FastJet  3.3.2
Public Member Functions | Protected Member Functions | List of all members
fastjet::ClusterSequenceAreaBase Class Reference

base class that sets interface for extensions of ClusterSequence that provide information about the area of each jet More...

#include <fastjet/ClusterSequenceAreaBase.hh>

Inheritance diagram for fastjet::ClusterSequenceAreaBase:
Inheritance graph
[legend]
Collaboration diagram for fastjet::ClusterSequenceAreaBase:
Collaboration graph
[legend]

Public Member Functions

template<class L >
 ClusterSequenceAreaBase (const std::vector< L > &pseudojets, const JetDefinition &jet_def_in, const bool &writeout_combinations=false)
 a constructor which just carries out the construction of the parent class
 
 ClusterSequenceAreaBase ()
 default constructor
 
virtual ~ClusterSequenceAreaBase ()
 destructor
 
virtual double area (const PseudoJet &) const
 return the area associated with the given jet; this base class returns 0. More...
 
virtual double area_error (const PseudoJet &) const
 return the error (uncertainty) associated with the determination of the area of this jet; this base class returns 0. More...
 
virtual PseudoJet area_4vector (const PseudoJet &) const
 return a PseudoJet whose 4-vector is defined by the following integral More...
 
virtual bool is_pure_ghost (const PseudoJet &) const
 true if a jet is made exclusively of ghosts More...
 
virtual bool has_explicit_ghosts () const
 returns true if ghosts are explicitly included within jets for this ClusterSequence; More...
 
virtual double empty_area (const Selector &selector) const
 return the total area, corresponding to the given Selector, that is free of jets, in general based on the inclusive jets. More...
 
double empty_area_from_jets (const std::vector< PseudoJet > &all_jets, const Selector &selector) const
 return the total area, corresponding to the given Selector, that is free of jets, based on the supplied all_jets More...
 
virtual double n_empty_jets (const Selector &selector) const
 return something similar to the number of pure ghost jets in the given selector's range in an active area case. More...
 
double median_pt_per_unit_area (const Selector &selector) const
 the median of (pt/area) for jets contained within the selector range, making use also of the info on n_empty_jets More...
 
double median_pt_per_unit_area_4vector (const Selector &selector) const
 the median of (pt/area_4vector) for jets contained within the selector range, making use also of the info on n_empty_jets More...
 
double median_pt_per_unit_something (const Selector &selector, bool use_area_4vector) const
 the function that does the work for median_pt_per_unit_area and median_pt_per_unit_area_4vector: More...
 
virtual void get_median_rho_and_sigma (const Selector &selector, bool use_area_4vector, double &median, double &sigma, double &mean_area) const
 using jets withing the selector range (and with 4-vector areas if use_area_4vector), calculate the median pt/area, as well as an "error" (uncertainty), which is defined as the 1-sigma half-width of the distribution of pt/A, obtained by looking for the point below which we have (1-0.6827)/2 of the jets (including empty jets). More...
 
virtual void get_median_rho_and_sigma (const std::vector< PseudoJet > &all_jets, const Selector &selector, bool use_area_4vector, double &median, double &sigma, double &mean_area, bool all_are_inclusive=false) const
 a more advanced version of get_median_rho_and_sigma, which allows one to use any "view" of the event containing all jets (so that, e.g. More...
 
virtual void get_median_rho_and_sigma (const Selector &selector, bool use_area_4vector, double &median, double &sigma) const
 same as the full version of get_median_rho_and_error, but without access to the mean_area More...
 
virtual void parabolic_pt_per_unit_area (double &a, double &b, const Selector &selector, double exclude_above=-1.0, bool use_area_4vector=false) const
 fits a form pt_per_unit_area(y) = a + b*y^2 in the selector range. More...
 
std::vector< PseudoJetsubtracted_jets (const double rho, const double ptmin=0.0) const
 return a vector of all subtracted jets, using area_4vector, given rho. More...
 
std::vector< PseudoJetsubtracted_jets (const Selector &selector, const double ptmin=0.0) const
 return a vector of subtracted jets, using area_4vector. More...
 
PseudoJet subtracted_jet (const PseudoJet &jet, const double rho) const
 return a subtracted jet, using area_4vector, given rho
 
PseudoJet subtracted_jet (const PseudoJet &jet, const Selector &selector) const
 return a subtracted jet, using area_4vector; note that this is potentially inefficient if repeatedly used for many different jets, because rho will be recalculated each time around. More...
 
double subtracted_pt (const PseudoJet &jet, const double rho, bool use_area_4vector=false) const
 return the subtracted pt, given rho
 
double subtracted_pt (const PseudoJet &jet, const Selector &selector, bool use_area_4vector=false) const
 return the subtracted pt; note that this is potentially inefficient if repeatedly used for many different jets, because rho will be recalculated each time around. More...
 
- Public Member Functions inherited from fastjet::ClusterSequence
 ClusterSequence ()
 default constructor
 
template<class L >
 ClusterSequence (const std::vector< L > &pseudojets, const JetDefinition &jet_def, const bool &writeout_combinations=false)
 create a ClusterSequence, starting from the supplied set of PseudoJets and clustering them with jet definition specified by jet_def (which also specifies the clustering strategy) More...
 
 ClusterSequence (const ClusterSequence &cs)
 copy constructor for a ClusterSequence
 
ClusterSequenceoperator= (const ClusterSequence &cs)
 explicit assignment operator for a ClusterSequence
 
std::vector< PseudoJetinclusive_jets (const double ptmin=0.0) const
 return a vector of all jets (in the sense of the inclusive algorithm) with pt >= ptmin. More...
 
int n_exclusive_jets (const double dcut) const
 return the number of jets (in the sense of the exclusive algorithm) that would be obtained when running the algorithm with the given dcut. More...
 
std::vector< PseudoJetexclusive_jets (const double dcut) const
 return a vector of all jets (in the sense of the exclusive algorithm) that would be obtained when running the algorithm with the given dcut. More...
 
std::vector< PseudoJetexclusive_jets (const int njets) const
 return a vector of all jets when the event is clustered (in the exclusive sense) to exactly njets. More...
 
std::vector< PseudoJetexclusive_jets_up_to (const int njets) const
 return a vector of all jets when the event is clustered (in the exclusive sense) to exactly njets. More...
 
double exclusive_dmerge (const int njets) const
 return the dmin corresponding to the recombination that went from n+1 to n jets (sometimes known as d_{n n+1}). More...
 
double exclusive_dmerge_max (const int njets) const
 return the maximum of the dmin encountered during all recombinations up to the one that led to an n-jet final state; identical to exclusive_dmerge, except in cases where the dmin do not increase monotonically. More...
 
double exclusive_ymerge (int njets) const
 return the ymin corresponding to the recombination that went from n+1 to n jets (sometimes known as y_{n n+1}). More...
 
double exclusive_ymerge_max (int njets) const
 same as exclusive_dmerge_max, but normalised to squared total energy
 
int n_exclusive_jets_ycut (double ycut) const
 the number of exclusive jets at the given ycut
 
std::vector< PseudoJetexclusive_jets_ycut (double ycut) const
 the exclusive jets obtained at the given ycut
 
std::vector< PseudoJetexclusive_subjets (const PseudoJet &jet, const double dcut) const
 return a vector of all subjets of the current jet (in the sense of the exclusive algorithm) that would be obtained when running the algorithm with the given dcut. More...
 
int n_exclusive_subjets (const PseudoJet &jet, const double dcut) const
 return the size of exclusive_subjets(...); still n ln n with same coefficient, but marginally more efficient than manually taking exclusive_subjets.size()
 
std::vector< PseudoJetexclusive_subjets (const PseudoJet &jet, int nsub) const
 return the list of subjets obtained by unclustering the supplied jet down to nsub subjets. More...
 
std::vector< PseudoJetexclusive_subjets_up_to (const PseudoJet &jet, int nsub) const
 return the list of subjets obtained by unclustering the supplied jet down to nsub subjets (or all constituents if there are fewer than nsub). More...
 
double exclusive_subdmerge (const PseudoJet &jet, int nsub) const
 returns the dij that was present in the merging nsub+1 -> nsub subjets inside this jet. More...
 
double exclusive_subdmerge_max (const PseudoJet &jet, int nsub) const
 returns the maximum dij that occurred in the whole event at the stage that the nsub+1 -> nsub merge of subjets occurred inside this jet. More...
 
double Q () const
 returns the sum of all energies in the event (relevant mainly for e+e-)
 
double Q2 () const
 return Q()^2
 
bool object_in_jet (const PseudoJet &object, const PseudoJet &jet) const
 returns true iff the object is included in the jet. More...
 
bool has_parents (const PseudoJet &jet, PseudoJet &parent1, PseudoJet &parent2) const
 if the jet has parents in the clustering, it returns true and sets parent1 and parent2 equal to them. More...
 
bool has_child (const PseudoJet &jet, PseudoJet &child) const
 if the jet has a child then return true and give the child jet otherwise return false and set the child to zero
 
bool has_child (const PseudoJet &jet, const PseudoJet *&childp) const
 Version of has_child that sets a pointer to the child if the child exists;.
 
bool has_partner (const PseudoJet &jet, PseudoJet &partner) const
 if this jet has a child (and so a partner) return true and give the partner, otherwise return false and set the partner to zero
 
std::vector< PseudoJetconstituents (const PseudoJet &jet) const
 return a vector of the particles that make up jet
 
void print_jets_for_root (const std::vector< PseudoJet > &jets, std::ostream &ostr=std::cout) const
 output the supplied vector of jets in a format that can be read by an appropriate root script; the format is: jet-n jet-px jet-py jet-pz jet-E particle-n particle-rap particle-phi particle-pt particle-n particle-rap particle-phi particle-pt ... More...
 
void print_jets_for_root (const std::vector< PseudoJet > &jets, const std::string &filename, const std::string &comment="") const
 print jets for root to the file labelled filename, with an optional comment at the beginning
 
void add_constituents (const PseudoJet &jet, std::vector< PseudoJet > &subjet_vector) const
 add on to subjet_vector the constituents of jet (for internal use mainly)
 
Strategy strategy_used () const
 return the enum value of the strategy used to cluster the event
 
std::string strategy_string () const
 return the name of the strategy used to cluster the event
 
std::string strategy_string (Strategy strategy_in) const
 return the name of the strategy associated with the enum strategy_in
 
const JetDefinitionjet_def () const
 return a reference to the jet definition
 
void delete_self_when_unused ()
 by calling this routine you tell the ClusterSequence to delete itself when all the Pseudojets associated with it have gone out of scope. More...
 
bool will_delete_self_when_unused () const
 return true if the object has been told to delete itself when unused
 
void signal_imminent_self_deletion () const
 tell the ClusterSequence it's about to be self deleted (internal use only)
 
double jet_scale_for_algorithm (const PseudoJet &jet) const
 returns the scale associated with a jet as required for this clustering algorithm (kt^2 for the kt-algorithm, 1 for the Cambridge algorithm). More...
 
void plugin_record_ij_recombination (int jet_i, int jet_j, double dij, int &newjet_k)
 record the fact that there has been a recombination between jets()[jet_i] and jets()[jet_k], with the specified dij, and return the index (newjet_k) allocated to the new jet, whose momentum is assumed to be the 4-vector sum of that of jet_i and jet_j
 
void plugin_record_ij_recombination (int jet_i, int jet_j, double dij, const PseudoJet &newjet, int &newjet_k)
 as for the simpler variant of plugin_record_ij_recombination, except that the new jet is attributed the momentum and user_index of newjet
 
void plugin_record_iB_recombination (int jet_i, double diB)
 record the fact that there has been a recombination between jets()[jet_i] and the beam, with the specified diB; when looking for inclusive jets, any iB recombination will returned to the user as a jet. More...
 
void plugin_associate_extras (Extras *extras_in)
 the plugin can associate some extra information with the ClusterSequence object by calling this function. More...
 
void plugin_associate_extras (std::auto_ptr< Extras > extras_in)
 the plugin can associate some extra information with the ClusterSequence object by calling this function More...
 
bool plugin_activated () const
 returns true when the plugin is allowed to run the show.
 
const Extrasextras () const
 returns a pointer to the extras object (may be null)
 
template<class GBJ >
void plugin_simple_N2_cluster ()
 allows a plugin to run a templated clustering (nearest-neighbour heuristic) More...
 
const std::vector< PseudoJet > & jets () const
 allow the user to access the internally stored _jets() array, which contains both the initial particles and the various intermediate and final stages of recombination. More...
 
const std::vector< history_element > & history () const
 allow the user to access the raw internal history. More...
 
unsigned int n_particles () const
 returns the number of particles that were provided to the clustering algorithm (helps the user find their way around the history and jets objects if they weren't paying attention beforehand). More...
 
std::vector< int > particle_jet_indices (const std::vector< PseudoJet > &) const
 returns a vector of size n_particles() which indicates, for each of the initial particles (in the order in which they were supplied), which of the supplied jets it belongs to; if it does not belong to any of the supplied jets, the index is set to -1;
 
std::vector< int > unique_history_order () const
 routine that returns an order in which to read the history such that clusterings that lead to identical jet compositions but different histories (because of degeneracies in the clustering order) will have matching constituents for each matching entry in the unique_history_order. More...
 
std::vector< PseudoJetunclustered_particles () const
 return the set of particles that have not been clustered. More...
 
std::vector< PseudoJetchildless_pseudojets () const
 Return the list of pseudojets in the ClusterSequence that do not have children (and are not among the inclusive jets). More...
 
bool contains (const PseudoJet &object) const
 returns true if the object (jet or particle) is contained by (ie belongs to) this cluster sequence. More...
 
void transfer_from_sequence (const ClusterSequence &from_seq, const FunctionOfPseudoJet< PseudoJet > *action_on_jets=0)
 transfer the sequence contained in other_seq into our own; any plugin "extras" contained in the from_seq will be lost from there. More...
 
const SharedPtr< PseudoJetStructureBase > & structure_shared_ptr () const
 retrieve a shared pointer to the wrapper to this ClusterSequence More...
 
template<>
void _bj_set_jetinfo (EEBriefJet *const jetA, const int _jets_index) const
 
template<>
double _bj_dist (const EEBriefJet *const jeta, const EEBriefJet *const jetb) const
 

Protected Member Functions

void _check_selector_good_for_median (const Selector &selector) const
 check the selector is suited for the computations i.e. applies jet by jet and has a finite area
 
virtual void _get_median_rho_and_sigma (const Selector &selector, bool use_area_4vector, double &median, double &sigma, double &mean_area) const
 
virtual void _get_median_rho_and_sigma (const std::vector< PseudoJet > &all_jets, const Selector &selector, bool use_area_4vector, double &median, double &sigma, double &mean_area, bool all_are_inclusive=false) const
 
virtual void _get_median_rho_and_sigma (const Selector &selector, bool use_area_4vector, double &median, double &sigma) const
 
virtual void _parabolic_pt_per_unit_area (double &a, double &b, const Selector &selector, double exclude_above=-1.0, bool use_area_4vector=false) const
 
- Protected Member Functions inherited from fastjet::ClusterSequence
template<class L >
void _transfer_input_jets (const std::vector< L > &pseudojets)
 transfer the vector<L> of input jets into our own vector<PseudoJet> _jets (with some reserved space for future growth). More...
 
void _initialise_and_run (const JetDefinition &jet_def, const bool &writeout_combinations)
 This is what is called to do all the initialisation and then run the clustering (may be called by various constructors). More...
 
void _initialise_and_run_no_decant ()
 
void _decant_options (const JetDefinition &jet_def, const bool &writeout_combinations)
 fills in the various member variables with "decanted" options from the jet_definition and writeout_combinations variables
 
void _decant_options_partial ()
 assuming that the jet definition, writeout_combinations and _structure_shared_ptr have been set (e.g. More...
 
void _fill_initial_history ()
 fill out the history (and jet cross refs) related to the initial set of jets (assumed already to have been "transferred"), without any clustering
 
void _do_ij_recombination_step (const int jet_i, const int jet_j, const double dij, int &newjet_k)
 carry out the recombination between the jets numbered jet_i and jet_j, at distance scale dij; return the index newjet_k of the result of the recombination of i and j. More...
 
void _do_iB_recombination_step (const int jet_i, const double diB)
 carry out an recombination step in which _jets[jet_i] merges with the beam, More...
 
void _set_structure_shared_ptr (PseudoJet &j)
 every time a jet is added internally during clustering, this should be called to set the jet's structure shared ptr to point to the CS (and the count of internally associated objects is also updated). More...
 
void _update_structure_use_count ()
 make sure that the CS's internal tally of the use count matches that of the _structure_shared_ptr
 
Strategy _best_strategy () const
 returns a suggestion for the best strategy to use on event multiplicity, algorithm, R, etc. More...
 
void get_subhist_set (std::set< const history_element *> &subhist, const PseudoJet &jet, double dcut, int maxjet) const
 set subhist to be a set pointers to history entries corresponding to the subjets of this jet; one stops going working down through the subjets either when More...
 

Additional Inherited Members

- Public Types inherited from fastjet::ClusterSequence
enum  JetType { Invalid =-3, InexistentParent = -2, BeamJet = -1 }
 
typedef ClusterSequenceStructure StructureType
 the structure type associated with a jet belonging to a ClusterSequence
 
- Static Public Member Functions inherited from fastjet::ClusterSequence
static void print_banner ()
 This is the function that is automatically called during clustering to print the FastJet banner. More...
 
static std::ostream * fastjet_banner_stream ()
 returns a pointer to the stream to be used to print banners (cout by default). More...
 
- Protected Attributes inherited from fastjet::ClusterSequence
JetDefinition _jet_def
 
std::vector< PseudoJet_jets
 This contains the physical PseudoJets; for each PseudoJet one can find the corresponding position in the _history by looking at _jets[i].cluster_hist_index(). More...
 
std::vector< history_element_history
 this vector will contain the branching history; for each stage, _history[i].jetp_index indicates where to look in the _jets vector to get the physical PseudoJet. More...
 
bool _writeout_combinations
 
int _initial_n
 
double _Rparam
 
double _R2
 
double _invR2
 
double _Qtot
 
Strategy _strategy
 
JetAlgorithm _jet_algorithm
 
SharedPtr< PseudoJetStructureBase_structure_shared_ptr
 
int _structure_use_count_after_construction
 
bool _deletes_self_when_unused
 if true then the CS will delete itself when the last external object referring to it disappears. More...
 

Detailed Description

base class that sets interface for extensions of ClusterSequence that provide information about the area of each jet

the virtual functions here all return 0, since no area determination is implemented.

Definition at line 48 of file ClusterSequenceAreaBase.hh.

Member Function Documentation

◆ area()

virtual double fastjet::ClusterSequenceAreaBase::area ( const PseudoJet ) const
inlinevirtual

return the area associated with the given jet; this base class returns 0.

Reimplemented in fastjet::ClusterSequenceActiveAreaExplicitGhosts, fastjet::ClusterSequenceArea, fastjet::ClusterSequenceActiveArea, and fastjet::ClusterSequenceVoronoiArea.

Definition at line 70 of file ClusterSequenceAreaBase.hh.

◆ area_error()

virtual double fastjet::ClusterSequenceAreaBase::area_error ( const PseudoJet ) const
inlinevirtual

return the error (uncertainty) associated with the determination of the area of this jet; this base class returns 0.

Reimplemented in fastjet::ClusterSequenceArea, fastjet::ClusterSequenceVoronoiArea, and fastjet::ClusterSequenceActiveArea.

Definition at line 74 of file ClusterSequenceAreaBase.hh.

◆ area_4vector()

virtual PseudoJet fastjet::ClusterSequenceAreaBase::area_4vector ( const PseudoJet ) const
inlinevirtual

return a PseudoJet whose 4-vector is defined by the following integral

drap d PseudoJet("rap,phi,pt=one") *

  • Theta("rap,phi inside jet boundary")

where PseudoJet("rap,phi,pt=one") is a 4-vector with the given rapidity (rap), azimuth (phi) and pt=1, while Theta("rap,phi inside jet boundary") is a function that is 1 when rap,phi define a direction inside the jet boundary and 0 otherwise.

This base class returns a null 4-vector.

Reimplemented in fastjet::ClusterSequenceActiveAreaExplicitGhosts, fastjet::ClusterSequenceArea, fastjet::ClusterSequenceActiveArea, and fastjet::ClusterSequenceVoronoiArea.

Definition at line 87 of file ClusterSequenceAreaBase.hh.

◆ is_pure_ghost()

virtual bool fastjet::ClusterSequenceAreaBase::is_pure_ghost ( const PseudoJet ) const
inlinevirtual

true if a jet is made exclusively of ghosts

NB: most area classes do not give any explicit ghost jets, but some do, and they should replace this function with their own version.

Reimplemented in fastjet::ClusterSequenceArea, and fastjet::ClusterSequenceActiveAreaExplicitGhosts.

Definition at line 95 of file ClusterSequenceAreaBase.hh.

◆ has_explicit_ghosts()

virtual bool fastjet::ClusterSequenceAreaBase::has_explicit_ghosts ( ) const
inlinevirtual

returns true if ghosts are explicitly included within jets for this ClusterSequence;

Derived classes that do include explicit ghosts should provide an alternative version of this routine and set it properly.

Reimplemented in fastjet::ClusterSequenceArea, and fastjet::ClusterSequenceActiveAreaExplicitGhosts.

Definition at line 104 of file ClusterSequenceAreaBase.hh.

◆ empty_area()

double fastjet::ClusterSequenceAreaBase::empty_area ( const Selector selector) const
virtual

return the total area, corresponding to the given Selector, that is free of jets, in general based on the inclusive jets.

return the total area, within the selector's range, that is free of jets.

The selector passed as an argument has to have a finite area and apply jet-by-jet (see the BackgroundEstimator and Subtractor tools for more generic usages)

Calculate this as (range area) - {i in range} A_i

for ClusterSequences with explicit ghosts, assume that there will never be any empty area, i.e. it is always filled in by pure ghosts jets. This holds for seq.rec. algorithms

Reimplemented in fastjet::ClusterSequenceActiveAreaExplicitGhosts, fastjet::ClusterSequenceActiveArea, fastjet::ClusterSequenceArea, and fastjet::ClusterSequencePassiveArea.

Definition at line 57 of file ClusterSequenceAreaBase.cc.

◆ empty_area_from_jets()

double fastjet::ClusterSequenceAreaBase::empty_area_from_jets ( const std::vector< PseudoJet > &  all_jets,
const Selector selector 
) const

return the total area, corresponding to the given Selector, that is free of jets, based on the supplied all_jets

return the total area, within range, that is free of jets.

The selector passed as an argument has to have a finite area and apply jet-by-jet (see the BackgroundEstimator and Subtractor tools for more generic usages)

Calculate this as (range area) - {i in range} A_i

Definition at line 69 of file ClusterSequenceAreaBase.cc.

◆ n_empty_jets()

virtual double fastjet::ClusterSequenceAreaBase::n_empty_jets ( const Selector selector) const
inlinevirtual

return something similar to the number of pure ghost jets in the given selector's range in an active area case.

For the local implementation we return empty_area/(0.55 pi R^2), based on measured properties of ghost jets with kt and cam (cf arXiv:0802.1188).

Note that the number returned is a double.

The selector passed as an argument has to have a finite area and apply jet-by-jet (see the BackgroundEstimator and Subtractor tools for more generic usages)

Reimplemented in fastjet::ClusterSequenceArea, fastjet::ClusterSequenceActiveArea, and fastjet::ClusterSequence1GhostPassiveArea.

Definition at line 136 of file ClusterSequenceAreaBase.hh.

◆ median_pt_per_unit_area()

double fastjet::ClusterSequenceAreaBase::median_pt_per_unit_area ( const Selector selector) const

the median of (pt/area) for jets contained within the selector range, making use also of the info on n_empty_jets

The selector passed as an argument has to have a finite area and apply jet-by-jet (see the BackgroundEstimator and Subtractor tools for more generic usages)

Definition at line 86 of file ClusterSequenceAreaBase.cc.

◆ median_pt_per_unit_area_4vector()

double fastjet::ClusterSequenceAreaBase::median_pt_per_unit_area_4vector ( const Selector selector) const

the median of (pt/area_4vector) for jets contained within the selector range, making use also of the info on n_empty_jets

The selector passed as an argument has to have a finite area and apply jet-by-jet

Definition at line 102 of file ClusterSequenceAreaBase.cc.

◆ median_pt_per_unit_something()

double fastjet::ClusterSequenceAreaBase::median_pt_per_unit_something ( const Selector selector,
bool  use_area_4vector 
) const

the function that does the work for median_pt_per_unit_area and median_pt_per_unit_area_4vector:

  • something_is_area_4vect = false -> use plain area
  • something_is_area_4vect = true -> use 4-vector area

Definition at line 118 of file ClusterSequenceAreaBase.cc.

◆ get_median_rho_and_sigma() [1/3]

void fastjet::ClusterSequenceAreaBase::get_median_rho_and_sigma ( const Selector selector,
bool  use_area_4vector,
double &  median,
double &  sigma,
double &  mean_area 
) const
virtual

using jets withing the selector range (and with 4-vector areas if use_area_4vector), calculate the median pt/area, as well as an "error" (uncertainty), which is defined as the 1-sigma half-width of the distribution of pt/A, obtained by looking for the point below which we have (1-0.6827)/2 of the jets (including empty jets).

The subtraction for a jet with uncorrected pt pt^U and area A is

pt^S = pt^U - median*A +- sigma*sqrt(A)

where the error is only that associated with the fluctuations in the noise and not that associated with the noise having caused changes in the hard-particle content of the jet.

The selector passed as an argument has to have a finite area and apply jet-by-jet (see the BackgroundEstimator and Subtractor tools for more generic usages)

NB: subtraction may also be done with 4-vector area of course, and this is recommended for jets with larger values of R, as long as rho has also been determined with a 4-vector area; using a scalar area causes one to neglect terms of relative order $R^2/8$ in the jet $p_t$.

Reimplemented in fastjet::ClusterSequenceArea.

Definition at line 200 of file ClusterSequenceAreaBase.cc.

◆ get_median_rho_and_sigma() [2/3]

virtual void fastjet::ClusterSequenceAreaBase::get_median_rho_and_sigma ( const std::vector< PseudoJet > &  all_jets,
const Selector selector,
bool  use_area_4vector,
double &  median,
double &  sigma,
double &  mean_area,
bool  all_are_inclusive = false 
) const
virtual

a more advanced version of get_median_rho_and_sigma, which allows one to use any "view" of the event containing all jets (so that, e.g.

one might use Cam on a different resolution scale without have to rerun the algorithm).

By default it will assume that "all" are not inclusive jets, so that in dealing with empty area it has to calculate the number of empty jets based on the empty area and the the observed <area> of jets rather than a surmised area

Note that for small effective radii, this can cause problems because the harder jets get an area >> <ghost-jet-area> and so the estimate comes out all wrong. In these situations it is highly advisable to use an area with explicit ghosts, since then the "empty" jets are actually visible.

The selector passed as an argument has to have a finite area and apply jet-by-jet (see the BackgroundEstimator and Subtractor tools for more generic usages)

Reimplemented in fastjet::ClusterSequenceArea.

◆ get_median_rho_and_sigma() [3/3]

virtual void fastjet::ClusterSequenceAreaBase::get_median_rho_and_sigma ( const Selector selector,
bool  use_area_4vector,
double &  median,
double &  sigma 
) const
inlinevirtual

same as the full version of get_median_rho_and_error, but without access to the mean_area

The selector passed as an argument has to have a finite area and apply jet-by-jet (see the BackgroundEstimator and Subtractor tools for more generic usages)

Reimplemented in fastjet::ClusterSequenceArea.

Definition at line 230 of file ClusterSequenceAreaBase.hh.

◆ parabolic_pt_per_unit_area()

void fastjet::ClusterSequenceAreaBase::parabolic_pt_per_unit_area ( double &  a,
double &  b,
const Selector selector,
double  exclude_above = -1.0,
bool  use_area_4vector = false 
) const
virtual

fits a form pt_per_unit_area(y) = a + b*y^2 in the selector range.

fits a form pt_per_unit_area(y) = a + b*y^2 for jets in range.

exclude_above allows one to exclude large values of pt/area from fit. (if negative, the cut is discarded) use_area_4vector = true uses the 4vector areas.

The selector passed as an argument has to have a finite area and apply jet-by-jet (see the BackgroundEstimator and Subtractor tools for more generic usages)

exclude_above allows one to exclude large values of pt/area from fit. use_area_4vector = true uses the 4vector areas.

Reimplemented in fastjet::ClusterSequenceArea.

Definition at line 138 of file ClusterSequenceAreaBase.cc.

◆ subtracted_jets() [1/2]

vector< PseudoJet > fastjet::ClusterSequenceAreaBase::subtracted_jets ( const double  rho,
const double  ptmin = 0.0 
) const

return a vector of all subtracted jets, using area_4vector, given rho.

Only inclusive_jets above ptmin are subtracted and returned. the ordering is the same as that of sorted_by_pt(cs.inclusive_jets()), i.e. not necessarily ordered in pt once subtracted

Definition at line 344 of file ClusterSequenceAreaBase.cc.

◆ subtracted_jets() [2/2]

vector< PseudoJet > fastjet::ClusterSequenceAreaBase::subtracted_jets ( const Selector selector,
const double  ptmin = 0.0 
) const

return a vector of subtracted jets, using area_4vector.

Only inclusive_jets above ptmin are subtracted and returned. the ordering is the same as that of sorted_by_pt(cs.inclusive_jets()), i.e. not necessarily ordered in pt once subtracted

The selector passed as an argument has to have a finite area and apply jet-by-jet (see the BackgroundEstimator and Subtractor tools for more generic usages)

Definition at line 366 of file ClusterSequenceAreaBase.cc.

◆ subtracted_jet()

PseudoJet fastjet::ClusterSequenceAreaBase::subtracted_jet ( const PseudoJet jet,
const Selector selector 
) const

return a subtracted jet, using area_4vector; note that this is potentially inefficient if repeatedly used for many different jets, because rho will be recalculated each time around.

The selector passed as an argument has to have a finite area and apply jet-by-jet (see the BackgroundEstimator and Subtractor tools for more generic usages)

Definition at line 404 of file ClusterSequenceAreaBase.cc.

◆ subtracted_pt()

double fastjet::ClusterSequenceAreaBase::subtracted_pt ( const PseudoJet jet,
const Selector selector,
bool  use_area_4vector = false 
) const

return the subtracted pt; note that this is potentially inefficient if repeatedly used for many different jets, because rho will be recalculated each time around.

The selector passed as an argument has to have a finite area and apply jet-by-jet (see the BackgroundEstimator and Subtractor tools for more generic usages)

Definition at line 439 of file ClusterSequenceAreaBase.cc.


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