ColinearityKinematicConstraint Class Reference

#include <ColinearityKinematicConstraint.h>

Inheritance diagram for ColinearityKinematicConstraint:

Public Types
enum	ConstraintDim { Phi, PhiTheta }

Public Member Functions
virtual ColinearityKinematicConstraint *	clone () const
	ColinearityKinematicConstraint (ConstraintDim dim=Phi)
virtual int	numberOfEquations () const
virtual AlgebraicMatrix	parametersDerivative (const std::vector< KinematicState > &states, const GlobalPoint &point) const
virtual AlgebraicMatrix	positionDerivative (const std::vector< KinematicState > &states, const GlobalPoint &point) const
virtual AlgebraicVector	value (const std::vector< KinematicState > &states, const GlobalPoint &point) const
Public Member Functions inherited from MultiTrackKinematicConstraint
	MultiTrackKinematicConstraint ()
virtual	~MultiTrackKinematicConstraint ()

Private Attributes
ConstraintDim	dimension
unsigned int	size

Detailed Description

Consstraint to force the two tracks to be colinear (parallel), in 2D (phi) or 3D (phi-theta).

Warning: Since this constraint makes only sense with two tracks, two and only two tracks should be used in the fit.

Definition at line 16 of file ColinearityKinematicConstraint.h.

Member Enumeration Documentation

enum ColinearityKinematicConstraint::ConstraintDim

Enumerator
Phi
PhiTheta

Definition at line 20 of file ColinearityKinematicConstraint.h.

{Phi, PhiTheta};

Constructor & Destructor Documentation

ColinearityKinematicConstraint::ColinearityKinematicConstraint

(

ConstraintDim

dim = Phi

)

Definition at line 4 of file ColinearityKinematicConstraint.cc.

References dimension, Phi, and size.

Referenced by clone().

{
  dimension = dim;
  if (dimension == Phi) size = 1;
  else size = 2;
}

Member Function Documentation

virtual ColinearityKinematicConstraint* ColinearityKinematicConstraint::clone ( void  ) const

inlinevirtual

Implements MultiTrackKinematicConstraint.

Definition at line 55 of file ColinearityKinematicConstraint.h.

References ColinearityKinematicConstraint().

  {return new ColinearityKinematicConstraint(*this);}

virtual int ColinearityKinematicConstraint::numberOfEquations ( ) const

inlinevirtual

Number of equations per track used for the fit

Implements MultiTrackKinematicConstraint.

Definition at line 53 of file ColinearityKinematicConstraint.h.

References size.

{return size;}

AlgebraicMatrix ColinearityKinematicConstraint::parametersDerivative ( const std::vector< KinematicState > &  states, const GlobalPoint &  point  ) const

virtual

Returns a matrix of derivatives of constraint equations w.r.t. particle parameters

Implements MultiTrackKinematicConstraint.

Definition at line 47 of file ColinearityKinematicConstraint.cc.

References dimension, relval_steps::k2, p1, p2, PhiTheta, size, mathSSE::sqrt(), PV3DBase< T, PVType, FrameType >::x(), and PV3DBase< T, PVType, FrameType >::y().

{
  int n_st = states.size();
  if(n_st<2) throw VertexException("ColinearityKinematicConstraint::<2 states passed");
  AlgebraicMatrix res(size,n_st*7,0);

  double a_1 = -states[0].particleCharge()*states[0].magneticField()->inInverseGeV(states[0].globalPosition()).z();
  double a_2 = -states[1].particleCharge()*states[1].magneticField()->inInverseGeV(states[1].globalPosition()).z();

  AlgebraicVector7 p1 = states[0].kinematicParameters().vector();
  AlgebraicVector7 p2 = states[1].kinematicParameters().vector();

  double p1vx = p1(3) - a_1*(point.y() - p1(1));
  double p1vy = p1(4) + a_1*(point.x() - p1(0));
  double k1 = 1.0/(p1vx*p1vx + p1vy*p1vy);
  double pt1 = sqrt(p1(3)*p1(3)+p1(4)*p1(4));
  double pTot1  = sqrt(p1(3)*p1(3)+p1(4)*p1(4)+p1(5)*p1(5));

  double p2vx = p2(3) - a_2*(point.y() - p2(1));
  double p2vy = p2(4) + a_2*(point.x() - p2(0));
  double k2 = 1.0/(p2vx*p2vx + p2vy*p2vy);
  double pt2  = sqrt(p2(3)*p2(3)+p2(4)*p2(4));
  double pTot2   = sqrt(p2(3)*p2(3)+p2(4)*p2(4)+p2(5)*p2(5));

  // H_phi:

  //x1 and x2 derivatives: 1st and 8th elements
  res(1,1) =  -k1*a_1*p1vx;
  res(1,8) =   k2*a_2*p2vx;

  //y1 and y2 derivatives: 2nd and 9th elements:
  res(1,2) = -k1*a_1*p1vy;
  res(1,9) =  k2*a_2*p2vy;

  //z1 and z2 components: 3d and 10th elmnets stay 0:
  res(1,3)  = 0.; res(1,10) = 0.;

  //px1 and px2 components: 4th and 11th elements:
  res(1,4)  = -k1*p1vy;
  res(1,11) =  k2*p2vy;

  //py1 and py2 components: 5th and 12 elements:
  res(1,5)  =  k1*p1vx;
  res(1,12) = -k2*p2vx;


  //pz1 and pz2 components: 6th and 13 elements:
  res(1,6)  = 0.; res(1,13) = 0.;
  //mass components: 7th and 14th elements:
  res(1,7)  = 0.; res(1,14) = 0.;

  if (dimension == PhiTheta)  {
    // H_theta:
    //x1 and x2 derivatives: 1st and 8th elements
    res(2,1) =  0.; res(2,8) = 0.;

    //y1 and y2 derivatives: 2nd and 9th elements:
    res(2,2) = 0.; res(2,9) = 0.;

    //z1 and z2 components: 3d and 10th elmnets stay 0:
    res(2,3) = 0.; res(2,10) = 0.;

    res(2,4)  =   p1(5)*p1(3) / (pTot1*pTot1*pt1);
    res(2,11) = - p2(5)*p2(3) / (pTot2*pTot2*pt2);

    //py1 and py2 components: 5th and 12 elements:
    res(2,5)  =   p1(5)*p1(4) / (pTot1*pTot1*pt1);
    res(2,12) = - p2(5)*p2(4) / (pTot2*pTot2*pt2);

    //pz1 and pz2 components: 6th and 13 elements:
    res(2,6)  = - pt1/(pTot1*pTot1);
    res(2,13) =   pt2/(pTot2*pTot2);
    //mass components: 7th and 14th elements:
    res(2,7)  = 0.; res(2,14) = 0.;
  }

  return res;
}

AlgebraicMatrix ColinearityKinematicConstraint::positionDerivative ( const std::vector< KinematicState > &  states, const GlobalPoint &  point  ) const

virtual

Returns a matrix of derivatives of constraint equations w.r.t. vertex position

Implements MultiTrackKinematicConstraint.

Definition at line 127 of file ColinearityKinematicConstraint.cc.

References dimension, relval_steps::k2, p1, p2, PhiTheta, size, PV3DBase< T, PVType, FrameType >::x(), and PV3DBase< T, PVType, FrameType >::y().

{
  AlgebraicMatrix res(size,3,0);
  if(states.size()<2) throw VertexException("ColinearityKinematicConstraint::<2 states passed");

  double a_1 = -states[0].particleCharge() * states[0].magneticField()->inInverseGeV(states[0].globalPosition()).z();
  double a_2 = -states[1].particleCharge() * states[1].magneticField()->inInverseGeV(states[1].globalPosition()).z();

  AlgebraicVector7 p1 = states[0].kinematicParameters().vector();
  AlgebraicVector7 p2 = states[1].kinematicParameters().vector();

  double p1vx = p1(3) - a_1*(point.y() - p1(1));
  double p1vy = p1(4) + a_1*(point.x() - p1(0));
  double k1 = 1.0/(p1vx*p1vx + p1vy*p1vy);
  //double pt1 = sqrt(p1(3)*p1(3)+p1(4)*p1(4));

  double p2vx = p2(3) - a_2*(point.y() - p2(1));
  double p2vy = p2(4) + a_2*(point.x() - p2(0));
  double k2 = 1.0/(p2vx*p2vx + p2vy*p2vy);
  //double pt2  = sqrt(p2(3)*p2(3)+p2(4)*p2(4));

  // H_phi:

  // xv component
  res(1,1) = k1*a_1*p1vx - k2*a_2*p2vx;

  //yv component
  res(1,2) = k1*a_1*p1vy - k2*a_2*p2vy;

  //zv component
  res(1,3) = 0.;

  // H_theta: no correlation with vertex position
  if (dimension == PhiTheta) {
    res(2,1) = 0.;
    res(2,2) = 0.;
    res(2,3) = 0.;
  }

  return res;
}

AlgebraicVector ColinearityKinematicConstraint::value ( const std::vector< KinematicState > &  states, const GlobalPoint &  point  ) const

virtual

Returns a vector of values of constraint equations at the point where the input particles are defined.

Implements MultiTrackKinematicConstraint.

Definition at line 11 of file ColinearityKinematicConstraint.cc.

References dimension, M_PI, p1, p2, PhiTheta, size, mathSSE::sqrt(), PV3DBase< T, PVType, FrameType >::x(), and PV3DBase< T, PVType, FrameType >::y().

{
  if(states.size()<2) throw VertexException("ColinearityKinematicConstraint::<2 states passed");
  AlgebraicVector res(size,0);

  double a_1 = -states[0].particleCharge()*states[0].magneticField()->inInverseGeV(states[0].globalPosition()).z();
  double a_2 = -states[1].particleCharge()*states[1].magneticField()->inInverseGeV(states[1].globalPosition()).z();
  
  AlgebraicVector7 p1 = states[0].kinematicParameters().vector();
  AlgebraicVector7 p2 = states[1].kinematicParameters().vector();

  double p1vx = p1(3) - a_1*(point.y() - p1(1));
  double p1vy = p1(4) + a_1*(point.x() - p1(0));
  double pt1  = sqrt(p1(3)*p1(3)+p1(4)*p1(4));

  double p2vx = p2(3) - a_2*(point.y() - p2(1));
  double p2vy = p2(4) + a_2*(point.x() - p2(0));
  double pt2  = sqrt(p2(3)*p2(3)+p2(4)*p2(4));

  // H_phi:
  res(1)  = atan2(p1vy,p1vx) - atan2(p2vy,p2vx);
  if ( res(1) >  M_PI ) res(1) -= 2.0*M_PI;
  if ( res(1) <= -M_PI ) res(1) += 2.0*M_PI;
  // H_theta:
  if (dimension == PhiTheta) {  
    res(2)  = atan2(pt1,p1(5)) - atan2(pt2,p2(5));
    if ( res(2) >  M_PI ) res(2) -= 2.0*M_PI;
    if ( res(2) <= -M_PI ) res(2) += 2.0*M_PI;
  }

// cout << res(1) << " "<<res(2) << "\n ";// res(2)

  return res;
}

Member Data Documentation

ConstraintDim ColinearityKinematicConstraint::dimension

private

Definition at line 59 of file ColinearityKinematicConstraint.h.

Referenced by ColinearityKinematicConstraint(), parametersDerivative(), positionDerivative(), and value().

unsigned int ColinearityKinematicConstraint::size

private

Definition at line 60 of file ColinearityKinematicConstraint.h.

Referenced by cuy.FindIssue::__init__(), ntuple._Collection::__iter__(), ntuple._Collection::__len__(), ColinearityKinematicConstraint(), numberOfEquations(), parametersDerivative(), positionDerivative(), and value().