[Trilinos-Users] Anasazi BlockKrylovSchur solver Error in F^H M F == I

Andris Freimanis andris.freimanis_1 at rtu.lv
Thu Sep 14 01:18:13 EDT 2017


Hello,

I'm trying to calculate few smallest eigenvalues of a linear system, 
where A - nonsymmetric sparse and M - sparse symmetric 
positive-definite, using Anasazi's Block Krylov Schur solver with 
shift-invert transformation that is solved by Belos's block GMRES 
solver. Both test matrices are  240x240 in size.

Unfortunately, I'm getting this error:  >> Error in F^H M F == I  : 
4.44e-16 (copied the full error message below), and can't find info on 
this in neither Anasazi nor Belos examples or documentation. Can you 
please take a look at the error message below?

This problem is similar to the one here: 
https://trilinos.org/pipermail/trilinos-users/2015-December/005270.html. 
However, the suggestion to use shift-invert doesn't help as I'm already 
doing that.

Best regards,

Andris Freimanis


Debugging checks: iteration 0: after initialize()
  >> Error in F^H M F == I  : 4.44e-16

================================================================================

                          BlockKrylovSchur Solver Status

The solver is initialized.
The number of iterations performed is 0
The block size is         1
The number of blocks is   24
The current basis size is 0
The number of auxiliary vectors is 0
The number of operations Op*x   is 0

CURRENT RITZ VALUES
    [ NONE COMPUTED ]

================================================================================

- StatusTestOutput: Failed
   (Num calls,Mod test,State test): (1, 1, Passed Failed Undefined )
    - StatusTestCombo: Failed
      - StatusTestWithOrdering: Undefined
        Quorum: 5
        Auxiliary values: [empty]
        - StatusTestResNorm: Failed
          (Tolerance,WhichNorm,Scaled,Quorum): 
(1.000000e-03,RITZRES_2NORM,true,5)
          Which vectors: [empty]
  Performing restart number 1 of 10

  Performing restart number 2 of 10

  Performing restart number 3 of 10

  Performing restart number 4 of 10

  Performing restart number 5 of 10

  Performing restart number 6 of 10

  Performing restart number 7 of 10

  Performing restart number 8 of 10

  Performing restart number 9 of 10

  Performing restart number 10 of 10

Failed.......OR Combination ->
   OK...........Number of Iterations = 264 < 1000
   Unconverged..(2-Norm Res Vec) / (2-Norm Prec Res0)
                residual [ 0 ] = 2.855202e-01 > 1.000000e-03

================================================================================

                       TimeMonitor results over 1 processor

Timer Name                                           Global time (num 
calls)
--------------------------------------------------------------------------------
Anasazi: BlockKrylovSchur::Computing Ritz vectors    0 (0)
Anasazi: BlockKrylovSchur::Computing Schur form      0 (0)
Anasazi: BlockKrylovSchur::Operation Op*x            0 (1)
Anasazi: BlockKrylovSchur::Orthogonalization         0.0001295 (1)
Anasazi: BlockKrylovSchur::Sorting Ritz values       0 (0)
Anasazi: BlockKrylovSchur::Sorting Schur form        0 (0)
Anasazi: BlockKrylovSchurSolMgr restarting           0 (0)
Anasazi: BlockKrylovSchurSolMgr::solve()             0 (1)
Belos: BlockGmresSolMgr total solve time             0.03066 (1)
Belos: Operation Op*x                                0.005605 (275)
--------------------------------------------------------------------------------
Belos: Operation Prec*x                              0.007409 (275)
Belos: Orthogonalization                             0.01177 (275)
Epetra_CrsMatrix::Multiply(TransA,X,Y)               0.005537 (280)
Epetra_CrsMatrix::Solve(Upper,Trans,UnitDiag,X,Y)    0.006862 (550)
Ifpack_ILU::ApplyInverse                             0.007275 (275)
Ifpack_ILU::ApplyInverse - Solve                     0.007074 (275)
Ifpack_ILU::Compute                                  0.002538 (1)
Ifpack_ILU::ComputeSetup                             0.0008707 (1)
Ifpack_ILU::Initialize                               0.0004559 (1)
================================================================================
Anasazi::BlockKrylovSchurSolMgr::solve() caught unexpected exception 
from Anasazi::BlockKrylovSchur::iterate() at iteration 1
/usr/local/trilinos/include/AnasaziEpetraAdapter.hpp:1401:

Throw number = 1

Throw test that evaluated to true: ret != 0

Anasazi::OperatorTraits<double,Epetra_Multivector,Epetra_Operator>::Apply(): 
Error in Epetra_Operator::Apply(). Code -1
Anasazi::BlockKrylovSchurSolMgr::solve() returning Unconverged with no 
solutions.

-- 
Andris Freimanis
PhD student

Riga Technical university
Institute of transporation
engineering

Ķīpsalas iela 6a, Riga, Latvia, LV1048
www.rtu.lv

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