Tpetra_Power_Method_From_File.cpp

Demonstrate reading a Harwell-Boeing file into a Tpetra::CrsMatrix and computing its leading eigenvalue using the TpetraExamples::powerMethod() function.

#include <Teuchos_GlobalMPISession.hpp>
#include <Teuchos_oblackholestream.hpp>
#include <Teuchos_CommandLineProcessor.hpp>
#include <Teuchos_Array.hpp>

// I/O for Harwell-Boeing files
#include <Tpetra_MatrixIO.hpp>

#include "Tpetra_Power_Method.hpp"

#include "Tpetra_DefaultPlatform.hpp"
#include "Tpetra_Version.hpp"
#include "Tpetra_Map.hpp"
#include "Tpetra_MultiVector.hpp"
#include "Tpetra_Vector.hpp"
#include "Tpetra_CrsMatrix.hpp"

int main(int argc, char *argv[]) {
  Teuchos::oblackholestream blackhole;
  Teuchos::GlobalMPISession mpiSession(&argc,&argv,&blackhole);

  //
  // Specify types used in this example
  // 
  typedef double Scalar;
  typedef Teuchos::ScalarTraits<Scalar>::magnitudeType Magnitude;
  typedef int Ordinal;
  typedef Tpetra::DefaultPlatform::DefaultPlatformType           Platform;
  typedef Tpetra::DefaultPlatform::DefaultPlatformType::NodeType Node;

  // 
  // Get the default communicator and node
  //
  Platform &platform = Tpetra::DefaultPlatform::getDefaultPlatform();
  Teuchos::RCP<const Teuchos::Comm<int> > comm = platform.getComm();
  Teuchos::RCP<Node>             node = platform.getNode();
  const int myRank = comm->getRank();

  //
  // Get example parameters from command-line processor
  //  
  bool printMatrix = false;
  bool verbose = (myRank==0);
  int niters = 100;
  Magnitude tolerance = 1.0e-2;
  std::string filename("bcsstk14.hb");
  Teuchos::CommandLineProcessor cmdp(false,true);
  cmdp.setOption("verbose","quiet",&verbose,"Print messages and results.");
  cmdp.setOption("filename",&filename,"Filename for Harwell-Boeing test matrix.");
  cmdp.setOption("tolerance",&tolerance,"Relative residual tolerance used for solver.");
  cmdp.setOption("iterations",&niters,"Maximum number of iterations.");
  cmdp.setOption("printMatrix","noPrintMatrix",&printMatrix,"Print the full matrix after reading it.");
  if (cmdp.parse(argc,argv) != Teuchos::CommandLineProcessor::PARSE_SUCCESSFUL) {
    return -1;
  }

  // 
  // Say hello, print some communicator info
  //
  if (verbose) {
    std::cout << "\n" << Tpetra::version() << std::endl << std::endl;
  }
  std::cout << "Comm info: " << *comm;

  //
  // Read Tpetra::CrsMatrix from file
  //
  Teuchos::RCP< Tpetra::CrsMatrix<Scalar,Ordinal> > A;
  Tpetra::Utils::readHBMatrix(filename,comm,node,A);
  if (printMatrix) {
    Teuchos::RCP<Teuchos::FancyOStream> fos = Teuchos::fancyOStream(Teuchos::rcpFromRef(std::cout));
    A->describe(*fos, Teuchos::VERB_EXTREME);
  }
  else if (verbose) {
    std::cout << std::endl << A->description() << std::endl << std::endl;
  }

  //
  // Iterate
  //
  Scalar lambda;
  lambda = TpetraExamples::powerMethod<Scalar,Ordinal>(A, niters, tolerance, verbose);

  if (verbose) {
    std::cout << "\nEnd Result: TEST PASSED" << std::endl;
  }
  return 0;
}