[petsc-users] CG with right preconditioning supports NONE norm type only

[Kong, Fande]

Thanks, Barry.

Fande,

On Wed, Mar 8, 2017 at 3:55 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:

>
>    A proposed fix https://urldefense.proofpoint.com/v2/url?u=https-3A__
> bitbucket.org_petsc_petsc_pull-2Drequests_645_do-2Dnot-
> 2Dassume-2Dthat-2Dall-2Dksp-2Dmethods-2Dsupport&d=DQIFAg&c=
> 54IZrppPQZKX9mLzcGdPfFD1hxrcB__aEkJFOKJFd00&r=DUUt3SRGI0_
> JgtNaS3udV68GRkgV4ts7XKfj2opmiCY&m=RbF_pG6G05IcrxiELCCV36C6Cb_
> GqQZ7H84RH1hRQik&s=p1nuatzGn2KrF98argO7-qTt4U64Rzny3KoN-IJLOv4&e=
>
>    Needs Jed's approval.
>
>    Barry
>
>
>
> > On Mar 8, 2017, at 10:33 AM, Barry Smith <bsmith at mcs.anl.gov> wrote:
> >
> >
> >  Please tell us how you got this output.
> >
> >  PETSc CG doesn't even implement right preconditioning. If you ask for
> it it should error out. CG supports no norm computation with left
> preconditioning.
> >
> >   Barry
> >
> >> On Mar 8, 2017, at 10:26 AM, Kong, Fande <fande.kong at inl.gov> wrote:
> >>
> >> Hi All,
> >>
> >> The NONE norm type is supported only when CG is used with a right
> preconditioner. Any reason for this?
> >>
> >>
> >>
> >> 0 Nonlinear |R| = 1.732051e+00
> >>      0 Linear |R| = 0.000000e+00
> >>      1 Linear |R| = 0.000000e+00
> >>      2 Linear |R| = 0.000000e+00
> >>      3 Linear |R| = 0.000000e+00
> >>      4 Linear |R| = 0.000000e+00
> >>      5 Linear |R| = 0.000000e+00
> >>      6 Linear |R| = 0.000000e+00
> >> 1 Nonlinear |R| = 1.769225e-08
> >>      0 Linear |R| = 0.000000e+00
> >>      1 Linear |R| = 0.000000e+00
> >>      2 Linear |R| = 0.000000e+00
> >>      3 Linear |R| = 0.000000e+00
> >>      4 Linear |R| = 0.000000e+00
> >>      5 Linear |R| = 0.000000e+00
> >>      6 Linear |R| = 0.000000e+00
> >>      7 Linear |R| = 0.000000e+00
> >>      8 Linear |R| = 0.000000e+00
> >>      9 Linear |R| = 0.000000e+00
> >>     10 Linear |R| = 0.000000e+00
> >> 2 Nonlinear |R| = 0.000000e+00
> >> SNES Object: 1 MPI processes
> >>  type: newtonls
> >>  maximum iterations=50, maximum function evaluations=10000
> >>  tolerances: relative=1e-08, absolute=1e-50, solution=1e-50
> >>  total number of linear solver iterations=18
> >>  total number of function evaluations=23
> >>  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: cg
> >>    maximum iterations=10000, initial guess is zero
> >>    tolerances:  relative=1e-05, absolute=1e-50, divergence=10000.
> >>    right preconditioning
> >>    using NONE norm type for convergence test
> >>  PC Object:   1 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 0.25
> >>      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: Not using more complex smoothers.
> >>      HYPRE BoomerAMG: Measure type        local
> >>      HYPRE BoomerAMG: Coarsen type        Falgout
> >>      HYPRE BoomerAMG: Interpolation type  classical
> >>    linear system matrix followed by preconditioner matrix:
> >>    Mat Object:     1 MPI processes
> >>      type: mffd
> >>      rows=9, cols=9
> >>        Matrix-free approximation:
> >>          err=1.49012e-08 (relative error in function evaluation)
> >>          Using wp compute h routine
> >>              Does not compute normU
> >>    Mat Object:    ()     1 MPI processes
> >>      type: seqaij
> >>      rows=9, cols=9
> >>      total: nonzeros=49, allocated nonzeros=49
> >>      total number of mallocs used during MatSetValues calls =0
> >>        not using I-node routines
> >>
> >> Fande,
> >>
> >
>
>
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