MassConstraint.h

/**************************************************************************
 * basf2 (Belle II Analysis Software Framework)                           *
 * Author: The Belle II Collaboration                                     *
 *                                                                        *
 * Forked from https://github.com/iLCSoft/MarlinKinfit                    *
 *                                                                        *
 * Further information about the fit engine and the user interface        *
 * provided in MarlinKinfit can be found at                               *
 * https://www.desy.de/~blist/kinfit/doc/html/                            *
 * and in the LCNotes LC-TOOL-2009-001 and LC-TOOL-2009-004 available     *
 * from http://www-flc.desy.de/lcnotes/                                   *
 *                                                                        *
 * See git log for contributors and copyright holders.                    *
 * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
 **************************************************************************/
 
#ifndef __MASSCONSTRAINT_H
#define __MASSCONSTRAINT_H
 
#include "analysis/OrcaKinFit/ParticleConstraint.h"
 
namespace Belle2 {
  namespace OrcaKinFit {
 
    class ParticleFitObject;
 
//  Class MassConstraint:
 
    class MassConstraint : public ParticleConstraint {
    public:
 
      explicit MassConstraint(double mass_ = 0.    
                             );
      virtual ~MassConstraint();
 
      virtual double getValue() const override;
 
      virtual void getDerivatives(int idim,      
                                  double der[]   
                                 ) const override;
 
      virtual double getMass(int flag = 1        
                            );
 
      virtual void setMass(double mass_            
                          );
 
      virtual int getVarBasis() const override;
 
    protected:
 
      double mass;   
 
      virtual bool secondDerivatives(int i,                         
                                     int j,                        
                                     double* derivatives           
                                    ) const override;
 
      virtual bool firstDerivatives(int i,                         
                                    double* derivatives           
                                   ) const override;
 
      enum { VAR_BASIS = 0 }; // this means that the constraint knows about E,px,py,pz
 
    };
 
  }// end OrcaKinFit namespace
} // end Belle2 namespace
 
 
#endif // __MASSCONSTRAINT_H