[petsc-users] Dose Petsc has DMPlex example
Justin Chang
jychang48 at gmail.com
Sun Jul 3 03:15:09 CDT 2016
Hoang, if you run this example shown from the config/builder.py
./ex62 -run_type full -refinement_limit 0.00625 -bc_type dirichlet
-interpolate 1 -vel_petscspace_order 2 -pres_petscspace_order 1 -ksp_type
fgmres -ksp_gmres_restart 100 -ksp_rtol 1.0e-9 -pc_type fieldsplit
-pc_fieldsplit_type schur -pc_fieldsplit_schur_factorization_type full
-fieldsplit_pressure_ksp_rtol 1e-10 -fieldsplit_velocity_ksp_type gmres
-fieldsplit_velocity_pc_type lu -fieldsplit_pressure_pc_type jacobi
-snes_monitor_short -ksp_monitor_short -snes_converged_reason
-ksp_converged_reason -snes_view -show_solution 0
it should work
On Sun, Jul 3, 2016 at 9:06 AM, Hoang Giang Bui <hgbk2008 at gmail.com> wrote:
> Hi Matt
>
> I tried to run ex62 with 1 proc (petsc 3.7.2), but it all produces zero
>
> The output is:
> hbui at bermuda:~/workspace/petsc/snes$ es$ ./ex62 run_type full -bc_type
> dirichlet -refinement_limit 0.00625 -interpolate 1 -snes_monitor_short
> -snes_converged_reason -snes_view -ksp_type fgmres -ksp_gmres_restart 100
> -ksp_rtol 1.0e-9 -ksp_monitor_short -pc_type fieldsplit -pc_fieldsplit_type
> schur -pc_fieldsplit_schur_factorization_type full
> -fieldsplit_velocity_ksp_type gmres -fieldsplit_velocity_pc_type lu
> -fieldsplit_pressure_ksp_rtol 1e-10 -fieldsplit_pressure_pc_type jacobi
> 0 SNES Function norm 0.265165
> 0 KSP Residual norm 0.265165
> Nonlinear solve did not converge due to DIVERGED_LINEAR_SOLVE iterations 0
> SNES Object: 1 MPI processes
> type: newtonls
> maximum iterations=50, maximum function evaluations=10000
> tolerances: relative=1e-08, absolute=1e-50, solution=1e-08
> total number of linear solver iterations=0
> total number of function evaluations=1
> norm schedule ALWAYS
> SNESLineSearch Object: 1 MPI processes
> type: bt
> interpolation: cubic
> alpha=1.000000e-04
> maxstep=1.000000e+08, minlambda=1.000000e-12
> tolerances: relative=1.000000e-08, absolute=1.000000e-15,
> lambda=1.000000e-08
> maximum iterations=40
> KSP Object: 1 MPI processes
> type: fgmres
> GMRES: restart=100, using Classical (unmodified) Gram-Schmidt
> Orthogonalization with no iterative refinement
> GMRES: happy breakdown tolerance 1e-30
> maximum iterations=10000, initial guess is zero
> tolerances: relative=1e-09, absolute=1e-50, divergence=10000.
> right preconditioning
> using UNPRECONDITIONED norm type for convergence test
> PC Object: 1 MPI processes
> type: fieldsplit
> FieldSplit with Schur preconditioner, factorization FULL
> Preconditioner for the Schur complement formed from A11
> Split info:
> Split number 0 Defined by IS
> Split number 1 Defined by IS
> KSP solver for A00 block
> KSP Object: (fieldsplit_velocity_) 1 MPI processes
> type: gmres
> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt
> Orthogonalization with no iterative refinement
> GMRES: happy breakdown tolerance 1e-30
> maximum iterations=10000, 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_velocity_) 1 MPI processes
> type: lu
> LU: out-of-place factorization
> tolerance for zero pivot 2.22045e-14
> matrix ordering: nd
> factor fill ratio given 5., needed 1.
> Factored matrix follows:
> Mat Object: 1 MPI processes
> type: seqaij
> rows=512, cols=512, bs=2
> package used to perform factorization: petsc
> total: nonzeros=1024, allocated nonzeros=1024
> total number of mallocs used during MatSetValues calls =0
> using I-node routines: found 256 nodes, limit used is 5
> linear system matrix = precond matrix:
> Mat Object: (fieldsplit_velocity_) 1 MPI
> processes
> type: seqaij
> rows=512, cols=512, bs=2
> total: nonzeros=1024, allocated nonzeros=1024
> total number of mallocs used during MatSetValues calls =0
> using I-node routines: found 256 nodes, limit used is 5
> KSP solver for S = A11 - A10 inv(A00) A01
> KSP Object: (fieldsplit_pressure_) 1 MPI processes
> type: gmres
> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt
> Orthogonalization with no iterative refinement
> GMRES: happy breakdown tolerance 1e-30
> maximum iterations=10000, initial guess is zero
> tolerances: relative=1e-10, absolute=1e-50, divergence=10000.
> left preconditioning
> using PRECONDITIONED norm type for convergence test
> PC Object: (fieldsplit_pressure_) 1 MPI processes
> type: jacobi
> linear system matrix followed by preconditioner matrix:
> Mat Object: (fieldsplit_pressure_) 1 MPI
> processes
> type: schurcomplement
> rows=256, cols=256
> has attached null space
> Schur complement A11 - A10 inv(A00) A01
> A11
> Mat Object:
> (fieldsplit_pressure_) 1 MPI processes
> type: seqaij
> rows=256, cols=256
> total: nonzeros=256, allocated nonzeros=256
> total number of mallocs used during MatSetValues calls =0
> has attached null space
> not using I-node routines
> A10
> Mat Object: 1 MPI processes
> type: seqaij
> rows=256, cols=512
> total: nonzeros=512, allocated nonzeros=512
> total number of mallocs used during MatSetValues calls =0
> not using I-node routines
> KSP of A00
> KSP Object:
> (fieldsplit_velocity_) 1 MPI processes
> type: gmres
> GMRES: restart=30, using Classical (unmodified)
> Gram-Schmidt Orthogonalization with no iterative refinement
> GMRES: happy breakdown tolerance 1e-30
> maximum iterations=10000, 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_velocity_) 1 MPI processes
> type: lu
> LU: out-of-place factorization
> tolerance for zero pivot 2.22045e-14
> matrix ordering: nd
> factor fill ratio given 5., needed 1.
> Factored matrix follows:
> Mat Object: 1 MPI processes
> type: seqaij
> rows=512, cols=512, bs=2
> package used to perform factorization: petsc
> total: nonzeros=1024, allocated nonzeros=1024
> total number of mallocs used during MatSetValues
> calls =0
> using I-node routines: found 256 nodes, limit
> used is 5
> linear system matrix = precond matrix:
> Mat Object:
> (fieldsplit_velocity_) 1 MPI processes
> type: seqaij
> rows=512, cols=512, bs=2
> total: nonzeros=1024, allocated nonzeros=1024
> total number of mallocs used during MatSetValues calls
> =0
> using I-node routines: found 256 nodes, limit used
> is 5
> A01
> Mat Object: 1 MPI processes
> type: seqaij
> rows=512, cols=256, rbs=2, cbs = 1
> total: nonzeros=512, allocated nonzeros=512
> total number of mallocs used during MatSetValues calls =0
> using I-node routines: found 256 nodes, limit used is 5
> Mat Object: (fieldsplit_pressure_) 1 MPI
> processes
> type: seqaij
> rows=256, cols=256
> total: nonzeros=256, allocated nonzeros=256
> total number of mallocs used during MatSetValues calls =0
> has attached null space
> not using I-node routines
> linear system matrix = precond matrix:
> Mat Object: 1 MPI processes
> type: seqaij
> rows=768, cols=768
> total: nonzeros=2304, allocated nonzeros=2304
> total number of mallocs used during MatSetValues calls =0
> has attached null space
> using I-node routines: found 256 nodes, limit used is 5
> Number of SNES iterations = 0
> L_2 Error: 1.01 [0.929, 0.407]
> Solution
> Vec Object: 1 MPI processes
> type: seq
> 0.
> 0.
> ....
>
> Am I doing something wrong?
>
> Giang
>
>
> Giang
>
> On Tue, May 3, 2016 at 4:44 AM, Matthew Knepley <knepley at gmail.com> wrote:
>
>> On Mon, May 2, 2016 at 8:29 PM, ztdepyahoo at 163.com <ztdepyahoo at 163.com>
>> wrote:
>>
>>> Dear professor:
>>> I want to write a parallel 3D CFD code based on unstructred grid,
>>> does Petsc has DMPlex examples to start with.
>>>
>>
>> SNES ex62 is an unstructured grid Stokes problem discretized with
>> low-order finite elements.
>>
>> Of course, all the different possible choices will impact the design.
>>
>> Matt
>>
>>
>>> Regards
>>>
>>
>>
>>
>> --
>> What most experimenters take for granted before they begin their
>> experiments is infinitely more interesting than any results to which their
>> experiments lead.
>> -- Norbert Wiener
>>
>
>
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