.<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">The first one gets the prefix as there is only a single split (and I choose as name the index) and the third split gets the name as it groups two other fields, so the “outer” name is taken. Is there any way to circumvent this, other than using custom names for the splits which are unique?<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"><u></u> <u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Thanks for your time and best regards,<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Sebastian Blauth<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"><u></u> <u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"><u></u> <u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">The output of “ksp_view” is the following<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"><u></u> <u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">KSP Object: 1 MPI process<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: fgmres<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> happy breakdown tolerance 1e-30<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> maximum iterations=1, initial guess is zero<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> tolerances: relative=1e-05, absolute=1e-50, divergence=10000.<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> right preconditioning<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using UNPRECONDITIONED norm type for convergence test<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">PC Object: 1 MPI process<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: fieldsplit<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> FieldSplit with MULTIPLICATIVE composition: total splits = 3<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Solver info for each split is in the following KSP objects:<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Split number 0 Defined by IS<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> KSP Object: (fieldsplit_0_) 1 MPI process<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: preonly<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> maximum iterations=10000, initial guess is zero<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> tolerances: relative=1e-05, absolute=1e-50, divergence=10000.<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> left preconditioning<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using NONE norm type for convergence test<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> PC Object: (fieldsplit_0_) 1 MPI process<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: jacobi<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type DIAGONAL<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> linear system matrix = precond matrix:<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: (fieldsplit_0_) 1 MPI process<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=243, cols=243<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=4473, allocated nonzeros=4473<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total number of mallocs used during MatSetValues calls=0<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using I-node routines: found 86 nodes, limit used is 5<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Split number 1 Defined by IS<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> KSP Object: (fieldsplit_2_) 1 MPI process<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: preonly<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> maximum iterations=10000, initial guess is zero<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> tolerances: relative=1e-05, absolute=1e-50, divergence=10000.<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> left preconditioning<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using NONE norm type for convergence test<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> PC Object: (fieldsplit_2_) 1 MPI process<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: jacobi<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type DIAGONAL<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> linear system matrix = precond matrix:<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: (fieldsplit_2_) 1 MPI process<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=81, cols=81<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=497, allocated nonzeros=497<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total number of mallocs used during MatSetValues calls=0<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> not using I-node routines<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Split number 2 Defined by IS<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> KSP Object: (fieldsplit_2_) 1 MPI process<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: preonly<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> maximum iterations=10000, initial guess is zero<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> tolerances: relative=1e-05, absolute=1e-50, divergence=10000.<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> left preconditioning<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using NONE norm type for convergence test<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> PC Object: (fieldsplit_2_) 1 MPI process<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: jacobi<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type DIAGONAL<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> linear system matrix = precond matrix:<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: (fieldsplit_2_) 1 MPI process<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=243, cols=243<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=4473, allocated nonzeros=4473<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total number of mallocs used during MatSetValues calls=0<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using I-node routines: found 85 nodes, limit used is 5<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> linear system matrix = precond matrix:<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: 1 MPI process<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=567, cols=567<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=24353, allocated nonzeros=24353<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total number of mallocs used during MatSetValues calls=0<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using I-node routines: found 173 nodes, limit used is 5<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"><u></u> <u></u></span></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">--<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Dr. Sebastian Blauth<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Fraunhofer-Institut für<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Techno- und Wirtschaftsmathematik ITWM<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Abteilung Transportvorgänge<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Fraunhofer-Platz 1, 67663 Kaiserslautern<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Telefon: +49 631 31600-4968<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><a href="mailto:sebastian.blauth@itwm.fraunhofer.de" style="color:blue;text-decoration:underline" target="_blank">sebastian.blauth@itwm.fraunhofer.de</a><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><a href="https://urldefense.us/v3/__https://www.itwm.fraunhofer.de/__;!!G_uCfscf7eWS!an6Idf-f7OiZlsU0N0Ftpr5mM5etD7GF_9ghya_ALFmQP_eL93oONwYYRLmLGz-0FSXHkB0bMsjj0cdfEbTa$" style="color:blue;text-decoration:underline" target="_blank">https://www.itwm.fraunhofer.de</a><u></u><u></u></div></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span><u></u> <u></u></span></div><div style="border-width:medium medium medium 1.5pt;border-style:none none none solid;border-color:currentcolor currentcolor currentcolor blue;padding:0cm 0cm 0cm 4pt"><div><div style="border-width:1pt medium medium;border-style:solid none none;border-color:rgb(225,225,225) currentcolor currentcolor;padding:3pt 0cm 0cm"><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><b><span lang="EN-US">From:</span></b><span lang="EN-US"><span> </span>petsc-users <<a href="mailto:petsc-users-bounces@mcs.anl.gov" style="color:blue;text-decoration:underline" target="_blank">petsc-users-bounces@mcs.anl.gov</a>><span> </span><b>On Behalf Of<span> </span></b>Blauth, Sebastian<br><b>Sent:</b><span> </span>Tuesday, July 2, 2024 11:47 AM<br><b>To:</b><span> </span>Matthew Knepley <<a href="mailto:knepley@gmail.com" style="color:blue;text-decoration:underline" target="_blank">knepley@gmail.com</a>><br><b>Cc:</b><span> </span><a href="mailto:petsc-users@mcs.anl.gov" style="color:blue;text-decoration:underline" target="_blank">petsc-users@mcs.anl.gov</a><br><b>Subject:</b><span> </span>Re: [petsc-users] Question regarding naming of fieldsplit splits<u></u><u></u></span></div></div></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><u></u> <u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span>Hi Matt,<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span><u></u> <u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">thanks fort he answer and clarification. Then I’ll work around this issue in python, where I set the options.<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"><u></u> <u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Best,<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Sebastian<u></u><u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"><u></u> <u></u></span></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">--<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Dr. Sebastian Blauth<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Fraunhofer-Institut für<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Techno- und Wirtschaftsmathematik ITWM<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Abteilung Transportvorgänge<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Fraunhofer-Platz 1, 67663 Kaiserslautern<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Telefon: +49 631 31600-4968<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><a href="mailto:sebastian.blauth@itwm.fraunhofer.de" style="color:blue;text-decoration:underline" target="_blank">sebastian.blauth@itwm.fraunhofer.de</a><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><a href="https://urldefense.us/v3/__https://www.itwm.fraunhofer.de/__;!!G_uCfscf7eWS!an6Idf-f7OiZlsU0N0Ftpr5mM5etD7GF_9ghya_ALFmQP_eL93oONwYYRLmLGz-0FSXHkB0bMsjj0cdfEbTa$" style="color:blue;text-decoration:underline" target="_blank">https://www.itwm.fraunhofer.de</a><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span><u></u> <u></u></span></div><div style="border-width:medium medium medium 1.5pt;border-style:none none none solid;border-color:currentcolor currentcolor currentcolor blue;padding:0cm 0cm 0cm 4pt"><div><div style="border-width:1pt medium medium;border-style:solid none none;border-color:rgb(225,225,225) currentcolor currentcolor;padding:3pt 0cm 0cm"><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><b><span lang="EN-US">From:</span></b><span lang="EN-US"><span> </span>Matthew Knepley <<a href="mailto:knepley@gmail.com" style="color:blue;text-decoration:underline" target="_blank">knepley@gmail.com</a>><span> </span><br><b>Sent:</b><span> </span>Monday, July 1, 2024 4:30 PM<br><b>To:</b><span> </span>Blauth, Sebastian <<a href="mailto:sebastian.blauth@itwm.fraunhofer.de" style="color:blue;text-decoration:underline" target="_blank">sebastian.blauth@itwm.fraunhofer.de</a>><br><b>Cc:</b><span> </span><a href="mailto:petsc-users@mcs.anl.gov" style="color:blue;text-decoration:underline" target="_blank">petsc-users@mcs.anl.gov</a><br><b>Subject:</b><span> </span>Re: [petsc-users] Question regarding naming of fieldsplit splits<u></u><u></u></span></div></div></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><u></u> <u></u></div><div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">On Mon, Jul 1, 2024 at 9:48 AM Blauth, Sebastian <<a href="mailto:sebastian.blauth@itwm.fraunhofer.de" style="color:blue;text-decoration:underline" target="_blank">sebastian.blauth@itwm.fraunhofer.de</a>> wrote:<u></u><u></u></div></div><div><blockquote style="border-width:medium medium medium 1pt;border-style:none none none solid;border-color:currentcolor currentcolor currentcolor rgb(204,204,204);padding:0cm 0cm 0cm 6pt;margin:5pt 0cm 5pt 4.8pt"><div><div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Dear Matt,<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> <u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">thanks a lot for your help. Unfortunately, for me these extra options do not have any effect, I still get the “u” and “p” fieldnames. Also, this would not help me to get rid of the “c” fieldname – on that level of the fieldsplit I am basically using your approach already, and still it does show up. The output of the -ksp_view is unchanged, so that I do not attach it here again. Maybe I misunderstood you?</span><u></u><u></u></div></div></div></div></blockquote><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><u></u> <u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Oh, we make an exception for single fields, since we think you would want to use the name. I have to make an extra option to shut off naming.<u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><u></u> <u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> Thanks,<u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><u></u> <u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> Matt<u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> <u></u><u></u></div></div><blockquote style="border-width:medium medium medium 1pt;border-style:none none none solid;border-color:currentcolor currentcolor currentcolor rgb(204,204,204);padding:0cm 0cm 0cm 6pt;margin:5pt 0cm 5pt 4.8pt"><div><div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Thanks for the help and best regards,</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Sebastian</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">--<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Dr. Sebastian Blauth<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Fraunhofer-Institut für<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Techno- und Wirtschaftsmathematik ITWM<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Abteilung Transportvorgänge<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Fraunhofer-Platz 1, 67663 Kaiserslautern<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Telefon: +49 631 31600-4968<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><a href="mailto:sebastian.blauth@itwm.fraunhofer.de" style="color:blue;text-decoration:underline" target="_blank">sebastian.blauth@itwm.fraunhofer.de</a><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><a href="https://urldefense.us/v3/__https://www.itwm.fraunhofer.de/__;!!G_uCfscf7eWS!an6Idf-f7OiZlsU0N0Ftpr5mM5etD7GF_9ghya_ALFmQP_eL93oONwYYRLmLGz-0FSXHkB0bMsjj0cdfEbTa$" style="color:blue;text-decoration:underline" target="_blank">https://www.itwm.fraunhofer.de</a><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> <u></u><u></u></div><div style="border-width:medium medium medium 1.5pt;border-style:none none none solid;border-color:currentcolor currentcolor currentcolor blue;padding:0cm 0cm 0cm 4pt"><div><div style="border-width:1pt medium medium;border-style:solid none none;border-color:rgb(225,225,225) currentcolor currentcolor;padding:3pt 0cm 0cm"><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><b><span lang="EN-US">From:</span></b><span lang="EN-US"><span> </span>Matthew Knepley <<a href="mailto:knepley@gmail.com" style="color:blue;text-decoration:underline" target="_blank">knepley@gmail.com</a>><span> </span><br><b>Sent:</b><span> </span>Monday, July 1, 2024 2:27 PM<br><b>To:</b><span> </span>Blauth, Sebastian <<a href="mailto:sebastian.blauth@itwm.fraunhofer.de" style="color:blue;text-decoration:underline" target="_blank">sebastian.blauth@itwm.fraunhofer.de</a>><br><b>Cc:</b><span> </span><a href="mailto:petsc-users@mcs.anl.gov" style="color:blue;text-decoration:underline" target="_blank">petsc-users@mcs.anl.gov</a><br><b>Subject:</b><span> </span>Re: [petsc-users] Question regarding naming of fieldsplit splits</span><u></u><u></u></div></div></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> <u></u><u></u></div><div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">On Fri, Jun 28, 2024 at 4:05 AM Blauth, Sebastian <<a href="mailto:sebastian.blauth@itwm.fraunhofer.de" style="color:blue;text-decoration:underline" target="_blank">sebastian.blauth@itwm.fraunhofer.de</a>> wrote:<u></u><u></u></div></div><div><blockquote style="border-width:medium medium medium 1pt;border-style:none none none solid;border-color:currentcolor currentcolor currentcolor rgb(204,204,204);padding:0cm 0cm 0cm 6pt;margin:5pt 0cm 5pt 4.8pt"><div><div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Hello everyone,<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> <u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">I have a question regarding the naming convention using PETSc’s PCFieldsplit. I have been following<span> </span><a href="https://urldefense.us/v3/__https://lists.mcs.anl.gov/pipermail/petsc-users/2019-January/037262.html__;!!G_uCfscf7eWS!an6Idf-f7OiZlsU0N0Ftpr5mM5etD7GF_9ghya_ALFmQP_eL93oONwYYRLmLGz-0FSXHkB0bMsjj0Qyn5DYX$" style="color:blue;text-decoration:underline" target="_blank">https://lists.mcs.anl.gov/pipermail/petsc-users/2019-January/037262.html</a><span> </span>to create a DMShell with FEniCS in order to customize PCFieldsplit for my application.<span> </span></span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">I am using the following options, which work nicely for me:</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-ksp_type fgmres</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-pc_type fieldsplit</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-pc_fieldsplit_0_fields 0, 1</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-pc_fieldsplit_1_fields 2</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-pc_fieldsplit_type additive</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_ksp_type fgmres</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_pc_type fieldsplit</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_pc_fieldsplit_type schur</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_pc_fieldsplit_schur_fact_type full</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_pc_fieldsplit_schur_precondition selfp</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_fieldsplit_u_ksp_type preonly</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_fieldsplit_u_pc_type lu</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_fieldsplit_p_ksp_type cg</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_fieldsplit_p_ksp_rtol 1e-14</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_fieldsplit_p_ksp_atol 1e-30</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_fieldsplit_p_pc_type icc</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_ksp_rtol 1e-14</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_ksp_atol 1e-30</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_0_ksp_monitor_true_residual</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_c_ksp_type preonly</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-fieldsplit_c_pc_type lu</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">-ksp_view</span><u></u><u></u></div></div></div></div></blockquote><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> <u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">By default, we use the field names, but you can prevent this by specifying the fields by hand, so<u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> <u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">-fieldsplit_0_pc_fieldsplit_0_fields 0<br>-fieldsplit_0_pc_fieldsplit_1_fields 1<u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> <u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">should remove the 'u' and 'p' fieldnames. It is somewhat hacky, but I think easier to remember than<u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">some extra option.<u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> <u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> Thanks,<u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> <u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> Matt<u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> <u></u><u></u></div></div><blockquote style="border-width:medium medium medium 1pt;border-style:none none none solid;border-color:currentcolor currentcolor currentcolor rgb(204,204,204);padding:0cm 0cm 0cm 6pt;margin:5pt 0cm 5pt 4.8pt"><div><div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Note that this is just an academic example (sorry for the low solver tolerances) to test the approach, consisting of a Stokes equation and some concentration equation (which is not even coupled to Stokes, just for testing).</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Completely analogous to<span> </span><a href="https://urldefense.us/v3/__https://lists.mcs.anl.gov/pipermail/petsc-users/2019-January/037262.html__;!!G_uCfscf7eWS!an6Idf-f7OiZlsU0N0Ftpr5mM5etD7GF_9ghya_ALFmQP_eL93oONwYYRLmLGz-0FSXHkB0bMsjj0Qyn5DYX$" style="color:blue;text-decoration:underline" target="_blank">https://lists.mcs.anl.gov/pipermail/petsc-users/2019-January/037262.html</a>, I translate my IS’s to a PETSc Section, which is then supplied to a DMShell and assigned to a KSP. I am not so familiar with the code or how / why this works, but it seems to do so perfectly. I name my sections with petsc4py using</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">section.setFieldName(0, "u")</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">section.setFieldName(1, "p")</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">section.setFieldName(2, "c")</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">However, this is also reflected in the way I can access the fieldsplit options from the command line. My question is: Is there any way of not using the FieldNames specified in python but use the index of the field as defined with “-pc_fieldsplit_0_fields 0, 1” and “-pc_fieldsplit_1_fields 2”, i.e., instead of the prefix “fieldsplit_0_fieldsplit_u” I want to write “fieldsplit_0_fieldsplit_0”, instead of “fieldsplit_0_fieldsplit_p” I want to use “fieldsplit_0_fieldsplit_1”, and instead of “fieldsplit_c” I want to use “fieldsplit_1”. Just changing the names of the fields to</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">section.setFieldName(0, "0")</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">section.setFieldName(1, "1")</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">section.setFieldName(2, "2")</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">does obviously not work as expected, as it works for velocity and pressure, but not for the concentration – the prefix there is then “fieldsplit_2” and not “fieldsplit_1”. In the docs, I have found<span> </span><a href="https://urldefense.us/v3/__https://petsc.org/main/manualpages/PC/PCFieldSplitSetFields/__;!!G_uCfscf7eWS!an6Idf-f7OiZlsU0N0Ftpr5mM5etD7GF_9ghya_ALFmQP_eL93oONwYYRLmLGz-0FSXHkB0bMsjj0X9GdD2a$" style="color:blue;text-decoration:underline" target="_blank">https://petsc.org/main/manualpages/PC/PCFieldSplitSetFields/</a><span> </span>which seems to suggest that the fieldname can potentially be supplied, but I don’t see how to do so from the command line. Also, for the sake of completeness, I attach the output of the solve with “-ksp_view” below.<span> </span></span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Thanks a lot in advance and best regards,</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">Sebastian</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">The output of ksp_view is the following:</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">KSP Object: 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: fgmres</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> happy breakdown tolerance 1e-30</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> maximum iterations=10000, initial guess is zero</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> tolerances: relative=1e-05, absolute=1e-11, divergence=10000.</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> right preconditioning</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using UNPRECONDITIONED norm type for convergence test</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US">PC Object: 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: fieldsplit</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> FieldSplit with ADDITIVE composition: total splits = 2</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Solver info for each split is in the following KSP objects:</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Split number 0 Defined by IS</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> KSP Object: (fieldsplit_0_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: fgmres</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> happy breakdown tolerance 1e-30</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> maximum iterations=10000, initial guess is zero</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> tolerances: relative=1e-14, absolute=1e-30, divergence=10000.</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> right preconditioning</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using UNPRECONDITIONED norm type for convergence test</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> PC Object: (fieldsplit_0_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: fieldsplit</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> FieldSplit with Schur preconditioner, factorization FULL</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Preconditioner for the Schur complement formed from Sp, an assembled approximation to S, which uses A00's diagonal's inverse</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Split info:</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Split number 0 Defined by IS</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Split number 1 Defined by IS</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> KSP solver for A00 block</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> KSP Object: (fieldsplit_0_fieldsplit_u_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: preonly</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> maximum iterations=10000, initial guess is zero</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> tolerances: relative=1e-05, absolute=1e-50, divergence=10000.</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> left preconditioning</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using NONE norm type for convergence test</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> PC Object: (fieldsplit_0_fieldsplit_u_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: lu</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> out-of-place factorization</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> tolerance for zero pivot 2.22045e-14</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> matrix ordering: nd</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> factor fill ratio given 5., needed 3.92639</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Factored matrix follows:</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=4290, cols=4290</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> package used to perform factorization: petsc</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=375944, allocated nonzeros=375944</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using I-node routines: found 2548 nodes, limit used is 5</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> linear system matrix = precond matrix:</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: (fieldsplit_0_fieldsplit_u_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=4290, cols=4290</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=95748, allocated nonzeros=95748</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total number of mallocs used during MatSetValues calls=0</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using I-node routines: found 3287 nodes, limit used is 5</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> KSP solver for S = A11 - A10 inv(A00) A01<span> </span></span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> KSP Object: (fieldsplit_0_fieldsplit_p_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: cg</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> maximum iterations=10000, initial guess is zero</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> tolerances: relative=1e-14, absolute=1e-30, divergence=10000.</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> left preconditioning</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using PRECONDITIONED norm type for convergence test</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> PC Object: (fieldsplit_0_fieldsplit_p_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: icc</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> out-of-place factorization</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> 0 levels of fill</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> tolerance for zero pivot 2.22045e-14</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using Manteuffel shift [POSITIVE_DEFINITE]</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> matrix ordering: natural</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> factor fill ratio given 1., needed 1.</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Factored matrix follows:</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqsbaij</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=561, cols=561</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> package used to perform factorization: petsc</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=5120, allocated nonzeros=5120</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> block size is 1</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> linear system matrix followed by preconditioner matrix:</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: (fieldsplit_0_fieldsplit_p_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: schurcomplement</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=561, cols=561</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Schur complement A11 - A10 inv(A00) A01</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> A11</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: (fieldsplit_0_fieldsplit_p_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=561, cols=561</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=3729, allocated nonzeros=3729</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total number of mallocs used during MatSetValues calls=0</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> not using I-node routines</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> A10</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=561, cols=4290</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=19938, allocated nonzeros=19938</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total number of mallocs used during MatSetValues calls=0</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> not using I-node routines</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> KSP of A00</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> KSP Object: (fieldsplit_0_fieldsplit_u_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: preonly</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> maximum iterations=10000, initial guess is zero</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> tolerances: relative=1e-05, absolute=1e-50, divergence=10000.</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> left preconditioning</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using NONE norm type for convergence test</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> PC Object: (fieldsplit_0_fieldsplit_u_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: lu</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> out-of-place factorization</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> tolerance for zero pivot 2.22045e-14</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> matrix ordering: nd</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> factor fill ratio given 5., needed 3.92639</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Factored matrix follows:</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=4290, cols=4290</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> package used to perform factorization: petsc</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=375944, allocated nonzeros=375944</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using I-node routines: found 2548 nodes, limit used is 5</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> linear system matrix = precond matrix:</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: (fieldsplit_0_fieldsplit_u_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=4290, cols=4290</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=95748, allocated nonzeros=95748</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total number of mallocs used during MatSetValues calls=0</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using I-node routines: found 3287 nodes, limit used is 5</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> A01</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=4290, cols=561</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=19938, allocated nonzeros=19938</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total number of mallocs used during MatSetValues calls=0</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using I-node routines: found 3287 nodes, limit used is 5</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=561, cols=561</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=9679, allocated nonzeros=9679</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total number of mallocs used during MatSetValues calls=0</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> not using I-node routines</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> linear system matrix = precond matrix:</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: (fieldsplit_0_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=4851, cols=4851</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=139353, allocated nonzeros=139353</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total number of mallocs used during MatSetValues calls=0</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using I-node routines: found 3830 nodes, limit used is 5</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Split number 1 Defined by IS</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> KSP Object: (fieldsplit_c_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: preonly</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> maximum iterations=10000, initial guess is zero</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> tolerances: relative=1e-05, absolute=1e-50, divergence=10000.</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> left preconditioning</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using NONE norm type for convergence test</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> PC Object: (fieldsplit_c_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: lu</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> out-of-place factorization</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> tolerance for zero pivot 2.22045e-14</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> matrix ordering: nd</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> factor fill ratio given 5., needed 4.24323</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Factored matrix follows:</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=561, cols=561</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> package used to perform factorization: petsc</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=15823, allocated nonzeros=15823</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> not using I-node routines</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> linear system matrix = precond matrix:</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: (fieldsplit_c_) 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=561, cols=561</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=3729, allocated nonzeros=3729</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total number of mallocs used during MatSetValues calls=0</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> not using I-node routines</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> linear system matrix = precond matrix:</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> Mat Object: 1 MPI processes</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> type: seqaij</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> rows=5412, cols=5412</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total: nonzeros=190416, allocated nonzeros=190416</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> total number of mallocs used during MatSetValues calls=0</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> using I-node routines: found 3833 nodes, limit used is 5</span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span lang="EN-US"> </span><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">--<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Dr. Sebastian Blauth<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Fraunhofer-Institut für<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Techno- und Wirtschaftsmathematik ITWM<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Abteilung Transportvorgänge<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Fraunhofer-Platz 1, 67663 Kaiserslautern<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">Telefon: +49 631 31600-4968<u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><a href="mailto:sebastian.blauth@itwm.fraunhofer.de" style="color:blue;text-decoration:underline" target="_blank">sebastian.blauth@itwm.fraunhofer.de</a><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><a href="https://urldefense.us/v3/__https://www.itwm.fraunhofer.de/__;!!G_uCfscf7eWS!an6Idf-f7OiZlsU0N0Ftpr5mM5etD7GF_9ghya_ALFmQP_eL93oONwYYRLmLGz-0FSXHkB0bMsjj0cdfEbTa$" style="color:blue;text-decoration:underline" target="_blank">https://www.itwm.fraunhofer.de</a><u></u><u></u></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> <u></u><u></u></div></div></div></div></blockquote></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><br clear="all"><u></u><u></u></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> <u></u><u></u></div></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span>--<span> </span></span><u></u><u></u></div><div><div><div><div><div><div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>-- Norbert Wiener<u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"> <u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><a href="https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!an6Idf-f7OiZlsU0N0Ftpr5mM5etD7GF_9ghya_ALFmQP_eL93oONwYYRLmLGz-0FSXHkB0bMsjj0VN-barz$" style="color:blue;text-decoration:underline" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><u></u><u></u></div></div></div></div></div></div></div></div></div></div></div></div></div></blockquote></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><br clear="all"><u></u><u></u></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><u></u> <u></u></div></div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><span>--<span> </span></span><u></u><u></u></div><div><div><div><div><div><div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif">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<u></u><u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><u></u> <u></u></div></div><div><div style="margin:0cm;font-size:11pt;font-family:Calibri,sans-serif"><a href="https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!an6Idf-f7OiZlsU0N0Ftpr5mM5etD7GF_9ghya_ALFmQP_eL93oONwYYRLmLGz-0FSXHkB0bMsjj0VN-barz$" style="color:blue;text-decoration:underline" target="_blank">https://www.cse.buffalo.edu/~knepley/</a></div></div></div></div></div></div></div></div></div></div></div></div></div></blockquote></div><br></div></div></blockquote></div><br clear="all"><div><br></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>-- Norbert Wiener</div><div><br></div><div><a href="https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!an6Idf-f7OiZlsU0N0Ftpr5mM5etD7GF_9ghya_ALFmQP_eL93oONwYYRLmLGz-0FSXHkB0bMsjj0VN-barz$" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><br></div></div></div></div></div></div></div></div>