tut02-page01-example.cc (flens/examples/tut02-page01-example.cc)

      1
      2
      3
      4
      5
      6
      7
      8
      9
     10
     11
     12
     13
     14
     15
     16
     17
     18
     19
     20
     21
     22
     23
     24
     25
     26
     27
     28
     29
     30
     31
     32
     33
     34
     35
     36
     37
     38
     39
     40
     41
     42
     43
     44
     45

#include <cxxstd/iostream.h>

#include <flens/flens.cxx>

using namespace flens;

using namespace std;

int

main()

{

    typedef double                               T;

    typedef DenseVector<Array<T> >               DEVector;

    typedef GeMatrix<FullStorage<T, ColMajor> >  GEMatrix;

    const T  alpha = 1.5,

             beta = 2.5;

    DEVector x(3), y(3), z(3);

    x = 1, 2, 3;

    y = 2, 3, 4;

    z = 3, 4, 5;

    GEMatrix A(3,3);

    A = 1, 2, 3,

        5, 6, 7,

        5, 4, 3;

    ///

    /// Compute $y = \beta y + \alpha A^T x$

    ///

    cxxblas::gemv(A.numRows(), A.numCols(),

                  alpha,

                  true, false, A.data(), A.strideRow(), A.strideCol(),

                  x.data(), x.stride(),

                  beta,

                  y.data(), y.stride());

    ///

    /// Compute the update $y = y + z$

    ///

    cxxblas::axpy(y.length(), T(1), z.data(), z.stride(), y.data(), y.stride());

    cout << "y = " << y << endl;

    return 0;

}