BLAS/cxx_main.cpp

This is an example of how to use the Teuchos::BLAS 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_BLAS.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 BLAS class for double-precision kernels looks like:
  Teuchos::BLAS<int, double> blas;

  // This instance provides the access to all the BLAS kernels listed in Figure \ref{blas_kernels}:
  const int n = 10;
  double alpha = 2.0;
  double x[ n ];
  for ( int i=0; i<n; i++ ) { x[i] = i; }
  blas.SCAL( n, alpha, x, 1 );
  int max_idx = blas.IAMAX( n, x, 1 );
  std::cout<< "The index of the maximum magnitude entry of x[] is the "
      <<  max_idx <<"-th and x[ " << max_idx-1 << " ] = "<< x[max_idx-1] 
      << std::endl;
  
  return 0;
}