[petsc-users] [petsc-3.2] LSQR new convergence test

[Alexander Grayver]

Hello,

In comparison with petsc-3.1-p7 in the latest petsc LSQR solver behaves 
differently.

In petsc31 I had:

   0 KSP Residual norm 9.386670021557e-17
...
  95 KSP Residual norm 9.341367317075e-18
Linear solve converged due to CONVERGED_RTOL iterations 95
KSP Object:
   type: lsqr
   maximum iterations=200, initial guess is zero
   tolerances:  relative=0.1, absolute=1e-50, divergence=10000
   left preconditioning
   using PRECONDITIONED norm type for convergence test
PC Object:
   type: none
   linear system matrix = precond matrix:
   Matrix Object:
     type=shell, rows=19584, cols=19584

relative residual norm =    0.9951737192872134E-01

Now, with petsc32 I have:

   0 KSP Residual norm 9.386670021557e-17
   1 KSP Residual norm 8.258308650175e-17
Linear solve converged due to CONVERGED_RTOL_NORMAL iterations 1
KSP Object: 12 MPI processes
   type: lsqr
   maximum iterations=200, initial guess is zero
   tolerances:  relative=0.1, absolute=1e-50, divergence=10000
   left preconditioning
   using UNPRECONDITIONED norm type for convergence test
PC Object: 12 MPI processes
   type: none
   linear system matrix = precond matrix:
   Matrix Object:   12 MPI processes
     type: shell
     rows=19584, cols=19584
relative residual norm =    0.8797910900468064E+00

So I found new convergence test here which sets CONVERGED_RTOL_NORMAL:
http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/docs/manualpages/KSP/KSPLSQRDefaultConverged.html

The question is, how to interpret this new test and make it works 
properly for me?
Thanks in advance.

Regards,
Alexander