schur.h

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//
// Copyright (C) 1994-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
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#if ! defined (octave_schur_h)
#define octave_schur_h 1
 
#include "octave-config.h"
 
#include <string>
 
// FIXME: Don't really need these for compiling schur.h, but it messes
// up compilation in liboctave/array if these are not present.
#include "CMatrix.h"
#include "dMatrix.h"
#include "fCMatrix.h"
#include "fMatrix.h"
 
namespace octave
{
  namespace math
  {
    template <typename T>
    class
    schur
    {
    public:
 
      schur (void) : schur_mat (), unitary_mat () { }
 
      schur (const T& a, const std::string& ord, bool calc_unitary = true)
        : schur_mat (), unitary_mat ()
      {
        init (a, ord, calc_unitary);
      }
 
      schur (const T& a, const std::string& ord, octave_f77_int_type& info,
             bool calc_unitary = true)
        : schur_mat (), unitary_mat ()
      {
        info = init (a, ord, calc_unitary);
      }
 
      // This one should really be protected or private but we need it in
      // rsf2csf and I don't see how to make that function a friend of
      // this class.
      schur (const T& s, const T& u) : schur_mat (s), unitary_mat (u) { }
 
      schur (const schur& a)
        : schur_mat (a.schur_mat), unitary_mat (a.unitary_mat)
      { }
 
      schur& operator = (const schur& a)
      {
        if (this != &a)
          {
            schur_mat = a.schur_mat;
            unitary_mat = a.unitary_mat;
          }
 
        return *this;
      }
 
      ~schur (void) = default;
 
      T schur_matrix (void) const { return schur_mat; }
 
      T unitary_matrix (void) const { return unitary_mat; }
 
    protected:
 
    private:
 
      T schur_mat;
      T unitary_mat;
 
      octave_f77_int_type
      init (const T& a, const std::string& ord, bool calc_unitary);
    };
 
    template <typename RT, typename AT>
    extern schur<RT>
    rsf2csf (const AT& s, const AT& u);
  }
}
 
#endif