// ===================================================
// Methods
// ===================================================
Int
SolverAztecOO::solve ( vector_type& solution, const vector_type& rhs )
{
M_solver.SetLHS ( &solution.epetraVector() );
// The Solver from Aztecoo takes a non const (because of rescaling?)
// We should be careful if you use scaling
Epetra_FEVector* rhsVectorPtr ( const_cast<Epetra_FEVector*> (&rhs.epetraVector() ) );
M_solver.SetRHS ( rhsVectorPtr );
Int maxiter (M_maxIter);
Real mytol (M_tolerance);
Int status;
if ( isPreconditionerSet() && M_preconditioner->preconditionerType().compare ("AztecOO") )
{
M_solver.SetPrecOperator (M_preconditioner->preconditioner() );
}
status = M_solver.Iterate (maxiter, mytol);
#ifdef HAVE_LIFEV_DEBUG
M_displayer->comm()->Barrier();
M_displayer->leaderPrint ( " o- Number of iterations = ", M_solver.NumIters() );
M_displayer->leaderPrint ( " o- Norm of the true residual = ", M_solver.TrueResidual() );
M_displayer->leaderPrint ( " o- Norm of the true ratio = ", M_solver.ScaledResidual() );
#endif
/* try to solve again (reason may be:
-2 "Aztec status AZ_breakdown: numerical breakdown"
-3 "Aztec status AZ_loss: loss of precision"
-4 "Aztec status AZ_ill_cond: GMRES hessenberg ill-conditioned"
*/
if ( status <= -2 )
{
maxiter = M_maxIter;
mytol = M_tolerance;
Int oldIter = M_solver.NumIters();
status = M_solver.Iterate (maxiter, mytol);
#ifdef HAVE_LIFEV_DEBUG
M_displayer->comm()->Barrier();
M_displayer->leaderPrint ( " o- Second run: number of iterations = ", M_solver.NumIters() );
M_displayer->leaderPrint ( " o- Norm of the true residual = ", M_solver.TrueResidual() );
M_displayer->leaderPrint ( " o- Norm of the true ratio = ", M_solver.ScaledResidual() );
#endif
return ( M_solver.NumIters() + oldIter );
}
return ( M_solver.NumIters() );
}
Real
SolverAztecOO::computeResidual ( vector_type& solution, vector_type& rhs )
{
vector_type Ax ( solution.map() );
vector_type res ( rhs );
M_solver.GetUserMatrix()->Apply ( solution.epetraVector(), Ax.epetraVector() );
res.epetraVector().Update ( 1, Ax.epetraVector(), -1 );
Real residual;
res.norm2 ( &residual );
return residual;
}
