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fastjet::PseudoJet

fastjet::PseudoJet Class Reference

Class to contain pseudojets, including minimal information of use to to jet-clustering routines. More...

#include <PseudoJet.hh>

Inheritance diagram for fastjet::PseudoJet:

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List of all members.

Public Types

enum  {
  X = 0, Y = 1, Z = 2, T = 3,
  NUM_COORDINATES = 4, SIZE = NUM_COORDINATES
}

Public Member Functions

 PseudoJet ()
 PseudoJet (const double px, const double py, const double pz, const double E)
 construct a pseudojet from explicit components
template<class L>
 PseudoJet (const L &some_four_vector)
 constructor from any object that has px,py,pz,E = some_four_vector[0--3],
double E () const
double e () const
double px () const
double py () const
double pz () const
const double phi () const
 returns phi (in the range 0..2pi)
const double phi_std () const
 returns phi in the range -pi..pi
const double phi_02pi () const
 returns phi in the range 0..2pi
double rap () const
 returns the rapidity or some large value when the rapidity is infinite
double rapidity () const
 the same as rap()
double pseudorapidity () const
 returns the pseudo-rapidity or some large value when the rapidity is infinite
double eta () const
double kt2 () const
 returns the squared transverse momentum
double perp2 () const
 returns the squared transverse momentum
double perp () const
 returns the scalar transverse momentum
double m2 () const
 returns the squared invariant mass // like CLHEP
double mperp2 () const
 returns the squared transverse mass = kt^2+m^2
double mperp () const
 returns the transverse mass = sqrt(kt^2+m^2)
double m () const
 specialization of the "reset" template for case where something is reset to a pseudojet -- it then takes the user and history indices from the psjet
double operator() (int i) const
 returns component i, where X==0, Y==1, Z==2, E==3
double operator[] (int i) const
 returns component i, where X==0, Y==1, Z==2, E==3
PseudoJet & boost (const PseudoJet &prest)
 transform this jet (given in the rest frame of prest) into a jet in the lab frame;
PseudoJet & unboost (const PseudoJet &prest)
 transform this jet (given in the rest frame of prest) into a jet in the lab frame;
const int & cluster_hist_index () const
 return the cluster_hist_index, intended to be used by clustering routines.
void set_cluster_hist_index (const int index)
 set the cluster_hist_index, intended to be used by clustering routines.
const int cluster_sequence_history_index () const
 alternative name for cluster_hist_index() [perhaps more meaningful]
void set_cluster_sequence_history_index (const int index)
 alternative name for set_cluster_hist_index(.
const int & user_index () const
 return the user_index, intended to allow the user to "add" information
void set_user_index (const int index)
 set the user_index, intended to allow the user to "add" information
std::valarray< double > four_mom () const
 return a valarray containing the four-momentum (components 0-2 are 3-mom, component 3 is energy).
double kt_distance (const PseudoJet &other) const
 returns kt distance (R=1) between this jet and another
double plain_distance (const PseudoJet &other) const
 returns squared cylinder (rap-phi) distance between this jet and another
double squared_distance (const PseudoJet &other) const
 returns squared cylinder (rap-phi) distance between this jet and another
double beam_distance () const
 returns distance between this jet and the beam
void operator *= (double)
 multiply the jet's momentum by the coefficient
void operator/= (double)
 divide the jet's momentum by the coefficient
void operator+= (const PseudoJet &)
 add the other jet's momentum to this jet
void operator-= (const PseudoJet &)
 subtract the other jet's momentum from this jet
void reset (double px, double py, double pz, double E)
 reset the 4-momentum according to the supplied components and put the user and history indices back to their default values
void reset (const PseudoJet &psjet)
 reset the PseudoJet to be equal to psjet (including its indices); NB if the argument is derived from a PseudoJet then the "reset" used will be the templated version (which does not know about indices.
template<class L>
void reset (const L &some_four_vector)
 reset the 4-momentum according to the supplied generic 4-vector (accessible via indexing, [0]==px,.
template<>
 PseudoJet (const Cmomentum &four_vector)
 shortcut for converting siscone Cmomentum into PseudoJet

Private Member Functions

void _finish_init ()
 do standard end of initialisation
void _reset_indices ()
 set the indices to default values

Private Attributes

double _px
double _py
double _pz
double _E
double _phi
double _rap
double _kt2
int _cluster_hist_index
int _user_index

Detailed Description

Class to contain pseudojets, including minimal information of use to to jet-clustering routines.

Definition at line 52 of file PseudoJet.hh.

Member Enumeration Documentation

anonymous enum
 

Enumeration values:
X 
Y 
Z 
T 
NUM_COORDINATES 
SIZE 

Definition at line 115 of file PseudoJet.hh.

00115 { X=0, Y=1, Z=2, T=3, NUM_COORDINATES=4, SIZE=NUM_COORDINATES };

Constructor & Destructor Documentation

fastjet::PseudoJet::PseudoJet (   )  [inline]
 

Definition at line 55 of file PseudoJet.hh.

Referenced by PseudoJet().

00055 {};

fastjet::PseudoJet::PseudoJet (  const double  px,
const double  py,
const double  pz,
const double  E
) 
 

construct a pseudojet from explicit components

Definition at line 47 of file PseudoJet.cc.

References _E, _finish_init(), _px, _py, _pz, and _reset_indices().

00047                                                                                       {
00048   
00049   _E  = E ;
00050   _px = px;
00051   _py = py;
00052   _pz = pz;
00053 
00054   this->_finish_init();
00055 
00056   // some default values for the history and user indices
00057   _reset_indices();
00058 
00059 }

template<class L>
fastjet::PseudoJet::PseudoJet (  const L &  some_four_vector  )  [inline]
 

constructor from any object that has px,py,pz,E = some_four_vector[0--3],

Definition at line 267 of file PseudoJet.hh.

References _E, _finish_init(), _px, _py, _pz, and _reset_indices().

00267                                                                           {
00268 
00269   _px = some_four_vector[0];
00270   _py = some_four_vector[1];
00271   _pz = some_four_vector[2];
00272   _E  = some_four_vector[3];
00273   _finish_init();
00274   // some default values for these two indices
00275   _reset_indices();
00276 }

template<>
fastjet::PseudoJet::PseudoJet (  const Cmomentum &  four_vector  ) 
 

shortcut for converting siscone Cmomentum into PseudoJet

Definition at line 55 of file SISConePlugin.cc.

References PseudoJet().

00055                                                              {
00056   (*this) = PseudoJet(four_vector.px,four_vector.py,four_vector.pz,
00057                       four_vector.E);
00058 }

Member Function Documentation

void fastjet::PseudoJet::_finish_init (   )  [private]
 

do standard end of initialisation

Definition at line 64 of file PseudoJet.cc.

References _E, _kt2, _phi, _pz, _rap, m2(), fastjet::MaxRap, px(), py(), and fastjet::twopi.

Referenced by boost(), operator+=(), operator-=(), PseudoJet(), reset(), and unboost().

00064                               {
00065   _kt2 = this->px()*this->px() + this->py()*this->py();
00066   if (_kt2 == 0.0) {
00067     _phi = 0.0; } 
00068   else {
00069     _phi = atan2(this->py(),this->px());
00070   }
00071   if (_phi < 0.0) {_phi += twopi;}
00072   if (_phi >= twopi) {_phi -= twopi;} // can happen if phi=-|eps<1e-15|?
00073   if (this->E() == abs(this->pz()) && _kt2 == 0) {
00074     // Point has infinite rapidity -- convert that into a very large
00075     // number, but in such a way that different 0-pt momenta will have
00076     // different rapidities (so as to lift the degeneracy between
00077     // them) [this can be relevant at parton-level]
00078     double MaxRapHere = MaxRap + abs(this->pz());
00079     if (this->pz() >= 0.0) {_rap = MaxRapHere;} else {_rap = -MaxRapHere;}
00080   } else {
00081     // get the rapidity in a way that's modestly insensitive to roundoff
00082     // error when things pz,E are large (actually the best we can do without
00083     // explicit knowledge of mass)
00084     double effective_m2 = max(0.0,m2()); // force non tachyonic mass
00085     double E_plus_pz    = _E + abs(_pz); // the safer of p+, p-
00086     // p+/p- = (p+ p-) / (p-)^2 = (kt^2+m^2)/(p-)^2
00087     _rap = 0.5*log((_kt2 + effective_m2)/(E_plus_pz*E_plus_pz));
00088     if (_pz > 0) {_rap = - _rap;}
00089   }
00090 
00092   //if (this->E() != abs(this->pz())) {
00093   //  _rap = 0.5*log((this->E() + this->pz())/(this->E() - this->pz()));
00094   //    } else {
00095   //  // Overlapping points can give problems. Let's lift the degeneracy
00096   //  // in case of multiple 0-pT points (can be found at parton-level)
00097   //  double MaxRapHere = MaxRap + abs(this->pz());
00098   //  if (this->pz() >= 0.0) {_rap = MaxRapHere;} else {_rap = -MaxRapHere;}
00099   //}
00100 }

void fastjet::PseudoJet::_reset_indices (   )  [inline, private]
 

set the indices to default values

Definition at line 280 of file PseudoJet.hh.

References set_cluster_hist_index(), and set_user_index().

Referenced by PseudoJet(), and reset().

00280                                       { 
00281   set_cluster_hist_index(-1);
00282   set_user_index(-1);
00283 }

double fastjet::PseudoJet::beam_distance (   )  const [inline]
 

returns distance between this jet and the beam

Definition at line 165 of file PseudoJet.hh.

00165 {return _kt2;}

PseudoJet & fastjet::PseudoJet::boost (  const PseudoJet &  prest  ) 
 

transform this jet (given in the rest frame of prest) into a jet in the lab frame;

Definition at line 234 of file PseudoJet.cc.

References _E, _finish_init(), _px, _py, _pz, E(), m(), px(), py(), and pz().

00234                                                     {
00235   
00236   if (prest.px() == 0.0 && prest.py() == 0.0 && prest.pz() == 0.0) 
00237     return *this;
00238 
00239   double m = prest.m();
00240   assert(m != 0);
00241 
00242   double pf4  = (  px()*prest.px() + py()*prest.py()
00243                  + pz()*prest.pz() + E()*prest.E() )/m;
00244   double fn   = (pf4 + E()) / (prest.E() + m);
00245   _px +=  fn*prest.px();
00246   _py +=  fn*prest.py();
00247   _pz +=  fn*prest.pz();
00248   _E = pf4;
00249 
00250   _finish_init(); // we need to recalculate phi,rap,kt2
00251   return *this;
00252 }

const int& fastjet::PseudoJet::cluster_hist_index (   )  const [inline]
 

return the cluster_hist_index, intended to be used by clustering routines.

Definition at line 127 of file PseudoJet.hh.

Referenced by fastjet::ClusterSequence::_potentially_valid(), fastjet::ClusterSequence::add_constituents(), fastjet::ClusterSequenceVoronoiArea::area(), fastjet::ClusterSequenceActiveArea::area(), fastjet::ClusterSequenceActiveAreaExplicitGhosts::area_4vector(), fastjet::ClusterSequenceVoronoiArea::area_4vector(), fastjet::ClusterSequenceActiveArea::area_4vector(), fastjet::ClusterSequenceActiveArea::area_error(), fastjet::ClusterSequence::has_child(), fastjet::ClusterSequence::has_partner(), fastjet::ClusterSequenceActiveAreaExplicitGhosts::is_pure_ghost(), fastjet::ClusterSequence::object_in_jet(), and fastjet::ClusterSequenceAreaBase::subtracted_jet().

00127 {return _cluster_hist_index;}

const int fastjet::PseudoJet::cluster_sequence_history_index (   )  const [inline]
 

alternative name for cluster_hist_index() [perhaps more meaningful]

Definition at line 132 of file PseudoJet.hh.

00132                                                           {
00133     return cluster_hist_index();}

double fastjet::PseudoJet::e (   )  const [inline]
 

Definition at line 67 of file PseudoJet.hh.

Referenced by operator()().

00067 {return _E;} // like CLHEP

double fastjet::PseudoJet::E (   )  const [inline]
 

Definition at line 66 of file PseudoJet.hh.

Referenced by fastjet::ClusterSequenceActiveArea::_throw_unless_jets_have_same_perp_or_E(), boost(), fastjet::have_same_momentum(), fastjet::operator+(), fastjet::operator-(), fastjet::JetDefinition::DefaultRecombiner::preprocess(), fastjet::SISConePlugin::run_clustering(), fastjet::CDFJetCluPlugin::run_clustering(), and unboost().

00066 {return _E;}

double fastjet::PseudoJet::eta (   )  const [inline]
 

Definition at line 92 of file PseudoJet.hh.

00092 {return pseudorapidity();}

valarray< double > fastjet::PseudoJet::four_mom (   )  const
 

return a valarray containing the four-momentum (components 0-2 are 3-mom, component 3 is energy).

Definition at line 105 of file PseudoJet.cc.

References _E, _px, _py, and _pz.

00105                                            {
00106   valarray<double> mom(4);
00107   mom[0] = _px;
00108   mom[1] = _py;
00109   mom[2] = _pz;
00110   mom[3] = _E ;
00111   return mom;
00112 }

double fastjet::PseudoJet::kt2 (   )  const [inline]
 

returns the squared transverse momentum

Definition at line 95 of file PseudoJet.hh.

Referenced by fastjet::ClusterSequence::jet_scale_for_algorithm().

00095 {return _kt2;}

double fastjet::PseudoJet::kt_distance (  const PseudoJet &  other  )  const
 

returns kt distance (R=1) between this jet and another

Definition at line 302 of file PseudoJet.cc.

References _kt2, _phi, _rap, fastjet::pi, and fastjet::twopi.

00302                                                            {
00303   //double distance = min(this->kt2(), other.kt2());
00304   double distance = min(_kt2, other._kt2);
00305   double dphi = abs(_phi - other._phi);
00306   if (dphi > pi) {dphi = twopi - dphi;}
00307   double drap = _rap - other._rap;
00308   distance = distance * (dphi*dphi + drap*drap);
00309   return distance;
00310 }

double fastjet::PseudoJet::m (   )  const [inline]
 

specialization of the "reset" template for case where something is reset to a pseudojet -- it then takes the user and history indices from the psjet

Definition at line 302 of file PseudoJet.hh.

References m2().

Referenced by boost(), and unboost().

00302                                  {
00303   double mm = m2();
00304   return mm < 0.0 ? -std::sqrt(-mm) : std::sqrt(mm);
00305 }

double fastjet::PseudoJet::m2 (   )  const [inline]
 

returns the squared invariant mass // like CLHEP

Definition at line 101 of file PseudoJet.hh.

Referenced by _finish_init(), and m().

00101 {return (_E+_pz)*(_E-_pz)-_kt2;}

double fastjet::PseudoJet::mperp (   )  const [inline]
 

returns the transverse mass = sqrt(kt^2+m^2)

Definition at line 105 of file PseudoJet.hh.

00105 {return sqrt(std::abs(mperp2()));}

double fastjet::PseudoJet::mperp2 (   )  const [inline]
 

returns the squared transverse mass = kt^2+m^2

Definition at line 103 of file PseudoJet.hh.

00103 {return (_E+_pz)*(_E-_pz);}

void fastjet::PseudoJet::operator *= (  double   ) 
 

multiply the jet's momentum by the coefficient

Definition at line 190 of file PseudoJet.cc.

References _E, _kt2, _px, _py, and _pz.

00190                                        {
00191   _px *= coeff;
00192   _py *= coeff;
00193   _pz *= coeff;
00194   _E  *= coeff;
00195   _kt2*= coeff*coeff;
00196   // phi and rap are unchanged
00197 }

double fastjet::PseudoJet::operator() (  int  i  )  const
 

returns component i, where X==0, Y==1, Z==2, E==3

Definition at line 117 of file PseudoJet.cc.

References e(), px(), py(), pz(), T, X, Y, and Z.

00117                                           {
00118   switch(i) {
00119   case X:
00120     return px();
00121   case Y:
00122     return py();
00123   case Z:
00124     return pz();
00125   case T:
00126     return e();
00127   default:
00128     ostringstream err;
00129     err << "PseudoJet subscripting: bad index (" << i << ")";
00130     throw Error(err.str());
00131   }
00132   return 0.;
00133 }

void fastjet::PseudoJet::operator+= (  const PseudoJet &   ) 
 

add the other jet's momentum to this jet

Definition at line 208 of file PseudoJet.cc.

References _E, _finish_init(), _px, _py, and _pz.

00208                                                       {
00209   _px += other_jet._px;
00210   _py += other_jet._py;
00211   _pz += other_jet._pz;
00212   _E  += other_jet._E ;
00213   _finish_init(); // we need to recalculate phi,rap,kt2
00214 }

void fastjet::PseudoJet::operator-= (  const PseudoJet &   ) 
 

subtract the other jet's momentum from this jet

Definition at line 219 of file PseudoJet.cc.

References _E, _finish_init(), _px, _py, and _pz.

00219                                                       {
00220   _px -= other_jet._px;
00221   _py -= other_jet._py;
00222   _pz -= other_jet._pz;
00223   _E  -= other_jet._E ;
00224   _finish_init(); // we need to recalculate phi,rap,kt2
00225 }

void fastjet::PseudoJet::operator/= (  double   ) 
 

divide the jet's momentum by the coefficient

Definition at line 201 of file PseudoJet.cc.

00201                                        {
00202   (*this) *= 1.0/coeff;
00203 }

double fastjet::PseudoJet::operator[] (  int  i  )  const [inline]
 

returns component i, where X==0, Y==1, Z==2, E==3

Definition at line 112 of file PseudoJet.hh.

00112 { return (*this)(i); }; // this too

double fastjet::PseudoJet::perp (   )  const [inline]
 

returns the scalar transverse momentum

Definition at line 99 of file PseudoJet.hh.

Referenced by pseudorapidity(), fastjet::JetDefinition::DefaultRecombiner::recombine(), fastjet::ClusterSequenceAreaBase::subtracted_jet(), and fastjet::ClusterSequenceAreaBase::subtracted_pt().

00099 {return sqrt(_kt2);}    // like CLHEP

double fastjet::PseudoJet::perp2 (   )  const [inline]
 

returns the squared transverse momentum

Definition at line 97 of file PseudoJet.hh.

Referenced by fastjet::ClusterSequenceActiveArea::_throw_unless_jets_have_same_perp_or_E(), fastjet::ClusterSequence::has_parents(), fastjet::ClusterSequence::inclusive_jets(), fastjet::JetDefinition::DefaultRecombiner::preprocess(), and fastjet::JetDefinition::DefaultRecombiner::recombine().

00097 {return _kt2;}  // like CLHEP

const double fastjet::PseudoJet::phi (   )  const [inline]
 

returns phi (in the range 0..2pi)

Definition at line 73 of file PseudoJet.hh.

Referenced by fastjet::RangeDefinition::is_in_range(), and fastjet::JetDefinition::DefaultRecombiner::recombine().

00073 {return phi_02pi();}

const double fastjet::PseudoJet::phi_02pi (   )  const [inline]
 

returns phi in the range 0..2pi

Definition at line 80 of file PseudoJet.hh.

00080 {return _phi;}

const double fastjet::PseudoJet::phi_std (   )  const [inline]
 

returns phi in the range -pi..pi

Definition at line 76 of file PseudoJet.hh.

References fastjet::pi, and twopi.

00076                                        {
00077     return _phi > pi ? _phi-twopi : _phi;}

double fastjet::PseudoJet::plain_distance (  const PseudoJet &  other  )  const
 

returns squared cylinder (rap-phi) distance between this jet and another

Definition at line 315 of file PseudoJet.cc.

References _phi, _rap, fastjet::pi, and fastjet::twopi.

00315                                                               {
00316   double dphi = abs(_phi - other._phi);
00317   if (dphi > pi) {dphi = twopi - dphi;}
00318   double drap = _rap - other._rap;
00319   return (dphi*dphi + drap*drap);
00320 }

double fastjet::PseudoJet::pseudorapidity (   )  const
 

returns the pseudo-rapidity or some large value when the rapidity is infinite

Definition at line 137 of file PseudoJet.cc.

References fastjet::MaxRap, perp(), fastjet::pi, px(), py(), and pz().

00137                                        {
00138   if (px() == 0.0 && py() ==0.0) return MaxRap;
00139   if (pz() == 0.0) return 0.0;
00140 
00141   double theta = atan(perp()/pz());
00142   if (theta < 0) theta += pi;
00143   return -log(tan(theta/2));
00144 }

double fastjet::PseudoJet::px (   )  const [inline]
 

Definition at line 68 of file PseudoJet.hh.

Referenced by _finish_init(), fastjet::ClusterSequenceActiveArea::_throw_unless_jets_have_same_perp_or_E(), boost(), fastjet::have_same_momentum(), operator()(), fastjet::operator+(), fastjet::operator-(), fastjet::JetDefinition::DefaultRecombiner::preprocess(), pseudorapidity(), fastjet::SISConePlugin::run_clustering(), fastjet::CDFJetCluPlugin::run_clustering(), and unboost().

00068 {return _px;}

double fastjet::PseudoJet::py (   )  const [inline]
 

Definition at line 69 of file PseudoJet.hh.

Referenced by _finish_init(), fastjet::ClusterSequenceActiveArea::_throw_unless_jets_have_same_perp_or_E(), boost(), fastjet::have_same_momentum(), operator()(), fastjet::operator+(), fastjet::operator-(), fastjet::JetDefinition::DefaultRecombiner::preprocess(), pseudorapidity(), fastjet::SISConePlugin::run_clustering(), fastjet::CDFJetCluPlugin::run_clustering(), and unboost().

00069 {return _py;}

double fastjet::PseudoJet::pz (   )  const [inline]
 

Definition at line 70 of file PseudoJet.hh.

Referenced by fastjet::ClusterSequenceActiveArea::_throw_unless_jets_have_same_perp_or_E(), boost(), fastjet::have_same_momentum(), operator()(), fastjet::operator+(), fastjet::operator-(), fastjet::JetDefinition::DefaultRecombiner::preprocess(), pseudorapidity(), fastjet::SISConePlugin::run_clustering(), fastjet::CDFJetCluPlugin::run_clustering(), and unboost().

00070 {return _pz;}

double fastjet::PseudoJet::rap (   )  const [inline]
 

returns the rapidity or some large value when the rapidity is infinite

Definition at line 84 of file PseudoJet.hh.

Referenced by fastjet::RangeDefinition::is_in_range(), main(), and fastjet::JetDefinition::DefaultRecombiner::recombine().

00084 {return _rap;}

double fastjet::PseudoJet::rapidity (   )  const [inline]
 

the same as rap()

Definition at line 87 of file PseudoJet.hh.

00087 {return _rap;} // like CLHEP

template<class L>
void fastjet::PseudoJet::reset (  const L &  some_four_vector  )  [inline]
 

reset the 4-momentum according to the supplied generic 4-vector (accessible via indexing, [0]==px,.

..[3]==E) and put the user and history indices back to their default values.

Definition at line 188 of file PseudoJet.hh.

00188                                                                    {
00189     reset(some_four_vector[0], some_four_vector[1],
00190           some_four_vector[2], some_four_vector[3]);
00191   }

void fastjet::PseudoJet::reset (  const PseudoJet &  psjet  )  [inline]
 

reset the PseudoJet to be equal to psjet (including its indices); NB if the argument is derived from a PseudoJet then the "reset" used will be the templated version (which does not know about indices.

..)

Definition at line 181 of file PseudoJet.hh.

00181                                              {
00182     (*this) = psjet;
00183   }

void fastjet::PseudoJet::reset (  double  px,
double  py,
double  pz,
double  E
)  [inline]
 

reset the 4-momentum according to the supplied components and put the user and history indices back to their default values

Definition at line 308 of file PseudoJet.hh.

References _E, _finish_init(), _px, _py, _pz, and _reset_indices().

00308                                                                       {
00309   _px = px;
00310   _py = py;
00311   _pz = pz;
00312   _E  = E;
00313   _finish_init();
00314   _reset_indices();
00315 }

void fastjet::PseudoJet::set_cluster_hist_index (  const int  index  )  [inline]
 

set the cluster_hist_index, intended to be used by clustering routines.

Definition at line 129 of file PseudoJet.hh.

Referenced by _reset_indices(), and fastjet::ClusterSequenceAreaBase::subtracted_jet().

00129 {_cluster_hist_index = index;}

void fastjet::PseudoJet::set_cluster_sequence_history_index (  const int  index  )  [inline]
 

alternative name for set_cluster_hist_index(.

..) [perhaps more meaningful]

Definition at line 136 of file PseudoJet.hh.

00136                                                                   {
00137     set_cluster_hist_index(index);}

void fastjet::PseudoJet::set_user_index (  const int  index  )  [inline]
 

set the user_index, intended to allow the user to "add" information

Definition at line 143 of file PseudoJet.hh.

Referenced by _reset_indices(), main(), fastjet::JetDefinition::DefaultRecombiner::preprocess(), fastjet::JetDefinition::DefaultRecombiner::recombine(), and fastjet::SISConePlugin::run_clustering().

00143 {_user_index = index;}

double fastjet::PseudoJet::squared_distance (  const PseudoJet &  other  )  const [inline]
 

returns squared cylinder (rap-phi) distance between this jet and another

Definition at line 156 of file PseudoJet.hh.

00156                                                                 {
00157     return plain_distance(other);}

PseudoJet & fastjet::PseudoJet::unboost (  const PseudoJet &  prest  ) 
 

transform this jet (given in the rest frame of prest) into a jet in the lab frame;

Definition at line 261 of file PseudoJet.cc.

References _E, _finish_init(), _px, _py, _pz, E(), m(), px(), py(), and pz().

00261                                                       {
00262   
00263   if (prest.px() == 0.0 && prest.py() == 0.0 && prest.pz() == 0.0) 
00264     return *this;
00265 
00266   double m = prest.m();
00267   assert(m != 0);
00268 
00269   double pf4  = ( -px()*prest.px() - py()*prest.py()
00270                  - pz()*prest.pz() + E()*prest.E() )/m;
00271   double fn   = (pf4 + E()) / (prest.E() + m);
00272   _px -=  fn*prest.px();
00273   _py -=  fn*prest.py();
00274   _pz -=  fn*prest.pz();
00275   _E = pf4;
00276 
00277   _finish_init(); // we need to recalculate phi,rap,kt2
00278   return *this;
00279 }

const int& fastjet::PseudoJet::user_index (   )  const [inline]
 

return the user_index, intended to allow the user to "add" information

Definition at line 141 of file PseudoJet.hh.

Referenced by fastjet::JetDefinition::DefaultRecombiner::preprocess().

00141 {return _user_index;}

Member Data Documentation

int fastjet::PseudoJet::_cluster_hist_index [private]
 

Definition at line 197 of file PseudoJet.hh.

double fastjet::PseudoJet::_E [private]
 

Definition at line 195 of file PseudoJet.hh.

Referenced by _finish_init(), boost(), four_mom(), operator *=(), operator+=(), operator-=(), PseudoJet(), reset(), and unboost().

double fastjet::PseudoJet::_kt2 [private]
 

Definition at line 196 of file PseudoJet.hh.

Referenced by _finish_init(), kt_distance(), and operator *=().

double fastjet::PseudoJet::_phi [private]
 

Definition at line 196 of file PseudoJet.hh.

Referenced by _finish_init(), kt_distance(), and plain_distance().

double fastjet::PseudoJet::_px [private]
 

Definition at line 195 of file PseudoJet.hh.

Referenced by boost(), four_mom(), operator *=(), operator+=(), operator-=(), PseudoJet(), reset(), and unboost().

double fastjet::PseudoJet::_py [private]
 

Definition at line 195 of file PseudoJet.hh.

Referenced by boost(), four_mom(), operator *=(), operator+=(), operator-=(), PseudoJet(), reset(), and unboost().

double fastjet::PseudoJet::_pz [private]
 

Definition at line 195 of file PseudoJet.hh.

Referenced by _finish_init(), boost(), four_mom(), operator *=(), operator+=(), operator-=(), PseudoJet(), reset(), and unboost().

double fastjet::PseudoJet::_rap [private]
 

Definition at line 196 of file PseudoJet.hh.

Referenced by _finish_init(), kt_distance(), and plain_distance().

int fastjet::PseudoJet::_user_index [private]
 

Definition at line 197 of file PseudoJet.hh.

The documentation for this class was generated from the following files:
Generated on Fri Aug 15 13:45:46 2008 for fastjet by  doxygen 1.4.2