PointingKinematicConstraint Class Reference

#include <PointingKinematicConstraint.h>

Inheritance diagram for PointingKinematicConstraint:

Public Member Functions
virtual PointingKinematicConstraint *	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
	PointingKinematicConstraint (const GlobalPoint &ref)
virtual std::pair < AlgebraicVector, AlgebraicVector >	value (const AlgebraicVector &exPoint) const
virtual std::pair < AlgebraicVector, AlgebraicVector >	value (const std::vector< RefCountedKinematicParticle > par) const
Public Member Functions inherited from KinematicConstraint
	KinematicConstraint ()
virtual	~KinematicConstraint ()

Private Member Functions
std::pair< AlgebraicMatrix, AlgebraicVector >	makeDerivative (const AlgebraicVector &exPoint) const
std::pair< AlgebraicVector, AlgebraicVector >	makeValue (const AlgebraicVector &exPoint) const

Private Attributes
GlobalPoint	refPoint

Detailed Description

Topological constraint making a momentum vector to point to the given location in space. Example: if b-meson momentum is reconstructed at b-meson decay position (secondary vertex), making reconstructed momentum pointing the the primary vertex

Multiple track refit is not supported in current version

Kirill Prokofiev, March 2004 MultiState version: July 2004

Definition at line 21 of file PointingKinematicConstraint.h.

Constructor & Destructor Documentation

PointingKinematicConstraint::PointingKinematicConstraint ( const GlobalPoint &  ref )

inline

Definition at line 25 of file PointingKinematicConstraint.h.

Referenced by clone().

                                                     :refPoint(ref)
  {}

Member Function Documentation

virtual PointingKinematicConstraint* PointingKinematicConstraint::clone ( ) const

inlinevirtual

Clone method

Implements KinematicConstraint.

Definition at line 53 of file PointingKinematicConstraint.h.

References PointingKinematicConstraint().

 {return new PointingKinematicConstraint(*this);}

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

virtual

Implements KinematicConstraint.

Definition at line 24 of file PointingKinematicConstraint.cc.

References makeDerivative().

{
 if(exPoint.num_row() ==0 ) throw VertexException("PointingKinematicConstraint::value requested for zero Linearization point");

//security check for extended cartesian parametrization 
 int inSize = exPoint.num_row(); 
 if((inSize%7) !=0) throw VertexException("PointingKinematicConstraint::linearization point has a wrong dimension");
 int nStates = inSize/7;
 if(nStates != 1) throw VertexException("PointingKinematicConstraint::Current version does not support the multistate refit");
 AlgebraicVector lPar = exPoint;

//2x7 derivative matrix for given particle
 AlgebraicMatrix lDeriv = makeDerivative(lPar).first;
 AlgebraicMatrix dr(2,7,0);
 dr.sub(1,1,lDeriv);
 return std::pair<AlgebraicMatrix,AlgebraicVector>(dr,lPar);
}

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

virtual

Vector of values and matrix of derivatives calculated using current state parameters as expansion point

Implements KinematicConstraint.

Definition at line 42 of file PointingKinematicConstraint.cc.

References makeDerivative().

{
 int nStates = par.size();
 if(nStates == 0) throw VertexException("PointingKinematicConstraint::Empty vector of particles passed");
 if(nStates != 1) throw VertexException("PointingKinematicConstraint::Current version does not support the multistate refit");
 
 AlgebraicMatrix dr(2,7,0);
 AlgebraicVector lPoint = asHepVector<7>(par.front()->currentState().kinematicParameters().vector());

//2x7 derivative matrix for given state  
 AlgebraicMatrix lDeriv = makeDerivative(lPoint).first;
 dr.sub(1,1,lDeriv);
 return std::pair<AlgebraicMatrix,AlgebraicVector>(dr,lPoint);
}

AlgebraicVector PointingKinematicConstraint::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 174 of file PointingKinematicConstraint.cc.

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

std::pair< AlgebraicMatrix, AlgebraicVector > PointingKinematicConstraint::makeDerivative ( const AlgebraicVector &  exPoint ) const

private

Definition at line 106 of file PointingKinematicConstraint.cc.

References point, refPoint, mathSSE::sqrt(), PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by derivative().

{
 AlgebraicMatrix dr(2,7,0);
 AlgebraicVector point = exPoint;
 double dx = point(1) - refPoint.x();
 double dy = point(2) - refPoint.y();
 double dz = point(3) - refPoint.z();
 double px = point(4);
 double py = point(5); 
 double pz = point(6);
                  
// double tr = px*px + py*py;
// double trd = dx*dx + dy*dy;
// double pr =1.5;
// double p_factor = pow(tr,pr);
// double x_factor = pow(trd,pr);
  
//tangent solution
/*
 dr(1,1) = -dy/(dx*dx);
 dr(1,2) = 1/dx;
 dr(1,3) = 0;
 dr(1,4) = py/(px*px);
 dr(1,5) = -1/px;
 dr(1,6) = 0;
 dr(1,7) = 0;
 
 dr(2,1) = -(dx*dz)/x_factor;
 dr(2,2) = -(dy*dz)/x_factor;
 dr(2,3) = 1/sqrt(dx*dx + dy*dy);
 dr(2,4) = (px*pz)/p_factor;
 dr(2,5) = (py*pz)/p_factor;
 dr(2,6) = -1/sqrt(px*px + py*py);
 dr(2,7) = 0.;
*/
//half angle solution corrected   
/*
 dr(1,1) = - dy/(dx*dx+dy*dy+dx*sqrt(dx*dx+dy*dy));
 dr(1,2) =   dx/(dx*dx+dy*dy+dx*sqrt(dx*dx+dy*dy));
 dr(1,3) = 0; 
 dr(1,4) = py/(px*px+py*py+px*sqrt(px*px+py*py));
 dr(1,5) = -px/(px*px+py*py+px*sqrt(px*px+py*py));
 dr(1,6) = 0;
 dr(1,7) = 0; 
*/

//half angle solution
 dr(1,1) = dx/(dy*sqrt(dx*dx + dy*dy)) - 1/dy;
 dr(1,2) = 1/sqrt(dx*dx+dy*dy) - sqrt(dx*dx+dy*dy)/(dy*dy)+ dx/(dy*dy);
 dr(1,3) = 0; 
 dr(1,4) = -(px/(py*sqrt(px*px + py*py)) - 1/py);
 dr(1,5) = -(1/sqrt(px*px+py*py) - sqrt(px*px+py*py)/(py*py)+ px/(py*py));
 dr(1,6) = 0;
 dr(1,7) = 0; 


//half angle solution
 dr(2,1) = (dx/dz)*(1/sqrt(dx*dx + dy*dy + dz*dz) - 1/sqrt(dx*dx + dy*dy));
 dr(2,2) = (dy/dz)*(1/sqrt(dx*dx + dy*dy + dz*dz) - 1/sqrt(dx*dx + dy*dy));
 dr(2,3) = (1/(dz*dz))*(sqrt(dx*dx + dy*dy) - sqrt(dx*dx+dy*dy+dz*dz)) + 1/sqrt(dx*dx+dy*dy+dz*dz);
 dr(2,4) = -(px/pz)*(1/sqrt(px*px + py*py + pz*pz) - 1/sqrt(px*px + py*py));
 dr(2,5) = -(py/pz)*(1/sqrt(px*px + py*py + pz*pz) - 1/sqrt(px*px + py*py));
 dr(2,6) = -((1/(pz*pz))*(sqrt(px*px + py*py) - sqrt(px*px+py*py+pz*pz)) + 1/sqrt(px*px+py*py+pz*pz));
 dr(2,7) = 0;
 
 return std::pair<AlgebraicMatrix,AlgebraicVector>(dr,point);
}

std::pair< AlgebraicVector, AlgebraicVector > PointingKinematicConstraint::makeValue ( const AlgebraicVector &  exPoint ) const

private

Definition at line 69 of file PointingKinematicConstraint.cc.

References point, refPoint, mathSSE::sqrt(), PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by value().

{
 AlgebraicVector vl(2,0);
 AlgebraicVector point = exPoint;
 double dx = point(1) - refPoint.x();
 double dy = point(2) - refPoint.y();
 double dz = point(3) - refPoint.z();
 double px = point(4);
 double py = point(5); 
 double pz = point(6);

// tangent solution
// vl(1) = dy/dx - py/px;
// vl(2) = dz/sqrt(dx*dx + dy*dy) - pz/sqrt(px*px + py*py); 


//half angle solution
 double sin_p = py/sqrt(px*px + py*py);
 double cos_p = px/sqrt(px*px + py*py);
 double sin_x = dy/sqrt(dx*dx + dy*dy);
 double cos_x = dx/sqrt(dx*dx + dy*dy);
 
 double sin_pt = pz/sqrt(px*px + py*py + pz*pz); 
 double cos_pt = sqrt(px*px + py*py)/sqrt(px*px + py*py + pz*pz);
 double sin_xt = dz/sqrt(dx*dx + dy*dy + dz*dz); 
 double cos_xt = sqrt(dx*dx + dy*dy)/sqrt(dx*dx + dy*dy + dz*dz);
 
 vl(1) = (1-cos_x)/sin_x - (1-cos_p)/sin_p;
 vl(2) = (1-cos_xt)/sin_xt - (1-cos_pt)/sin_pt;

//half angle corrected
// vl(1) = (sin_x/(1+cos_x)) - (sin_p/(1+cos_p));
// vl(2) = (sin_xt/(1+cos_xt)) - (sin_pt/(1+cos_pt));
 return std::pair<AlgebraicVector,AlgebraicVector>(vl,point);
}

int PointingKinematicConstraint::numberOfEquations ( ) const

virtual

Returns number of constraint equations used for fitting. Method is relevant for proper NDF calculations.

Implements KinematicConstraint.

Definition at line 177 of file PointingKinematicConstraint.cc.

{return 2;}

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

virtual

Vector of values and matrix of derivatives calculated at given expansion 7xNumberOfStates point

Implements KinematicConstraint.

Definition at line 4 of file PointingKinematicConstraint.cc.

References makeValue().

{
 if(exPoint.num_row() ==0 ) throw VertexException("PointingKinematicConstraint::value requested for zero Linearization point");

//security check for extended cartesian parametrization 
 int inSize = exPoint.num_row(); 
 if((inSize%7) !=0) throw VertexException("PointingKinematicConstraint::linearization point has a wrong dimension");
 int nStates = inSize/7;
 if(nStates != 1) throw VertexException("PointingKinematicConstraint::Current version does not support the multistate refit");
 
 AlgebraicVector lPar = exPoint;
 AlgebraicVector vl(2,0);
 
//vector of values 1x2  for given particle
 AlgebraicVector lValue = makeValue(lPar).first;
 vl(1) =lValue(1);
 vl(2) =lValue(2);
 return std::pair<AlgebraicVector,AlgebraicVector>(vl,lPar); 
}

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

virtual

Methods making value and derivative matrix using current state parameters as expansion 7-point. Constraint can be made equaly for single and multiple states

Implements KinematicConstraint.

Definition at line 57 of file PointingKinematicConstraint.cc.

References makeValue().

{
 int nStates = par.size();
 if(nStates == 0) throw VertexException("PointingKinematicConstraint::Empty vector of particles passed");
 if(nStates != 1) throw VertexException("PointingKinematicConstraint::Current version does not support the multistate refit");
 AlgebraicVector vl(2,0);
 AlgebraicVector lPoint = asHepVector<7>(par.front()->currentState().kinematicParameters().vector());
 vl(1) = makeValue(lPoint).first(1);
 vl(2) = makeValue(lPoint).first(2);
 return std::pair<AlgebraicVector,AlgebraicVector>(vl,lPoint); 
}

Member Data Documentation

GlobalPoint PointingKinematicConstraint::refPoint

private

Definition at line 61 of file PointingKinematicConstraint.h.

Referenced by makeDerivative(), and makeValue().