lapack-complex-getrs.cc (flens/examples/lapack-complex-getrs.cc)

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#include <cxxstd/iostream.h>

#include <flens/flens.cxx>

using namespace std;

using namespace flens;

int

main()

{

    typedef complex<double>             Complex;

    const Complex                       I(0,1);

    GeMatrix<FullStorage<Complex> >     A(4, 4);

    DenseVector<Array<Complex> >        b(4);

    DenseVector<Array<int> >            piv(4);

///

/// Setup matrix $A$.  Note that `2+I` or `2*I` would not work.  That's because

/// the STL does not define the operation `int+complex<double>` or

/// `int*complex<double>`.

///

    A =   2,    3,  -I,    0,

         -6,   -5,   0, 2.+I,

       2.*I,   -5,   6,   -6,

          4, 6.*I,   2,   -3;

    b = 20,

       -33.*I,

       -43,

        49;

    cout << "A = " << A << endl;

    cout << "b = " << b << endl;

///

/// Compute the $PLU = A$ factorization with __lapack::trf__

///

    lapack::trf(A, piv);

///

/// Solve the system of linear equation $PLUx = b$ using __lapack::trs__.

/// Vector $b$ gets overwritten with vector $x$.

///

    lapack::trs(NoTrans, A, piv, b);

    cout << "X = " << b << endl;

}

///

///  :links: __lapack::trf__ -> file:flens/lapack/ge/trf.h

///          __lapack::trs__ -> file:flens/lapack/ge/trs.h

///