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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Thanks for your tutorials. Yes. I tried PCFIELDSPLIT. However, it only works for sequential runs. When I run the code in distributed memory, it reports errors.
In fact, the essence of my wonder is (a) how to set up superlu_dist in petsc for solving saddle point problem in distributed memory? (b) does the direct solvers in petsc can run in distributed memory for solving saddle point problem?<o:p></o:p></span></p>
<p class="MsoNormal"><a name="_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></a></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Stefano Zampini [mailto:stefano.zampini@gmail.com]
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<b>Sent:</b> Tuesday, 28 July 2020 6:55 PM<br>
<b>To:</b> Bin Liu <lbllm2018@hotmail.com><br>
<b>Cc:</b> petsc-users@mcs.anl.gov<br>
<b>Subject:</b> Re: [petsc-users] solving saddle point problem in distributed memory<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">If you want advice you should post the error trace PETSc reports.<o:p></o:p></p>
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<p class="MsoNormal">Anyway, solving Stokes is not so trivial (without direct solvers, you may need mesh dependent information), but we have examples for it<o:p></o:p></p>
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<p class="MsoNormal"><a href="https://gitlab.com/petsc/petsc/-/blob/master/src/ksp/ksp/tutorials/ex42.c">https://gitlab.com/petsc/petsc/-/blob/master/src/ksp/ksp/tutorials/ex42.c</a><o:p></o:p></p>
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<p class="MsoNormal"><a href="https://gitlab.com/petsc/petsc/-/blob/master/src/ksp/ksp/tutorials/ex43.c">https://gitlab.com/petsc/petsc/-/blob/master/src/ksp/ksp/tutorials/ex43.c</a><o:p></o:p></p>
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<p class="MsoNormal"><a href="https://gitlab.com/petsc/petsc/-/blob/master/src/snes/tutorials/ex69.c">https://gitlab.com/petsc/petsc/-/blob/master/src/snes/tutorials/ex69.c</a><o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">If you scroll to the end of those files, you see a bunch of possible options either using PCFIELDSPLIT, PCBDDC or KSPFETIDP.<o:p></o:p></p>
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<p class="MsoNormal">On Jul 28, 2020, at 12:37 PM, Bin Liu <<a href="mailto:lbllm2018@hotmail.com">lbllm2018@hotmail.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif">I would like to solve a saddle point problem arising from the stokes equation. I got successful to use the direct solvers in sequential runs. However, I would like to extend it for distributed
memory computation. I tried to use superlu_dist, but the program returns errors. Is it possible to solve a saddle point problem in distributed memory using superlu_dist? Could anyone give a simple sample code to set up the parameters of the solver?<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif">Thanks<o:p></o:p></span></p>
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