LAPACK/cxx_main.cpp

This is an example of how to use the Teuchos::LAPACK class.

/*
// @HEADER
// ***********************************************************************
//
//                    Teuchos: Common Tools Package
//                 Copyright (2004) Sandia Corporation
//
// Under terms of Contract DE-AC04-94AL85000, there is a non-exclusive
// license for use of this work by or on behalf of the U.S. Government.
//
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 2.1 of the
// License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA
// Questions? Contact Michael A. Heroux (maherou@sandia.gov)
//
// ***********************************************************************
// @HEADER
*/

#include "Teuchos_LAPACK.hpp"
#include "Teuchos_SerialDenseMatrix.hpp"
#include "Teuchos_SerialDenseVector.hpp"
#include "Teuchos_Version.hpp"

int main(int argc, char* argv[])
{
  std::cout << Teuchos::Teuchos_Version() << std::endl << std::endl;

  // Creating an instance of the LAPACK class for double-precision routines looks like:
  Teuchos::LAPACK<int, double> lapack;

  // This instance provides the access to all the LAPACK routines.
  Teuchos::SerialDenseMatrix<int, double> My_Matrix(4,4);
  Teuchos::SerialDenseVector<int, double> My_Vector(4);
  My_Matrix.random();
  My_Vector.random();

  // Perform an LU factorization of this matrix. 
  int ipiv[4], info;
  char TRANS = 'N';
  lapack.GETRF( 4, 4, My_Matrix.values(), My_Matrix.stride(), ipiv, &info ); 
  
  // Solve the linear system.
  lapack.GETRS( TRANS, 4, 1, My_Matrix.values(), My_Matrix.stride(), 
    ipiv, My_Vector.values(), My_Vector.stride(), &info );  

  // Print out the solution.
  std::cout << My_Vector << std::endl;

  return 0;
}