PixelVertexProducerMedian Class Reference

#include <PixelVertexProducerMedian.h>

Inheritance diagram for PixelVertexProducerMedian:

List of all members.

Public Member Functions
	PixelVertexProducerMedian (const edm::ParameterSet &ps)
virtual void	produce (edm::Event &ev, const edm::EventSetup &es)
	~PixelVertexProducerMedian ()
Private Attributes
edm::ParameterSet	theConfig
double	thePtMin

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Detailed Description

Definition at line 9 of file PixelVertexProducerMedian.h.

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Constructor & Destructor Documentation

PixelVertexProducerMedian::PixelVertexProducerMedian

(

const edm::ParameterSet &

ps

)

[explicit]

Definition at line 35 of file PixelVertexProducerMedian.cc.

                              : theConfig(ps)
{
  produces<reco::VertexCollection>();
}

PixelVertexProducerMedian::~PixelVertexProducerMedian

(

)

Definition at line 42 of file PixelVertexProducerMedian.cc.

{ 
}

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Member Function Documentation

void PixelVertexProducerMedian::produce	(	edm::Event &	ev,
		const edm::EventSetup &	es
	)		[virtual]

Implements edm::EDProducer.

Definition at line 48 of file PixelVertexProducerMedian.cc.

References connectstrParser::f1, edm::Event::getByLabel(), trackerHits::histo, i, LogTrace, edm::Handle< T >::product(), edm::Event::put(), python::multivaluedict::sort(), testEve_cfg::tracks, and tracks_.

{
  // Get pixel tracks
  edm::Handle<reco::TrackCollection> trackCollection;
  std::string trackCollectionName =
    theConfig.getParameter<std::string>("TrackCollection");
  ev.getByLabel(trackCollectionName, trackCollection);
  const reco::TrackCollection tracks_ = *(trackCollection.product());

  thePtMin = theConfig.getParameter<double>("PtMin");

  // Select tracks 
  std::vector<const reco::Track *> tracks;
  for (unsigned int i=0; i<tracks_.size(); i++)
  {
    if (tracks_[i].pt() > thePtMin)
    {
      reco::TrackRef recTrack(trackCollection, i);
      tracks.push_back( &(*recTrack));
    }
  }

  LogTrace("MinBiasTracking")
            << " [VertexProducer] selected tracks: "
            << tracks.size() << " (out of " << tracks_.size()
            << ")"; 

  std::auto_ptr<reco::VertexCollection> vertices(new reco::VertexCollection);

  if(tracks.size() > 0)
  {
  // Sort along vertex z position
  std::sort(tracks.begin(), tracks.end(), ComparePairs());
  
  // Median
  float med;
  if(tracks.size() % 2 == 0)
    med = (tracks[tracks.size()/2-1]->vz() + tracks[tracks.size()/2]->vz())/2;
  else
    med =  tracks[tracks.size()/2  ]->vz();

  LogTrace("MinBiasTracking")
   << "  [vertex position] median    = " << med << " cm";

  if(tracks.size() > 10)
  {
    // Binning around med, halfWidth
    int nBin = 100;
    float halfWidth = 0.1; // cm
  
    // Most probable
    TH1F histo("histo","histo", nBin, -halfWidth,halfWidth);
  
    for(std::vector<const reco::Track *>::const_iterator
        track = tracks.begin(); track!= tracks.end(); track++)
      if(fabs((*track)->vz() - med) < halfWidth)
        histo.Fill((*track)->vz() - med);
  
    LogTrace("MinBiasTracking")
              << "  [vertex position] most prob = "
              << med + histo.GetBinCenter(histo.GetMaximumBin())
              << " cm";
  
    // Fit above max/2
    histo.Sumw2();
  
    TF1 f1("f1","[0]*exp(-0.5 * ((x-[1])/[2])^2) + [3]");
    f1.SetParameters(10.,0.,0.01, 1.);
  
    histo.Fit("f1","QN");
  
    LogTrace("MinBiasTracking")
              << "  [vertex position] fitted    = "
              << med + f1.GetParameter(1) << " +- " << f1.GetParError(1)
              << " cm";
    
    // Store
    reco::Vertex::Error err;
    err(2,2) = f1.GetParError(1) * f1.GetParError(1); 
    reco::Vertex ver(reco::Vertex::Point(0,0,med + f1.GetParameter(1)),
                                         err, 0, 1, 1);
    vertices->push_back(ver);
  }
  else
  {
    // Store
    reco::Vertex::Error err;
    err(2,2) = 0.1 * 0.1;
    reco::Vertex ver(reco::Vertex::Point(0,0,med),
                                         err, 0, 1, 1);
    vertices->push_back(ver);
  }
  }
  ev.put(vertices);
}

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Member Data Documentation

edm::ParameterSet PixelVertexProducerMedian::theConfig [private]

Definition at line 17 of file PixelVertexProducerMedian.h.

double PixelVertexProducerMedian::thePtMin [private]

Definition at line 18 of file PixelVertexProducerMedian.h.