DivisiveVertexFinder Class Reference

#include <RecoPixelVertexing/PixelVertexFinding/interface/DivisiveVertexFinder.h>

Public Member Functions
	DivisiveVertexFinder (double zOffset=5.0, int ntrkMin=5, bool useError=true, double zSeparation=0.05, bool wtAverage=true, int verbosity=0)
bool	findVertexes (const reco::TrackRefVector &trks, reco::VertexCollection &vertexes)
	Run the divisive algorithm and return a vector of vertexes for the input track collection. More...
bool	findVertexesAlt (const reco::TrackRefVector &trks, reco::VertexCollection &vertexes, const math::XYZPoint &bs)
	~DivisiveVertexFinder ()

Private Attributes
pixeltemp::DivisiveClusterizer1D < reco::Track >	divmeth_
	We use Wolfgang's templated class that implements the actual divisive method. More...
int	ntrkMin_
bool	useError_
int	verbose_
bool	wtAverage_
double	zOffset_
	Cuts on vertex formation and other options. More...
double	zSeparation_

Detailed Description

Description: Fits a primary vertex in 1D (z) using the "divisive method"

Implementation: This class was ported from ORCA by me (Aaron). It was originally written by ... Find the PV candidates with a simple divisive method. Divide the luminosity region in several regions according to the track distance and for each of them make a PVCluster. Iteratively discard tracks and recover them in a new PVCluster. Return a sorted vector<Vertex> (aka VertexCollection) with the z coordinate of PV candidates

Parameters

ntkmin	Minimum number of tracks required to form a cluster.
useError	physical distances or weighted distances.
zsep	Maximum distance between two adjacent tracks that belong to the same initial cluster.
wei	Compute the cluster "center" with an unweighted or a weighted average of the tracks. Weighted means weighted with the error of the data point.

Author

Aaron Dominguez (UNL)

Definition at line 32 of file DivisiveVertexFinder.h.

Constructor & Destructor Documentation

DivisiveVertexFinder::DivisiveVertexFinder	(	double	zOffset = 5.0,
		int	ntrkMin = 5,
		bool	useError = true,
		double	zSeparation = 0.05,
		bool	wtAverage = true,
		int	verbosity = 0
	)

Definition at line 14 of file DivisiveVertexFinder.cc.

  : zOffset_(zOffset), zSeparation_(zSeparation), ntrkMin_(ntrkMin), useError_(useError),
    wtAverage_(wtAverage),
    divmeth_(zOffset, ntrkMin, useError, zSeparation, wtAverage),
    verbose_(verbosity)
{

}

DivisiveVertexFinder::~DivisiveVertexFinder

(

)

Definition at line 25 of file DivisiveVertexFinder.cc.

{}

Member Function Documentation

bool DivisiveVertexFinder::findVertexes	(	const reco::TrackRefVector &	trks,
		reco::VertexCollection &	vertexes
	)

Run the divisive algorithm and return a vector of vertexes for the input track collection.

Definition at line 27 of file DivisiveVertexFinder.cc.

References PVPositionBuilder::average(), Measurement1D::error(), i, edm::isNotFinite(), edm::RefVector< C, T, F >::size(), findQualityFiles::v, Measurement1D::value(), PVPositionBuilder::wtAverage(), and wtAverage_.

Referenced by PixelVertexProducer::produce().

                                                   { // output
  PVPositionBuilder pos;
  Measurement1D vz;
  if (wtAverage_) {
    vz = pos.wtAverage(trks);
  }
  else {
    vz = pos.average(trks);
  }
  reco::Vertex::Error err;
  err(2,2) = vz.error()*vz.error();

  reco::Vertex v( reco::Vertex::Point(0,0,vz.value()), err, 0, 1, trks.size() );
    for (unsigned int i=0; i<trks.size(); i++) {
      double vz = trks[i]->vz();
      if(edm::isNotFinite(vz)) continue;
      v.add(reco::TrackBaseRef(trks[i]));
    }
    
  vertexes.push_back(v);

  return true;
}

bool DivisiveVertexFinder::findVertexesAlt	(	const reco::TrackRefVector &	trks,
		reco::VertexCollection &	vertexes,
		const math::XYZPoint &	bs
	)

Definition at line 52 of file DivisiveVertexFinder.cc.

References divmeth_, i, recoMuon::in, edm::isNotFinite(), dbtoconf::out, pixeltemp::DivisiveClusterizer1D< T >::setBeamSpot(), edm::RefVector< C, T, F >::size(), python.multivaluedict::sort(), mathSSE::sqrt(), groupFilesInBlocks::temp, findQualityFiles::v, and verbose_.

Referenced by PixelVertexProducer::produce().

                                                                               { // output
  std::vector< PVCluster > in;
  std::pair< std::vector< PVCluster >, std::vector< const reco::Track* > > out;
  
  // Convert input track collection into container needed by Wolfgang's templated code
  // Need to save a map to reconvert from bare pointers, oy vey
  std::map< const reco::Track*, reco::TrackRef > mapa; 
  //  std::vector< std::vector< const reco::Track* > > trkps;
  for (unsigned int i=0; i<trks.size(); ++i) {
    double vz = trks[i]->vz();
    if(edm::isNotFinite(vz)) continue;
    std::vector< const reco::Track* > temp;
    temp.clear();
    temp.push_back( &(*trks[i]) );

    in.push_back( PVCluster( Measurement1D(trks[i]->dz(bs), trks[i]->dzError() ), temp ) );
    mapa[temp[0]] = trks[i];
  }

  if (verbose_ > 0 ) {
    edm::LogInfo("DivisiveVertexFinder") << "size of input vector of clusters " << in.size();
    for (unsigned int i=0; i<in.size(); ++i) {
      edm::LogInfo("DivisiveVertexFinder") << "Track " << i << " addr " << in[i].tracks()[0] 
                       << " dz " << in[i].tracks()[0]->dz(bs)
                       << " +- " << in[i].tracks()[0]->dzError()
                       << " prodID " << mapa[in[i].tracks()[0]].id()
                       << " dz from RefTrack " << mapa[in[i].tracks()[0]]->dz(bs)
                       << " +- " << mapa[in[i].tracks()[0]]->dzError();
    }
  }

  // Run the darn thing
  divmeth_.setBeamSpot(bs);
  out = divmeth_(in);

  if (verbose_ > 0) edm::LogInfo("DivisiveVertexFinder") << " DivisiveClusterizer1D found " 
                             << out.first.size() << " vertexes";

  // Now convert the output yet again into something we can safely store in the event
  for (unsigned int iv=0; iv<out.first.size(); ++iv) { // loop over output vertexes
    reco::Vertex::Error err;
    err(2,2) = out.first[iv].position().error()*out.first[iv].position().error();
    
    reco::Vertex v( reco::Vertex::Point(0,0,out.first[iv].position().value()), err, 0, 1, out.second.size() );
    if (verbose_ > 0 ) edm::LogInfo("DivisiveVertexFinder") << " DivisiveClusterizer1D vertex " << iv 
                                << " has " << out.first[iv].tracks().size()
                                << " tracks and a position of " << v.z() 
                                << " +- " << std::sqrt(v.covariance(2,2));
    for (unsigned int itrk=0; itrk<out.first[iv].tracks().size(); ++itrk) {
      v.add( reco::TrackBaseRef(mapa[out.first[iv].tracks()[itrk]] ) );
    }
    vertexes.push_back(v); // Done with horrible conversion, save it
  }

  // Finally, sort the vertexes in decreasing sumPtSquared
  std::sort(vertexes.begin(), vertexes.end(), PVClusterComparer());

  return true;
}

Member Data Documentation

pixeltemp::DivisiveClusterizer1D< reco::Track > DivisiveVertexFinder::divmeth_

private

We use Wolfgang's templated class that implements the actual divisive method.

Definition at line 50 of file DivisiveVertexFinder.h.

Referenced by findVertexesAlt().

int DivisiveVertexFinder::ntrkMin_

private

Definition at line 46 of file DivisiveVertexFinder.h.

bool DivisiveVertexFinder::useError_

private

Definition at line 47 of file DivisiveVertexFinder.h.

int DivisiveVertexFinder::verbose_

private

Definition at line 54 of file DivisiveVertexFinder.h.

Referenced by findVertexesAlt().

bool DivisiveVertexFinder::wtAverage_

private

Definition at line 47 of file DivisiveVertexFinder.h.

Referenced by findVertexes().

double DivisiveVertexFinder::zOffset_

private

Cuts on vertex formation and other options.

Definition at line 45 of file DivisiveVertexFinder.h.

double DivisiveVertexFinder::zSeparation_

private

Definition at line 45 of file DivisiveVertexFinder.h.