[petsc-users] fieldsplit_0_ monitor in combination with selfp
Matthew Knepley
knepley at gmail.com
Thu Sep 4 17:36:39 CDT 2014
On Thu, Sep 4, 2014 at 7:26 AM, Klaij, Christiaan <C.Klaij at marin.nl> wrote:
> Sorry, here's the ksp_view. I'm expecting
>
> -fieldsplit_1_inner_ksp_type preonly
>
> to set the ksp(A00) in the Schur complement only, but it seems to set it
> in the inv(A00) of the diagonal as well.
>
I think something is wrong in your example (we strongly advise against
using MatNest directly). I cannot reproduce this using SNES ex62:
./config/builder2.py check src/snes/examples/tutorials/ex62.c
--testnum=36 --args="-fieldsplit_pressure_inner_ksp_type preonly
-fieldsplit_pressure_inner_pc_type jacobi"
which translates to
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
-fieldsplit_pressure_inner_ksp_type preonly
-fieldsplit_pressure_inner_pc_type jacobi
gives
Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE iterations 1
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=20
total number of function evaluations=2
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
has attached null space
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 3.45047
Factored matrix follows:
Mat Object: 1 MPI processes
type: seqaij
rows=962, cols=962
package used to perform factorization: petsc
total: nonzeros=68692, allocated nonzeros=68692
total number of mallocs used during MatSetValues calls =0
using I-node routines: found 456 nodes, limit used is 5
linear system matrix = precond matrix:
Mat Object: (fieldsplit_velocity_) 1 MPI
processes
type: seqaij
rows=962, cols=962
total: nonzeros=19908, allocated nonzeros=19908
total number of mallocs used during MatSetValues calls =0
using I-node routines: found 481 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
has attached null space
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=145, cols=145
has attached null space
Schur complement A11 - A10 inv(A00) A01
A11
Mat Object: (fieldsplit_pressure_)
1 MPI processes
type: seqaij
rows=145, cols=145
total: nonzeros=945, allocated nonzeros=945
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=145, cols=962
total: nonzeros=4466, allocated nonzeros=4466
total number of mallocs used during MatSetValues calls =0
not using I-node routines
KSP of A00
KSP Object: (fieldsplit_pressure_inner_)
1 MPI processes
type: preonly
maximum iterations=10000, initial guess is zero
tolerances: relative=1e-09, absolute=1e-50,
divergence=10000
left preconditioning
using NONE norm type for convergence test
PC Object: (fieldsplit_pressure_inner_)
1 MPI processes
type: jacobi
linear system matrix = precond matrix:
Mat Object: (fieldsplit_velocity_)
1 MPI processes
type: seqaij
rows=962, cols=962
total: nonzeros=19908, allocated nonzeros=19908
total number of mallocs used during MatSetValues calls
=0
using I-node routines: found 481 nodes, limit used is
5
A01
Mat Object: 1 MPI processes
type: seqaij
rows=962, cols=145
total: nonzeros=4466, allocated nonzeros=4466
total number of mallocs used during MatSetValues calls =0
using I-node routines: found 481 nodes, limit used is 5
Mat Object: (fieldsplit_pressure_) 1 MPI
processes
type: seqaij
rows=145, cols=145
total: nonzeros=945, allocated nonzeros=945
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=1107, cols=1107
total: nonzeros=29785, allocated nonzeros=29785
total number of mallocs used during MatSetValues calls =0
has attached null space
using I-node routines: found 513 nodes, limit used is 5
Matt
> Chris
>
> 0 KSP Residual norm 1.229687498638e+00
> Residual norms for fieldsplit_1_ solve.
> 0 KSP Residual norm 7.185799114488e+01
> 1 KSP Residual norm 3.873274154012e+01
> 1 KSP Residual norm 1.107969383366e+00
> KSP Object: 1 MPI processes
> type: fgmres
> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt
> Orthogonalization with no iterative refinement
> GMRES: happy breakdown tolerance 1e-30
> maximum iterations=1, initial guess is zero
> tolerances: relative=1e-05, 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 LOWER
> Preconditioner for the Schur complement formed from Sp, an assembled
> approximation to S, which uses (the lumped) A00's diagonal's inverse
> Split info:
> Split number 0 Defined by IS
> Split number 1 Defined by IS
> KSP solver for A00 block
> KSP Object: (fieldsplit_0_) 1 MPI processes
> type: preonly
> maximum iterations=1, 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_0_) 1 MPI processes
> type: bjacobi
> block Jacobi: number of blocks = 1
> Local solve is same for all blocks, in the following KSP and PC
> objects:
> KSP Object: (fieldsplit_0_sub_) 1 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_0_sub_) 1 MPI processes
> type: ilu
> ILU: out-of-place factorization
> 0 levels of fill
> tolerance for zero pivot 2.22045e-14
> using diagonal shift on blocks to prevent zero pivot
> [INBLOCKS]
> matrix ordering: natural
> factor fill ratio given 1, needed 1
> Factored matrix follows:
> Mat Object: 1 MPI processes
> type: seqaij
> rows=48, cols=48
> package used to perform factorization: petsc
> total: nonzeros=200, allocated nonzeros=200
> total number of mallocs used during MatSetValues calls
> =0
> not using I-node routines
> linear system matrix = precond matrix:
> Mat Object: (fieldsplit_0_) 1 MPI
> processes
> type: seqaij
> rows=48, cols=48
> total: nonzeros=200, allocated nonzeros=240
> total number of mallocs used during MatSetValues calls =0
> not using I-node routines
> linear system matrix = precond matrix:
> Mat Object: (fieldsplit_0_) 1 MPI processes
> type: mpiaij
> rows=48, cols=48
> total: nonzeros=200, allocated nonzeros=480
> total number of mallocs used during MatSetValues calls =0
> not using I-node (on process 0) routines
> KSP solver for S = A11 - A10 inv(A00) A01
> KSP Object: (fieldsplit_1_) 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=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_1_) 1 MPI processes
> type: bjacobi
> block Jacobi: number of blocks = 1
> Local solve is same for all blocks, in the following KSP and PC
> objects:
> KSP Object: (fieldsplit_1_sub_) 1 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_1_sub_) 1 MPI processes
> type: bjacobi
> block Jacobi: number of blocks = 1
> Local solve is same for all blocks, in the following KSP and
> PC objects:
> KSP Object:
> (fieldsplit_1_sub_sub_) 1 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_1_sub_sub_) 1 MPI processes
> type: ilu
> ILU: out-of-place factorization
> 0 levels of fill
> tolerance for zero pivot 2.22045e-14
> using diagonal shift on blocks to prevent zero pivot
> [INBLOCKS]
> matrix ordering: natural
> factor fill ratio given 1, needed 1
> Factored matrix follows:
> Mat Object: 1 MPI processes
> type: seqaij
> rows=24, cols=24
> package used to perform factorization: petsc
> total: nonzeros=120, allocated nonzeros=120
> total number of mallocs used during MatSetValues
> calls =0
> not using I-node routines
> linear system matrix = precond matrix:
> Mat Object: 1 MPI processes
> type: seqaij
> rows=24, cols=24
> total: nonzeros=120, allocated nonzeros=120
> total number of mallocs used during MatSetValues calls =0
> not using I-node routines
> linear system matrix = precond matrix:
> Mat Object: 1 MPI processes
> type: mpiaij
> rows=24, cols=24
> total: nonzeros=120, allocated nonzeros=120
> total number of mallocs used during MatSetValues calls =0
> not using I-node (on process 0) routines
> linear system matrix followed by preconditioner matrix:
> Mat Object: (fieldsplit_1_) 1 MPI processes
> type: schurcomplement
> rows=24, cols=24
> Schur complement A11 - A10 inv(A00) A01
> A11
> Mat Object: (fieldsplit_1_) 1 MPI
> processes
> type: mpiaij
> rows=24, cols=24
> total: nonzeros=0, allocated nonzeros=0
> total number of mallocs used during MatSetValues calls =0
> using I-node (on process 0) routines: found 5 nodes,
> limit used is 5
> A10
> Mat Object: (a10_) 1 MPI processes
> type: mpiaij
> rows=24, cols=48
> total: nonzeros=96, allocated nonzeros=96
> total number of mallocs used during MatSetValues calls =0
> not using I-node (on process 0) routines
> KSP of A00
> KSP Object: (fieldsplit_1_inner_)
> 1 MPI processes
> type: preonly
> maximum iterations=1, 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_1_inner_)
> 1 MPI processes
> type: jacobi
> linear system matrix = precond matrix:
> Mat Object: (fieldsplit_0_)
> 1 MPI processes
> type: mpiaij
> rows=48, cols=48
> total: nonzeros=200, allocated nonzeros=480
> total number of mallocs used during MatSetValues calls =0
> not using I-node (on process 0) routines
> A01
> Mat Object: (a01_) 1 MPI processes
> type: mpiaij
> rows=48, cols=24
> total: nonzeros=96, allocated nonzeros=480
> total number of mallocs used during MatSetValues calls =0
> not using I-node (on process 0) routines
> Mat Object: 1 MPI processes
> type: mpiaij
> rows=24, cols=24
> total: nonzeros=120, allocated nonzeros=120
> total number of mallocs used during MatSetValues calls =0
> not using I-node (on process 0) routines
> linear system matrix = precond matrix:
> Mat Object: 1 MPI processes
> type: nest
> rows=72, cols=72
> Matrix object:
> type=nest, rows=2, cols=2
> MatNest structure:
> (0,0) : prefix="fieldsplit_0_", type=mpiaij, rows=48, cols=48
> (0,1) : prefix="a01_", type=mpiaij, rows=48, cols=24
> (1,0) : prefix="a10_", type=mpiaij, rows=24, cols=48
> (1,1) : prefix="fieldsplit_1_", type=mpiaij, rows=24, cols=24
>
>
> From: Matthew Knepley <knepley at gmail.com>
> Sent: Thursday, September 04, 2014 2:20 PM
> To: Klaij, Christiaan
> Cc: petsc-users at mcs.anl.gov
> Subject: Re: [petsc-users] fieldsplit_0_ monitor in combination with selfp
>
>
>
>
> On Thu, Sep 4, 2014 at 7:06 AM, Klaij, Christiaan <C.Klaij at marin.nl>
> wrote:
> I'm playing with the selfp option in fieldsplit using
> snes/examples/tutorials/ex70.c. For example:
>
> mpiexec -n 2 ./ex70 -nx 4 -ny 6 \
> -ksp_type fgmres \
> -pc_type fieldsplit \
> -pc_fieldsplit_type schur \
> -pc_fieldsplit_schur_fact_type lower \
> -pc_fieldsplit_schur_precondition selfp \
> -fieldsplit_1_inner_ksp_type preonly \
> -fieldsplit_1_inner_pc_type jacobi \
> -fieldsplit_0_ksp_monitor -fieldsplit_0_ksp_max_it 1 \
> -fieldsplit_1_ksp_monitor -fieldsplit_1_ksp_max_it 1 \
> -ksp_monitor -ksp_max_it 1
>
> gives the following output
>
> 0 KSP Residual norm 1.229687498638e+00
> Residual norms for fieldsplit_1_ solve.
> 0 KSP Residual norm 2.330138480101e+01
> 1 KSP Residual norm 1.609000846751e+01
> 1 KSP Residual norm 1.180287268335e+00
>
> To my suprise I don't see anything for the fieldsplit_0_ solve,
> why?
>
>
>
> Always run with -ksp_view for any solver question.
>
>
> Thanks,
>
>
> Matt
> Furthermore, if I understand correctly the above should be
> exactly equivalent with
>
> mpiexec -n 2 ./ex70 -nx 4 -ny 6 \
> -ksp_type fgmres \
> -pc_type fieldsplit \
> -pc_fieldsplit_type schur \
> -pc_fieldsplit_schur_fact_type lower \
> -user_ksp \
> -fieldsplit_0_ksp_monitor -fieldsplit_0_ksp_max_it 1 \
> -fieldsplit_1_ksp_monitor -fieldsplit_1_ksp_max_it 1 \
> -ksp_monitor -ksp_max_it 1
>
> 0 KSP Residual norm 1.229687498638e+00
> Residual norms for fieldsplit_0_ solve.
> 0 KSP Residual norm 5.486639587672e-01
> 1 KSP Residual norm 6.348354253703e-02
> Residual norms for fieldsplit_1_ solve.
> 0 KSP Residual norm 2.321938107977e+01
> 1 KSP Residual norm 1.605484031258e+01
> 1 KSP Residual norm 1.183225251166e+00
>
> because -user_ksp replaces the Schur complement by the simple
> approximation A11 - A10 inv(diag(A00)) A01. Beside the missing
> fielsplit_0_ part, the numbers are pretty close but not exactly
> the same. Any explanation?
>
> Chris
>
>
> dr. ir. Christiaan Klaij
> CFD Researcher
> Research & Development
> E mailto:C.Klaij at marin.nl
> T +31 317 49 33 44
>
>
> MARIN
> 2, Haagsteeg, P.O. Box 28, 6700 AA Wageningen, The Netherlands
> T +31 317 49 39 11, F +31 317 49 32 45, I www.marin.nl
>
>
>
>
>
> --
> 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
--
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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