FastJet  3.1.1
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fastjet::PxConePlugin Class Reference

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

#include <fastjet/PxConePlugin.hh>

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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: More...
 
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. More...
 
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: More...
 
virtual double R () const
 the plugin mechanism's standard way of accessing the jet radius
 
- Public Member Functions inherited from fastjet::JetDefinition::Plugin
virtual bool supports_ghosted_passive_areas () const
 return true if there is specific support for the measurement of passive areas, in the sense that areas determined from all particles below the ghost separation scale will be a passive area. More...
 
virtual void set_ghost_separation_scale (double scale) const
 set the ghost separation scale for passive area determinations in future runs (strictly speaking that makes the routine a non const, so related internal info must be stored as a mutable)
 
virtual double ghost_separation_scale () const
 
virtual bool exclusive_sequence_meaningful () const
 if this returns false then a warning will be given whenever the user requests "exclusive" jets from the cluster sequence
 
virtual bool is_spherical () const
 returns true if the plugin implements an algorithm intended for use on a spherical geometry (e.g. More...
 
virtual ~Plugin ()
 a destructor to be replaced if necessary in derived classes...
 

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 68 of file PxConePlugin.hh.

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 92 of file PxConePlugin.hh.

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 119 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 60 of file PxConePlugin.cc.


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