CandKinematicVertexFitter Class Reference

#include <CandKinematicVertexFitter.h>

Public Types
typedef reco::Vertex::CovarianceMatrix	CovarianceMatrix

Public Member Functions
	CandKinematicVertexFitter (const edm::ParameterSet &cfg)
	CandKinematicVertexFitter (const CandKinematicVertexFitter &o)
RefCountedKinematicParticle	currentParticle () const
bool	fit (const std::vector< RefCountedKinematicParticle > &tracks) const
void	set (const MagneticField *bField)
void	set (const ParticleDataTable *pdt)
void	set (reco::VertexCompositeCandidate &) const

Private Member Functions
void	fill (std::vector< RefCountedKinematicParticle > &, std::vector< reco::Candidate *> &, std::vector< reco::RecoCandidate::TrackType > &, reco::Candidate &) const

Private Attributes
const MagneticField *	bField_
double	chi2_
	chi-sqared More...
CovarianceMatrix	cov_
	covariance matrix (3x3) More...
KinematicParticleFactoryFromTransientTrack	factory_
	particle factor More...
KinematicParticleVertexFitter	fitter_
	fitter More...
std::shared_ptr< std::vector< CandKinematicVertexFitter > >	fitters_
	fitters used for recursive calls More...
double	ndof_
	number of degrees of freedom More...
const ParticleDataTable *	pdt_
RefCountedKinematicTree	tree_
	fit tree More...

Detailed Description

Definition at line 24 of file CandKinematicVertexFitter.h.

Member Typedef Documentation

CovarianceMatrix

typedef reco::Vertex::CovarianceMatrix CandKinematicVertexFitter::CovarianceMatrix

Definition at line 26 of file CandKinematicVertexFitter.h.

Constructor & Destructor Documentation

CandKinematicVertexFitter() [1/2]

CandKinematicVertexFitter::CandKinematicVertexFitter ( const edm::ParameterSet &  cfg )

inline

Definition at line 27 of file CandKinematicVertexFitter.h.

      : bField_(nullptr), pdt_(nullptr), fitter_(), fitters_(new std::vector<CandKinematicVertexFitter>) {}

CandKinematicVertexFitter() [2/2]

CandKinematicVertexFitter::CandKinematicVertexFitter ( const CandKinematicVertexFitter &  o )

inline

Definition at line 29 of file CandKinematicVertexFitter.h.

      : bField_(o.bField_), pdt_(o.pdt_), fitter_(), fitters_(new std::vector<CandKinematicVertexFitter>) {}

Member Function Documentation

currentParticle()

RefCountedKinematicParticle CandKinematicVertexFitter::currentParticle ( ) const

inline

Definition at line 35 of file CandKinematicVertexFitter.h.

References tree_.

                                                      {
    tree_->movePointerToTheTop();
    return tree_->currentParticle();
  }

fill()

void CandKinematicVertexFitter::fill ( std::vector< RefCountedKinematicParticle > &  particles, std::vector< reco::Candidate *> &  daughters, std::vector< reco::RecoCandidate::TrackType > &  trackTypes, reco::Candidate &  c  ) const

private

Definition at line 103 of file CandKinematicVertexFitter.cc.

References HltBtagPostValidation_cff::c, DMR_cfg::cerr, hltPixelTracks_cff::chi2, ztail::d, d1, data, BPhysicsValidation_cfi::daughters, Exception, ntuplemaker::fill, KinematicParticleFitter::fit(), edm::errors::InvalidReference, edm::Ref< C, T, F >::isNull(), dqmiolumiharvest::j, EgHLTOffHistBins_cfi::mass, reco::LeafCandidate::massConstraint(), ndof, reco::RecoCandidate::noTrackType, ecalTrigSettings_cff::particles, reco::LeafCandidate::pdgId(), and reco::VertexCompositeCandidate::vertexChi2().

                                                         {
  size_t nDau = c.numberOfDaughters();
  // loop through CompositeCandidate daughters
  for (unsigned int j = 0; j < nDau; ++j) {
    Candidate *d = c.daughter(j);
    if (d == nullptr) {
      ostringstream message;
      message << "Can't access in write mode candidate daughters. "
              << "pdgId = " << c.pdgId() << ".\n";
      const Candidate *d1 = c.daughter(j);
      if (d1 == nullptr)
        message << "Null daughter also found in read-only mode\n";
      else
        message << "Daughter found in read-only mode with id: " << d1->pdgId() << "\n";
      throw edm::Exception(edm::errors::InvalidReference) << message.str();
    }
    //check for a daughter which itself is a composite
    if (d->numberOfDaughters() > 0) {
      //try to cast to VertexCompositeCandiate
      VertexCompositeCandidate *vtxDau = dynamic_cast<VertexCompositeCandidate *>(d);
      if (vtxDau != nullptr && vtxDau->vertexChi2() > 0) {
        // if VertexCompositeCandidate refit vtxDau via the set method
        (*this).set(*vtxDau);
        // if mass constraint is desired, do it here
        if (vtxDau->massConstraint()) {
          KinematicParticleFitter csFitter;
          //get particle mass from pdg table via pdgid number
          const ParticleData *data = pdt_->particle(vtxDau->pdgId());
          ParticleMass mass = data->mass();
          float mass_sigma = mass * 0.000001;  //needs a sigma for the fit
          // create a KinematicConstraint and refit the tree with it
          //KinematicConstraint * mass_c = new MassKinematicConstraint(mass,mass_sigma);
          MassKinematicConstraint mkc(mass, mass_sigma);
          KinematicConstraint *mass_c(&mkc);
          tree_ = csFitter.fit(mass_c, tree_);
          //CHECK THIS! the following works, but might not be safe
          //tree_ = csFitter.fit(&(MassKinematicConstraint(mass,mass_sigma)),tree_);
        }
        // add the kinematic particle from the fit to particles
        RefCountedKinematicParticle current = (*this).currentParticle();
        particles.push_back(current);
        daughters.push_back(d);
        trackTypes.push_back(RecoCandidate::noTrackType);
      } else {
        fill(particles, daughters, trackTypes, *d);
      }
    } else {
      //get track, make KinematicParticle and add to particles so it can be fit
      TrackRef trk = d->get<TrackRef>();
      RecoCandidate::TrackType type = d->get<RecoCandidate::TrackType>();
      if (!trk.isNull()) {
        TransientTrack trTrk(trk, bField_);
        float chi2 = 0, ndof = 0;
        ParticleMass mass = d->mass();
        float sigma = mass * 1.e-6;
        particles.push_back(factory_.particle(trTrk, mass, chi2, ndof, sigma));
        daughters.push_back(d);
        trackTypes.push_back(type);
      } else {
        cerr << ">>> warning: candidate of type " << d->pdgId() << " has no track reference." << endl;
      }
    }
  }
}

fit()

bool CandKinematicVertexFitter::fit

(

const std::vector< RefCountedKinematicParticle > &

tracks

)

const

Definition at line 15 of file CandKinematicVertexFitter.cc.

References DMR_cfg::cerr, submitPVResolutionJobs::err, cppFunctionSkipper::exception, and ecalTrigSettings_cff::particles.

Referenced by trackingPlots.Iteration::modules().

                                                                                              {
  try {
    tree_ = fitter_.fit(particles);
  } catch (std::exception &err) {
    std::cerr << ">>> exception thrown by KinematicParticleVertexFitter:\n"
              << err.what() << "\n"
              << ">>> candidate not fitted to common vertex" << std::endl;
    return false;
  }
  //check tree_ is valid here!
  if (tree_->isValid())
    return true;
  else
    return false;
}

set() [1/3]

void CandKinematicVertexFitter::set ( const MagneticField *  bField )

inline

Definition at line 31 of file CandKinematicVertexFitter.h.

References Calorimetry_cff::bField, and bField_.

Referenced by reco::modules::CandKinematicVertexFitterEventSetupInit::init().

{ bField_ = bField; }

set() [2/3]

void CandKinematicVertexFitter::set ( const ParticleDataTable *  pdt )

inline

Definition at line 32 of file CandKinematicVertexFitter.h.

References pdt_.

{ pdt_ = pdt; }

set() [3/3]

void CandKinematicVertexFitter::set

(

reco::VertexCompositeCandidate &

c

)

const

Definition at line 32 of file CandKinematicVertexFitter.cc.

References cms::cuda::assert(), HltBtagPostValidation_cff::c, BPhysicsValidation_cfi::daughters, HCALHighEnergyHPDFilter_cfi::energy, reco::Candidate::energy(), submitPVResolutionJobs::err, Exception, ntuplemaker::fill, l1tTowerCalibrationProducer_cfi::fit, reco::RecoCandidate::gsfTrackType, edm::errors::InvalidReference, reco::Candidate::longLived(), EgHLTOffHistBins_cfi::mass, AlCaHLTBitMon_ParallelJobs::p, chargedHadronTrackResolutionFilter_cfi::p3, ecalTrigSettings_cff::particles, multPhiCorr_741_25nsDY_cfi::px, multPhiCorr_741_25nsDY_cfi::py, L1EGammaClusterEmuProducer_cfi::scale, reco::Candidate::setP4(), reco::Candidate::setVertex(), mathSSE::sqrt(), bphysicsOniaDQM_cfi::vertex, and extraflags_cff::vtx.

                                                                     {
  if (bField_ == nullptr)
    throw edm::Exception(edm::errors::InvalidReference)
        << "B-Field was not set up CandKinematicVertexFitter.\n"
        << "the following method must be called before fitting a candidate:\n"
        << " CandKinematicVertexFitter:.set( const MagneticField * )" << endl;
  vector<RefCountedKinematicParticle> particles;
  vector<Candidate *> daughters;
  vector<RecoCandidate::TrackType> trackTypes;
  // fill particles with KinematicParticles and daughters with Candidates of the daughters of c
  fill(particles, daughters, trackTypes, c);
  assert(particles.size() == daughters.size());

  // attempt to fit the KinematicParticles, particles
  if (fit(particles)) {
    // after the fit, tree_ contains the KinematicTree from the fit
    tree_->movePointerToTheTop();
    // set the kinematic properties of the daughters from the fit
    RefCountedKinematicVertex vertex = tree_->currentDecayVertex();
    if (vertex->vertexIsValid()) {
      Candidate::Point vtx(vertex->position());
      c.setVertex(vtx);
      vector<RefCountedKinematicParticle> treeParticles = tree_->daughterParticles();
      vector<RefCountedKinematicParticle>::const_iterator particleIt = treeParticles.begin();
      vector<Candidate *>::const_iterator daughterIt = daughters.begin(), daughtersEnd = daughters.end();
      vector<RecoCandidate::TrackType>::const_iterator trackTypeIt = trackTypes.begin();
      Candidate::LorentzVector mp4(0, 0, 0, 0);
      for (; daughterIt != daughtersEnd; ++particleIt, ++daughterIt, ++trackTypeIt) {
        Candidate &daughter = **daughterIt;
        GlobalVector p3 = (*particleIt)->currentState().globalMomentum();
        double px = p3.x(), py = p3.y(), pz = p3.z(), p = p3.mag();
        double energy;

        if (!daughter.longLived())
          daughter.setVertex(vtx);
        double scale;
        switch (*trackTypeIt) {
          case RecoCandidate::gsfTrackType:
            //gsf used for electron tracks
            energy = daughter.energy();
            scale = energy / p;
            px *= scale;
            py *= scale;
            pz *= scale;
            [[fallthrough]];
          default:
            double mass = (*particleIt)->currentState().mass();
            energy = sqrt(p * p + mass * mass);
        };
        Candidate::LorentzVector dp4(px, py, pz, energy);
        daughter.setP4(dp4);
        mp4 += dp4;
      }
      c.setP4(mp4);
      c.setChi2AndNdof(chi2_ = vertex->chiSquared(), ndof_ = vertex->degreesOfFreedom());
      GlobalError err = vertex->error();
      cov_(0, 0) = err.cxx();
      cov_(0, 1) = err.cyx();
      cov_(0, 2) = err.czx();
      cov_(1, 2) = err.czy();
      cov_(1, 1) = err.cyy();
      cov_(2, 2) = err.czz();
      c.setCovariance(cov_);
    }
  } else {
    c.setChi2AndNdof(chi2_ = -1, ndof_ = 0);
    c.setCovariance(cov_ = CovarianceMatrix(ROOT::Math::SMatrixIdentity()));
  }
}

Member Data Documentation

bField_

const MagneticField* CandKinematicVertexFitter::bField_

private

Definition at line 41 of file CandKinematicVertexFitter.h.

Referenced by set().

chi2_

double CandKinematicVertexFitter::chi2_

mutableprivate

chi-sqared

Definition at line 54 of file CandKinematicVertexFitter.h.

cov_

CovarianceMatrix CandKinematicVertexFitter::cov_

mutableprivate

covariance matrix (3x3)

Definition at line 58 of file CandKinematicVertexFitter.h.

factory_

KinematicParticleFactoryFromTransientTrack CandKinematicVertexFitter::factory_

private

particle factor

Definition at line 52 of file CandKinematicVertexFitter.h.

fitter_

KinematicParticleVertexFitter CandKinematicVertexFitter::fitter_

private

fitter

Definition at line 48 of file CandKinematicVertexFitter.h.

fitters_

std::shared_ptr<std::vector<CandKinematicVertexFitter> > CandKinematicVertexFitter::fitters_

private

fitters used for recursive calls

Definition at line 60 of file CandKinematicVertexFitter.h.

ndof_

double CandKinematicVertexFitter::ndof_

mutableprivate

number of degrees of freedom

Definition at line 56 of file CandKinematicVertexFitter.h.

pdt_

const ParticleDataTable* CandKinematicVertexFitter::pdt_

private

Definition at line 42 of file CandKinematicVertexFitter.h.

Referenced by set().

tree_

RefCountedKinematicTree CandKinematicVertexFitter::tree_

mutableprivate

fit tree

Definition at line 50 of file CandKinematicVertexFitter.h.

Referenced by currentParticle().