BackToBackKinematicConstraint Class Reference

#include <BackToBackKinematicConstraint.h>

Inheritance diagram for BackToBackKinematicConstraint:

Public Member Functions
	BackToBackKinematicConstraint ()
virtual KinematicConstraint *	clone () const
virtual std::pair < AlgebraicMatrix, AlgebraicVector >	derivative (const AlgebraicVector &exPoint) const
virtual std::pair < AlgebraicMatrix, AlgebraicVector >	derivative (const std::vector< RefCountedKinematicParticle > par) const
virtual AlgebraicVector	deviations (int nStates) const
virtual int	numberOfEquations () const
virtual std::pair < AlgebraicVector, AlgebraicVector >	value (const AlgebraicVector &exPoint) const
virtual std::pair < AlgebraicVector, AlgebraicVector >	value (const std::vector< RefCountedKinematicParticle > par) const
	~BackToBackKinematicConstraint ()
Public Member Functions inherited from KinematicConstraint
	KinematicConstraint ()
virtual	~KinematicConstraint ()

Detailed Description

Class implementing the back-to-back geometry constraints for 2 KinematicParticles. Current version does not implement an actual back-to-back. Current class forces 2 tracks to have the opposite direction, bud does not force them to emerge from the single point. Coorect version to be implemented later.

This is just an illustrative piece of code, showing possible approach to constraint application on multiple tracks.

Kirill Prokofiev, July 2004

Definition at line 21 of file BackToBackKinematicConstraint.h.

Constructor & Destructor Documentation

BackToBackKinematicConstraint::BackToBackKinematicConstraint ( )

inline

Definition at line 25 of file BackToBackKinematicConstraint.h.

Referenced by clone().

{}

BackToBackKinematicConstraint::~BackToBackKinematicConstraint ( )

inline

Definition at line 27 of file BackToBackKinematicConstraint.h.

{}

Member Function Documentation

KinematicConstraint * BackToBackKinematicConstraint::clone ( ) const

virtual

Clone method

Implements KinematicConstraint.

Definition at line 86 of file BackToBackKinematicConstraint.cc.

References BackToBackKinematicConstraint().

{return new BackToBackKinematicConstraint(*this);}

std::pair< AlgebraicMatrix, AlgebraicVector > BackToBackKinematicConstraint::derivative ( const AlgebraicVector &  exPoint ) const

virtual

Implements KinematicConstraint.

Definition at line 20 of file BackToBackKinematicConstraint.cc.

{
//security check for extended cartesian parametrization 
 int inSize = exPoint.num_row(); 
 if(inSize != 14) throw VertexException("BackToBackKinematicConstraint::linearization point has a wrong dimension");
 AlgebraicVector pr = exPoint;
 
//number of states should be always equal to 2 for such a constraint 
 AlgebraicMatrix dr(3,14,0);
 dr(1,4) = 1.;
 dr(1,11) = 1.;
 dr(2,5) = 1;
 dr(2,12) = 1;
 dr(3,6) = 1;
 dr(3,13) = 1;
 return std::pair<AlgebraicMatrix, AlgebraicVector>(dr,pr); 
}

std::pair< AlgebraicMatrix, AlgebraicVector > BackToBackKinematicConstraint::derivative ( const std::vector< RefCountedKinematicParticle >  par ) const

virtual

Implements KinematicConstraint.

Definition at line 60 of file BackToBackKinematicConstraint.cc.

References i, j, and point.

{
 int nStates = par.size();
 if(nStates != 2) throw VertexException("BackToBackKinematicConstraint::number of tracks is not equal to 2"); 
 AlgebraicVector point(14,0);
 int co = 0;
 for(std::vector<RefCountedKinematicParticle>::const_iterator i = par.begin(); i!=par.end(); i++)
 {
  AlgebraicVector7 cPar = (*i)->currentState().kinematicParameters().vector();
  for(int j = 1; j<8; j++){point((co-1)*7+j) = cPar(j-1);}
  co++;
 }
 AlgebraicMatrix dr(3,14,0);

 return std::pair<AlgebraicMatrix, AlgebraicVector>(dr,point);
}

AlgebraicVector BackToBackKinematicConstraint::deviations ( int  nStates ) const

virtual

Returns vector of sigma squared associated to the KinematicParameters of refitted particles Initial deviations are given by user for the constraining parameters (mass, momentum components etc). In case of multiple states exactly the same values are added to every particle parameters

Implements KinematicConstraint.

Definition at line 77 of file BackToBackKinematicConstraint.cc.

References createTree::dd.

{
 AlgebraicVector dd(7*nStates,0);
 return dd;
}

int BackToBackKinematicConstraint::numberOfEquations ( ) const

virtual

Returns an actual number of equations in particular constraint (corresponds to the number of strings in constraint derivative matrix, for example)

Implements KinematicConstraint.

Definition at line 83 of file BackToBackKinematicConstraint.cc.

{return 3;}

std::pair< AlgebraicVector, AlgebraicVector > BackToBackKinematicConstraint::value ( const AlgebraicVector &  exPoint ) const

virtual

Derivatives and value calculated at given expansion point Vector should always be of size 14 (2 particles)

Implements KinematicConstraint.

Definition at line 5 of file BackToBackKinematicConstraint.cc.

{
//security check for extended cartesian parametrization 
 int inSize = exPoint.num_row(); 
 if(inSize != 14) throw VertexException("BackToBackKinematicConstraint::linearization point has a wrong dimension");
 AlgebraicVector pr = exPoint;
 
//number of states should be always equal to 2 for such a constraint
 AlgebraicVector vl(3,0);
 vl(1) = pr(4)+pr(11);
 vl(2) = pr(5)+pr(12);
 vl(3) = pr(6)+pr(13);
 return std::pair<AlgebraicVector, AlgebraicVector>(vl,pr); 
}

std::pair< AlgebraicVector, AlgebraicVector > BackToBackKinematicConstraint::value ( const std::vector< RefCountedKinematicParticle >  par ) const

virtual

Derivatives and values calculated at expansion point, taken at current state of input particles. Number of input particles should be always equal to 2

Implements KinematicConstraint.

Definition at line 38 of file BackToBackKinematicConstraint.cc.

References i, j, and point.

{
 int nStates = par.size();
 if(nStates != 2) throw VertexException("BackToBackKinematicConstraint::number of tracks is not equal to 2");
 AlgebraicVector point(14,0);
 int co = 0;
 for(std::vector<RefCountedKinematicParticle>::const_iterator i = par.begin(); i!=par.end(); i++)
 {
  AlgebraicVector7 cPar = (*i)->currentState().kinematicParameters().vector();
  for(int j = 1; j<8; j++){point((co-1)*7+j) = cPar(j-1);}
  co++;
 }
 AlgebraicVector vl(3,0);
 AlgebraicVector st1 = asHepVector<7>(par[0]->currentState().kinematicParameters().vector());
 AlgebraicVector st2 = asHepVector<7>(par[1]->currentState().kinematicParameters().vector());
 vl(1) = st1(4)+st2(4);
 vl(2) = st1(5)+st2(5);
 vl(3) = st1(6)+st2(6);
 
 return std::pair<AlgebraicVector, AlgebraicVector>(vl,point); 
}