<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Mon, Sep 22, 2014 at 9:15 PM, Jean-Arthur Louis Olive <span dir="ltr"><<a href="mailto:jaolive@mit.edu" target="_blank">jaolive@mit.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
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Hi all,
<div>I am using PETSc (dev version) to solve the Stokes + temperature equations. My DM has fields (vx, vy, p, T).</div></div></blockquote><div><br></div><div>I have finally had time to look at this. I have tried to reproduce this setup in a PETSc example. Here is SNES ex19:</div><div><br></div><div>cd src/snes/examples/tutorials</div><div>make ex19</div><div>./ex19 -ksp_type fgmres -pc_type fieldsplit -pc_fieldsplit_block_size 4 -pc_fieldsplit_type SCHUR -pc_fieldsplit_0_fields 0,1,2 -pc_fieldsplit_1_fields 3 -fieldsplit_1_pc_type lu -fieldsplit_0_pc_type fieldsplit -fieldsplit_0_pc_fieldsplit_block_size 3 -fieldsplit_0_pc_fieldsplit_0_fields 0,1 -fieldsplit_0_pc_fieldsplit_1_fields 2 -fieldsplit_0_pc_fieldsplit_type schur -fieldsplit_0_fieldsplit_0_pc_type lu -fieldsplit_0_fieldsplit_1_pc_type lu -snes_monitor_short -ksp_monitor_short -snes_view<br></div><div><br></div><div><div>lid velocity = 0.0625, prandtl # = 1, grashof # = 1</div><div> 0 SNES Function norm 0.239155 </div><div> 0 KSP Residual norm 0.239155 </div><div> 1 KSP Residual norm 8.25786e-07 </div><div> 1 SNES Function norm 6.82106e-05 </div><div> 0 KSP Residual norm 6.82106e-05 </div><div> 1 KSP Residual norm 1.478e-11 </div><div> 2 SNES Function norm 1.533e-11 </div><div>SNES Object: 1 MPI processes</div><div> type: newtonls</div><div> maximum iterations=50, maximum function evaluations=10000</div><div> tolerances: relative=1e-08, absolute=1e-50, solution=1e-08</div><div> total number of linear solver iterations=2</div><div> total number of function evaluations=3</div><div> SNESLineSearch Object: 1 MPI processes</div><div> type: bt</div><div> interpolation: cubic</div><div> alpha=1.000000e-04</div><div> maxstep=1.000000e+08, minlambda=1.000000e-12</div><div> tolerances: relative=1.000000e-08, absolute=1.000000e-15, lambda=1.000000e-08</div><div> maximum iterations=40</div><div> KSP Object: 1 MPI processes</div><div> type: fgmres</div><div> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement</div><div> GMRES: happy breakdown tolerance 1e-30</div><div> maximum iterations=10000, initial guess is zero</div><div> tolerances: relative=1e-05, absolute=1e-50, divergence=10000</div><div> right preconditioning</div><div> using UNPRECONDITIONED norm type for convergence test</div><div> PC Object: 1 MPI processes</div><div> type: fieldsplit</div><div> FieldSplit with Schur preconditioner, blocksize = 4, factorization FULL</div><div> Preconditioner for the Schur complement formed from A11</div><div> Split info:</div><div> Split number 0 Fields 0, 1, 2</div><div> Split number 1 Fields 3</div><div> KSP solver for A00 block</div><div> KSP Object: (fieldsplit_0_) 1 MPI processes</div><div> type: gmres</div><div> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement</div><div> GMRES: happy breakdown tolerance 1e-30</div><div> maximum iterations=10000, initial guess is zero</div><div> tolerances: relative=1e-05, absolute=1e-50, divergence=10000</div><div> left preconditioning</div><div> using PRECONDITIONED norm type for convergence test</div><div> PC Object: (fieldsplit_0_) 1 MPI processes</div><div> type: fieldsplit</div><div> FieldSplit with Schur preconditioner, blocksize = 3, factorization FULL</div><div> Preconditioner for the Schur complement formed from A11</div><div> Split info:</div><div> Split number 0 Fields 0, 1</div><div> Split number 1 Fields 2</div><div> KSP solver for A00 block</div><div> KSP Object: (fieldsplit_0_fieldsplit_0_) 1 MPI processes</div><div> type: gmres</div><div> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement</div><div> GMRES: happy breakdown tolerance 1e-30</div><div> maximum iterations=10000, initial guess is zero</div><div> tolerances: relative=1e-05, absolute=1e-50, divergence=10000</div><div> left preconditioning</div><div> using PRECONDITIONED norm type for convergence test</div><div> PC Object: (fieldsplit_0_fieldsplit_0_) 1 MPI processes</div><div> type: lu</div><div> LU: out-of-place factorization</div><div> tolerance for zero pivot 2.22045e-14</div><div> matrix ordering: nd</div><div> factor fill ratio given 5, needed 1.875</div><div> Factored matrix follows:</div><div> Mat Object: 1 MPI processes</div><div> type: seqaij</div><div> rows=32, cols=32</div><div> package used to perform factorization: petsc</div><div> total: nonzeros=480, allocated nonzeros=480</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 12 nodes, limit used is 5</div><div> linear system matrix = precond matrix:</div><div> Mat Object: (fieldsplit_0_fieldsplit_0_) 1 MPI processes</div><div> type: seqaij</div><div> rows=32, cols=32</div><div> total: nonzeros=256, allocated nonzeros=256</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 16 nodes, limit used is 5</div><div> KSP solver for S = A11 - A10 inv(A00) A01 </div><div> KSP Object: (fieldsplit_0_fieldsplit_1_) 1 MPI processes</div><div> type: gmres</div><div> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement</div><div> GMRES: happy breakdown tolerance 1e-30</div><div> maximum iterations=10000, initial guess is zero</div><div> tolerances: relative=1e-05, absolute=1e-50, divergence=10000</div><div> left preconditioning</div><div> using PRECONDITIONED norm type for convergence test</div><div> PC Object: (fieldsplit_0_fieldsplit_1_) 1 MPI processes</div><div> type: lu</div><div> LU: out-of-place factorization</div><div> tolerance for zero pivot 2.22045e-14</div><div> matrix ordering: nd</div><div> factor fill ratio given 5, needed 1.875</div><div> Factored matrix follows:</div><div> Mat Object: 1 MPI processes</div><div> type: seqaij</div><div> rows=16, cols=16</div><div> package used to perform factorization: petsc</div><div> total: nonzeros=120, allocated nonzeros=120</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 12 nodes, limit used is 5</div><div> linear system matrix followed by preconditioner matrix:</div><div> Mat Object: (fieldsplit_0_fieldsplit_1_) 1 MPI processes</div><div> type: schurcomplement</div><div> rows=16, cols=16</div><div> Schur complement A11 - A10 inv(A00) A01</div><div> A11</div><div> Mat Object: (fieldsplit_0_fieldsplit_1_) 1 MPI processes</div><div> type: seqaij</div><div> rows=16, cols=16</div><div> total: nonzeros=64, allocated nonzeros=64</div><div> total number of mallocs used during MatSetValues calls =0</div><div> not using I-node routines</div><div> A10</div><div> Mat Object: 1 MPI processes</div><div> type: seqaij</div><div> rows=16, cols=32</div><div> total: nonzeros=128, allocated nonzeros=128</div><div> total number of mallocs used during MatSetValues calls =0</div><div> not using I-node routines</div><div> KSP of A00</div><div> KSP Object: (fieldsplit_0_fieldsplit_0_) 1 MPI processes</div><div> type: gmres</div><div> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement</div><div> GMRES: happy breakdown tolerance 1e-30</div><div> maximum iterations=10000, initial guess is zero</div><div> tolerances: relative=1e-05, absolute=1e-50, divergence=10000</div><div> left preconditioning</div><div> using PRECONDITIONED norm type for convergence test</div><div> PC Object: (fieldsplit_0_fieldsplit_0_) 1 MPI processes</div><div> type: lu</div><div> LU: out-of-place factorization</div><div> tolerance for zero pivot 2.22045e-14</div><div> matrix ordering: nd</div><div> factor fill ratio given 5, needed 1.875</div><div> Factored matrix follows:</div><div> Mat Object: 1 MPI processes</div><div> type: seqaij</div><div> rows=32, cols=32</div><div> package used to perform factorization: petsc</div><div> total: nonzeros=480, allocated nonzeros=480</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 12 nodes, limit used is 5</div><div> linear system matrix = precond matrix:</div><div> Mat Object: (fieldsplit_0_fieldsplit_0_) 1 MPI processes</div><div> type: seqaij</div><div> rows=32, cols=32</div><div> total: nonzeros=256, allocated nonzeros=256</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 16 nodes, limit used is 5</div><div> A01</div><div> Mat Object: 1 MPI processes</div><div> type: seqaij</div><div> rows=32, cols=16</div><div> total: nonzeros=128, allocated nonzeros=128</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 16 nodes, limit used is 5</div><div> Mat Object: (fieldsplit_0_fieldsplit_1_) 1 MPI processes</div><div> type: seqaij</div><div> rows=16, cols=16</div><div> total: nonzeros=64, allocated nonzeros=64</div><div> total number of mallocs used during MatSetValues calls =0</div><div> not using I-node routines</div><div> linear system matrix = precond matrix:</div><div> Mat Object: (fieldsplit_0_) 1 MPI processes</div><div> type: seqaij</div><div> rows=48, cols=48</div><div> total: nonzeros=576, allocated nonzeros=576</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 16 nodes, limit used is 5</div><div> KSP solver for S = A11 - A10 inv(A00) A01 </div><div> KSP Object: (fieldsplit_1_) 1 MPI processes</div><div> type: gmres</div><div> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement</div><div> GMRES: happy breakdown tolerance 1e-30</div><div> maximum iterations=10000, initial guess is zero</div><div> tolerances: relative=1e-05, absolute=1e-50, divergence=10000</div><div> left preconditioning</div><div> using PRECONDITIONED norm type for convergence test</div><div> PC Object: (fieldsplit_1_) 1 MPI processes</div><div> type: lu</div><div> LU: out-of-place factorization</div><div> tolerance for zero pivot 2.22045e-14</div><div> matrix ordering: nd</div><div> factor fill ratio given 5, needed 1.875</div><div> Factored matrix follows:</div><div> Mat Object: 1 MPI processes</div><div> type: seqaij</div><div> rows=16, cols=16</div><div> package used to perform factorization: petsc</div><div> total: nonzeros=120, allocated nonzeros=120</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 12 nodes, limit used is 5</div><div> linear system matrix followed by preconditioner matrix:</div><div> Mat Object: (fieldsplit_1_) 1 MPI processes</div><div> type: schurcomplement</div><div> rows=16, cols=16</div><div> Schur complement A11 - A10 inv(A00) A01</div><div> A11</div><div> Mat Object: (fieldsplit_1_) 1 MPI processes</div><div> type: seqaij</div><div> rows=16, cols=16</div><div> total: nonzeros=64, allocated nonzeros=64</div><div> total number of mallocs used during MatSetValues calls =0</div><div> not using I-node routines</div><div> A10</div><div> Mat Object: 1 MPI processes</div><div> type: seqaij</div><div> rows=16, cols=48</div><div> total: nonzeros=192, allocated nonzeros=192</div><div> total number of mallocs used during MatSetValues calls =0</div><div> not using I-node routines</div><div> KSP of A00</div><div> KSP Object: (fieldsplit_0_) 1 MPI processes</div><div> type: gmres</div><div> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement</div><div> GMRES: happy breakdown tolerance 1e-30</div><div> maximum iterations=10000, initial guess is zero</div><div> tolerances: relative=1e-05, absolute=1e-50, divergence=10000</div><div> left preconditioning</div><div> using PRECONDITIONED norm type for convergence test</div><div> PC Object: (fieldsplit_0_) 1 MPI processes</div><div> type: fieldsplit</div><div> FieldSplit with Schur preconditioner, blocksize = 3, factorization FULL</div><div> Preconditioner for the Schur complement formed from A11</div><div> Split info:</div><div> Split number 0 Fields 0, 1</div><div> Split number 1 Fields 2</div><div> KSP solver for A00 block</div><div> KSP Object: (fieldsplit_0_fieldsplit_0_) 1 MPI processes</div><div> type: gmres</div><div> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement</div><div> GMRES: happy breakdown tolerance 1e-30</div><div> maximum iterations=10000, initial guess is zero</div><div> tolerances: relative=1e-05, absolute=1e-50, divergence=10000</div><div> left preconditioning</div><div> using PRECONDITIONED norm type for convergence test</div><div> PC Object: (fieldsplit_0_fieldsplit_0_) 1 MPI processes</div><div> type: lu</div><div> LU: out-of-place factorization</div><div> tolerance for zero pivot 2.22045e-14</div><div> matrix ordering: nd</div><div> factor fill ratio given 5, needed 1.875</div><div> Factored matrix follows:</div><div> Mat Object: 1 MPI processes</div><div> type: seqaij</div><div> rows=32, cols=32</div><div> package used to perform factorization: petsc</div><div> total: nonzeros=480, allocated nonzeros=480</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 12 nodes, limit used is 5</div><div> linear system matrix = precond matrix:</div><div> Mat Object: (fieldsplit_0_fieldsplit_0_) 1 MPI processes</div><div> type: seqaij</div><div> rows=32, cols=32</div><div> total: nonzeros=256, allocated nonzeros=256</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 16 nodes, limit used is 5</div><div> KSP solver for S = A11 - A10 inv(A00) A01 </div><div> KSP Object: (fieldsplit_0_fieldsplit_1_) 1 MPI processes</div><div> type: gmres</div><div> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement</div><div> GMRES: happy breakdown tolerance 1e-30</div><div> maximum iterations=10000, initial guess is zero</div><div> tolerances: relative=1e-05, absolute=1e-50, divergence=10000</div><div> left preconditioning</div><div> using PRECONDITIONED norm type for convergence test</div><div> PC Object: (fieldsplit_0_fieldsplit_1_) 1 MPI processes</div><div> type: lu</div><div> LU: out-of-place factorization</div><div> tolerance for zero pivot 2.22045e-14</div><div> matrix ordering: nd</div><div> factor fill ratio given 5, needed 1.875</div><div> Factored matrix follows:</div><div> Mat Object: 1 MPI processes</div><div> type: seqaij</div><div> rows=16, cols=16</div><div> package used to perform factorization: petsc</div><div> total: nonzeros=120, allocated nonzeros=120</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 12 nodes, limit used is 5</div><div> linear system matrix followed by preconditioner matrix:</div><div> Mat Object: (fieldsplit_0_fieldsplit_1_) 1 MPI processes</div><div> type: schurcomplement</div><div> rows=16, cols=16</div><div> Schur complement A11 - A10 inv(A00) A01</div><div> A11</div><div> Mat Object: (fieldsplit_0_fieldsplit_1_) 1 MPI processes</div><div> type: seqaij</div><div> rows=16, cols=16</div><div> total: nonzeros=64, allocated nonzeros=64</div><div> total number of mallocs used during MatSetValues calls =0</div><div> not using I-node routines</div><div> A10</div><div> Mat Object: 1 MPI processes</div><div> type: seqaij</div><div> rows=16, cols=32</div><div> total: nonzeros=128, allocated nonzeros=128</div><div> total number of mallocs used during MatSetValues calls =0</div><div> not using I-node routines</div><div> KSP of A00</div><div> KSP Object: (fieldsplit_0_fieldsplit_0_) 1 MPI processes</div><div> type: gmres</div><div> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt Orthogonalization with no iterative refinement</div><div> GMRES: happy breakdown tolerance 1e-30</div><div> maximum iterations=10000, initial guess is zero</div><div> tolerances: relative=1e-05, absolute=1e-50, divergence=10000</div><div> left preconditioning</div><div> using PRECONDITIONED norm type for convergence test</div><div> PC Object: (fieldsplit_0_fieldsplit_0_) 1 MPI processes</div><div> type: lu</div><div> LU: out-of-place factorization</div><div> tolerance for zero pivot 2.22045e-14</div><div> matrix ordering: nd</div><div> factor fill ratio given 5, needed 1.875</div><div> Factored matrix follows:</div><div> Mat Object: 1 MPI processes</div><div> type: seqaij</div><div> rows=32, cols=32</div><div> package used to perform factorization: petsc</div><div> total: nonzeros=480, allocated nonzeros=480</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 12 nodes, limit used is 5</div><div> linear system matrix = precond matrix:</div><div> Mat Object: (fieldsplit_0_fieldsplit_0_) 1 MPI processes</div><div> type: seqaij</div><div> rows=32, cols=32</div><div> total: nonzeros=256, allocated nonzeros=256</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 16 nodes, limit used is 5</div><div> A01</div><div> Mat Object: 1 MPI processes</div><div> type: seqaij</div><div> rows=32, cols=16</div><div> total: nonzeros=128, allocated nonzeros=128</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 16 nodes, limit used is 5</div><div> Mat Object: (fieldsplit_0_fieldsplit_1_) 1 MPI processes</div><div> type: seqaij</div><div> rows=16, cols=16</div><div> total: nonzeros=64, allocated nonzeros=64</div><div> total number of mallocs used during MatSetValues calls =0</div><div> not using I-node routines</div><div> linear system matrix = precond matrix:</div><div> Mat Object: (fieldsplit_0_) 1 MPI processes</div><div> type: seqaij</div><div> rows=48, cols=48</div><div> total: nonzeros=576, allocated nonzeros=576</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 16 nodes, limit used is 5</div><div> A01</div><div> Mat Object: 1 MPI processes</div><div> type: seqaij</div><div> rows=48, cols=16</div><div> total: nonzeros=192, allocated nonzeros=192</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 16 nodes, limit used is 5</div><div> Mat Object: (fieldsplit_1_) 1 MPI processes</div><div> type: seqaij</div><div> rows=16, cols=16</div><div> total: nonzeros=64, allocated nonzeros=64</div><div> total number of mallocs used during MatSetValues calls =0</div><div> not using I-node routines</div><div> linear system matrix = precond matrix:</div><div> Mat Object: 1 MPI processes</div><div> type: seqaij</div><div> rows=64, cols=64, bs=4</div><div> total: nonzeros=1024, allocated nonzeros=1024</div><div> total number of mallocs used during MatSetValues calls =0</div><div> using I-node routines: found 16 nodes, limit used is 5</div><div>Number of SNES iterations = 2</div></div><div><br></div><div>I cannot replicate your failure here. I am running on the 'next' branch here. What are you using?</div><div>Also, are you using the DMDA for data layout?</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div style="word-wrap:break-word">
<div>I would like to use nested fieldsplits to separate the T part from the Stokes part, and apply a Schur complement approach to the Stokes block.</div>
<div>Unfortunately, I keep getting this error message:</div>
<div><span style="color:rgb(41,249,20);font-family:'Andale Mono';background-color:rgb(0,0,0)">[1]PETSC ERROR: DMCreateFieldDecomposition() line 1274 in /home/jolive/petsc/src/dm/interface/dm.c Decomposition defined only after DMSetUp</span></div>
<div><br>
</div>
<div>Here are the command line options I tried:</div>
<div><br>
</div>
<div>
<div><span style="font-family:Menlo;font-size:11px">-snes_type ksponly \</span></div>
<div>
<div style="margin:0px;font-size:11px;font-family:Menlo">-ksp_type fgmres \</div>
<div style="margin:0px;font-size:11px;font-family:Menlo"><span style="color:rgb(0,132,0)"># define 2 fields: [vx vy p] and [T] </span></div>
<div style="margin:0px;font-size:11px;font-family:Menlo">-pc_type fieldsplit -pc_fieldsplit_<span style="color:rgb(39,42,216)">0</span>_fields <span style="color:rgb(39,42,216)">0</span>,<span style="color:rgb(39,42,216)">1</span>,<span style="color:rgb(39,42,216)">2</span> -pc_fieldsplit_<span style="color:rgb(39,42,216)">1</span>_fields <span style="color:rgb(39,42,216)">3</span> \</div>
<div style="margin:0px;font-size:11px;font-family:Menlo"><span style="color:rgb(0,132,0)"># split [vx vy p] into 2 fields: [vx vy] and [p] </span></div>
<div style="margin:0px;font-size:11px;font-family:Menlo">-fieldsplit_<span style="color:rgb(39,42,216)">0</span>_pc_type fieldsplit \</div>
<div style="margin:0px;font-size:11px;font-family:Menlo">
<div style="margin:0px">-pc_fieldsplit_<span style="color:rgb(39,42,216)">0</span>_fieldsplit_<span style="color:rgb(39,42,216)">0</span>_fields <span style="color:rgb(39,42,216)">0</span>,<span style="color:rgb(39,42,216)">1</span> -pc_fieldsplit_<span style="color:rgb(39,42,216)">0</span>_fieldsplit_<span style="color:rgb(39,42,216)">1</span>_fields <span style="color:rgb(39,42,216)">2</span> \</div></div></div></div></div></blockquote><div><br></div><div>Note that the 2 options above are wrong. It should be -fieldsplit_0_pc_fieldsplit_0_fields 0,1</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-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div style="word-wrap:break-word"><div><div><div style="margin:0px;font-size:11px;font-family:Menlo">
<div style="margin:0px"><span style="color:rgb(0,132,0)"># apply schur complement to [vx vy p]</span></div>
</div>
<div style="margin:0px;font-size:11px;font-family:Menlo">-fieldsplit_<span style="color:rgb(39,42,216)">0</span>_pc_fieldsplit_type schur \</div>
<div style="margin:0px;font-size:11px;font-family:Menlo">-fieldsplit_<span style="color:rgb(39,42,216)">0</span>_pc_fieldsplit_schur_factorization_type upper \</div>
<div style="margin:0px;font-size:11px;font-family:Menlo"><br>
</div>
<div style="margin:0px;font-size:11px;font-family:Menlo"><span style="color:rgb(0,132,0)"># solve everything with lu, just for testing</span></div>
<div style="margin:0px;font-size:11px;font-family:Menlo">-fieldsplit_<span style="color:rgb(39,42,216)">0</span>_fieldsplit_<span style="color:rgb(39,42,216)">0</span>_ksp_type preonly \</div>
<div style="margin:0px;font-size:11px;font-family:Menlo">-fieldsplit_<span style="color:rgb(39,42,216)">0</span>_fieldsplit_<span style="color:rgb(39,42,216)">0</span>_pc_type lu -fieldsplit_<span style="color:rgb(39,42,216)">0</span>_fieldsplit_<span style="color:rgb(39,42,216)">0</span>_pc_factor_mat_solver_package
superlu_dist \</div>
<div style="margin:0px;font-size:11px;font-family:Menlo">-fieldsplit_<span style="color:rgb(39,42,216)">0</span>_fieldsplit_<span style="color:rgb(39,42,216)">1</span>_ksp_type preonly \</div>
<div style="margin:0px;font-size:11px;font-family:Menlo">-fieldsplit_<span style="color:rgb(39,42,216)">0</span>_fieldsplit_<span style="color:rgb(39,42,216)">1</span>_pc_type lu -fieldsplit_<span style="color:rgb(39,42,216)">0</span>_fieldsplit_<span style="color:rgb(39,42,216)">1</span>_pc_factor_mat_solver_package
superlu_dist \</div>
<div style="margin:0px;font-size:11px;font-family:Menlo">-fieldsplit_<span style="color:rgb(39,42,216)">1</span>_ksp_type preonly \</div>
<div style="margin:0px;font-size:11px;font-family:Menlo">-fieldsplit_<span style="color:rgb(39,42,216)">1</span>_pc_type lu -fieldsplit_<span style="color:rgb(39,42,216)">1</span>_pc_factor_mat_solver_package superlu_dist \</div>
</div>
</div>
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<div style="margin:0px;font-size:11px;font-family:Menlo"><span style="font-family:Helvetica;font-size:12px">Any idea what could be causing this?</span></div>
<div style="margin:0px;font-size:11px;font-family:Menlo"><span style="font-family:Helvetica;font-size:12px">Thanks a lot,</span></div>
<div style="margin:0px;font-size:11px;font-family:Menlo"><span style="font-family:Helvetica;font-size:12px">Arthur</span></div>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br>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
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