Atlfast::ClusterConeStrategy Class Reference

Implements the cone jet finder as a clustering strategy. More...

#include <ClusterConeStrategy.h>

Inheritance diagram for Atlfast::ClusterConeStrategy:

[legend]Collaboration diagram for Atlfast::ClusterConeStrategy:

[legend]List of all members.

Public Member Functions
	ClusterConeStrategy (double rConeBarrel, double rConeForward, double minInitiatorET, double minClusterET, bool masslessJets)
virtual void	makeClusters (MsgStream &log, const std::vector< IKinematic * > &storedCells, IKinematicVector &unusedCells, IClusterCollection *clusters) const
Private Member Functions
double	rCone () const
Private Attributes
double	m_rConeBarrel
double	m_rConeForward
double	m_minInitiatorET
double	m_minClusterET
bool	m_masslessJets
KinematicHelper	m_kinehelp
Cluster *	lnkCluster
Classes
class	PreCluster

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Detailed Description

Implements the cone jet finder as a clustering strategy.

Default R-cone value is 0.401. The 0.001 avoids problems with the 0.1x0.1 grid when running on Atlfast calorimeter cells. This strategy has been shown to produce different results than the JetRec cone jet finder and should be superseded soon.

Definition at line 62 of file ClusterConeStrategy.h.

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Constructor & Destructor Documentation

Atlfast::ClusterConeStrategy::ClusterConeStrategy	(	double	rConeBarrel,
		double	rConeForward,
		double	minInitiatorET,
		double	minClusterET,
		bool	masslessJets
	)			[inline]

Constructor initialises R-cone and min ET values, and massless jets switch.

Definition at line 66 of file ClusterConeStrategy.h.

00072                          :
00073       m_rConeBarrel(rConeBarrel),
00074       m_rConeForward(rConeForward),
00075       m_minInitiatorET(minInitiatorET), 
00076       m_minClusterET(minClusterET),
00077       m_masslessJets(masslessJets){}
    

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Member Function Documentation

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

Performs the cone clustering

Implements Atlfast::IClusterStrategy.

Definition at line 34 of file ClusterConeStrategy.cxx.

                                                                        {
    log << MSG::DEBUG << storedCells.size() << "cells to start with"<<endreq;
    // The cell collection suppplied is not mutable as it contains items
    // (or pointers to items) in the TES. 
    // Therefore we copy pointers to two local mutable collections  as we want 
    // to manipulate them as part of the clustering strategy
    
    // This is to hold cells remaining available for cluster formation. 
    localCellCollection availableCells(storedCells.begin(), 
                                       storedCells.end() );
    localCellIterator firstAvailableCell = availableCells.begin() ;
    localCellIterator lastAvailableCell  = availableCells.end() ;
    
    // This is to keep remaining candidate initiators.
    localCellCollection availableInitiators( storedCells.begin(), 
                                             storedCells.end() ) ;
    localCellIterator firstAvailableInitiator  = availableInitiators.begin() ;
    localCellIterator lastAvailableInitiator   = availableInitiators.end() ;

    // Partition the inititator candidates to retain only those above threshold
    lastAvailableInitiator 
      = partition( firstAvailableInitiator, 
                   lastAvailableInitiator,
                   PartitionCondition::AboveThresholdET( m_minInitiatorET )
                   );
    
    // Sort the remaining initiator candidates into descending order of eT
    // This means the first available initiator will always be the highest eT
    sort( firstAvailableInitiator, 
          lastAvailableInitiator, 
          SortAttribute::DescendingET() 
          );
    
    
    // Iterate over all initiator candidates
    
    while( firstAvailableInitiator != lastAvailableInitiator  ) {
      
      // Partition the cells to find those within the required R-cone
      
      //substitute an rCone with no args to stop the compiler wingeing
      // about unused parameters
      // double rCone = this->rCone( *firstAvailableInitiator ) ;
      double rCone = this->rCone( ) ;
      
      localCellIterator endCellInCone = partition
        ( 
         firstAvailableCell, 
         lastAvailableCell, 
         PartitionCondition::BelowThresholdDeltaR( *firstAvailableInitiator, 
                                                   rCone )
         );
      
      // Accumulate all cells in cone to get weighted kinematic centre
      // We use a PreCluster helper object for this
      PreCluster preclus( firstAvailableCell, endCellInCone, m_masslessJets);
      
      // Test if sum eT is above minumum. 
      if( preclus.eT() > m_minClusterET ){
        // Make a cluster and add to the collection
        HepLorentzVector temp=preclus;
        ICluster* newclus =  
          new Cluster( temp, firstAvailableCell, endCellInCone ) ;
        //      Cluster* newclus =  
        //        new Cluster( preclus, firstAvailableCell, endCellInCone ) ;
        clusters->push_back( newclus ) ;
        
        //log << MSG::DEBUG << "New Cluster created " << newclus << endreq ;
        
        // Remove all used cells from the available initiator range
        localCellIterator cell= firstAvailableCell; 
        for(; cell != endCellInCone; ++cell ){ 
          lastAvailableInitiator =
            std::remove( firstAvailableInitiator, 
                         lastAvailableInitiator, *cell );
        }
        
        // Remove all used cells from the available cell range
        firstAvailableCell = endCellInCone ;
        
      }else{
        //log << MSG::DEBUG << "Failed to form new cluster" 
        //    << *firstAvailableInitiator << endreq ;
        
        // This initiator didnt lead to a good cluster.
        // Remove it from the available initiator  range
        ++firstAvailableInitiator ;
      }
      
    }

    localCellIterator cellIter = firstAvailableCell;
    for(; cellIter!=lastAvailableCell; ++cellIter){
      //      unusedCells.push_back(new Cell(**cellIter));
      //PS 24/01/03
      //the next line replaces the previous line
      // but why was it there in the first place?
      //      unusedCells.push_back( (*cellIter)->clone() );
      unusedCells.push_back(*cellIter);
    }
    return;
  }

double Atlfast::ClusterConeStrategy::rCone

(

)

const [private]

Strategy for making clusters from cells

Definition at line 147 of file ClusterConeStrategy.cxx.

                                          {
    // Temporary: return barrel always as we dont have mechanism
    // to determine calorimeter geometry yet.
    return m_rConeBarrel ;
  }

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Member Data Documentation

double Atlfast::ClusterConeStrategy::m_rConeBarrel [private]

R-cone size for summation of Cells within barrel region

Definition at line 102 of file ClusterConeStrategy.h.

double Atlfast::ClusterConeStrategy::m_rConeForward [private]

R-cone size for summation of Cells within forward regions

Definition at line 104 of file ClusterConeStrategy.h.

double Atlfast::ClusterConeStrategy::m_minInitiatorET [private]

Minimun eT needed for a Cell to initiate a new Cluster

Definition at line 107 of file ClusterConeStrategy.h.

double Atlfast::ClusterConeStrategy::m_minClusterET [private]

Minimum eT which a candidate cluster must have to be retained

Definition at line 110 of file ClusterConeStrategy.h.

bool Atlfast::ClusterConeStrategy::m_masslessJets [private]

Definition at line 111 of file ClusterConeStrategy.h.

KinematicHelper Atlfast::ClusterConeStrategy::m_kinehelp [private]

Help with common kinematic operations

Definition at line 118 of file ClusterConeStrategy.h.

Cluster* Atlfast::ClusterConeStrategy::lnkCluster [private]

0..* output

Definition at line 164 of file ClusterConeStrategy.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/ClusterConeStrategy.h
• /afs/cern.ch/user/s/sdean/project_builds/AtlasOffline-rel_1/Simulation/Atlfast/AtlfastAlgs/src/ClusterConeStrategy.cxx

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