New changes for CG set type in 2.3.1-p7 ?

[Satish Balay]

Sorry - the test code had SetFromOptions after KSPCGSetType()

Satish

---

      call KSPCreate(PETSC_COMM_WORLD,ksp,ierr)
      call KSPSetType(ksp,KSPCG,ierr)
      call KSPCGSetType(ksp,KSP_CG_SYMMETRIC,ierr)
      call KSPSetOperators(ksp,A,A,DIFFERENT_NONZERO_PATTERN,ierr)
      call KSPSetFromOptions(ksp,ierr)
      call KSPSolve(ksp,b,x,ierr)



On Thu, 23 Feb 2006, Barry Smith wrote:

> 
>    What about calling SetFromOptions after the call to KSPCGSetType()?
> 
>     Thanks
>      Barry
> 
> 
> On Thu, 23 Feb 2006, Satish Balay wrote:
> 
> > 
> > I just tried the following [with both c & fortran examples
> > ksp/examples/tutorials/ex2.c, ex2f.F] And I get the expected behavior.
> > 
> > Maybe KSPSetType() was not called before KSPCGSetType()?
> > 
> > Satish
> > 
> > --------
> > 
> > > > > 
> >      call KSPCreate(PETSC_COMM_WORLD,ksp,ierr)
> >      call KSPSetType(ksp,KSPCG,ierr)
> >      call KSPCGSetType(ksp,KSP_CG_SYMMETRIC,ierr)
> >      call KSPSetOperators(ksp,A,A,DIFFERENT_NONZERO_PATTERN,ierr)
> > > > > 
> > 
> > asterix:/home/balay/spetsc/src/ksp/ksp/examples/tutorials>./ex2f -ksp_view
> > KSP Object:
> >  type: cg
> >    CG or CGNE: variant SYMMETRIC
> >  maximum iterations=10000, initial guess is zero
> >  tolerances:  relative=1e-05, absolute=1e-50, divergence=10000
> >  left preconditioning
> > PC Object:
> >  type: ilu
> >    ILU: 0 levels of fill
> >    ILU: max fill ratio allocated 1
> >    ILU: tolerance for zero pivot 1e-12
> >         out-of-place factorization
> >         matrix ordering: natural
> >         Factored matrix follows
> >    Matrix Object:
> >      type=aij, rows=9, cols=9
> >      total: nonzeros=33, allocated nonzeros=45
> >        not using I-node routines
> >  linear system matrix = precond matrix:
> >  Matrix Object:
> >    type=aij, rows=9, cols=9
> >    total: nonzeros=33, allocated nonzeros=45
> >      not using I-node routines
> > Norm of error 0.1215E-05 iterations     4
> > asterix:/home/balay/spetsc/src/ksp/ksp/examples/tutorials>
> > 
> > 
> > On Thu, 23 Feb 2006, Barry Smith wrote:
> > 
> > > 
> > >    Satish,
> > > 
> > >     Can you please check this? We should be able to
> > > call KSPCGSetType() either before or afterwards. It could
> > > be that KSPSetFromOptions_CG() wrongly resets to the default
> > > value. I looked at the code and didn't see any wrong logic.
> > > Probably it may be easiest to just run in the debugger and
> > > check if it wrongly reset.
> > > 
> > >     Thanks
> > > 
> > >     Barry
> > > 
> > > 
> > > On Thu, 23 Feb 2006, abdul-rahman at tu-harburg.de wrote:
> > > 
> > > > 
> > > > 
> > > > On Wed, 22 Feb 2006, Satish Balay wrote:
> > > > 
> > > > I know where I did wrong now: the call below:
> > > > 
> > > > > > > >       call KSPCGSetType( ksp, KSP_CG_SYMMETRIC, ierr )
> > > > 
> > > > should have come _after_:
> > > > 
> > > >  call KSPSetFromOptions(ksp,ierr)
> > > > 
> > > > Otherwise it just goes with the default Hermitian even if I don't set
> > > > the
> > > > switch to Hermitian.
> > > > 
> > > > 
> > > > > You should be able to verify if the correct type is used with
> > > > > '-ksp_view' option.
> > > > > 
> > > > > Satish
> > > > > 
> > > > 
> > > > Thank you again
> > > > 
> > > > 
> > > > Razi
> > > > 
> > > > 
> > > 
> > > 
> > 
> > 
> 
>