Thanks Barry, We are using "KSPSetPCSide(ksp, pcside)" in the code. I just tried "-ksp_pc_side right", and petsc did not error out.
I like to understand why CG does not work with right preconditioning? Mathematically, the right preconditioning does not make sense? Fande, On Wed, Mar 8, 2017 at 9:33 AM, Barry Smith <[email protected]> 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 <[email protected]> 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, > > > >
