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<body class='hmmessage'><div dir='ltr'>Dear Users,<br><br>The following is the full error message. Thank you so much!<br><br> *************** Linear iteration 1 ***********<br>[0]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------<br>[0]PETSC ERROR: Object is in wrong state<br>[0]PETSC ERROR: Matrix is missing diagonal entry 0<br>[0]PETSC ERROR: See <a target="" href="http://www.mcs.anl.gov/petsc/documentation/faq.html">http://www.mcs.anl.gov/petsc/documentation/faq.html</a> for trouble shooting.<br>[0]PETSC ERROR: Petsc Release Version 3.6.1, unknown<br>[0]PETSC ERROR: ./PCFieldSplit_ex13 on a arch-linux2-cxx-opt named linux-394h by coyigg Wed Feb 3 14:57:21 2016<br>[0]PETSC
ERROR: Configure options --with-clanguage=cxx --with-debugging=0
--download-fblaslapack=1 --download-hdf5=1 --download-openmpi=1
--download-metis=1 --download-parmetis=1 --with-shared-libraries=1
--with-cc=gcc --with-fc=gfortran --with-cxx=g++ --download-blacs=1
--download-scalapack=1 --download-mumps=1<br>[0]PETSC ERROR: #1 MatILUFactorSymbolic_SeqAIJ() line 1729 in /home/eaulisa/software/petsc/src/mat/impls/aij/seq/aijfact.c<br>[0]PETSC ERROR: #2 MatILUFactorSymbolic() line 6457 in /home/eaulisa/software/petsc/src/mat/interface/matrix.c<br>[0]PETSC ERROR: #3 PCSetUp_ILU() line 204 in /home/eaulisa/software/petsc/src/ksp/pc/impls/factor/ilu/ilu.c<br>[0]PETSC ERROR: #4 PCSetUp() line 983 in /home/eaulisa/software/petsc/src/ksp/pc/interface/precon.c<br>[0]PETSC ERROR: #5 KSPSetUp() line 332 in /home/eaulisa/software/petsc/src/ksp/ksp/interface/itfunc.c<br>[0]PETSC ERROR: #6 KSPSolve() line 546 in /home/eaulisa/software/petsc/src/ksp/ksp/interface/itfunc.c<br>[0]PETSC ERROR: #7 PCApply_LSC() line 83 in /home/eaulisa/software/petsc/src/ksp/pc/impls/lsc/lsc.c<br>[0]PETSC ERROR: #8 PCApply() line 483 in /home/eaulisa/software/petsc/src/ksp/pc/interface/precon.c<br>[0]PETSC ERROR: #9 KSP_PCApply() line 242 in /home/eaulisa/software/petsc/include/petsc/private/kspimpl.h<br>[0]PETSC ERROR: #10 KSPSolve_PREONLY() line 26 in /home/eaulisa/software/petsc/src/ksp/ksp/impls/preonly/preonly.c<br>[0]PETSC ERROR: #11 KSPSolve() line 604 in /home/eaulisa/software/petsc/src/ksp/ksp/interface/itfunc.c<br>[0]PETSC ERROR: #12 PCApply_FieldSplit_Schur() line 874 in /home/eaulisa/software/petsc/src/ksp/pc/impls/fieldsplit/fieldsplit.c<br>[0]PETSC ERROR: #13 PCApply() line 483 in /home/eaulisa/software/petsc/src/ksp/pc/interface/precon.c<br>[0]PETSC ERROR: #14 KSP_PCApply() line 242 in /home/eaulisa/software/petsc/include/petsc/private/kspimpl.h<br>[0]PETSC ERROR: #15 KSPInitialResidual() line 63 in /home/eaulisa/software/petsc/src/ksp/ksp/interface/itres.c<br>[0]PETSC ERROR: #16 KSPSolve_GMRES() line 235 in /home/eaulisa/software/petsc/src/ksp/ksp/impls/gmres/gmres.c<br>[0]PETSC ERROR: #17 KSPSolve() line 604 in /home/eaulisa/software/petsc/src/ksp/ksp/interface/itfunc.c<br>[0]PETSC ERROR: #18 PCMGMCycle_Private() line 19 in /home/eaulisa/software/petsc/src/ksp/pc/impls/mg/mg.c<br>[0]PETSC ERROR: #19 PCApply_MG() line 340 in /home/eaulisa/software/petsc/src/ksp/pc/impls/mg/mg.c<br>[0]PETSC ERROR: #20 PCApply() line 483 in /home/eaulisa/software/petsc/src/ksp/pc/interface/precon.c<br>[0]PETSC ERROR: #21 KSPSolve() line 582 in /home/eaulisa/software/petsc/src/ksp/ksp/interface/itfunc.c<br> *************** MG linear solver time: 0.002<br> *************** Number of outer ksp solver iterations = 0<br> *************** Convergence reason = 0<br> *************** Residual norm = 0<br> *************** Level Max 2 Linear Res L2norm U = 4.033131e-02<br> *************** Level Max 2 Linear Res L2norm V = 5.330749e-02<br> *************** Level Max 2 Linear Res L2norm P = 1.396813e-01<br><br><br><div>> Subject: Re: [petsc-users] Problem with least squares commutators(LSC)<br>> From: bsmith@mcs.anl.gov<br>> Date: Wed, 3 Feb 2016 22:26:42 -0600<br>> CC: petsc-users@mcs.anl.gov<br>> To: coyigg@hotmail.com<br>> <br>> <br>> We'd need the full error message to determine what is happening.<br>> <br>> But note that since the lower right block is all 0 any attempt to use a factorization of that inside a preconditioner will fail with zero pivot. <br>> <br>> <br>> > On Feb 2, 2016, at 10:40 PM, keguoyi <coyigg@hotmail.com> wrote:<br>> > <br>> > Dear PETSc users,<br>> > <br>> > This is Guoyi Ke, a graduate student of Texas Tech University. I have a 2D Navier Stokes problem that has block matrices: J=[F B^T; B 0]. I use Schur complement preconditioner for block J. The code was set as:<br>> > <br>> > PCFieldSplitSetType( pc, PC_COMPOSITE_SCHUR );<br>> > PCFieldSplitSetSchurFactType(pc, PC_FIELDSPLIT_SCHUR_FACT_LOWER);<br>> > PCFieldSplitSetSchurPre(pc,PC_FIELDSPLIT_SCHUR_PRE_SELFP,NULL);<br>> > <br>> > For both velocity block (fieldsplit: 0) and pressure block (fieldsplit: 1) , we set the KSP as KSPPREONLY and PC as PCILU. For this case, it works fine for us. <br>> > However, in order to use LSC we change the code as:<br>> > <br>> > PCFieldSplitSetType( pc, PC_COMPOSITE_SCHUR );<br>> > PCFieldSplitSetSchurFactType(pc, PC_FIELDSPLIT_SCHUR_FACT_LOWER);<br>> > PCFieldSplitSetSchurPre(pc,PC_FIELDSPLIT_SCHUR_PRE_SELF,NULL);<br>> > <br>> > We keep the same setup for velocity block (fieldsplit: 0) as above. For pressure block (fieldsplit: 1), we set the KSP as KSPGMRES and PC as PCLSU. I got the following errors:<br>> > <br>> > [0]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------<br>> > [0]PETSC ERROR: Object is in wrong state<br>> > [0]PETSC ERROR: Matrix is missing diagonal entry 0<br>> > <br>> > <br>> > Any suggestion and help will be highly appreciated. Thank you so much!<br>> > <br>> > Best,<br>> > Guoyi <br>> <br></div> </div></body>
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