lapack-gels-case3.cc (flens/examples/lapack-gels-case3.cc)

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#include <cxxstd/iostream.h>

#include <flens/flens.cxx>

using namespace flens;

using namespace std;

int

main()

{

    typedef GeMatrix<FullStorage<double> >   GeMatrix;

    typedef DenseVector<Array<double> >      DenseVector;

    typedef typename DenseVector::IndexType  IndexType;

    const Underscore<IndexType>  _;

    GeMatrix     A(3, 4);

    DenseVector  x(4);

///

/// Setup the $3 \times 4$ matrix $A$.

///

    A =  1,  2,  3,  4,

         5,  6,  7,  8,

         9, 10, 11, 12;

///

/// The right hand side vector $b$ will be stored in vector $x$.

///

    auto b = x(_(1,3));

    b =  30,

         70,

        110;

///

/// Find the minimal norm solution of $Ax = b$.

///

    lapack::ls(NoTrans, A, x);

    cout << "x = " << x << endl;

    return 0;

}