FastJet 3.4.1
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Class that helps perform jet background subtraction. More...
#include <fastjet/tools/Subtractor.hh>
Public Member Functions | |
Subtractor (const BackgroundEstimatorBase *bge) | |
define a subtractor based on a BackgroundEstimator More... | |
Subtractor (double rho) | |
define a subtractor that uses a fixed value of rho, the background pt density per unit area (which must be positive) More... | |
Subtractor (double rho, double rho_m) | |
define a subtractor that uses a fixed value of rho and rho_m; both must be >= 0; More... | |
Subtractor () | |
default constructor More... | |
virtual | ~Subtractor () |
default dtor More... | |
configuring the behaviour | |
void | set_defaults () |
reset all parameters to default values More... | |
void | set_background_estimator (const BackgroundEstimatorBase *bge) |
void | set_use_rho_m (bool use_rho_m_in=true) |
when 'use_rho_m' is true, include in the subtraction the correction from rho_m, the purely longitudinal, particle-mass-induced component of the background density per unit area More... | |
bool | use_rho_m () const |
returns whether or not the rho_m component is used More... | |
void | set_safe_mass (bool safe_mass_in=true) |
when 'safe_mass' is true, ensure that the mass of the subtracted 4-vector remain positive More... | |
bool | safe_mass () const |
returns whether or not safety tests on the mass are included More... | |
void | set_known_selectors (const Selector &sel_known_vertex, const Selector &sel_leading_vertex) |
This is mostly intended for cherge-hadron-subtracted type of events where we wich to use vertex information to improve the subtraction. More... | |
Public Member Functions inherited from fastjet::Transformer | |
Transformer () | |
default ctor More... | |
virtual | ~Transformer () |
default dtor More... | |
virtual PseudoJet | result (const PseudoJet &original) const =0 |
the result of the Transformer acting on the PseudoJet. More... | |
virtual std::string | description () const =0 |
This should be overloaded to return a description of the Transformer. More... | |
Public Member Functions inherited from fastjet::FunctionOfPseudoJet< PseudoJet > | |
FunctionOfPseudoJet () | |
default ctor More... | |
virtual | ~FunctionOfPseudoJet () |
default dtor (virtual to allow safe polymorphism) More... | |
virtual std::string | description () const |
returns a description of the function (an empty string by default) More... | |
virtual PseudoJet | result (const PseudoJet &pj) const=0 |
the action of the function this has to be overloaded in derived classes More... | |
PseudoJet | operator() (const PseudoJet &pj) const |
apply the function using the "traditional" () operator. More... | |
std::vector< PseudoJet > | operator() (const std::vector< PseudoJet > &pjs) const |
apply the function on a vector of PseudoJet, returning a vector of the results. More... | |
description and action | |
const BackgroundEstimatorBase * | _bge |
the tool used to estimate the background if has to be mutable in case its underlying selector takes a reference jet More... | |
double | _rho |
the fixed value of rho and/or rho_m to use if the user has selected that option More... | |
double | _rho_m |
bool | _use_rho_m |
include the rho_m correction More... | |
bool | _safe_mass |
ensures that the subtracted mass is +ve More... | |
Selector | _sel_known_vertex |
selects the particles with a known vertex origin More... | |
Selector | _sel_leading_vertex |
amongst the particles with a known vertex origin, select those coming from the leading vertex More... | |
static const double | _invalid_rho = -numeric_limits<double>::infinity() |
a value of rho that is used as a default to label that the stored rho is not valid for subtraction. More... | |
static LimitedWarning | _unused_rho_m_warning |
virtual PseudoJet | result (const PseudoJet &jet) const |
returns a jet that's subtracted More... | |
virtual std::string | description () const |
class description More... | |
PseudoJet | _amount_to_subtract (const PseudoJet &jet) const |
compute the 4-vector that should be subtracted from the given jet More... | |
Additional Inherited Members | |
Public Types inherited from fastjet::Transformer | |
typedef PseudoJetStructureBase | StructureType |
A typedef that is needed to ensure that the PseudoJet::structure_of() template function works. More... | |
Class that helps perform jet background subtraction.
This class derives from Transformer and makes use of a pointer to a BackgroundEstimatorBase object in order to determine the background in the vicinity of a given jet and then subtract area*background from the jet. It can also be initialised with a specific fixed value for the background pt density.
The original jet must have area support (4-vector)
The underlying structure of the returned, subtracted jet (i.e. constituents, pieces, etc.) is identical to that of the original jet.
Definition at line 62 of file Subtractor.hh.
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inline |
define a subtractor based on a BackgroundEstimator
Definition at line 65 of file Subtractor.hh.
fastjet::Subtractor::Subtractor | ( | double | rho | ) |
define a subtractor that uses a fixed value of rho, the background pt density per unit area (which must be positive)
Definition at line 45 of file Subtractor.cc.
fastjet::Subtractor::Subtractor | ( | double | rho, |
double | rho_m | ||
) |
define a subtractor that uses a fixed value of rho and rho_m; both must be >= 0;
Definition at line 52 of file Subtractor.cc.
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inline |
default constructor
Definition at line 77 of file Subtractor.hh.
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inlinevirtual |
default dtor
Definition at line 80 of file Subtractor.hh.
void fastjet::Subtractor::set_defaults | ( | ) |
reset all parameters to default values
Note: by default, the rho_m term is not included and the safety test for the mass is not done. This is mostly for backwards compatibility with FastJet 3.0 and is highly likely to change in a future release of FastJet
Definition at line 61 of file Subtractor.cc.
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inline |
Definition at line 94 of file Subtractor.hh.
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inline |
when 'use_rho_m' is true, include in the subtraction the correction from rho_m, the purely longitudinal, particle-mass-induced component of the background density per unit area
Note: this will be switched off by default (for backwards compatibility with FastJet 3.0) but is highly likely to change in a future release of FastJet
Definition at line 107 of file Subtractor.hh.
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inline |
returns whether or not the rho_m component is used
Definition at line 115 of file Subtractor.hh.
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inline |
when 'safe_mass' is true, ensure that the mass of the subtracted 4-vector remain positive
when true, if the subtracted mass is negative, we return a 4-vector with 0 mass, pt and phi from the subtracted 4-vector and the rapidity of the original, unsubtracted jet.
Note: this will be switched off by default (for backwards compatibility with FastJet 3.0) but is highly likely to change in a future release of FastJet
Definition at line 127 of file Subtractor.hh.
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inline |
returns whether or not safety tests on the mass are included
Definition at line 130 of file Subtractor.hh.
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inline |
This is mostly intended for cherge-hadron-subtracted type of events where we wich to use vertex information to improve the subtraction.
Given the following parameters:
sel_known_vertex | selects the particles with a known vertex origin |
sel_leading_vertex | amongst the particles with a known vertex origin, select those coming from the leading vertex Momentum identified as coming from the leading vertex will be kept, momentum identified as coming from a non-leading vertex will be eliminated and a regular area-median subtraction will be applied on the 4-vector sum of the particles with unknown vertex origin. |
When this is set, we shall ensure that the pt of the subtracted 4-vector is at least the pt of the particles that are known to come from the leading vertex (if it fails, subtraction returns the component that is known to come from the leading vertex — or, the original unsubtracted jet if it contains no particles from the leading vertex). Furthermore, when safe_mass() is on, we also impose a similar constraint on the mass of the subtracted 4-vector (if the test fails, the longitudinal part of the subtracted 4-vector is taken from the component that is known to come from the leading vertex).
Definition at line 158 of file Subtractor.hh.
returns a jet that's subtracted
jet | the jet that is to be subtracted |
Implements fastjet::Transformer.
Definition at line 72 of file Subtractor.cc.
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virtual |
compute the 4-vector that should be subtracted from the given jet
Definition at line 176 of file Subtractor.cc.
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protected |
the tool used to estimate the background if has to be mutable in case its underlying selector takes a reference jet
Definition at line 187 of file Subtractor.hh.
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protected |
the fixed value of rho and/or rho_m to use if the user has selected that option
Definition at line 189 of file Subtractor.hh.
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protected |
Definition at line 189 of file Subtractor.hh.
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include the rho_m correction
Definition at line 192 of file Subtractor.hh.
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protected |
ensures that the subtracted mass is +ve
Definition at line 193 of file Subtractor.hh.
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protected |
selects the particles with a known vertex origin
Definition at line 195 of file Subtractor.hh.
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protected |
amongst the particles with a known vertex origin, select those coming from the leading vertex
Definition at line 197 of file Subtractor.hh.
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staticprotected |
a value of rho that is used as a default to label that the stored rho is not valid for subtraction.
Definition at line 208 of file Subtractor.hh.
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staticprotected |
Definition at line 210 of file Subtractor.hh.