Class used to split and merge jets. More...

#include <split_merge.h>

Inheritance diagram for siscone::Csplit_merge:

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Collaboration diagram for siscone::Csplit_merge:

Classes
class	Cuser_scale_base
	base class for user-defined ordering of stable cones More...

Public Member Functions
	Csplit_merge ()
	default ctor

	~Csplit_merge ()
	default dtor

int	init (std::vector< Cmomentum > &_particles, std::vector< Cmomentum > *protocones, double R2, double ptmin=0.0)
	initialisation function

int	init_particles (std::vector< Cmomentum > &_particles)
	initialisation function for particle list

int	init_pleft ()
	build initial list of left particles

int	set_pt_weighted_splitting (bool _use_pt_weighted_splitting)
	use a pt-dependent boundary for splitting When called with true, the criterium for splitting two protojets will be to compare D1^2/kt1^2 vs.

int	partial_clear ()
	partial clearance

int	full_clear ()
	full clearance

void	set_user_scale (const Cuser_scale_base *user_scale_in)
	associate a user-defined scale to order the stable cones

const Cuser_scale_base *	user_scale () const
	return the user-defined scale (NULL if none)

int	merge_collinear_and_remove_soft ()
	build the list 'p_uncol_hard' from p_remain by clustering collinear particles and removing particles softer than stable_cone_soft_pt2_cutoff note that thins in only used for stable-cone detection so the parent_index field is unnecessary

int	add_protocones (std::vector< Cmomentum > *protocones, double R2, double ptmin=0.0)
	add a list of protocones

int	add_hardest_protocone_to_jets (std::vector< Cmomentum > *protocones, double R2, double ptmin=0.0)
	remove the hardest protocone and declare it a jet

int	perform (double overlap_tshold, double ptmin=0.0)
	really do the splitting and merging At the end, the vector jets is filled with the jets found.

int	save_contents (FILE *flux)
	save final jets

int	show ()
	show jets/candidates status

Public Attributes
int	n
	number of particles

std::vector< Cmomentum >	particles
	list of particles

std::vector< double >	pt
	list of particles' pt

int	n_left
	numer of particles that does not belong to any jet

std::vector< Cmomentum >	p_remain
	list of particles remaining to deal with

std::vector< Cmomentum >	p_uncol_hard
	list of particles remaining with collinear clustering

int	n_pass
	index of the run

double	most_ambiguous_split
	minimal difference in squared distance between a particle and two overlapping protojets when doing a split (useful when testing approx.

std::vector< Cjet >	jets
	list of jets

int *	indices
	maximal size array for indices works

int	idx_size
	number of elements in indices1

bool	merge_identical_protocones
	The following flag indicates that identical protocones are to be merged automatically each time around the split-merge loop and before anything else happens.

Csplit_merge_ptcomparison	ptcomparison
	member used for detailed comparisons of pt's

double	SM_var2_hardest_cut_off
	stop split–merge or progressive-removal when the squared SM_var of the hardest protojet is below this cut-off.

double	stable_cone_soft_pt2_cutoff
	pt cutoff for the particles to put in p_uncol_hard this is meant to allow removing soft particles in the stable-cone search.

Detailed Description

Class used to split and merge jets.

Definition at line 180 of file split_merge.h.

Constructor & Destructor Documentation

◆ Csplit_merge()

siscone::Csplit_merge::Csplit_merge ( )

default ctor

Definition at line 226 of file split_merge.cpp.

References indices, merge_identical_protocones, siscone::Csplit_merge_ptcomparison::particles, particles, siscone::Csplit_merge_ptcomparison::pt, pt, ptcomparison, SM_var2_hardest_cut_off, and stable_cone_soft_pt2_cutoff.

◆ ~Csplit_merge()

siscone::Csplit_merge::~Csplit_merge ( )

default dtor

Definition at line 254 of file split_merge.cpp.

References full_clear().

Member Function Documentation

◆ add_hardest_protocone_to_jets()

int siscone::Csplit_merge::add_hardest_protocone_to_jets	(	std::vector< Cmomentum > *	protocones,
		double	R2,
		double	ptmin = `0.0`
	)

remove the hardest protocone and declare it a jet

Parameters

protocones	list of protocones (initial jet candidates)
R2	cone radius (squared)
ptmin	minimal pT allowed for jets

Returns: 0 on success, 1 on error

The list of remaining particles (and the uncollinear-hard ones) is updated.

Definition at line 571 of file split_merge.cpp.

References siscone::Cmomentum::eta, siscone::Cmomentum::index, jets, merge_collinear_and_remove_soft(), n_left, n_pass, p_remain, siscone::Cmomentum::parent_index, particles, siscone::Cmomentum::phi, pt, ptcomparison, and twopi.

Referenced by siscone::Csiscone::compute_jets_progressive_removal().

◆ add_protocones()

int siscone::Csplit_merge::add_protocones	(	std::vector< Cmomentum > *	protocones,
		double	R2,
		double	ptmin = `0.0`
	)

add a list of protocones

Parameters

protocones	list of protocones (initial jet candidates)
R2	cone radius (squared)
ptmin	minimal pT allowed for jets

Returns: 0 on success, 1 on error

Definition at line 460 of file split_merge.cpp.

References siscone::Cmomentum::eta, siscone::Cmomentum::index, merge_collinear_and_remove_soft(), n_left, n_pass, p_remain, siscone::Cmomentum::parent_index, particles, siscone::Cmomentum::phi, pt, and twopi.

Referenced by siscone::Csiscone::compute_jets(), init(), and siscone::Csiscone::recompute_jets().

◆ full_clear()

int siscone::Csplit_merge::full_clear ( )

full clearance

Definition at line 389 of file split_merge.cpp.

References indices, partial_clear(), and particles.

Referenced by init_particles(), and ~Csplit_merge().

◆ init()

int siscone::Csplit_merge::init	(	std::vector< Cmomentum > &	_particles,
		std::vector< Cmomentum > *	protocones,
		double	R2,
		double	ptmin = `0.0`
	)

initialisation function

Parameters

_particles	list of particles
protocones	list of protocones (initial jet candidates)
R2	cone radius (squared)
ptmin	minimal pT allowed for jets

Returns: 0 on success, 1 on error

Definition at line 265 of file split_merge.cpp.

References add_protocones().

◆ init_particles()

int siscone::Csplit_merge::init_particles ( std::vector< Cmomentum > & _particles )

initialisation function for particle list

Parameters

_particles list of particles

Returns: 0 on success, 1 on error

Definition at line 274 of file split_merge.cpp.

References full_clear(), indices, init_pleft(), n, siscone::Csplit_merge_ptcomparison::particles, particles, siscone::Csplit_merge_ptcomparison::pt, pt, and ptcomparison.

Referenced by siscone::Csiscone::compute_jets(), and siscone::Csiscone::compute_jets_progressive_removal().

◆ init_pleft()

int siscone::Csplit_merge::init_pleft ( )

build initial list of left particles

for the Ceta_phi_range static member!

Definition at line 303 of file split_merge.cpp.

References merge_collinear_and_remove_soft(), n, n_left, n_pass, p_remain, and particles.

Referenced by init_particles(), and siscone::Csiscone::recompute_jets().

◆ merge_collinear_and_remove_soft()

int siscone::Csplit_merge::merge_collinear_and_remove_soft ( )

build the list 'p_uncol_hard' from p_remain by clustering collinear particles and removing particles softer than stable_cone_soft_pt2_cutoff note that thins in only used for stable-cone detection so the parent_index field is unnecessary

Definition at line 406 of file split_merge.cpp.

References EPSILON_COLLINEAR, n_left, p_remain, p_uncol_hard, stable_cone_soft_pt2_cutoff, and twopi.

Referenced by add_hardest_protocone_to_jets(), add_protocones(), and init_pleft().

◆ partial_clear()

int siscone::Csplit_merge::partial_clear ( )

partial clearance

Definition at line 364 of file split_merge.cpp.

References jets, merge_identical_protocones, most_ambiguous_split, p_remain, and ptcomparison.

Referenced by siscone::Csiscone::compute_jets(), siscone::Csiscone::compute_jets_progressive_removal(), full_clear(), and siscone::Csiscone::recompute_jets().

◆ perform()

int siscone::Csplit_merge::perform	(	double	overlap_tshold,
		double	ptmin = `0.0`
	)

really do the splitting and merging At the end, the vector jets is filled with the jets found.

the 'contents' field of each jets contains the indices of the particles included in that jet.

Parameters

overlap_tshold	threshold for splitting/merging transition
ptmin	minimal pT allowed for jets

Returns: the number of jets is returned

Definition at line 716 of file split_merge.cpp.

References jets, particles, show(), and SM_var2_hardest_cut_off.

Referenced by siscone::Csiscone::compute_jets(), and siscone::Csiscone::recompute_jets().

◆ save_contents()

int siscone::Csplit_merge::save_contents ( FILE * flux )

save final jets

Parameters

flux	stream to save the jet contentss

Definition at line 829 of file split_merge.cpp.

References jets, and particles.

◆ set_pt_weighted_splitting()

int siscone::Csplit_merge::set_pt_weighted_splitting ( bool _use_pt_weighted_splitting )

inline

use a pt-dependent boundary for splitting When called with true, the criterium for splitting two protojets will be to compare D1^2/kt1^2 vs.

D2^2/kt2^2, the (anti-)kt-weighted distance instead of the plain distance D1^2 vs. D2^2. This can be set in order to produce more circular hard jets, with the same underlying philosophy as for the anti-kt algorithm. We thus expect a behaviour closer to the IterativeCone one. By default, we use the standard D1^2 vs. D2^2 comparison and this function is not called.

Definition at line 226 of file split_merge.h.

◆ set_user_scale()

void siscone::Csplit_merge::set_user_scale ( const Cuser_scale_base * user_scale_in )

inline

associate a user-defined scale to order the stable cones

Note that this is only used in "progressive-removal mode", e.g. in add_hardest_protocone_to_jets().

Definition at line 280 of file split_merge.h.

◆ show()

int siscone::Csplit_merge::show ( )

show jets/candidates status

Definition at line 859 of file split_merge.cpp.

References siscone::Cjet::contents, siscone::Cmomentum::E, jets, siscone::Cjet::n, siscone::Cmomentum::px, siscone::Cmomentum::py, siscone::Cmomentum::pz, and siscone::Cjet::v.

Referenced by perform().

◆ user_scale()

const Cuser_scale_base * siscone::Csplit_merge::user_scale ( ) const

inline

return the user-defined scale (NULL if none)

Definition at line 285 of file split_merge.h.

Member Data Documentation

◆ idx_size

int siscone::Csplit_merge::idx_size

number of elements in indices1

Definition at line 364 of file split_merge.h.

◆ indices

int* siscone::Csplit_merge::indices

maximal size array for indices works

Definition at line 363 of file split_merge.h.

Referenced by Csplit_merge(), full_clear(), and init_particles().

◆ jets

std::vector<Cjet> siscone::Csplit_merge::jets

list of jets

Definition at line 360 of file split_merge.h.

Referenced by add_hardest_protocone_to_jets(), siscone::Carea::compute_active_areas(), siscone::Carea::compute_areas(), siscone::Csiscone::compute_jets_progressive_removal(), siscone::Carea::compute_passive_areas(), partial_clear(), perform(), save_contents(), and show().

◆ merge_identical_protocones

bool siscone::Csplit_merge::merge_identical_protocones

The following flag indicates that identical protocones are to be merged automatically each time around the split-merge loop and before anything else happens.

This flag is only effective if ALLOW_MERGE_IDENTICAL_PROTOCONES is set in 'defines.h' Note that this lead to infrared-unsafety so it is disabled by default

Definition at line 374 of file split_merge.h.

Referenced by Csplit_merge(), and partial_clear().

◆ most_ambiguous_split

double siscone::Csplit_merge::most_ambiguous_split

minimal difference in squared distance between a particle and two overlapping protojets when doing a split (useful when testing approx.

collinear safety)

Definition at line 357 of file split_merge.h.

Referenced by partial_clear().

◆ n

int siscone::Csplit_merge::n

number of particles

Definition at line 346 of file split_merge.h.

Referenced by siscone::Carea::compute_active_areas(), siscone::Carea::compute_areas(), siscone::Carea::compute_passive_areas(), init_particles(), and init_pleft().

◆ n_left

int siscone::Csplit_merge::n_left

numer of particles that does not belong to any jet

Definition at line 349 of file split_merge.h.

Referenced by add_hardest_protocone_to_jets(), add_protocones(), siscone::Csiscone::compute_jets(), siscone::Csiscone::compute_jets_progressive_removal(), init_pleft(), and merge_collinear_and_remove_soft().

◆ n_pass

int siscone::Csplit_merge::n_pass

index of the run

Definition at line 352 of file split_merge.h.

Referenced by add_hardest_protocone_to_jets(), add_protocones(), and init_pleft().

◆ p_remain

std::vector<Cmomentum> siscone::Csplit_merge::p_remain

list of particles remaining to deal with

Definition at line 350 of file split_merge.h.

Referenced by add_hardest_protocone_to_jets(), add_protocones(), init_pleft(), merge_collinear_and_remove_soft(), and partial_clear().

◆ p_uncol_hard

std::vector<Cmomentum> siscone::Csplit_merge::p_uncol_hard

list of particles remaining with collinear clustering

Definition at line 351 of file split_merge.h.

Referenced by siscone::Csiscone::compute_jets(), siscone::Csiscone::compute_jets_progressive_removal(), and merge_collinear_and_remove_soft().

◆ particles

std::vector<Cmomentum> siscone::Csplit_merge::particles

list of particles

Definition at line 347 of file split_merge.h.

Referenced by add_hardest_protocone_to_jets(), add_protocones(), Csplit_merge(), full_clear(), init_particles(), init_pleft(), perform(), and save_contents().

◆ pt

std::vector<double> siscone::Csplit_merge::pt

list of particles' pt

Definition at line 348 of file split_merge.h.

Referenced by add_hardest_protocone_to_jets(), add_protocones(), Csplit_merge(), and init_particles().

◆ ptcomparison

Csplit_merge_ptcomparison siscone::Csplit_merge::ptcomparison

member used for detailed comparisons of pt's

Definition at line 377 of file split_merge.h.

Referenced by add_hardest_protocone_to_jets(), siscone::Csiscone::compute_jets(), siscone::Csiscone::compute_jets_progressive_removal(), Csplit_merge(), init_particles(), partial_clear(), and siscone::Csiscone::recompute_jets().

◆ SM_var2_hardest_cut_off

double siscone::Csplit_merge::SM_var2_hardest_cut_off

stop split–merge or progressive-removal when the squared SM_var of the hardest protojet is below this cut-off.

Note that this is a signed square (ie SM_var*|SM_var|) to be able to handle negative values.

Note that the cut-off is set on the variable squared.

Definition at line 385 of file split_merge.h.

Referenced by siscone::Carea::compute_active_areas(), siscone::Carea::compute_areas(), Csplit_merge(), and perform().

◆ stable_cone_soft_pt2_cutoff

double siscone::Csplit_merge::stable_cone_soft_pt2_cutoff

pt cutoff for the particles to put in p_uncol_hard this is meant to allow removing soft particles in the stable-cone search.

This is not collinear-safe so you should not use this variable unless you really know what you are doing Note that the cut-off is set on the variable squared.

Definition at line 394 of file split_merge.h.

Referenced by siscone::Carea::compute_passive_areas(), Csplit_merge(), and merge_collinear_and_remove_soft().

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

siscone/split_merge.h
siscone/split_merge.cpp

The SISCone Jet Algorithm

Version 3.1.1

Classes

Public Member Functions

Public Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Csplit_merge()

◆ ~Csplit_merge()

Member Function Documentation

◆ add_hardest_protocone_to_jets()

◆ add_protocones()

◆ full_clear()

◆ init()

◆ init_particles()

◆ init_pleft()

◆ merge_collinear_and_remove_soft()

◆ partial_clear()

◆ perform()

◆ save_contents()

◆ set_pt_weighted_splitting()

◆ set_user_scale()

◆ show()

◆ user_scale()

Member Data Documentation

◆ idx_size

◆ indices

◆ jets

◆ merge_identical_protocones

◆ most_ambiguous_split

◆ n

◆ n_left

◆ n_pass

◆ p_remain

◆ p_uncol_hard

◆ particles

◆ pt

◆ ptcomparison

◆ SM_var2_hardest_cut_off

◆ stable_cone_soft_pt2_cutoff