Run again using LU on both blocks to see what happens.
> On Apr 27, 2017, at 2:14 AM, Hoang Giang Bui <[email protected]> wrote: > > I have changed the way to tie the nonconforming mesh. It seems the matrix now > is better > > with -pc_type lu the output is > 0 KSP preconditioned resid norm 3.308678584240e-01 true resid norm > 9.006493082896e+06 ||r(i)||/||b|| 1.000000000000e+00 > 1 KSP preconditioned resid norm 2.004313395301e-12 true resid norm > 2.549872332830e-05 ||r(i)||/||b|| 2.831148938173e-12 > Linear solve converged due to CONVERGED_ATOL iterations 1 > > > with -pc_type fieldsplit -fieldsplit_u_pc_type hypre -fieldsplit_wp_pc_type > lu the convergence is slow > 0 KSP preconditioned resid norm 1.116302362553e-01 true resid norm > 9.006493083520e+06 ||r(i)||/||b|| 1.000000000000e+00 > 1 KSP preconditioned resid norm 2.582134825666e-02 true resid norm > 9.268347719866e+06 ||r(i)||/||b|| 1.029073984060e+00 > ... > 824 KSP preconditioned resid norm 1.018542387738e-09 true resid norm > 2.906608839310e+02 ||r(i)||/||b|| 3.227237074804e-05 > 825 KSP preconditioned resid norm 9.743727947637e-10 true resid norm > 2.820369993061e+02 ||r(i)||/||b|| 3.131485215062e-05 > Linear solve converged due to CONVERGED_ATOL iterations 825 > > checking with additional -fieldsplit_u_ksp_type richardson > -fieldsplit_u_ksp_monitor -fieldsplit_u_ksp_max_it 1 -fieldsplit_wp_ksp_type > richardson -fieldsplit_wp_ksp_monitor -fieldsplit_wp_ksp_max_it 1 gives > > 0 KSP preconditioned resid norm 1.116302362553e-01 true resid norm > 9.006493083520e+06 ||r(i)||/||b|| 1.000000000000e+00 > Residual norms for fieldsplit_u_ solve. > 0 KSP Residual norm 5.803507549280e-01 > 1 KSP Residual norm 2.069538175950e-01 > Residual norms for fieldsplit_wp_ solve. > 0 KSP Residual norm 0.000000000000e+00 > 1 KSP preconditioned resid norm 2.582134825666e-02 true resid norm > 9.268347719866e+06 ||r(i)||/||b|| 1.029073984060e+00 > Residual norms for fieldsplit_u_ solve. > 0 KSP Residual norm 7.831796195225e-01 > 1 KSP Residual norm 1.734608520110e-01 > Residual norms for fieldsplit_wp_ solve. > 0 KSP Residual norm 0.000000000000e+00 > .... > 823 KSP preconditioned resid norm 1.065070135605e-09 true resid norm > 3.081881356833e+02 ||r(i)||/||b|| 3.421843916665e-05 > Residual norms for fieldsplit_u_ solve. > 0 KSP Residual norm 6.113806394327e-01 > 1 KSP Residual norm 1.535465290944e-01 > Residual norms for fieldsplit_wp_ solve. > 0 KSP Residual norm 0.000000000000e+00 > 824 KSP preconditioned resid norm 1.018542387746e-09 true resid norm > 2.906608839353e+02 ||r(i)||/||b|| 3.227237074851e-05 > Residual norms for fieldsplit_u_ solve. > 0 KSP Residual norm 6.123437055586e-01 > 1 KSP Residual norm 1.524661826133e-01 > Residual norms for fieldsplit_wp_ solve. > 0 KSP Residual norm 0.000000000000e+00 > 825 KSP preconditioned resid norm 9.743727947718e-10 true resid norm > 2.820369990571e+02 ||r(i)||/||b|| 3.131485212298e-05 > Linear solve converged due to CONVERGED_ATOL iterations 825 > > > The residual for wp block is zero since in this first step the rhs is zero. > As can see in the output, the multigrid does not perform well to reduce the > residual in the sub-solve. Is my observation right? what can be done to > improve this? > > > Giang > > On Tue, Apr 25, 2017 at 12:17 AM, Barry Smith <[email protected]> wrote: > > This can happen in the matrix is singular or nearly singular or if the > factorization generates small pivots, which can occur for even nonsingular > problems if the matrix is poorly scaled or just plain nasty. > > > > On Apr 24, 2017, at 5:10 PM, Hoang Giang Bui <[email protected]> wrote: > > > > It took a while, here I send you the output > > > > 0 KSP preconditioned resid norm 3.129073545457e+05 true resid norm > > 9.015150492169e+06 ||r(i)||/||b|| 1.000000000000e+00 > > 1 KSP preconditioned resid norm 7.442444222843e-01 true resid norm > > 1.003356247696e+02 ||r(i)||/||b|| 1.112966720375e-05 > > 2 KSP preconditioned resid norm 3.267453132529e-07 true resid norm > > 3.216722968300e+01 ||r(i)||/||b|| 3.568130084011e-06 > > 3 KSP preconditioned resid norm 1.155046883816e-11 true resid norm > > 3.234460376820e+01 ||r(i)||/||b|| 3.587805194854e-06 > > Linear solve converged due to CONVERGED_ATOL iterations 3 > > KSP Object: 4 MPI processes > > type: gmres > > GMRES: restart=1000, using Modified Gram-Schmidt Orthogonalization > > GMRES: happy breakdown tolerance 1e-30 > > maximum iterations=1000, initial guess is zero > > tolerances: relative=1e-20, absolute=1e-09, divergence=10000 > > left preconditioning > > using PRECONDITIONED norm type for convergence test > > PC Object: 4 MPI processes > > type: lu > > LU: out-of-place factorization > > tolerance for zero pivot 2.22045e-14 > > matrix ordering: natural > > factor fill ratio given 0, needed 0 > > Factored matrix follows: > > Mat Object: 4 MPI processes > > type: mpiaij > > rows=973051, cols=973051 > > package used to perform factorization: pastix > > Error : 3.24786e-14 > > total: nonzeros=0, allocated nonzeros=0 > > total number of mallocs used during MatSetValues calls =0 > > PaStiX run parameters: > > Matrix type : Unsymmetric > > Level of printing (0,1,2): 0 > > Number of refinements iterations : 3 > > Error : 3.24786e-14 > > linear system matrix = precond matrix: > > Mat Object: 4 MPI processes > > type: mpiaij > > rows=973051, cols=973051 > > Error : 3.24786e-14 > > total: nonzeros=9.90037e+07, allocated nonzeros=9.90037e+07 > > total number of mallocs used during MatSetValues calls =0 > > using I-node (on process 0) routines: found 78749 nodes, limit used > > is 5 > > Error : 3.24786e-14 > > > > It doesn't do as you said. Something is not right here. I will look in > > depth. > > > > Giang > > > > On Mon, Apr 24, 2017 at 8:21 PM, Barry Smith <[email protected]> wrote: > > > > > On Apr 24, 2017, at 12:47 PM, Hoang Giang Bui <[email protected]> wrote: > > > > > > Good catch. I get this for the very first step, maybe at that time the > > > rhs_w is zero. > > > > With the multiplicative composition the right hand side of the second > > solve is the initial right hand side of the second solve minus A_10*x where > > x is the solution to the first sub solve and A_10 is the lower left block > > of the outer matrix. So unless both the initial right hand side has a zero > > for the second block and A_10 is identically zero the right hand side for > > the second sub solve should not be zero. Is A_10 == 0? > > > > > > > In the later step, it shows 2 step convergence > > > > > > Residual norms for fieldsplit_u_ solve. > > > 0 KSP Residual norm 3.165886479830e+04 > > > 1 KSP Residual norm 2.905922877684e-01 > > > Residual norms for fieldsplit_wp_ solve. > > > 0 KSP Residual norm 2.397669419027e-01 > > > 1 KSP Residual norm 0.000000000000e+00 > > > 0 KSP preconditioned resid norm 3.165886479920e+04 true resid norm > > > 7.963616922323e+05 ||r(i)||/||b|| 1.000000000000e+00 > > > Residual norms for fieldsplit_u_ solve. > > > 0 KSP Residual norm 9.999891813771e-01 > > > 1 KSP Residual norm 1.512000395579e-05 > > > Residual norms for fieldsplit_wp_ solve. > > > 0 KSP Residual norm 8.192702188243e-06 > > > 1 KSP Residual norm 0.000000000000e+00 > > > 1 KSP preconditioned resid norm 5.252183822848e-02 true resid norm > > > 7.135927677844e+04 ||r(i)||/||b|| 8.960661653427e-02 > > > > The outer residual norms are still wonky, the preconditioned residual > > norm goes from 3.165886479920e+04 to 5.252183822848e-02 which is a huge > > drop but the 7.963616922323e+05 drops very much less 7.135927677844e+04. > > This is not normal. > > > > What if you just use -pc_type lu for the entire system (no fieldsplit), > > does the true residual drop to almost zero in the first iteration (as it > > should?). Send the output. > > > > > > > > > Residual norms for fieldsplit_u_ solve. > > > 0 KSP Residual norm 6.946213936597e-01 > > > 1 KSP Residual norm 1.195514007343e-05 > > > Residual norms for fieldsplit_wp_ solve. > > > 0 KSP Residual norm 1.025694497535e+00 > > > 1 KSP Residual norm 0.000000000000e+00 > > > 2 KSP preconditioned resid norm 8.785709535405e-03 true resid norm > > > 1.419341799277e+04 ||r(i)||/||b|| 1.782282866091e-02 > > > Residual norms for fieldsplit_u_ solve. > > > 0 KSP Residual norm 7.255149996405e-01 > > > 1 KSP Residual norm 6.583512434218e-06 > > > Residual norms for fieldsplit_wp_ solve. > > > 0 KSP Residual norm 1.015229700337e+00 > > > 1 KSP Residual norm 0.000000000000e+00 > > > 3 KSP preconditioned resid norm 7.110407712709e-04 true resid norm > > > 5.284940654154e+02 ||r(i)||/||b|| 6.636357205153e-04 > > > Residual norms for fieldsplit_u_ solve. > > > 0 KSP Residual norm 3.512243341400e-01 > > > 1 KSP Residual norm 2.032490351200e-06 > > > Residual norms for fieldsplit_wp_ solve. > > > 0 KSP Residual norm 1.282327290982e+00 > > > 1 KSP Residual norm 0.000000000000e+00 > > > 4 KSP preconditioned resid norm 3.482036620521e-05 true resid norm > > > 4.291231924307e+01 ||r(i)||/||b|| 5.388546393133e-05 > > > Residual norms for fieldsplit_u_ solve. > > > 0 KSP Residual norm 3.423609338053e-01 > > > 1 KSP Residual norm 4.213703301972e-07 > > > Residual norms for fieldsplit_wp_ solve. > > > 0 KSP Residual norm 1.157384757538e+00 > > > 1 KSP Residual norm 0.000000000000e+00 > > > 5 KSP preconditioned resid norm 1.203470314534e-06 true resid norm > > > 4.544956156267e+00 ||r(i)||/||b|| 5.707150658550e-06 > > > Residual norms for fieldsplit_u_ solve. > > > 0 KSP Residual norm 3.838596289995e-01 > > > 1 KSP Residual norm 9.927864176103e-08 > > > Residual norms for fieldsplit_wp_ solve. > > > 0 KSP Residual norm 1.066298905618e+00 > > > 1 KSP Residual norm 0.000000000000e+00 > > > 6 KSP preconditioned resid norm 3.331619244266e-08 true resid norm > > > 2.821511729024e+00 ||r(i)||/||b|| 3.543002829675e-06 > > > Residual norms for fieldsplit_u_ solve. > > > 0 KSP Residual norm 4.624964188094e-01 > > > 1 KSP Residual norm 6.418229775372e-08 > > > Residual norms for fieldsplit_wp_ solve. > > > 0 KSP Residual norm 9.800784311614e-01 > > > 1 KSP Residual norm 0.000000000000e+00 > > > 7 KSP preconditioned resid norm 8.788046233297e-10 true resid norm > > > 2.849209671705e+00 ||r(i)||/||b|| 3.577783436215e-06 > > > Linear solve converged due to CONVERGED_ATOL iterations 7 > > > > > > The outer operator is an explicit matrix. > > > > > > Giang > > > > > > On Mon, Apr 24, 2017 at 7:32 PM, Barry Smith <[email protected]> wrote: > > > > > > > On Apr 24, 2017, at 3:16 AM, Hoang Giang Bui <[email protected]> wrote: > > > > > > > > Thanks Barry, trying with -fieldsplit_u_type lu gives better > > > > convergence. I still used 4 procs though, probably with 1 proc it > > > > should also be the same. > > > > > > > > The u block used a Nitsche-type operator to connect two non-matching > > > > domains. I don't think it will leave some rigid body motion leads to > > > > not sufficient constraints. Maybe you have other idea? > > > > > > > > Residual norms for fieldsplit_u_ solve. > > > > 0 KSP Residual norm 3.129067184300e+05 > > > > 1 KSP Residual norm 5.906261468196e-01 > > > > Residual norms for fieldsplit_wp_ solve. > > > > 0 KSP Residual norm 0.000000000000e+00 > > > > > > ^^^^ something is wrong here. The sub solve should not be starting > > > with a 0 residual (this means the right hand side for this sub solve is > > > zero which it should not be). > > > > > > > FieldSplit with MULTIPLICATIVE composition: total splits = 2 > > > > > > > > > How are you providing the outer operator? As an explicit matrix or > > > with some shell matrix? > > > > > > > > > > > > > 0 KSP preconditioned resid norm 3.129067184300e+05 true resid norm > > > > 9.015150492169e+06 ||r(i)||/||b|| 1.000000000000e+00 > > > > Residual norms for fieldsplit_u_ solve. > > > > 0 KSP Residual norm 9.999955993437e-01 > > > > 1 KSP Residual norm 4.019774691831e-06 > > > > Residual norms for fieldsplit_wp_ solve. > > > > 0 KSP Residual norm 0.000000000000e+00 > > > > 1 KSP preconditioned resid norm 5.003913641475e-01 true resid norm > > > > 4.692996324114e+01 ||r(i)||/||b|| 5.205677185522e-06 > > > > Residual norms for fieldsplit_u_ solve. > > > > 0 KSP Residual norm 1.000012180204e+00 > > > > 1 KSP Residual norm 1.017367950422e-05 > > > > Residual norms for fieldsplit_wp_ solve. > > > > 0 KSP Residual norm 0.000000000000e+00 > > > > 2 KSP preconditioned resid norm 2.330910333756e-07 true resid norm > > > > 3.474855463983e+01 ||r(i)||/||b|| 3.854461960453e-06 > > > > Residual norms for fieldsplit_u_ solve. > > > > 0 KSP Residual norm 1.000004200085e+00 > > > > 1 KSP Residual norm 6.231613102458e-06 > > > > Residual norms for fieldsplit_wp_ solve. > > > > 0 KSP Residual norm 0.000000000000e+00 > > > > 3 KSP preconditioned resid norm 8.671259838389e-11 true resid norm > > > > 3.545103468011e+01 ||r(i)||/||b|| 3.932384125024e-06 > > > > Linear solve converged due to CONVERGED_ATOL iterations 3 > > > > KSP Object: 4 MPI processes > > > > type: gmres > > > > GMRES: restart=1000, using Modified Gram-Schmidt Orthogonalization > > > > GMRES: happy breakdown tolerance 1e-30 > > > > maximum iterations=1000, initial guess is zero > > > > tolerances: relative=1e-20, absolute=1e-09, divergence=10000 > > > > left preconditioning > > > > using PRECONDITIONED norm type for convergence test > > > > PC Object: 4 MPI processes > > > > type: fieldsplit > > > > FieldSplit with MULTIPLICATIVE composition: total splits = 2 > > > > Solver info for each split is in the following KSP objects: > > > > Split number 0 Defined by IS > > > > KSP Object: (fieldsplit_u_) 4 MPI processes > > > > type: richardson > > > > Richardson: damping factor=1 > > > > maximum iterations=1, initial guess is zero > > > > tolerances: relative=1e-05, absolute=1e-50, divergence=10000 > > > > left preconditioning > > > > using PRECONDITIONED norm type for convergence test > > > > PC Object: (fieldsplit_u_) 4 MPI processes > > > > type: lu > > > > LU: out-of-place factorization > > > > tolerance for zero pivot 2.22045e-14 > > > > matrix ordering: natural > > > > factor fill ratio given 0, needed 0 > > > > Factored matrix follows: > > > > Mat Object: 4 MPI processes > > > > type: mpiaij > > > > rows=938910, cols=938910 > > > > package used to perform factorization: pastix > > > > total: nonzeros=0, allocated nonzeros=0 > > > > Error : 3.36878e-14 > > > > total number of mallocs used during MatSetValues calls =0 > > > > PaStiX run parameters: > > > > Matrix type : Unsymmetric > > > > Level of printing (0,1,2): 0 > > > > Number of refinements iterations : 3 > > > > Error : 3.36878e-14 > > > > linear system matrix = precond matrix: > > > > Mat Object: (fieldsplit_u_) 4 MPI processes > > > > type: mpiaij > > > > rows=938910, cols=938910, bs=3 > > > > Error : 3.36878e-14 > > > > Error : 3.36878e-14 > > > > total: nonzeros=8.60906e+07, allocated nonzeros=8.60906e+07 > > > > total number of mallocs used during MatSetValues calls =0 > > > > using I-node (on process 0) routines: found 78749 nodes, > > > > limit used is 5 > > > > Split number 1 Defined by IS > > > > KSP Object: (fieldsplit_wp_) 4 MPI processes > > > > type: richardson > > > > Richardson: damping factor=1 > > > > maximum iterations=1, initial guess is zero > > > > tolerances: relative=1e-05, absolute=1e-50, divergence=10000 > > > > left preconditioning > > > > using PRECONDITIONED norm type for convergence test > > > > PC Object: (fieldsplit_wp_) 4 MPI processes > > > > type: lu > > > > LU: out-of-place factorization > > > > tolerance for zero pivot 2.22045e-14 > > > > matrix ordering: natural > > > > factor fill ratio given 0, needed 0 > > > > Factored matrix follows: > > > > Mat Object: 4 MPI processes > > > > type: mpiaij > > > > rows=34141, cols=34141 > > > > package used to perform factorization: pastix > > > > Error : -nan > > > > Error : -nan > > > > Error : -nan > > > > total: nonzeros=0, allocated nonzeros=0 > > > > total number of mallocs used during MatSetValues calls =0 > > > > PaStiX run parameters: > > > > Matrix type : Symmetric > > > > Level of printing (0,1,2): 0 > > > > Number of refinements iterations : 0 > > > > Error : -nan > > > > linear system matrix = precond matrix: > > > > Mat Object: (fieldsplit_wp_) 4 MPI processes > > > > type: mpiaij > > > > rows=34141, cols=34141 > > > > total: nonzeros=485655, allocated nonzeros=485655 > > > > total number of mallocs used during MatSetValues calls =0 > > > > not using I-node (on process 0) routines > > > > linear system matrix = precond matrix: > > > > Mat Object: 4 MPI processes > > > > type: mpiaij > > > > rows=973051, cols=973051 > > > > total: nonzeros=9.90037e+07, allocated nonzeros=9.90037e+07 > > > > total number of mallocs used during MatSetValues calls =0 > > > > using I-node (on process 0) routines: found 78749 nodes, limit > > > > used is 5 > > > > > > > > > > > > > > > > Giang > > > > > > > > On Sun, Apr 23, 2017 at 10:19 PM, Barry Smith <[email protected]> > > > > wrote: > > > > > > > > > On Apr 23, 2017, at 2:42 PM, Hoang Giang Bui <[email protected]> > > > > > wrote: > > > > > > > > > > Dear Matt/Barry > > > > > > > > > > With your options, it results in > > > > > > > > > > 0 KSP preconditioned resid norm 1.106709687386e+31 true resid norm > > > > > 9.015150491938e+06 ||r(i)||/||b|| 1.000000000000e+00 > > > > > Residual norms for fieldsplit_u_ solve. > > > > > 0 KSP Residual norm 2.407308987203e+36 > > > > > 1 KSP Residual norm 5.797185652683e+72 > > > > > > > > It looks like Matt is right, hypre is seemly producing useless garbage. > > > > > > > > First how do things run on one process. If you have similar problems > > > > then debug on one process (debugging any kind of problem is always far > > > > easy on one process). > > > > > > > > First run with -fieldsplit_u_type lu (instead of using hypre) to see if > > > > that works or also produces something bad. > > > > > > > > What is the operator and the boundary conditions for u? It could be > > > > singular. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Residual norms for fieldsplit_wp_ solve. > > > > > 0 KSP Residual norm 0.000000000000e+00 > > > > > ... > > > > > 999 KSP preconditioned resid norm 2.920157329174e+12 true resid norm > > > > > 9.015683504616e+06 ||r(i)||/||b|| 1.000059124102e+00 > > > > > Residual norms for fieldsplit_u_ solve. > > > > > 0 KSP Residual norm 1.533726746719e+36 > > > > > 1 KSP Residual norm 3.692757392261e+72 > > > > > Residual norms for fieldsplit_wp_ solve. > > > > > 0 KSP Residual norm 0.000000000000e+00 > > > > > > > > > > Do you suggest that the pastix solver for the "wp" block encounters > > > > > small pivot? In addition, seem like the "u" block is also singular. > > > > > > > > > > Giang > > > > > > > > > > On Sun, Apr 23, 2017 at 7:39 PM, Barry Smith <[email protected]> > > > > > wrote: > > > > > > > > > > Huge preconditioned norms but normal unpreconditioned norms almost > > > > > always come from a very small pivot in an LU or ILU factorization. > > > > > > > > > > The first thing to do is monitor the two sub solves. Run with the > > > > > additional options -fieldsplit_u_ksp_type richardson > > > > > -fieldsplit_u_ksp_monitor -fieldsplit_u_ksp_max_it 1 > > > > > -fieldsplit_wp_ksp_type richardson -fieldsplit_wp_ksp_monitor > > > > > -fieldsplit_wp_ksp_max_it 1 > > > > > > > > > > > On Apr 23, 2017, at 12:22 PM, Hoang Giang Bui <[email protected]> > > > > > > wrote: > > > > > > > > > > > > Hello > > > > > > > > > > > > I encountered a strange convergence behavior that I have trouble to > > > > > > understand > > > > > > > > > > > > KSPSetFromOptions completed > > > > > > 0 KSP preconditioned resid norm 1.106709687386e+31 true resid > > > > > > norm 9.015150491938e+06 ||r(i)||/||b|| 1.000000000000e+00 > > > > > > 1 KSP preconditioned resid norm 2.933141742664e+29 true resid > > > > > > norm 9.015152282123e+06 ||r(i)||/||b|| 1.000000198575e+00 > > > > > > 2 KSP preconditioned resid norm 9.686409637174e+16 true resid > > > > > > norm 9.015354521944e+06 ||r(i)||/||b|| 1.000022631902e+00 > > > > > > 3 KSP preconditioned resid norm 4.219243615809e+15 true resid > > > > > > norm 9.017157702420e+06 ||r(i)||/||b|| 1.000222648583e+00 > > > > > > ..... > > > > > > 999 KSP preconditioned resid norm 3.043754298076e+12 true resid > > > > > > norm 9.015425041089e+06 ||r(i)||/||b|| 1.000030454195e+00 > > > > > > 1000 KSP preconditioned resid norm 3.043000287819e+12 true resid > > > > > > norm 9.015424313455e+06 ||r(i)||/||b|| 1.000030373483e+00 > > > > > > Linear solve did not converge due to DIVERGED_ITS iterations 1000 > > > > > > KSP Object: 4 MPI processes > > > > > > type: gmres > > > > > > GMRES: restart=1000, using Modified Gram-Schmidt > > > > > > Orthogonalization > > > > > > GMRES: happy breakdown tolerance 1e-30 > > > > > > maximum iterations=1000, initial guess is zero > > > > > > tolerances: relative=1e-20, absolute=1e-09, divergence=10000 > > > > > > left preconditioning > > > > > > using PRECONDITIONED norm type for convergence test > > > > > > PC Object: 4 MPI processes > > > > > > type: fieldsplit > > > > > > FieldSplit with MULTIPLICATIVE composition: total splits = 2 > > > > > > Solver info for each split is in the following KSP objects: > > > > > > Split number 0 Defined by IS > > > > > > KSP Object: (fieldsplit_u_) 4 MPI processes > > > > > > type: preonly > > > > > > maximum iterations=10000, initial guess is zero > > > > > > tolerances: relative=1e-05, absolute=1e-50, divergence=10000 > > > > > > left preconditioning > > > > > > using NONE norm type for convergence test > > > > > > PC Object: (fieldsplit_u_) 4 MPI processes > > > > > > type: hypre > > > > > > HYPRE BoomerAMG preconditioning > > > > > > HYPRE BoomerAMG: Cycle type V > > > > > > HYPRE BoomerAMG: Maximum number of levels 25 > > > > > > HYPRE BoomerAMG: Maximum number of iterations PER hypre > > > > > > call 1 > > > > > > HYPRE BoomerAMG: Convergence tolerance PER hypre call 0 > > > > > > HYPRE BoomerAMG: Threshold for strong coupling 0.6 > > > > > > HYPRE BoomerAMG: Interpolation truncation factor 0 > > > > > > HYPRE BoomerAMG: Interpolation: max elements per row 0 > > > > > > HYPRE BoomerAMG: Number of levels of aggressive coarsening 0 > > > > > > HYPRE BoomerAMG: Number of paths for aggressive coarsening 1 > > > > > > HYPRE BoomerAMG: Maximum row sums 0.9 > > > > > > HYPRE BoomerAMG: Sweeps down 1 > > > > > > HYPRE BoomerAMG: Sweeps up 1 > > > > > > HYPRE BoomerAMG: Sweeps on coarse 1 > > > > > > HYPRE BoomerAMG: Relax down symmetric-SOR/Jacobi > > > > > > HYPRE BoomerAMG: Relax up symmetric-SOR/Jacobi > > > > > > HYPRE BoomerAMG: Relax on coarse Gaussian-elimination > > > > > > HYPRE BoomerAMG: Relax weight (all) 1 > > > > > > HYPRE BoomerAMG: Outer relax weight (all) 1 > > > > > > HYPRE BoomerAMG: Using CF-relaxation > > > > > > HYPRE BoomerAMG: Measure type local > > > > > > HYPRE BoomerAMG: Coarsen type PMIS > > > > > > HYPRE BoomerAMG: Interpolation type classical > > > > > > linear system matrix = precond matrix: > > > > > > Mat Object: (fieldsplit_u_) 4 MPI processes > > > > > > type: mpiaij > > > > > > rows=938910, cols=938910, bs=3 > > > > > > total: nonzeros=8.60906e+07, allocated nonzeros=8.60906e+07 > > > > > > total number of mallocs used during MatSetValues calls =0 > > > > > > using I-node (on process 0) routines: found 78749 nodes, > > > > > > limit used is 5 > > > > > > Split number 1 Defined by IS > > > > > > KSP Object: (fieldsplit_wp_) 4 MPI processes > > > > > > type: preonly > > > > > > maximum iterations=10000, initial guess is zero > > > > > > tolerances: relative=1e-05, absolute=1e-50, divergence=10000 > > > > > > left preconditioning > > > > > > using NONE norm type for convergence test > > > > > > PC Object: (fieldsplit_wp_) 4 MPI processes > > > > > > type: lu > > > > > > LU: out-of-place factorization > > > > > > tolerance for zero pivot 2.22045e-14 > > > > > > matrix ordering: natural > > > > > > factor fill ratio given 0, needed 0 > > > > > > Factored matrix follows: > > > > > > Mat Object: 4 MPI processes > > > > > > type: mpiaij > > > > > > rows=34141, cols=34141 > > > > > > package used to perform factorization: pastix > > > > > > Error : -nan > > > > > > Error : -nan > > > > > > total: nonzeros=0, allocated nonzeros=0 > > > > > > Error : -nan > > > > > > total number of mallocs used during MatSetValues calls =0 > > > > > > PaStiX run parameters: > > > > > > Matrix type : Symmetric > > > > > > Level of printing (0,1,2): 0 > > > > > > Number of refinements iterations : 0 > > > > > > Error : -nan > > > > > > linear system matrix = precond matrix: > > > > > > Mat Object: (fieldsplit_wp_) 4 MPI processes > > > > > > type: mpiaij > > > > > > rows=34141, cols=34141 > > > > > > total: nonzeros=485655, allocated nonzeros=485655 > > > > > > total number of mallocs used during MatSetValues calls =0 > > > > > > not using I-node (on process 0) routines > > > > > > linear system matrix = precond matrix: > > > > > > Mat Object: 4 MPI processes > > > > > > type: mpiaij > > > > > > rows=973051, cols=973051 > > > > > > total: nonzeros=9.90037e+07, allocated nonzeros=9.90037e+07 > > > > > > total number of mallocs used during MatSetValues calls =0 > > > > > > using I-node (on process 0) routines: found 78749 nodes, > > > > > > limit used is 5 > > > > > > > > > > > > The pattern of convergence gives a hint that this system is somehow > > > > > > bad/singular. But I don't know why the preconditioned error goes up > > > > > > too high. Anyone has an idea? > > > > > > > > > > > > Best regards > > > > > > Giang Bui > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
