[Trilinos-Users] BlockKrylovSchur: number of required Ritz vectors splits a complex conjugate pair.

[Michael Junge]

Hi,
when running the Block Krylov Schur solver of the trilinos package 8.0.3 
for an unsymmetric eigenvalue problem, I get the error message
"Anasazi::BlockKrylovSchur::computeRitzVectors(): the number of required 
Ritz vectors splits a complex conjugate pair."
after the 6-th iteration.
Is there any possibility to cope with this error? Can I instead of 
throwing this exception
lower the variable numRitzVecs_ by one and proceed without any 
subsequent error?
Any suggestions to resolve this error are greatly appreciated.

Michael

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

                         BlockKrylovSchur Solver Status

The solver is initialized.
The number of iterations performed is 6
The block size is         12
The number of blocks is   7
The current basis size is 72
The number of auxiliary vectors is    0
The number of operations Op*x   is 72

CURRENT RITZ VALUES             
              Ritz Value                 Ritz Residual
--------------------------------------------------------------------------------
   9.565366e-05 + i   0.000000e+00        5.162558e-14
   6.535990e-05 + i   0.000000e+00        3.367828e-13
   1.531108e-05 + i   0.000000e+00        3.643859e-11
   1.074612e-05 + i   0.000000e+00        7.339283e-10
   6.653571e-06 + i   0.000000e+00        3.781330e-09
   5.151594e-06 + i   0.000000e+00        1.167965e-08
   4.963956e-06 + i   0.000000e+00        4.357004e-09
   4.831631e-06 + i   0.000000e+00        9.323526e-09
   4.176412e-06 + i   0.000000e+00        1.887900e-08
   3.687791e-06 + i   0.000000e+00        4.500353e-08
   2.792135e-06 + i   0.000000e+00        1.260036e-07
   2.676274e-06 + i   0.000000e+00        1.066106e-07
   2.485754e-06 + i   0.000000e+00        2.336125e-07
   2.265135e-06 + i   0.000000e+00        1.216118e-07
   2.123651e-06 + i   0.000000e+00        1.984118e-07
   2.083278e-06 + i   0.000000e+00        1.851201e-07
   1.964699e-06 + i   0.000000e+00        3.001937e-07
   1.894537e-06 + i   0.000000e+00        2.210573e-07
   1.808296e-06 + i   0.000000e+00        2.643175e-07
   1.767787e-06 + i   0.000000e+00        1.857689e-07
   1.712140e-06 + i   0.000000e+00        1.948303e-07
   1.673696e-06 + i   0.000000e+00        2.257906e-07
   1.666248e-06 + i   0.000000e+00        2.148936e-07
   1.623681e-06 + i   0.000000e+00        2.166838e-07
   1.609906e-06 + i   0.000000e+00        1.941363e-07
   1.468962e-06 + i   0.000000e+00        2.552411e-07
   1.426348e-06 + i   0.000000e+00        2.757035e-07
   1.405264e-06 + i   0.000000e+00        2.400259e-07
   1.376019e-06 + i   0.000000e+00        2.659608e-07
   1.301969e-06 + i   0.000000e+00        3.079990e-07
   1.284877e-06 + i   0.000000e+00        3.499356e-07
   1.246154e-06 + i   0.000000e+00        3.004309e-07
   1.233486e-06 + i   0.000000e+00        2.883003e-07
   1.125078e-06 + i   0.000000e+00        3.013997e-07
   1.083713e-06 + i   0.000000e+00        3.703915e-07
   1.021817e-06 + i   0.000000e+00        3.098594e-07

================================================================================
Error! Caught exception in BlockKrylovSchur::iterate() at iteration 7
St9exception
terminate called after throwing an instance of 'std::logic_error'
  what():  solver/EVP/AnasaziBlockKrylovSchurTrackRes.hpp:1410:
Throw number = 1
Throw test that evaluated to true: ritzIndex_[numRitzVecs_-1]==1
Anasazi::BlockKrylovSchur::computeRitzVectors(): the number of required 
Ritz vectors splits a complex conjugate pair.