Teuchos - Trilinos Tools Package Version of the Day
BLAS/cxx_main.cpp

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

/*
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//
//                    Teuchos: Common Tools Package
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// Under terms of Contract DE-AC04-94AL85000, there is a non-exclusive
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*/

#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;
}