fastjet Namespace Reference

Namespaces
	gas
	namespace to hold default parameters for the active area spec

Classes
class	_NoInfo
class	AreaDefinition
class	ATLASConePlugin
class	BackgroundEstimatorBase
class	BackgroundJetPtDensity
class	BackgroundJetPtMDensity
class	BackgroundJetScalarPtDensity
class	BackgroundRescalingYPolynomial
class	Boost
class	CASubJetTagger
class	CASubJetTaggerStructure
class	CDFJetCluPlugin
class	CDFMidPointPlugin
class	ClusterSequence
class	ClusterSequence1GhostPassiveArea
class	ClusterSequenceActiveArea
class	ClusterSequenceActiveAreaExplicitGhosts
class	ClusterSequenceArea
class	ClusterSequenceAreaBase
class	ClusterSequencePassiveArea
class	ClusterSequenceStructure
class	ClusterSequenceVoronoiArea
class	CMSIterativeConePlugin
class	CompositeJetStructure
class	D0RunIBaseConePlugin
class	D0RunIConePlugin
class	D0RunIIConePlugin
class	D0RunIpre96ConePlugin
class	EECambridgePlugin
class	Error
class	EtaPhi
	Shortcut for dealing with eta-phi coordinates. More...
class	Filter
class	FilterStructure
class	FunctionOfPseudoJet
class	GhostedAreaSpec
class	GridJetPlugin
class	GridMedianBackgroundEstimator
class	InternalError
class	JadePlugin
class	JetDefinition
class	JetMedianBackgroundEstimator
class	JHTopTagger
class	JHTopTaggerStructure
class	LimitedWarning
class	MassDropTagger
class	MassDropTaggerStructure
class	NestedDefsPlugin
class	NNBase
class	NNFJN2Plain
class	NNFJN2Tiled
class	NNH
class	NNInfo
class	NNInfo< _NoInfo >
class	Pruner
class	PrunerStructure
class	PseudoJet
class	PseudoJetStructureBase
class	PxConePlugin
class	RangeDefinition
class	Recluster
class	RectangularGrid
	Class that holds a generic rectangular tiling. More...
class	RestFrameNSubjettinessTagger
class	RestFrameNSubjettinessTaggerStructure
class	Selector
class	SelectorWorker
class	SharedPtr
class	SISConeBaseExtras
class	SISConeExtras
class	SISConePlugin
class	SISConeSphericalExtras
class	SISConeSphericalPlugin
class	Subtractor
class	TiledJet
	structure analogous to BriefJet, but with the extra information needed for dealing with tiles More...
class	TilingBase
	Class to indicate generic structure of tilings. More...
class	TilingExtent
	class to perform a fast analysis of the appropriate rapidity range in which to perform tiling More...
class	TopTaggerBase
class	TopTaggerBaseStructure
class	TrackJetPlugin
class	Transformer
class	Unboost
class	VoronoiAreaSpec
class	WrappedStructure

Typedefs
typedef ClusterSequenceActiveAreaExplicitGhosts	ClustSeqActAreaEG
typedef ClusterSequenceVoronoiArea::VoronoiAreaCalc	VAC
typedef ClusterSequenceAreaBase	ClusterSequenceWithArea
typedef GhostedAreaSpec	ActiveAreaSpec
	just provide a typedef for backwards compatibility with programs based on versions 2.0 and 2.1 of fastjet. More...
typedef JetAlgorithm	JetFinder
	make standard Les Houches nomenclature JetAlgorithm (algorithm is general recipe without the parameters) backward-compatible with old JetFinder
typedef integral_type< bool, true >	true_type
	the bool 'true' value promoted to a type
typedef integral_type< bool, false >	false_type
	the bool 'false' value promoted to a type
typedef char(&	__yes_type)[1]
typedef char(&	__no_type)[2]
typedef Tile2Base< 25 >	Tile25
typedef Tile2Base< 9 >	Tile2
typedef CGAL::Triangulation_vertex_base_with_info_2< InitialisedInt, K >	Vbb
typedef CGAL::Triangulation_hierarchy_vertex_base_2< Vbb >	Vb
typedef CGAL::Triangulation_face_base_2< K >	Fb
typedef CGAL::Triangulation_data_structure_2< Vb, Fb >	Tds
typedef CGAL::Delaunay_triangulation_2< K, Tds >	Dt
typedef CGAL::Triangulation_hierarchy_2< Dt >	Triangulation
typedef Triangulation::Vertex_handle	Vertex_handle
typedef Triangulation::Point	Point
typedef Triangulation::Vertex_circulator	Vertex_circulator
	CGAL Point structure.
typedef Triangulation::Face_circulator	Face_circulator
typedef Triangulation::Face_handle	Face_handle

Enumerations
enum	AreaType {   invalid_area = -1, active_area = 0, active_area_explicit_ghosts = 1, one_ghost_passive_area = 10,   passive_area = 11, voronoi_area =20 }
	the different types of area that are supported
enum	Strategy {   N2MHTLazy9AntiKtSeparateGhosts = -10, N2MHTLazy9 = -7, N2MHTLazy25 = -6, N2MHTLazy9Alt = -5,   N2MinHeapTiled = -4, N2Tiled = -3, N2PoorTiled = -2, N2Plain = -1,   N3Dumb = 0, Best = 1, NlnN = 2, NlnN3pi = 3,   NlnN4pi = 4, NlnNCam4pi = 14, NlnNCam2pi2R = 13, NlnNCam = 12,   BestFJ30 = 21, plugin_strategy = 999 }
	the various options for the algorithmic strategy to adopt in clustering events with kt and cambridge style algorithms. More...
enum	JetAlgorithm {   kt_algorithm =0, cambridge_algorithm =1, antikt_algorithm =2, genkt_algorithm =3,   cambridge_for_passive_algorithm =11, genkt_for_passive_algorithm =13, ee_kt_algorithm =50, ee_genkt_algorithm =53,   plugin_algorithm = 99, undefined_jet_algorithm = 999 }
enum	RecombinationScheme {   E_scheme =0, pt_scheme =1, pt2_scheme =2, Et_scheme =3,   Et2_scheme =4, BIpt_scheme =5, BIpt2_scheme =6, WTA_pt_scheme =7,   WTA_modp_scheme =8, external_scheme = 99 }
	The various recombination schemes. More...

Functions
int	__default_random_generator (int *__iseed)
string	fastjet_version_string ()
	return a string containing information about the release
PseudoJet	join (const vector< PseudoJet > &pieces, const JetDefinition::Recombiner &recombiner)
PseudoJet	join (const PseudoJet &j1, const JetDefinition::Recombiner &recombiner)
	build a "CompositeJet" from a single PseudoJet with an extended structure of type T derived from CompositeJetStructure More...
PseudoJet	join (const PseudoJet &j1, const PseudoJet &j2, const JetDefinition::Recombiner &recombiner)
	build a "CompositeJet" from two PseudoJet with an extended structure of type T derived from CompositeJetStructure More...
PseudoJet	join (const PseudoJet &j1, const PseudoJet &j2, const PseudoJet &j3, const JetDefinition::Recombiner &recombiner)
	build a "CompositeJet" from 3 PseudoJet with an extended structure of type T derived from CompositeJetStructure More...
PseudoJet	join (const PseudoJet &j1, const PseudoJet &j2, const PseudoJet &j3, const PseudoJet &j4, const JetDefinition::Recombiner &recombiner)
	build a "CompositeJet" from 4 PseudoJet with an extended structure of type T derived from CompositeJetStructure More...
ostream &	operator<< (ostream &ostr, const TiledJet &jet)
PseudoJet	operator+ (const PseudoJet &jet1, const PseudoJet &jet2)
PseudoJet	operator- (const PseudoJet &jet1, const PseudoJet &jet2)
PseudoJet	operator* (double coeff, const PseudoJet &jet)
PseudoJet	operator* (const PseudoJet &jet, double coeff)
PseudoJet	operator/ (const PseudoJet &jet, double coeff)
bool	operator== (const PseudoJet &, const PseudoJet &)
	returns true if the 4 momentum components of the two PseudoJets are identical and all the internal indices (user, cluster_history) More...
bool	operator== (const PseudoJet &jet, const double val)
	Can only be used with val=0 and tests whether all four momentum components are equal to val (=0.0)
bool	have_same_momentum (const PseudoJet &jeta, const PseudoJet &jetb)
	returns true if the momenta of the two input jets are identical
PseudoJet	PtYPhiM (double pt, double y, double phi, double m)
	return a pseudojet with the given pt, y, phi and mass More...
void	sort_indices (vector< int > &indices, const vector< double > &values)
vector< PseudoJet >	sorted_by_pt (const vector< PseudoJet > &jets)
	return a vector of jets sorted into decreasing kt2
vector< PseudoJet >	sorted_by_rapidity (const vector< PseudoJet > &jets)
	return a vector of jets sorted into increasing rapidity
vector< PseudoJet >	sorted_by_E (const vector< PseudoJet > &jets)
	return a vector of jets sorted into decreasing energy
vector< PseudoJet >	sorted_by_pz (const vector< PseudoJet > &jets)
	return a vector of jets sorted into increasing pz
PseudoJet	join (const vector< PseudoJet > &pieces)
PseudoJet	join (const PseudoJet &j1)
	build a "CompositeJet" from a single PseudoJet with an extended structure of type T derived from CompositeJetStructure More...
PseudoJet	join (const PseudoJet &j1, const PseudoJet &j2)
	build a "CompositeJet" from two PseudoJet with an extended structure of type T derived from CompositeJetStructure More...
PseudoJet	join (const PseudoJet &j1, const PseudoJet &j2, const PseudoJet &j3)
	build a "CompositeJet" from 3 PseudoJet with an extended structure of type T derived from CompositeJetStructure More...
PseudoJet	join (const PseudoJet &j1, const PseudoJet &j2, const PseudoJet &j3, const PseudoJet &j4)
	build a "CompositeJet" from 4 PseudoJet with an extended structure of type T derived from CompositeJetStructure More...
Selector	SelectorIdentity ()
Selector	operator! (const Selector &s)
	logical not applied on a selector More...
Selector	operator&& (const Selector &s1, const Selector &s2)
	logical and between two selectors More...
Selector	operator|| (const Selector &s1, const Selector &s2)
	logical or between two selectors More...
Selector	operator* (const Selector &s1, const Selector &s2)
	successive application of 2 selectors More...
Selector	SelectorPtMin (double ptmin)
	select objects with pt >= ptmin
Selector	SelectorPtMax (double ptmax)
	select objects with pt <= ptmax
Selector	SelectorPtRange (double ptmin, double ptmax)
	select objects with ptmin <= pt <= ptmax
Selector	SelectorEtMin (double Etmin)
	select objects with Et >= Etmin
Selector	SelectorEtMax (double Etmax)
	select objects with Et <= Etmax
Selector	SelectorEtRange (double Etmin, double Etmax)
	select objects with Etmin <= Et <= Etmax
Selector	SelectorEMin (double Emin)
	select objects with E >= Emin
Selector	SelectorEMax (double Emax)
	select objects with E <= Emax
Selector	SelectorERange (double Emin, double Emax)
	select objects with Emin <= E <= Emax
Selector	SelectorMassMin (double Mmin)
	select objects with Mass >= Mmin
Selector	SelectorMassMax (double Mmax)
	select objects with Mass <= Mmax
Selector	SelectorMassRange (double Mmin, double Mmax)
	select objects with Mmin <= Mass <= Mmax
Selector	SelectorRapMin (double rapmin)
	select objects with rap >= rapmin
Selector	SelectorRapMax (double rapmax)
	select objects with rap <= rapmax
Selector	SelectorRapRange (double rapmin, double rapmax)
	select objects with rapmin <= rap <= rapmax
Selector	SelectorAbsRapMin (double absrapmin)
	select objects with |rap| >= absrapmin
Selector	SelectorAbsRapMax (double absrapmax)
	select objects with |rap| <= absrapmax
Selector	SelectorAbsRapRange (double absrapmin, double absrapmax)
	select objects with absrapmin <= |rap| <= absrapmax
Selector	SelectorEtaMin (double etamin)
	select objects with eta >= etamin
Selector	SelectorEtaMax (double etamax)
	select objects with eta <= etamax
Selector	SelectorEtaRange (double etamin, double etamax)
	select objects with etamin <= eta <= etamax
Selector	SelectorAbsEtaMin (double absetamin)
	select objects with |eta| >= absetamin
Selector	SelectorAbsEtaMax (double absetamax)
	select objects with |eta| <= absetamax
Selector	SelectorAbsEtaRange (double absetamin, double absetamax)
	select objects with absetamin <= |eta| <= absetamax
Selector	SelectorPhiRange (double phimin, double phimax)
	select objects with phimin <= phi <= phimax
Selector	SelectorRapPhiRange (double rapmin, double rapmax, double phimin, double phimax)
	select objects with rapmin <= rap <= rapmax && phimin <= phi <= phimax More...
Selector	SelectorNHardest (unsigned int n)
	select the n hardest objects
Selector	SelectorCircle (const double radius)
	select objets within a distance 'radius' from the location of the reference jet, set by Selector::set_reference(...)
Selector	SelectorDoughnut (const double radius_in, const double radius_out)
	select objets with distance from the reference jet is between 'radius_in' and 'radius_out'; the reference jet is set by Selector::set_reference(...)
Selector	SelectorStrip (const double half_width)
	select objets within a rapidity distance 'half_width' from the location of the reference jet, set by Selector::set_reference(...)
Selector	SelectorRectangle (const double half_rap_width, const double half_phi_width)
	select objets within rapidity distance 'half_rap_width' from the reference jet and azimuthal-angle distance within 'half_phi_width'; the reference jet is set by Selector::set_reference(...)
Selector	SelectorPtFractionMin (double fraction)
	select objects that carry at least a fraction "fraction" of the reference jet. More...
Selector	SelectorIsZero ()
	select PseudoJet with 0 momentum
Selector	SelectorIsPureGhost ()
	select objects that are (or are only made of) ghosts. More...
int	scomp (const void *p1, const void *p2)
template<typename T >
PseudoJet	join (const std::vector< PseudoJet > &pieces)
	build a "CompositeJet" from the vector of its pieces with an extended structure of type T derived from CompositeJetStructure More...
template<typename T >
PseudoJet	join (const std::vector< PseudoJet > &pieces, const JetDefinition::Recombiner &recombiner)
	build a "CompositeJet" from the vector of its pieces with an extended structure of type T derived from CompositeJetStructure More...
bool	operator!= (const PseudoJet &a, const PseudoJet &b)
	inequality test which is exact opposite of operator==
bool	operator== (const double val, const PseudoJet &jet)
bool	operator!= (const PseudoJet &a, const double val)
	Can only be used with val=0 and tests whether at least one of the four momentum components is different from val (=0.0)
bool	operator!= (const double val, const PseudoJet &a)
double	dot_product (const PseudoJet &a, const PseudoJet &b)
	returns the 4-vector dot product of a and b
double	cos_theta (const PseudoJet &a, const PseudoJet &b)
	returns the cosine of the angle between a and b
double	theta (const PseudoJet &a, const PseudoJet &b)
	returns the angle between a and b
std::vector< PseudoJet >	sorted_by_pt (const std::vector< PseudoJet > &jets)
	return a vector of jets sorted into decreasing transverse momentum
std::vector< PseudoJet >	sorted_by_rapidity (const std::vector< PseudoJet > &jets)
	return a vector of jets sorted into increasing rapidity
std::vector< PseudoJet >	sorted_by_E (const std::vector< PseudoJet > &jets)
	return a vector of jets sorted into decreasing energy
std::vector< PseudoJet >	sorted_by_pz (const std::vector< PseudoJet > &jets)
	return a vector of jets sorted into increasing pz
void	sort_indices (std::vector< int > &indices, const std::vector< double > &values)
	sort the indices so that values[indices[0->n-1]] is sorted into increasing order
template<class T >
std::vector< T >	objects_sorted_by_values (const std::vector< T > &objects, const std::vector< double > &values)
	given a vector of values with a one-to-one correspondence with the vector of objects, sort objects into an order such that the associated values would be in increasing order (but don't actually touch the values vector in the process).
template<class T , class U >
bool	operator== (SharedPtr< T > const &t, SharedPtr< U > const &u)
	comparison: equality
template<class T , class U >
bool	operator!= (SharedPtr< T > const &t, SharedPtr< U > const &u)
	comparison: difference
template<class T , class U >
bool	operator< (SharedPtr< T > const &t, SharedPtr< U > const &u)
	comparison: orgering
template<class T >
void	swap (SharedPtr< T > &a, SharedPtr< T > &b)
	swapping
template<class T >
T *	get_pointer (SharedPtr< T > const &t)
	getting the pointer
bool	floor_ln2_less (unsigned x, unsigned y)
	returns true if floor(ln_base2(x)) < floor(ln_base2(y)), using Chan's neat trick...
template<class B , class D >
B *	cast_if_derived (D *d)
	a little helper that returns a pointer to d of type B* if D is derived from B and NULL otherwise
double	norm (const VPoint p)
	norm of a vector
double	vector_product (const VPoint &p1, const VPoint &p2)
	2D vector product
double	scalar_product (const VPoint &p1, const VPoint &p2)
	scalar product
template<class T >
T	deltaPhi (T phi1, T phi2)
template<class T >
T	deltaR2 (T eta1, T phi1, T eta2, T phi2)

Variables
BasicRandom< int >	_G_random_int
BasicRandom< double >	_G_random_double
const unsigned int	twopow31 = 2147483648U
const JetAlgorithm	aachen_algorithm = cambridge_algorithm
	provide other possible names for the Cambridge/Aachen algorithm
const JetAlgorithm	cambridge_aachen_algorithm = cambridge_algorithm
const double	MaxRap = 1e5
	Used to protect against parton-level events where pt can be zero for some partons, giving rapidity=infinity. More...
const double	pseudojet_invalid_phi = -100.0
	default value for phi, meaning it (and rapidity) have yet to be calculated)
const double	pseudojet_invalid_rap = -1e200
const double	tile_edge_security_margin =1.0e-7
	Rounding errors in the Lazy strategies may cause the following problem: when browsing tiles in the vicinity of the particles being clustered in order to decide which of these tiles may contain particles that need to be updated (because theit NN is one of the particles that are currently clustered), we discard tiles that are deemed "too far from the cell" by the "max_NN_dist" criterion. More...
const int	n_tile_neighbours = 9
const double	pi = 3.141592653589793238462643383279502884197
const double	twopi = 6.283185307179586476925286766559005768394
const double	pisq = 9.869604401089358618834490999876151135314
const double	zeta2 = 1.644934066848226436472415166646025189219
const double	zeta3 = 1.202056903159594285399738161511449990765
const double	eulergamma = 0.577215664901532860606512090082402431042
const double	ln2 = 0.693147180559945309417232121458176568076
const int	INFINITE_VERTEX =-1
const int	NEW_VERTEX =-2
const double	HUGE_DOUBLE =1e300

Detailed Description

the FastJet namespace

all the fastjet-related material is put under that namespace

Typedef Documentation

ActiveAreaSpec

typedef GhostedAreaSpec fastjet::ActiveAreaSpec

just provide a typedef for backwards compatibility with programs based on versions 2.0 and 2.1 of fastjet.

Since there is no easy way of telling people this is deprecated at compile or run time, we should be careful before removing this in the future.

Definition at line 248 of file GhostedAreaSpec.hh.

Enumeration Type Documentation

Strategy

enum fastjet::Strategy

the various options for the algorithmic strategy to adopt in clustering events with kt and cambridge style algorithms.

Enumerator
N2MHTLazy9AntiKtSeparateGhosts	Like N2MHTLazy9 in a number of respects, but does not calculate ghost-ghost distances and so does not carry out ghost-ghost recombination. If you want active ghosted areas, then this is only suitable for use with the anti-kt algorithm (or genkt with negative p), and does not produce any pure ghost jets. If used with active areas with Kt or Cam algorithms it will actually produce a passive area. Particles are deemed to be ghosts if their pt is below a threshold (currently 1e-50, hard coded as ghost_limit in LazyTiling9SeparateGhosts). Currently for events with a couple of thousand normal particles and O(10k) ghosts, this can be quicker than N2MHTLazy9, which would otherwise be the best strategy. New in FJ3.1
N2MHTLazy9	only looks into a neighbouring tile for a particle's nearest neighbour (NN) if that particle's in-tile NN is further than the distance to the edge of the neighbouring tile. Uses tiles of size R and a 3x3 tile grid around the particle. New in FJ3.1
N2MHTLazy25	Similar to N2MHTLazy9, but uses tiles of size R/2 and a 5x5 tile grid around the particle. New in FJ3.1
N2MHTLazy9Alt	Like to N2MHTLazy9 but uses slightly different optimizations, e.g. for calculations of distance to nearest tile; as of 2014-07-18 it is slightly slower and not recommended for production use. To considered deprecated. New in FJ3.1
N2MinHeapTiled	faster that N2Tiled above about 500 particles; differs from it by retainig the di(closest j) distances in a MinHeap (sort of priority queue) rather than a simple vector.
N2Tiled	fastest from about 50..500
N2PoorTiled	legacy
N2Plain	fastest below 50
N3Dumb	worse even than the usual N^3 algorithms
Best	automatic selection of the best (based on N), including the LazyTiled strategies that are new to FJ3.1
NlnN	best of the NlnN variants – best overall for N>10^4. (Does not work for R>=2pi)
NlnN3pi	legacy N ln N using 3pi coverage of cylinder. (Does not work for R>=2pi)
NlnN4pi	legacy N ln N using 4pi coverage of cylinder
NlnNCam4pi	Chan's closest pair method (in a variant with 4pi coverage), for use exclusively with the Cambridge algorithm. (Does not work for R>=2pi)
NlnNCam2pi2R	Chan's closest pair method (in a variant with 2pi+2R coverage), for use exclusively with the Cambridge algorithm. (Does not work for R>=2pi)
NlnNCam	Chan's closest pair method (in a variant with 2pi+minimal extra variant), for use exclusively with the Cambridge algorithm. (Does not work for R>=2pi)
BestFJ30	the automatic strategy choice that was being made in FJ 3.0 (restricted to strategies that were present in FJ 3.0)
plugin_strategy	the plugin has been used...

Definition at line 51 of file JetDefinition.hh.

JetAlgorithm

enum fastjet::JetAlgorithm

the various families of jet-clustering algorithm

Enumerator
kt_algorithm	the longitudinally invariant kt algorithm
cambridge_algorithm	the longitudinally invariant variant of the cambridge algorithm (aka Aachen algoithm).
antikt_algorithm	like the k_t but with distance measures dij = min(1/kti^2,1/ktj^2) Delta R_{ij}^2 / R^2 diB = 1/kti^2
genkt_algorithm	like the k_t but with distance measures dij = min(kti^{2p},ktj^{2p}) Delta R_{ij}^2 / R^2 diB = 1/kti^{2p} where p = extra_param()
cambridge_for_passive_algorithm	a version of cambridge with a special distance measure for particles whose pt is < extra_param(); this is not usually intended for end users, but is instead automatically selected when requesting a passive Cambridge area.
genkt_for_passive_algorithm	a version of genkt with a special distance measure for particles whose pt is < extra_param() [relevant for passive areas when p<=0] ***** NB: THERE IS CURRENTLY NO IMPLEMENTATION FOR THIS ALG *******
ee_kt_algorithm	the e+e- kt algorithm
ee_genkt_algorithm	the e+e- genkt algorithm (R > 2 and p=1 gives ee_kt)
plugin_algorithm	any plugin algorithm supplied by the user
undefined_jet_algorithm	the value for the jet algorithm in a JetDefinition for which no algorithm has yet been defined

Definition at line 137 of file JetDefinition.hh.

RecombinationScheme

enum fastjet::RecombinationScheme

The various recombination schemes.

Note that the schemes that recombine with non-linear weighting of the directions (e.g. pt2, winner-takes-all) are collinear safe only for algorithms with a suitable ordering of the recombinations: orderings in which, for particles of comparable energies, small-angle clusterings take place before large-angle clusterings. This property is satisfied by all gen-kt algorithms.

Enumerator
E_scheme	summing the 4-momenta
pt_scheme	pt weighted recombination of y,phi (and summing of pt's) with preprocessing to make things massless by rescaling E=|\vec p|
pt2_scheme	pt^2 weighted recombination of y,phi (and summing of pt's) with preprocessing to make things massless by rescaling E=|\vec p|
Et_scheme	pt weighted recombination of y,phi (and summing of pt's) with preprocessing to make things massless by rescaling |\vec p|->=E
Et2_scheme	pt^2 weighted recombination of y,phi (and summing of pt's) with preprocessing to make things massless by rescaling |\vec p|->=E
BIpt_scheme	pt weighted recombination of y,phi (and summing of pt's), with no preprocessing
BIpt2_scheme	pt^2 weighted recombination of y,phi (and summing of pt's) no preprocessing
WTA_pt_scheme	pt-based Winner-Takes-All (WTA) recombination: the result of the recombination has the rapidity, azimuth and mass of the PseudoJet with the larger pt, and a pt equal to the sum of the two pt's
WTA_modp_scheme	mod-p-based Winner-Takes-All (WTA) recombination: the result of the recombination gets the 3-vector direction and mass of the PseudoJet with the larger |3-momentum| (modp), and a |3-momentum| equal to the scalar sum of the two |3-momenta|.
external_scheme	for the user's external scheme

Definition at line 193 of file JetDefinition.hh.

Function Documentation

join() [1/10]

PseudoJet fastjet::join	(	const PseudoJet &	j1,
		const JetDefinition::Recombiner &	recombiner
	)

build a "CompositeJet" from a single PseudoJet with an extended structure of type T derived from CompositeJetStructure

build a MergedJet from a single PseudoJet

Definition at line 475 of file JetDefinition.cc.

join() [2/10]

PseudoJet fastjet::join	(	const PseudoJet &	j1,
		const PseudoJet &	j2,
		const JetDefinition::Recombiner &	recombiner
	)

build a "CompositeJet" from two PseudoJet with an extended structure of type T derived from CompositeJetStructure

build a MergedJet from 2 PseudoJet

Definition at line 481 of file JetDefinition.cc.

join() [3/10]

PseudoJet fastjet::join	(	const PseudoJet &	j1,
		const PseudoJet &	j2,
		const PseudoJet &	j3,
		const JetDefinition::Recombiner &	recombiner
	)

build a "CompositeJet" from 3 PseudoJet with an extended structure of type T derived from CompositeJetStructure

build a MergedJet from 3 PseudoJet

Definition at line 490 of file JetDefinition.cc.

join() [4/10]

PseudoJet fastjet::join	(	const PseudoJet &	j1,
		const PseudoJet &	j2,
		const PseudoJet &	j3,
		const PseudoJet &	j4,
		const JetDefinition::Recombiner &	recombiner
	)

build a "CompositeJet" from 4 PseudoJet with an extended structure of type T derived from CompositeJetStructure

build a MergedJet from 4 PseudoJet

Definition at line 500 of file JetDefinition.cc.

operator==()

bool fastjet::operator==	(	const PseudoJet &	,
		const PseudoJet &
	)

returns true if the 4 momentum components of the two PseudoJets are identical and all the internal indices (user, cluster_history)

• structure and user-info shared pointers are too

Definition at line 255 of file PseudoJet.cc.

PtYPhiM()

PseudoJet fastjet::PtYPhiM	(	double	pt,
		double	y,
		double	phi,
		double	m
	)

return a pseudojet with the given pt, y, phi and mass

return a pseudojet with the given pt, y, phi and mass (phi should satisfy -2pi<phi<4pi)

Definition at line 365 of file PseudoJet.cc.

join() [5/10]

PseudoJet fastjet::join

(

const PseudoJet &

j1

)

build a "CompositeJet" from a single PseudoJet with an extended structure of type T derived from CompositeJetStructure

build a MergedJet from a single PseudoJet

Definition at line 831 of file PseudoJet.cc.

join() [6/10]

PseudoJet fastjet::join	(	const PseudoJet &	j1,
		const PseudoJet &	j2
	)

build a "CompositeJet" from two PseudoJet with an extended structure of type T derived from CompositeJetStructure

build a MergedJet from 2 PseudoJet

Definition at line 836 of file PseudoJet.cc.

join() [7/10]

PseudoJet fastjet::join	(	const PseudoJet &	j1,
		const PseudoJet &	j2,
		const PseudoJet &	j3
	)

build a "CompositeJet" from 3 PseudoJet with an extended structure of type T derived from CompositeJetStructure

build a MergedJet from 3 PseudoJet

Definition at line 845 of file PseudoJet.cc.

join() [8/10]

PseudoJet fastjet::join	(	const PseudoJet &	j1,
		const PseudoJet &	j2,
		const PseudoJet &	j3,
		const PseudoJet &	j4
	)

build a "CompositeJet" from 4 PseudoJet with an extended structure of type T derived from CompositeJetStructure

build a MergedJet from 4 PseudoJet

Definition at line 855 of file PseudoJet.cc.

join() [9/10]

template<typename T >

PseudoJet fastjet::join

(

const std::vector< PseudoJet > &

pieces

)

build a "CompositeJet" from the vector of its pieces with an extended structure of type T derived from CompositeJetStructure

build a "CompositeJet" from the vector of its pieces

In this case, E-scheme recombination is assumed to compute the total momentum

Definition at line 155 of file CompositeJetStructure.hh.

join() [10/10]

template<typename T >

PseudoJet fastjet::join	(	const std::vector< PseudoJet > &	pieces,
		const JetDefinition::Recombiner &	recombiner
	)

build a "CompositeJet" from the vector of its pieces with an extended structure of type T derived from CompositeJetStructure

build a "CompositeJet" from the vector of its pieces

In this case, E-scheme recombination is assumed to compute the total momentum

Definition at line 218 of file CompositeJetStructure.hh.

Variable Documentation

MaxRap

const double fastjet::MaxRap = 1e5

Used to protect against parton-level events where pt can be zero for some partons, giving rapidity=infinity.

KtJet fails in those cases.

Definition at line 52 of file PseudoJet.hh.

tile_edge_security_margin

const double fastjet::tile_edge_security_margin =1.0e-7

Rounding errors in the Lazy strategies may cause the following problem: when browsing tiles in the vicinity of the particles being clustered in order to decide which of these tiles may contain particles that need to be updated (because theit NN is one of the particles that are currently clustered), we discard tiles that are deemed "too far from the cell" by the "max_NN_dist" criterion.

Because of rounding error, this condition can sometimes miss cases where an update is needed.

An example of this happens if a particle '1' is, say, at the lower edge of the rapidity of a given tile, with a particle '2' in the tile directly on its left at the same rapidity. Assume also that max_NN_dist in 2's tile corresponds to the distance between 2 and teh tile of 1. If 2 is 1's NN then in case 2 gets clustered, 1's NN needs to be updated. However, rounding errors in the calculation of the distance between 1 and 2 may result is something slightly larger than the max_NN_dist in 2's tile.

This situation corresponds to the bug reported by Jochen Olt on February 12 2015 [see issue-tracker/2015-02-infinite-loop], causing an infinite loop.

To prevent this, the simplest solution is, when looking at tiles to browse for updateds, to add a margin of security close to the edges of the cell, i.e. instead of updating only tiles for which distance<=max_NN_dist, we will update tiles for which distance<=max_NN_dist+tile_edge_security_margin.

Note that this does not need to be done when computing nearest neighbours [rounding errors are tolerated there] but it is critical when tracking points that have to be updated.

Definition at line 71 of file LazyTiling9Alt.hh.