fastjet::PxConePlugin Class Reference

Implementation of the PxCone algorithm (plugin for fastjet v2.1 upwards) More...

#include <fastjet/PxConePlugin.hh>

Inheritance diagram for fastjet::PxConePlugin:

Collaboration diagram for fastjet::PxConePlugin:

List of all members.

Public Member Functions
	PxConePlugin (double cone_radius_in, double min_jet_energy_in=5.0, double overlap_threshold_in=0.5, bool E_scheme_jets_in=false)
	constructor for the PxConePlugin, whose arguments have the following meaning:
double	cone_radius () const
	the cone radius
double	min_jet_energy () const
	minimum jet energy (protojets below this are thrown own before merging/splitting) -- called epslon in pxcone
double	overlap_threshold () const
	Maximum fraction of overlap energy in a jet -- called ovlim in pxcone.
bool	E_scheme_jets () const
	if true then the final jets are returned as the E-scheme recombination of the particle momenta (by default, pxcone returns massless jets with a mean phi,eta type of recombination); regardless of what is returned, the internal pxcone jet-finding procedure is unaffected.
virtual std::string	description () const
	return a textual description of the jet-definition implemented in this plugin
virtual void	run_clustering (ClusterSequence &) const
	given a ClusterSequence that has been filled up with initial particles, the following function should fill up the rest of the ClusterSequence, using the following member functions of ClusterSequence:
virtual double	R () const
	the plugin mechanism's standard way of accessing the jet radius

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Detailed Description

Implementation of the PxCone algorithm (plugin for fastjet v2.1 upwards)

PxConePlugin is a plugin for fastjet (v2.1 upwards) that provides an interface to the fortran pxcone iterative cone algorithm with midpoint seeds.

Pxcone was written by Luis del Pozo and Michael H. Seymour. It is not a "supported" program, so if you encounter problems, you are on your own...

Note that pxcone sometimes encounters non-stable iterations; in such cases it returns an error -- the plugin propagates this by throwing a fastjet::Error exception; if the user wishes to have robust code, they should catch this exception.

Pxcone has a hard-coded limit (by default 4000) on the maximum number of particles and protojets; if the number of particles or protojets exceeds this, again a fastjet::Error exception will be thrown.

The functionality of pxcone is described at http://www.hep.man.ac.uk/u/wplano/ConeJet.ps

Definition at line 66 of file PxConePlugin.hh.

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Constructor & Destructor Documentation

fastjet::PxConePlugin::PxConePlugin	(	double	cone_radius_in,
		double	min_jet_energy_in = 5.0,
		double	overlap_threshold_in = 0.5,
		bool	E_scheme_jets_in = false
	)		[inline]

constructor for the PxConePlugin, whose arguments have the following meaning:

• the cone_radius is as usual in cone algorithms

• stables cones (protojets) below min_jet_energy are discarded before calling the splitting procedure to resolve overlaps (called epslon in pxcone).

• when two protojets overlap, if (overlapping_Et)/(Et_of_softer_protojet) < overlap_threshold the overlapping energy is split between the two protojets; otherwise the less energetic protojet is discarded. Called ovlim in pxcone.

• pxcone carries out p-scheme recombination, and the resulting jets are massless; setting E_scheme_jets = true (default false) doesn't change the jet composition, but the final momentum sum for the jets is carried out by direct four-vector addition instead of p-scheme recombination.

Definition at line 90 of file PxConePlugin.hh.

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Member Function Documentation

bool fastjet::PxConePlugin::E_scheme_jets

(

)

const [inline]

if true then the final jets are returned as the E-scheme recombination of the particle momenta (by default, pxcone returns massless jets with a mean phi,eta type of recombination); regardless of what is returned, the internal pxcone jet-finding procedure is unaffected.

Definition at line 117 of file PxConePlugin.hh.

void fastjet::PxConePlugin::run_clustering

(

ClusterSequence &

)

const [virtual]

given a ClusterSequence that has been filled up with initial particles, the following function should fill up the rest of the ClusterSequence, using the following member functions of ClusterSequence:

• plugin_do_ij_recombination(...)
• plugin_do_iB_recombination(...)

Implements fastjet::JetDefinition::Plugin.

Definition at line 58 of file PxConePlugin.cc.

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

• plugins/PxCone/fastjet/PxConePlugin.hh
• plugins/PxCone/PxConePlugin.cc