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KinematicConstrainedVertexFitter Class Reference

Class fitting the veretx out of set of tracks via usual LMS with Lagrange multipliers. More...

#include <RecoVertex/KinematicFit/interface/KinematicConstrainedVertexFitter.h>

List of all members.

Public Member Functions
RefCountedKinematicTree	fit (vector< RefCountedKinematicParticle > part, MultiTrackKinematicConstraint *cs) const
	If multitrack constraint is empty, the output will be just a simple vertex fit performed by LMS with Lagrange multipliers method.
	KinematicConstrainedVertexFitter (const LinearizationPointFinder &fnd)
	Constructor with user-provided LinearizationPointFinder.
	KinematicConstrainedVertexFitter ()
	Default constructor using LMSLinearizationPointFinder.
	~KinematicConstrainedVertexFitter ()
Private Member Functions
void	readParameters ()
Private Attributes
LinearizationPointFinder *	finder
ConstrainedTreeBuilder *	tBuilder
float	theMaxDiff
int	theMaxStep
KinematicConstrainedVertexUpdator *	updator
VertexKinematicConstraint *	vCons

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Detailed Description

Class fitting the veretx out of set of tracks via usual LMS with Lagrange multipliers.

Additional constraints can be applyed to the tracks during the vertex fit (solves non-factorizabele cases) Example: Vertex fit with collinear tracks..

Kirill Prokofiev September 2003.

Definition at line 23 of file KinematicConstrainedVertexFitter.h.

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Constructor & Destructor Documentation

KinematicConstrainedVertexFitter::KinematicConstrainedVertexFitter

(

)

Default constructor using LMSLinearizationPointFinder.

Definition at line 10 of file KinematicConstrainedVertexFitter.cc.

References finder, readParameters(), tBuilder, updator, and vCons.

{
 finder = new DefaultLinearizationPointFinder();
 vCons = new VertexKinematicConstraint();
 updator = new KinematicConstrainedVertexUpdator();
 tBuilder = new ConstrainedTreeBuilder;
 readParameters();
}

KinematicConstrainedVertexFitter::KinematicConstrainedVertexFitter

(

const LinearizationPointFinder &

fnd

)

Constructor with user-provided LinearizationPointFinder.

Definition at line 19 of file KinematicConstrainedVertexFitter.cc.

References LinearizationPointFinder::clone(), finder, readParameters(), tBuilder, updator, and vCons.

{
 
 finder = fnd.clone();
 vCons = new VertexKinematicConstraint();
 updator = new KinematicConstrainedVertexUpdator();
 tBuilder = new ConstrainedTreeBuilder;
 readParameters();
}

KinematicConstrainedVertexFitter::~KinematicConstrainedVertexFitter

(

)

Definition at line 29 of file KinematicConstrainedVertexFitter.cc.

References finder, tBuilder, updator, and vCons.

{
 delete finder;
 delete vCons;
 delete updator;
 delete tBuilder;
}

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Member Function Documentation

RefCountedKinematicTree KinematicConstrainedVertexFitter::fit	(	vector< RefCountedKinematicParticle >	part,
		MultiTrackKinematicConstraint *	cs
	)			const

If multitrack constraint is empty, the output will be just a simple vertex fit performed by LMS with Lagrange multipliers method.

Definition at line 51 of file KinematicConstrainedVertexFitter.cc.

References funct::abs(), ConstrainedTreeBuilder::buildTree(), edm::eq(), finder, LinearizationPointFinder::getLinearizationPoint(), i, iggi_31X_cfg::input, j, InputSort::sort(), tBuilder, theMaxDiff, KinematicConstrainedVertexUpdator::update(), updator, VertexKinematicConstraint::value(), MultiTrackKinematicConstraint::value(), vCons, PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by KineExample::analyze().

{
 if(part.size()<2) throw VertexException("KinematicConstrainedVertexFitter::input states are less than 2");
  
//sorting out the input particles
 InputSort iSort;
 pair<vector<RefCountedKinematicParticle>, vector<FreeTrajectoryState> > input = iSort.sort(part);
 const vector<RefCountedKinematicParticle> & prt  = input.first;
 const vector<FreeTrajectoryState> & fStates = input.second;

// linearization point: 
 GlobalPoint linPoint  = finder->getLinearizationPoint(fStates);

//initial parameters:  
 int vSize = prt.size();
 AlgebraicVector inPar(3 + 7*vSize,0);

//final parameters 
 AlgebraicVector finPar(3 + 7*vSize,0);

//initial covariance 
 AlgebraicMatrix inCov(3 + 7*vSize,3 + 7*vSize,0);

//making initial vector of parameters and initial particle-related covariance
 int nSt = 0;   
 vector<KinematicState> inStates;
 for(vector<RefCountedKinematicParticle>::const_iterator i = prt.begin(); i!=prt.end(); i++)
 {
  AlgebraicVector prPar = asHepVector<7>((*i)->stateAtPoint(linPoint).kinematicParameters().vector());
  for(int j = 1; j<8; j++){inPar(3 + 7*nSt + j) = prPar(j);}
  AlgebraicSymMatrix l_cov  = asHepMatrix<7>((*i)->stateAtPoint(linPoint).kinematicParametersError().matrix());
  inCov.sub(4 + 7*nSt,4 + 7*nSt ,l_cov); 
  inStates.push_back((*i)->stateAtPoint(linPoint));
  ++nSt;
 }

//initial vertex error matrix components (huge error method)
//and vertex related initial vector components
 double in_er = 100.;
 inCov(1,1) = in_er;
 inCov(2,2) = in_er;
 inCov(3,3) = in_er;
 
 inPar(1) = linPoint.x();
 inPar(2) = linPoint.y();
 inPar(3) = linPoint.z(); 
 
//constraint equations value and number of iterations 
 double eq;   
 int nit = 0; 
 
 vector<KinematicState> lStates = inStates;
 GlobalPoint lPoint  = linPoint;
 RefCountedKinematicVertex rVtx;
 AlgebraicMatrix refCCov;

//iterarions over the updator: each time updated parameters 
//are taken as new linearization point 
 do{ 
  eq = 0.;
  pair< pair< vector<KinematicState>, AlgebraicMatrix >,RefCountedKinematicVertex> lRes = 
                                      updator->update(inPar,inCov,lStates,lPoint,cs);
  lStates = lRes.first.first;
  rVtx = lRes.second;
  lPoint = rVtx->position(); 
  AlgebraicVector vValue = vCons->value(lStates, lPoint);
  for(int i = 1; i<vValue.num_row();++i)
  {eq += abs(vValue(i));}
  if(cs !=0)
  {
   AlgebraicVector cVal = cs->value(lStates, lPoint);
   for(int i = 1; i<cVal.num_row();++i)
   {eq += abs(cVal(i));}
  }
  refCCov = lRes.first.second;
  nit++;
 }while(nit<theMaxStep && eq>theMaxDiff);

// cout<<"number of relinearizations "<<nit<<endl;
// cout<<"value obtained: "<<eq<<endl;

//making refitted particles out of refitted states.
//none of the operations above violates the order of particles 
 if(prt.size() != lStates.size()) throw VertexException("KinematicConstrainedVertexFitter::updator failure");
 vector<RefCountedKinematicParticle>::const_iterator i;
 vector<KinematicState>::const_iterator j;
 vector<RefCountedKinematicParticle> rParticles;
 for(i = prt.begin(),j = lStates.begin(); i != prt.end(),j != lStates.end(); ++i,++j)
 {
  rParticles.push_back((*i)->refittedParticle((*j),rVtx->chiSquared(),rVtx->degreesOfFreedom()));
 }   
 
// cout<<"Constrained Vertex Fitter covariance: "<<refCCov <<endl;
 return  tBuilder->buildTree(rParticles,rVtx,refCCov); 
}

void KinematicConstrainedVertexFitter::readParameters

(

)

[private]

Definition at line 37 of file KinematicConstrainedVertexFitter.cc.

References theMaxDiff, and theMaxStep.

Referenced by KinematicConstrainedVertexFitter().

{
//FIXME
//  static SimpleConfigurable<double>
//    maxEquationValueConfigurable(0.01,"KinematicConstrainedVertexFitterVertexFitter:maximumValue");
//  theMaxDiff = maxEquationValueConfigurable.value();
// 
//  static SimpleConfigurable<int>
//    maxStepConfigurable(10,"KinematicConstrainedVertexFitter:maximumNumberOfIterations");
//  theMaxStep = maxStepConfigurable.value();
  theMaxDiff = 0.01;
  theMaxStep = 10;
}

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Member Data Documentation

LinearizationPointFinder* KinematicConstrainedVertexFitter::finder [private]

Definition at line 55 of file KinematicConstrainedVertexFitter.h.

Referenced by fit(), KinematicConstrainedVertexFitter(), and ~KinematicConstrainedVertexFitter().

ConstrainedTreeBuilder* KinematicConstrainedVertexFitter::tBuilder [private]

Definition at line 58 of file KinematicConstrainedVertexFitter.h.

Referenced by fit(), KinematicConstrainedVertexFitter(), and ~KinematicConstrainedVertexFitter().

float KinematicConstrainedVertexFitter::theMaxDiff [private]

Definition at line 53 of file KinematicConstrainedVertexFitter.h.

Referenced by fit(), and readParameters().

int KinematicConstrainedVertexFitter::theMaxStep [private]

Definition at line 54 of file KinematicConstrainedVertexFitter.h.

Referenced by readParameters().

KinematicConstrainedVertexUpdator* KinematicConstrainedVertexFitter::updator [private]

Definition at line 56 of file KinematicConstrainedVertexFitter.h.

Referenced by fit(), KinematicConstrainedVertexFitter(), and ~KinematicConstrainedVertexFitter().

VertexKinematicConstraint* KinematicConstrainedVertexFitter::vCons [private]

Definition at line 57 of file KinematicConstrainedVertexFitter.h.

Referenced by fit(), KinematicConstrainedVertexFitter(), and ~KinematicConstrainedVertexFitter().

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The documentation for this class was generated from the following files:

• RecoVertex/KinematicFit/interface/KinematicConstrainedVertexFitter.h
• RecoVertex/KinematicFit/src/KinematicConstrainedVertexFitter.cc

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