projection_Maximum_SU_N.h

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#ifndef PROJECTION_MAXIMUM_SU_N_INCLUDED
#define PROJECTION_MAXIMUM_SU_N_INCLUDED

#include "projection.h"

#include "IO/bridgeIO.h"
using Bridge::vout;


class Projection_Maximum_SU_N : public Projection
{
 public:
  static const std::string class_name;

 private:
  int m_Niter;     
  double m_Enorm;  

 public:
  Projection_Maximum_SU_N()
  {
    //- defaults
    m_Niter = 100;
    m_Enorm = 1.0e-12;
  }

  ~Projection_Maximum_SU_N() {}

  void set_parameters(const Parameters& params);
  void set_parameters(const int Niter, const double Enorm);

  void project(Field_G& U,
               const double alpha,
               const Field_G& C, const Field_G& Uorg);

  void force_recursive(Field_G& Xi, Field_G& iTheta,
                       const double alpha, const Field_G& Sigmap,
                       const Field_G& C, const Field_G& U);

 private:
  //- maximization of ReTr[U^\dag V].
  void maxTr(Field_G& U, const Field_G& V);

  //- maximization by SU(2) subgroup.
  void maxTr_SU2(const int, const int, Field_G&, Field_G&, Field_G&);

  //- matrix index for convenience.
  int mindex(const int i, const int j, const int Nc)
  {
    return i + j * Nc;
  }

#ifdef USE_FACTORY
 private:
  static Projection *create_object()
  {
    return new Projection_Maximum_SU_N();
  }

 public:
  static bool register_factory()
  {
    return Projection::Factory::Register("Maximum_SU_N", create_object);
  }
#endif
};
#endif