int main(int argc, char* argv[])
{
using Teuchos::describe;
using Teuchos::rcp;
using Teuchos::rcp_dynamic_cast;
using Teuchos::rcp_const_cast;
using Teuchos::RCP;
using Teuchos::CommandLineProcessor;
using Teuchos::ParameterList;
using Teuchos::sublist;
using Teuchos::getParametersFromXmlFile;
typedef ParameterList::PrintOptions PLPrintOptions;
using Thyra::inverse;
using Thyra::initializePreconditionedOp;
using Thyra::initializeOp;
using Thyra::unspecifiedPrec;
using Thyra::solve;
typedef RCP<const Thyra::LinearOpBase<double> > LinearOpPtr;
typedef RCP<Thyra::VectorBase<double> > VectorPtr;
bool success = true;
bool verbose = true;
Teuchos::GlobalMPISession mpiSession(&argc,&argv);
Teuchos::RCP<Teuchos::FancyOStream>
out = Teuchos::VerboseObjectBase::getDefaultOStream();
try {
//
// Read in options from the command line
//
CommandLineProcessor clp(false); // Don't throw exceptions
const int numVerbLevels = 6;
Teuchos::EVerbosityLevel
verbLevelValues[] =
{
Teuchos::VERB_DEFAULT, Teuchos::VERB_NONE,
Teuchos::VERB_LOW, Teuchos::VERB_MEDIUM,
Teuchos::VERB_HIGH, Teuchos::VERB_EXTREME
};
const char*
verbLevelNames[] =
{ "default", "none", "low", "medium", "high", "extreme" };
Teuchos::EVerbosityLevel verbLevel = Teuchos::VERB_MEDIUM;
clp.setOption( "verb-level", &verbLevel,
numVerbLevels, verbLevelValues, verbLevelNames,
"Verbosity level used for all objects."
);
std::string matrixFile = ".";
clp.setOption( "matrix-file", &matrixFile,
"Matrix file."
);
std::string paramListFile = "";
clp.setOption( "param-list-file", ¶mListFile,
"Parameter list for preconditioner and solver blocks."
);
bool showParams = false;
clp.setOption( "show-params", "no-show-params", &showParams,
"Show the parameter list or not."
);
bool testPrecIsLinearOp = true;
clp.setOption( "test-prec-is-linear-op", "test-prec-is-linear-op", &testPrecIsLinearOp,
"Test if the preconditioner is a linear operator or not."
);
double solveTol = 1e-8;
clp.setOption( "solve-tol", &solveTol,
"Tolerance for the solution to determine success or failure!"
);
clp.setDocString(
"This example program shows how to use one linear solver (e.g. AztecOO)\n"
"as a preconditioner for another iterative solver (e.g. Belos).\n"
);
// Note: Use --help on the command line to see the above documentation
CommandLineProcessor::EParseCommandLineReturn parse_return = clp.parse(argc,argv);
if( parse_return != CommandLineProcessor::PARSE_SUCCESSFUL ) return parse_return;
//
*out << "\nA) Reading in the matrix ...\n";
//
#ifdef HAVE_MPI
Epetra_MpiComm comm(MPI_COMM_WORLD);
#else
Epetra_SerialComm comm;
#endif
const LinearOpPtr A = readEpetraCrsMatrixFromMatrixMarketAsLinearOp(
matrixFile, comm, "A");
*out << "\nA = " << describe(*A,verbLevel) << "\n";
const RCP<ParameterList> paramList = getParametersFromXmlFile(paramListFile);
if (showParams) {
*out << "\nRead in parameter list:\n\n";
paramList->print(*out, PLPrintOptions().indent(2).showTypes(true));
}
//
*out << "\nB) Get the preconditioner as a forward solver\n";
//
const RCP<ParameterList> precParamList = sublist(paramList, "Preconditioner Solver");
Stratimikos::DefaultLinearSolverBuilder precSolverBuilder;
precSolverBuilder.setParameterList(precParamList);
const RCP<const Thyra::LinearOpWithSolveFactoryBase<double> > precSolverStrategy
= createLinearSolveStrategy(precSolverBuilder);
//precSolverStrategy->setVerbLevel(verbLevel);
const LinearOpPtr A_inv_prec = inverse<double>(*precSolverStrategy, A,
Thyra::SUPPORT_SOLVE_FORWARD_ONLY,
Teuchos::null, // Use internal solve criteria
Thyra::IGNORE_SOLVE_FAILURE // Ignore solve failures since this is just a prec
);
*out << "\nA_inv_prec = " << describe(*A_inv_prec, verbLevel) << "\n";
if (testPrecIsLinearOp) {
*out << "\nTest that the preconditioner A_inv_prec is indeed a linear operator.\n";
Thyra::LinearOpTester<double> linearOpTester;
linearOpTester.check_adjoint(false);
const bool linearOpCheck = linearOpTester.check(*A_inv_prec, out.ptr());
if (!linearOpCheck) {
success = false;
}
}
//
*out << "\nC) Create the forward solver using the created preconditioner ...\n";
//
const RCP<ParameterList> fwdSolverParamList = sublist(paramList, "Forward Solver");
Stratimikos::DefaultLinearSolverBuilder fwdSolverSolverBuilder;
fwdSolverSolverBuilder.setParameterList(fwdSolverParamList);
const RCP<const Thyra::LinearOpWithSolveFactoryBase<double> > fwdSolverSolverStrategy
= createLinearSolveStrategy(fwdSolverSolverBuilder);
const RCP<Thyra::LinearOpWithSolveBase<double> >
A_lows = fwdSolverSolverStrategy->createOp();
initializePreconditionedOp<double>( *fwdSolverSolverStrategy, A,
unspecifiedPrec(A_inv_prec), A_lows.ptr());
//A_lows->setVerbLevel(verbLevel);
*out << "\nA_lows = " << describe(*A_lows, verbLevel) << "\n";
//
*out << "\nD) Solve the linear system for a random RHS ...\n";
//
VectorPtr x = createMember(A->domain());
VectorPtr b = createMember(A->range());
Thyra::randomize(-1.0, +1.0, b.ptr());
Thyra::assign(x.ptr(), 0.0); // Must give an initial guess!
Thyra::SolveStatus<double>
solveStatus = solve<double>( *A_lows, Thyra::NOTRANS, *b, x.ptr() );
*out << "\nSolve status:\n" << solveStatus;
*out << "\nSolution ||x|| = " << Thyra::norm(*x) << "\n";
if(showParams) {
*out << "\nParameter list after use:\n\n";
paramList->print(*out, PLPrintOptions().indent(2).showTypes(true));
}
//
*out << "\nF) Checking the error in the solution of r=b-A*x ...\n";
//
VectorPtr Ax = Thyra::createMember(b->space());
Thyra::apply( *A, Thyra::NOTRANS, *x, Ax.ptr() );
VectorPtr r = Thyra::createMember(b->space());
Thyra::V_VmV<double>(r.ptr(), *b, *Ax);
double
Ax_nrm = Thyra::norm(*Ax),
r_nrm = Thyra::norm(*r),
b_nrm = Thyra::norm(*b),
r_nrm_over_b_nrm = r_nrm / b_nrm;
bool resid_tol_check = ( r_nrm_over_b_nrm <= solveTol );
if(!resid_tol_check) success = false;
*out
<< "\n||A*x|| = " << Ax_nrm << "\n";
*out
<< "\n||A*x-b||/||b|| = " << r_nrm << "/" << b_nrm
<< " = " << r_nrm_over_b_nrm << " <= " << solveTol
<< " : " << Thyra::passfail(resid_tol_check) << "\n";
Teuchos::TimeMonitor::summarize(*out<<"\n");
}
TEUCHOS_STANDARD_CATCH_STATEMENTS(verbose, std::cerr, success)
if (verbose) {
if(success) *out << "\nCongratulations! All of the tests checked out!\n";
else *out << "\nOh no! At least one of the tests failed!\n";
}
return ( success ? EXIT_SUCCESS : EXIT_FAILURE );
}
