PxConePlugin.hh

//FJSTARTHEADER
// $Id: PxConePlugin.hh 3433 2014-07-23 08:17:03Z salam $
//
// Copyright (c) 2005-2014, Matteo Cacciari, Gavin P. Salam and Gregory Soyez
//
//----------------------------------------------------------------------
// This file is part of FastJet.
//
//  FastJet is free software; you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation; either version 2 of the License, or
//  (at your option) any later version.
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//  The algorithms that underlie FastJet have required considerable
//  development. They are described in the original FastJet paper,
//  hep-ph/0512210 and in the manual, arXiv:1111.6097. If you use
//  FastJet as part of work towards a scientific publication, please
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//FJENDHEADER
 
#ifndef __PXCONEPLUGIN_HH__
#define __PXCONEPLUGIN_HH__
 
#include "fastjet/JetDefinition.hh"
 
// questionable whether this should be in fastjet namespace or not...
 
//FASTJET_BEGIN_NAMESPACE      // defined in fastjet/internal/base.hh
namespace Rivet {
  //----------------------------------------------------------------------
  //
  //
  //----------------------------------------------------------------------
  class PxConePlugin : public fastjet::JetDefinition::Plugin {
  public:

    PxConePlugin(double cone_radius_in,
                 double min_jet_energy_in = 5.0,
                 double overlap_threshold_in = 0.5,
                 bool E_scheme_jets_in = false)
        : _cone_radius(cone_radius_in),
          _min_jet_energy(min_jet_energy_in),
          _overlap_threshold(overlap_threshold_in),
          _E_scheme_jets(E_scheme_jets_in) {
      std::string msg = "Using own c++ version of PxCone, since FastJet doesn't install it by default. ";
      msg += "Please notify the Rivet authors if this behaviour should be changed.";
      std::cerr << msg << std::endl;
    }
 
 
    // some functions to return info about parameters ----------------

    double cone_radius() const {
      return _cone_radius;
    }

    double min_jet_energy() const {
      return _min_jet_energy;
    }

    double overlap_threshold() const {
      return _overlap_threshold;
    }

    bool E_scheme_jets() const {
      return _E_scheme_jets;
    }
 
 
    // the things that are required by base class
    virtual std::string description() const;
    virtual void run_clustering(fastjet::ClusterSequence&) const;
    virtual double R() const {
      return cone_radius();
    }
 
  private:
 
    double _cone_radius;
    double _min_jet_energy;
    double _overlap_threshold;
 
    bool _E_scheme_jets;
 
    static bool _first_time;

    void _print_banner(std::ostream* ostr) const;
  };
 
 
  // actual physical parameters:
  //
  // coner
  // epsilon
  // ovlim
 
  void pxcone_(int mode,            // 1=>e+e-, 2=>hadron-hadron
               int ntrak,           // Number of particles
               int itkdm,           // First dimension of PTRAK array:
               const double* ptrak, // Array of particle 4-momenta (Px,Py,Pz,E)
               double coner,        // Cone size (half angle) in radians
               double epslon,       // Minimum Jet energy (GeV)
               double ovlim,        // Maximum fraction of overlap energy in a jet
               int mxjet,           // Maximum possible number of jets
               int& njet,           // Number of jets found
               double* pjet,        // 5-vectors of jets
               int* ipass,          // Particle k belongs to jet number IPASS(k)-1
                                    // IPASS = -1 if not assosciated to a jet
               int* ijmul,          // Jet i contains IJMUL[i] particles
               int* ierr            // = 0 if all is OK ;   = -1 otherwise
  );
 
  //FASTJET_END_NAMESPACE      // defined in fastjet/internal/base.hh
}
 
#endif