fastjet::ClusterSequenceActiveAreaExplicitGhosts

fastjet::ClusterSequenceActiveAreaExplicitGhosts Class Reference

Class that behaves essentially like ClusterSequence except that it also provides access to the area of a jet (which will be a random quantity. More...

#include <ClusterSequenceActiveAreaExplicitGhosts.hh>

Inheritance diagram for fastjet::ClusterSequenceActiveAreaExplicitGhosts:

[legend]Collaboration diagram for fastjet::ClusterSequenceActiveAreaExplicitGhosts:

[legend]List of all members.


Public Member Functions
template<class L>
	ClusterSequenceActiveAreaExplicitGhosts (const std::vector< L > &pseudojets, const JetDefinition &jet_def, const ActiveAreaSpec &area_spec, const bool &writeout_combinations=false)
	constructor using a ActiveAreaSpec to specify how the area is to be measured
template<class L>
void	_initialise (const std::vector< L > &pseudojets, const JetDefinition &jet_def, const ActiveAreaSpec &area_spec, const bool &writeout_combinations)
	does the actual work of initialisation
unsigned int	n_hard_particles () const
	returns the number of hard particles (i.e. those supplied by the user).
virtual double	area (const PseudoJet &jet) const
	returns the area of a jet
virtual PseudoJet	area_4vector (const PseudoJet &jet) const
	returns a four vector corresponding to the sum (E-scheme) of the ghost four-vectors composing the jet area, normalised such that for a small contiguous area the p_t of the extended_area jet is equal to area of the jet.
bool	is_pure_ghost (const PseudoJet &jet) const
	true if a jet is made exclusively of ghosts
bool	is_pure_ghost (int history_index) const
	true if the entry in the history index corresponds to a ghost; if hist_ix does not correspond to an actual particle (i.e.
double	total_area () const
	returns the total area under study
Private Member Functions
void	_add_ghosts (const ActiveAreaSpec &area_spec)
void	_post_process ()
	routine to be called after the processing is done so as to establish summary information on all the jets (areas, whether pure ghost, etc.
Private Attributes
int	_n_ghosts
double	_ghost_area
std::vector< bool >	_is_pure_ghost
std::vector< double >	_areas
std::vector< PseudoJet >	_area_4vectors
unsigned int	_initial_hard_n

Detailed Description

Class that behaves essentially like ClusterSequence except that it also provides access to the area of a jet (which will be a random quantity.

.. Figure out what to do about seeds later...)

Definition at line 47 of file ClusterSequenceActiveAreaExplicitGhosts.hh.

Constructor & Destructor Documentation

template<class L>

fastjet::ClusterSequenceActiveAreaExplicitGhosts::ClusterSequenceActiveAreaExplicitGhosts ( const std::vector< L > & pseudojets,

const JetDefinition & jet_def,

const ActiveAreaSpec & area_spec,

const bool & writeout_combinations = false

) [inline]

constructor using a ActiveAreaSpec to specify how the area is to be measured

Definition at line 53 of file ClusterSequenceActiveAreaExplicitGhosts.hh.
00057 : ClusterSequenceWithArea() { 00058 _initialise(pseudojets,jet_def,area_spec,writeout_combinations); }

Member Function Documentation

void fastjet::ClustSeqActAreaEG::_add_ghosts ( const ActiveAreaSpec & area_spec ) [private]

Definition at line 44 of file ClusterSequenceActiveAreaExplicitGhosts.cc.
References _ghost_area, _initial_hard_n, _is_pure_ghost, fastjet::ClusterSequence::_jets, _n_ghosts, fastjet::ActiveAreaSpec::actual_ghost_area(), fastjet::ActiveAreaSpec::add_ghosts(), and fastjet::ActiveAreaSpec::n_ghosts().
00045 { 00046 00047 // add the ghosts to the jets 00048 area_spec.add_ghosts(_jets); 00049 00050 // now add labelling... 00051 for (unsigned i = _initial_hard_n; i < _jets.size(); i++) { 00052 //_jets[i].set_user_index(1); 00053 _is_pure_ghost.push_back(true); 00054 } 00055 00056 // and record some info from the area_spec 00057 _ghost_area = area_spec.actual_ghost_area(); 00058 _n_ghosts = area_spec.n_ghosts(); 00059 }

template<class L>

void fastjet::ClusterSequenceActiveAreaExplicitGhosts::_initialise ( const std::vector< L > & pseudojets,

const JetDefinition & jet_def,

const ActiveAreaSpec & area_spec,

const bool & writeout_combinations

)

does the actual work of initialisation

Definition at line 118 of file ClusterSequenceActiveAreaExplicitGhosts.hh.
00121 { 00122 // don't reserve space yet -- will be done below 00123 00124 // insert initial jets this way so that any type L that can be 00125 // converted to a pseudojet will work fine (basically PseudoJet 00126 // and any type that has [] subscript access to the momentum 00127 // components, such as CLHEP HepLorentzVector). 00128 for (unsigned int i = 0; i < pseudojets.size(); i++) { 00129 PseudoJet mom(pseudojets[i]); 00130 //mom.set_user_index(0); // for user's particles (user index now lost...) 00131 _jets.push_back(mom); 00132 _is_pure_ghost.push_back(false); 00133 } 00134 00135 _initial_hard_n = _jets.size(); 00136 00137 _add_ghosts(area_spec); 00138 00139 if (writeout_combinations) { 00140 std::cout << "# Printing particles including ghosts\n"; 00141 for (unsigned j = 0; j < _jets.size(); j++) { 00142 printf("%5u %20.13f %20.13f %20.13e\n", 00143 j,_jets[j].rap(),_jets[j].phi_02pi(),_jets[j].kt2()); 00144 } 00145 std::cout << "# Finished printing particles including ghosts\n"; 00146 } 00147 00148 // this will ensure that we can still point to jets without 00149 // difficulties arising! 00150 _jets.reserve(_jets.size()*2); 00151 00152 // run the clustering 00153 _initialise_and_run(jet_def,writeout_combinations); 00154 00155 // set up all other information 00156 _post_process(); 00157 }

void fastjet::ClustSeqActAreaEG::_post_process ( ) [private]

routine to be called after the processing is done so as to establish summary information on all the jets (areas, whether pure ghost, etc.
)
Definition at line 97 of file ClusterSequenceActiveAreaExplicitGhosts.cc.
References _area_4vectors, _areas, _ghost_area, fastjet::ClusterSequence::_history, fastjet::ClusterSequence::_initial_n, _is_pure_ghost, fastjet::ClusterSequence::_jet_def, fastjet::ClusterSequence::_jets, fastjet::ClusterSequence::BeamJet, and fastjet::JetDefinition::recombiner().
00097 { 00098 00099 // sort out sizes 00100 _areas.resize(_history.size()); 00101 _area_4vectors.resize(_history.size()); 00102 _is_pure_ghost.resize(_history.size()); 00103 00104 // First set up areas for the initial particles (ghost=_ghost_area, 00105 // real particles = 0); recall that _initial_n here is the number of 00106 // particles including ghosts 00107 for (int i = 0; i < _initial_n; i++) { 00108 if (_is_pure_ghost[i]) { 00109 _areas[i] = _ghost_area; 00110 // normalise pt to be _ghost_area (NB we make use of fact that 00111 // for initial particles, jet and clust_hist index are the same). 00112 _area_4vectors[i] = (_ghost_area/_jets[i].perp()) * _jets[i]; 00113 } else { 00114 _areas[i] = 0; 00115 _area_4vectors[i] = PseudoJet(0.0,0.0,0.0,0.0); 00116 } 00117 } 00118 00119 // next follow the branching through and set up the areas 00120 // and ghost-nature at each step of the clustering (rather than 00121 // each jet). 00122 for (unsigned i = _initial_n; i < _history.size(); i++) { 00123 if (_history[i].parent2 == BeamJet) { 00124 _is_pure_ghost[i] = _is_pure_ghost[_history[i].parent1]; 00125 _areas[i] = _areas[_history[i].parent1]; 00126 _area_4vectors[i] = _area_4vectors[_history[i].parent1]; 00127 } else { 00128 _is_pure_ghost[i] = _is_pure_ghost[_history[i].parent1] && 00129 _is_pure_ghost[_history[i].parent2] ; 00130 _areas[i] = _areas[_history[i].parent1] + 00131 _areas[_history[i].parent2] ; 00132 _jet_def.recombiner()->recombine(_area_4vectors[_history[i].parent1], 00133 _area_4vectors[_history[i].parent2], 00134 _area_4vectors[i]); 00135 // _area_4vectors[i] = _area_4vectors[_history[i].parent1] + 00136 // _area_4vectors[_history[i].parent2] ; 00137 } 00138 00139 } 00140 00141 }

double fastjet::ClustSeqActAreaEG::area ( const PseudoJet & jet ) const [virtual]

returns the area of a jet

Reimplemented from fastjet::ClusterSequenceWithArea.
Definition at line 64 of file ClusterSequenceActiveAreaExplicitGhosts.cc.
References _areas.
Referenced by fastjet::ClusterSequenceActiveArea::_transfer_areas().
00064 { 00065 return _areas[jet.cluster_hist_index()]; 00066 }

PseudoJet fastjet::ClustSeqActAreaEG::area_4vector ( const PseudoJet & jet ) const [virtual]

returns a four vector corresponding to the sum (E-scheme) of the ghost four-vectors composing the jet area, normalised such that for a small contiguous area the p_t of the extended_area jet is equal to area of the jet.

Reimplemented from fastjet::ClusterSequenceWithArea.
Definition at line 78 of file ClusterSequenceActiveAreaExplicitGhosts.cc.
References _area_4vectors, and fastjet::PseudoJet::cluster_hist_index().
Referenced by fastjet::ClusterSequenceActiveArea::_transfer_areas().
00078 { 00079 return _area_4vectors[jet.cluster_hist_index()]; 00080 }

bool fastjet::ClustSeqActAreaEG::is_pure_ghost ( int history_index ) const

true if the entry in the history index corresponds to a ghost; if hist_ix does not correspond to an actual particle (i.e.
hist_ix < 0), then the result is false.
Definition at line 89 of file ClusterSequenceActiveAreaExplicitGhosts.cc.
References _is_pure_ghost.
00090 { 00091 return hist_ix >= 0 ? _is_pure_ghost[hist_ix] : false; 00092 }

bool fastjet::ClustSeqActAreaEG::is_pure_ghost ( const PseudoJet & jet ) const

true if a jet is made exclusively of ghosts

Definition at line 83 of file ClusterSequenceActiveAreaExplicitGhosts.cc.
References _is_pure_ghost, and fastjet::PseudoJet::cluster_hist_index().
Referenced by fastjet::ClusterSequenceActiveArea::_transfer_areas(), and fastjet::ClusterSequenceActiveArea::_transfer_ghost_free_history().
00084 { 00085 return _is_pure_ghost[jet.cluster_hist_index()]; 00086 }

unsigned int fastjet::ClusterSequenceActiveAreaExplicitGhosts::n_hard_particles ( ) const [inline]

returns the number of hard particles (i.e. those supplied by the user).

Definition at line 160 of file ClusterSequenceActiveAreaExplicitGhosts.hh.
References _initial_hard_n.
00160 {return _initial_hard_n;}

double fastjet::ClustSeqActAreaEG::total_area ( ) const

returns the total area under study

Definition at line 71 of file ClusterSequenceActiveAreaExplicitGhosts.cc.
References _ghost_area, and _n_ghosts.
00071 { 00072 return _n_ghosts * _ghost_area; 00073 }