Atlfast::ClusterKtStrategy Class Reference

Builds Atlfast::KtClusters from Atlfast::Cells. More...

#include <ClusterKtStrategy.h>

Inheritance diagram for Atlfast::ClusterKtStrategy:

[legend]Collaboration diagram for Atlfast::ClusterKtStrategy:

[legend]List of all members.

Public Member Functions
	ClusterKtStrategy (double, double, std::string, std::string, int)
virtual void	makeClusters (MsgStream &log, const std::vector< IKinematic * > &storedCells, IKinematicVector &unusedCells, IClusterCollection *clusters) const
Private Attributes
double	m_minClusterET
double	m_rParameter
int	m_subjet
int	m_angle
int	m_recom

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Detailed Description

Builds Atlfast::KtClusters from Atlfast::Cells.

It uses the KT++ Algorithm based on the fortran Kt clustering Algorithm written by mike seymour. This algorithm was written by the UCL & Manchester groups It stores the Atlfast::KtClusters as Atlfast::Cluster* in a std::vector. All unused cells are put in the a std::vector of Atlfast::Cells

Author:

Jon Couchman

Definition at line 71 of file ClusterKtStrategy.h.

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Constructor & Destructor Documentation

Atlfast::ClusterKtStrategy::ClusterKtStrategy	(	double	,
		double	,
		std::string	,
		std::string	,
		int
	)

Constructor

Definition at line 30 of file ClusterKtStrategy.cxx.

                                                                                                            : 
    m_minClusterET(minet), m_rParameter(rp), m_subjet(subjet){
    //set kt angle scheme
    if(angle == "angular") {m_angle = 1;}
    else if (angle == "deltaR") {m_angle = 2;}
    else if (angle == "QCD") {m_angle = 3;}
    else{
      std::cerr << "Warning, unknown Kt angle scheme. Scheme set to \"angular\"" << std::endl;
      m_angle = 1;
    }
    //set kt rcombination scheme
    if(recom == "E") {m_recom = 1;}
    else if (recom == "pt") {m_recom = 2;}
    else if (recom == "pt2") {m_recom = 3;}
    else if (recom == "et") {m_recom = 4;}
    else if (recom == "et2") {m_recom = 5;}
    else{
      std::cerr << "Warning, unknown Kt recombination scheme. Scheme set to \"E\"" << std::endl;
      m_recom = 1;
    }
  }

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Member Function Documentation

void Atlfast::ClusterKtStrategy::makeClusters	(	MsgStream &	log,
		const std::vector< IKinematic * > &	storedCells,
		IKinematicVector &	unusedCells,
		IClusterCollection *	clusters
	)			const [virtual]

only method required by IClusterStrategy. Runs KT++ via the KtJet::KtEvent interface.

First we make a std::vector<KtLorentzVector> from the Atlfast::Cells We need to fill a map relating KtLorentzVectors to Cells so that we can associate the Atlfast::Cells with the Atlfast::KtClusters

Now make a KtEvent object from the std::vector<KtLorentzVector> This Object calculates all the Clusters using the Kt clustering scheme defined by the input variables.

Now we retrieve all the Clusters made by the KtEvent

We can construct Atlfast::KtClusters from the returned KtLorentzVectors as they are HepLorentzVectors. Also use the map to get list of Clusters associated Cells. Also make a second KtEvent from each KtLorentzVectors constituents to calculate the y-cut

put cluster into main vector

Put copies of all the unassociated cells into the unusedCells vector

Implements Atlfast::IClusterStrategy.

Definition at line 53 of file ClusterKtStrategy.cxx.

                                                                      {
    log << MSG::DEBUG << storedCells.size() << " cells to start with"<<endreq;
    
    std::vector<IKinematic*>::const_iterator itr = storedCells.begin();
    std::vector<KtJet::KtLorentzVector> jetvec;
    std::map<KtJet::KtLorentzVector,IKinematic*> CellMap;
    for(; itr != storedCells.end() ; ++itr){
      KtJet::KtLorentzVector tempVec = KtJet::KtLorentzVector((*itr)->momentum());
      jetvec.push_back(tempVec);
      CellMap[tempVec] = (*itr);
    }
    log << MSG::DEBUG << "Made jetvec"<<endreq;
    KtJet::KtEvent ev(jetvec,4,m_angle,m_recom,m_rParameter);
    log << MSG::DEBUG << "Made KtEvent"<<endreq;

    vector<KtJet::KtLorentzVector> jets0 = ev.getJets();
    log << MSG::DEBUG << "Got events jets "<< jets0.size() << endreq;
    std::vector<KtJet::KtLorentzVector>::const_iterator iter = jets0.begin();
    for (; iter != jets0.end() ; ++iter){
      if((*iter).et() > m_minClusterET) { 
        std::vector<KtJet::KtLorentzVector> tompVec;
        tompVec = (*iter).copyConstituents();
        //Make a vector of associated cells
        std::vector<IKinematic*> tempCellVec;
        std::vector<KtJet::KtLorentzVector>::const_iterator iter2  = tompVec.begin();
        for (; iter2 != tompVec.end() ; ++iter2){
          if(CellMap.find((*iter2)) == CellMap.end()){
            log << MSG::ERROR <<  "Cannot find this key" << endreq;
          }else {
            tempCellVec.push_back(CellMap[(*iter2)]);
            CellMap.erase((*iter2));
            //log << MSG::DEBUG << "Removed cell from map" << endreq;
          }
        }
        //now do sub-jet analysis if required
        double yCut = 0.;
        if(m_subjet){
          KtJet::KtEvent subev(*iter,m_angle,m_recom);
          yCut = subev.getYMerge(m_subjet); 
        }
        //Make a Atlfast::KtCluster
        ICluster* clu = new KtCluster(*iter,tempCellVec.begin(),tempCellVec.end(),yCut);
        log << MSG::DEBUG << "Made a KtCluster" << endreq;
        clusters->push_back(clu);
      }
    }
    //return;
    log << MSG::DEBUG 
        <<  "Number of clusters Made by Kt algo " << clusters->size() 
        << endreq;
    std::map<KtJet::KtLorentzVector,IKinematic*>::iterator celit = 
      CellMap.begin();

    for (; celit != CellMap.end() ; ++celit){

      unusedCells.push_back( ( (*celit).second ) );

      log << MSG::DEBUG 
          << "Size of unusedCells vector " << unusedCells.size() 
          << endreq;
    }

    return;
  }

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Member Data Documentation

double Atlfast::ClusterKtStrategy::m_minClusterET [private]

Cut on cluster et

Definition at line 87 of file ClusterKtStrategy.h.

double Atlfast::ClusterKtStrategy::m_rParameter [private]

Definition at line 88 of file ClusterKtStrategy.h.

int Atlfast::ClusterKtStrategy::m_subjet [private]

Definition at line 89 of file ClusterKtStrategy.h.

int Atlfast::ClusterKtStrategy::m_angle [private]

Definition at line 90 of file ClusterKtStrategy.h.

int Atlfast::ClusterKtStrategy::m_recom [private]

Definition at line 91 of file ClusterKtStrategy.h.

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

• /afs/cern.ch/user/s/sdean/project_builds/AtlasOffline-rel_1/Simulation/Atlfast/AtlfastAlgs/AtlfastAlgs/ClusterKtStrategy.h
• /afs/cern.ch/user/s/sdean/project_builds/AtlasOffline-rel_1/Simulation/Atlfast/AtlfastAlgs/src/ClusterKtStrategy.cxx

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