Abstract base class that provides the basic interface for classes that estimate levels of background radiation in hadron and heavy-ion collider events. More...

#include <fastjet/tools/BackgroundEstimatorBase.hh>

Inheritance diagram for fastjet::BackgroundEstimatorBase:

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Collaboration diagram for fastjet::BackgroundEstimatorBase:

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Public Member Functions
virtual	~BackgroundEstimatorBase ()
	a default virtual destructor that does nothing

constructors and destructors
	BackgroundEstimatorBase ()

setting a new event
virtual void	set_particles (const std::vector< PseudoJet > &particles)=0
	tell the background estimator that it has a new event, composed of the specified particles. More...

retrieving fundamental information
virtual double	rho () const =0
	get rho, the background density per unit area

virtual double	sigma () const
	get sigma, the background fluctuations per unit area; must be multipled by sqrt(area) to get fluctuations for a region of a given area. More...

virtual double	rho (const PseudoJet &jet)=0
	get rho, the background density per unit area, locally at the position of a given jet. More...

virtual double	sigma (const PseudoJet &)
	get sigma, the background fluctuations per unit area, locally at the position of a given jet. More...

virtual bool	has_sigma ()
	returns true if this background estimator has support for determination of sigma

virtual double	rho_m () const
	returns rho_m, the purely longitudinal, particle-mass-induced component of the background density per unit area

virtual double	sigma_m () const
	returns sigma_m, a measure of the fluctuations in the purely longitudinal, particle-mass-induced component of the background density per unit area; must be multipled by sqrt(area) to get fluctuations for a region of a given area. More...

virtual double	rho_m (const PseudoJet &)
	Returns rho_m locally at the jet position. As for rho(jet), it is non-const.

virtual double	sigma_m (const PseudoJet &)
	Returns sigma_m locally at the jet position. As for rho(jet), it is non-const.

virtual bool	has_rho_m () const
	Returns true if this background estimator has support for determination of rho_m. More...

configuring the behaviour
virtual void	set_rescaling_class (const FunctionOfPseudoJet< double > *rescaling_class_in)
	Set a pointer to a class that calculates the rescaling factor as a function of the jet (position). More...

const FunctionOfPseudoJet < double > *	rescaling_class () const
	return the pointer to the jet density class

description
virtual std::string	description () const =0
	returns a textual description of the background estimator

Protected Member Functions
helpers for derived classes
Note that these helpers are related to median-based estimation of the background, so there is no guarantee that they will remain in this base class in the long term
void	_median_and_stddev (const std::vector< double > &quantity_vector, double n_empty_jets, double &median, double &stand_dev_if_gaussian, bool do_fj2_calculation=false) const
	given a quantity in a vector (e.g. More...

double	_percentile (const std::vector< double > &sorted_quantity_vector, const double percentile, const double nempty=0.0, const bool do_fj2_calculation=false) const
	computes a percentile of a given sorted vector More...

Protected Attributes
const FunctionOfPseudoJet < double > *	_rescaling_class

Static Protected Attributes
static LimitedWarning	_warnings_empty_area

Detailed Description

Abstract base class that provides the basic interface for classes that estimate levels of background radiation in hadron and heavy-ion collider events.

Definition at line 50 of file BackgroundEstimatorBase.hh.

Member Function Documentation

virtual void fastjet::BackgroundEstimatorBase::set_particles ( const std::vector< PseudoJet > & particles )

pure virtual

tell the background estimator that it has a new event, composed of the specified particles.

Implemented in fastjet::GridMedianBackgroundEstimator, and fastjet::JetMedianBackgroundEstimator.

virtual double fastjet::BackgroundEstimatorBase::sigma ( ) const

inlinevirtual

get sigma, the background fluctuations per unit area; must be multipled by sqrt(area) to get fluctuations for a region of a given area.

Reimplemented in fastjet::JetMedianBackgroundEstimator, and fastjet::GridMedianBackgroundEstimator.

Definition at line 82 of file BackgroundEstimatorBase.hh.

virtual double fastjet::BackgroundEstimatorBase::rho ( const PseudoJet & jet )

pure virtual

get rho, the background density per unit area, locally at the position of a given jet.

Note that this is not const, because a user may then wish to query other aspects of the background that could depend on the position of the jet last used for a rho(jet) determination.

Implemented in fastjet::JetMedianBackgroundEstimator, and fastjet::GridMedianBackgroundEstimator.

virtual double fastjet::BackgroundEstimatorBase::sigma ( const PseudoJet & )

inlinevirtual

get sigma, the background fluctuations per unit area, locally at the position of a given jet.

As for rho(jet), it is non-const.

Reimplemented in fastjet::JetMedianBackgroundEstimator, and fastjet::GridMedianBackgroundEstimator.

Definition at line 95 of file BackgroundEstimatorBase.hh.

virtual double fastjet::BackgroundEstimatorBase::sigma_m ( ) const

inlinevirtual

returns sigma_m, a measure of the fluctuations in the purely longitudinal, particle-mass-induced component of the background density per unit area; must be multipled by sqrt(area) to get fluctuations for a region of a given area.

Reimplemented in fastjet::JetMedianBackgroundEstimator, and fastjet::GridMedianBackgroundEstimator.

Definition at line 116 of file BackgroundEstimatorBase.hh.

virtual bool fastjet::BackgroundEstimatorBase::has_rho_m ( ) const

inlinevirtual

Returns true if this background estimator has support for determination of rho_m.

Note that support for sigma_m is automatic is one has sigma and rho_m support.

Reimplemented in fastjet::JetMedianBackgroundEstimator, and fastjet::GridMedianBackgroundEstimator.

Definition at line 135 of file BackgroundEstimatorBase.hh.

virtual void fastjet::BackgroundEstimatorBase::set_rescaling_class ( const FunctionOfPseudoJet< double > * rescaling_class_in )

inlinevirtual

Set a pointer to a class that calculates the rescaling factor as a function of the jet (position).

Note that the rescaling factor is used both in the determination of the "global" rho (the pt/A of each jet is divided by this factor) and when asking for a local rho (the result is multiplied by this factor).

The BackgroundRescalingYPolynomial class can be used to get a rescaling that depends just on rapidity.

There is currently no support for different rescaling classes for rho and rho_m determinations.

Reimplemented in fastjet::JetMedianBackgroundEstimator, and fastjet::GridMedianBackgroundEstimator.

Definition at line 154 of file BackgroundEstimatorBase.hh.

void fastjet::BackgroundEstimatorBase::_median_and_stddev	(	const std::vector< double > &	quantity_vector,
		double	n_empty_jets,
		double &	median,
		double &	stand_dev_if_gaussian,
		bool	do_fj2_calculation = `false`
	)		const

protected

given a quantity in a vector (e.g.

pt_over_area) and knowledge about the number of empty jets, calculate the median and stand_dev_if_gaussian (roughly from the 16th percentile)

If do_fj2_calculation is set to true then this performs FastJet 2.X estimation of the standard deviation, which has a spurious offset in the limit of a small number of jets.

Definition at line 48 of file BackgroundEstimatorBase.cc.

double fastjet::BackgroundEstimatorBase::_percentile	(	const std::vector< double > &	sorted_quantity_vector,
		const double	percentile,
		const double	nempty = `0.0`,
		const bool	do_fj2_calculation = `false`
	)		const

protected

computes a percentile of a given sorted vector

Parameters

sorted_quantity_vector	the vector contains the data sample
percentile	the percentile (defined between 0 and 1) to compute
nempty	an additional number of 0's (considered at the beginning of the quantity vector)
do_fj2_calculation	carry out the calculation as it was done in fj2 (suffers from "edge effects")

Definition at line 95 of file BackgroundEstimatorBase.cc.

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

tools/fastjet/tools/BackgroundEstimatorBase.hh
tools/BackgroundEstimatorBase.cc

Public Member Functions

Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

Member Function Documentation