Pythia6 Class Reference

The C++ interface class to Pythia6. More...

#include <Doxymodules_eventgenerator.h>

Public Member Functions
	Pythia6 ()
virtual	~Pythia6 ()
int	Pycomp (int kf)
void	Py1ent (int line, int kf, double pe, double theta, double phi)
ParticleVector *	ImportParticles ()
int	ImportParticles (ParticleVector *particles, const char *option="")
void	SetMSTJ (int i, int m)
int	GetMDCY (int i, int j)
int	GetKFDP (int i, int j)
void	SetMDCY (int i, int j, int m)
void	SetMDME (int i, int j, int m)

Static Public Member Functions
static Pythia6 *	Instance ()

Private Attributes
ParticleVector *	fParticles
Pyjets_t *	fPyjets
Pydat1_t *	fPydat1
Pydat3_t *	fPydat3

Static Private Attributes
static Pythia6 *	fgInstance = 0

Detailed Description

The C++ interface class to Pythia6.

According to TPythia6 class from Root: (The TPythia6 class is an interface class to F77 routines in Pythia6 // CERNLIB event generators, written by T.Sjostrand.)
http://root.cern.ch/ see http://root.cern.ch/root/License.html

The complete Pythia6 documentation can be found at: http://home.thep.lu.se/~torbjorn/pythiaaux/recent.html

Definition at line 117 of file Doxymodules_eventgenerator.h.

Constructor & Destructor Documentation

Pythia6()

Pythia6::Pythia6

(

)

Pythia6 constructor: creates a vector of Pythia6Particle in which it will store all particles. Note that there may be only one functional Pythia6 object at a time, so it's not use to create more than one instance of it.

Definition at line 135 of file Pythia6.cc.

  : fParticles(0),
    fPyjets(0),
    fPydat1(0),
    fPydat3(0)
{
/// Pythia6 constructor: creates a vector of Pythia6Particle in which it will 
/// store all particles. Note that there may be only one functional Pythia6 
/// object at a time, so it's not use to create more than one instance of it.
  
   // Protect against multiple objects.   All access should be via the
   // Instance member function. 
   if ( fgInstance ) {
      std::cerr << "There's already an instance of Pythia6" << std::endl;
      exit (1);
   }   
  
   fParticles = new ParticleVector();
 
   // Initialize common-blocks 
   fPyjets = (Pyjets_t*) pythia6_common_address("PYJETS");
   fPydat1 = (Pydat1_t*) pythia6_common_address("PYDAT1");
   fPydat3 = (Pydat3_t*) pythia6_common_address("PYDAT3");
 
   // Alternative way to initialize common-blocks
   // usind direct declaration of pythia6 common blocks
   // fPyjets = &pyjets_;
   // fPydat1 = &pydat1_;
   // fPydat3 = &pydat3_;
}

~Pythia6()

Pythia6::~Pythia6 ( )

virtual

Destroy the object, delete and dispose all Pythia6Particles currently on list.

Definition at line 168 of file Pythia6.cc.

{
/// Destroy the object, delete and dispose all Pythia6Particles currently on 
/// list.
 
   if ( fParticles ) {
      ParticleVector::const_iterator it;
      for ( it = fParticles->begin(); it != fParticles->end(); it++ )
        delete  *it;
      delete fParticles;
   }
}

Member Function Documentation

Instance()

Pythia6 * Pythia6::Instance ( )

static

Static access method

Definition at line 124 of file Pythia6.cc.

{
/// Static access method
 
   if ( ! fgInstance ) fgInstance = new Pythia6();
 
   return fgInstance;
}

Pycomp()

int Pythia6::Pycomp

(

int

kf

)

Interface with fortran routine pycomp

Definition at line 183 of file Pythia6.cc.

{
/// Interface with fortran routine pycomp
 
   return pycomp(&kf);
}

Py1ent()

void Pythia6::Py1ent	(	int	line,
		int	kf,
		double	pe,
		double	theta,
		double	phi
	)

Add one entry to the event record, i.e. either a parton or a particle.

IP: normally line number for the parton/particle. There are two exceptions:

If IP = 0: line number 1 is used and PYEXEC is called. If IP < 0: line -IP is used, with status code K(-IP,2)=2 rather than 1; thus a parton system may be built up by filling all but the last parton of the system with IP < 0.
KF: parton/particle flavour code (PDG code) PE: parton/particle energy. If PE is smaller than the mass, the parton/particle is taken to be at rest.
THETA: PHI: polar and azimuthal angle for the momentum vector of the parton/particle.

Definition at line 192 of file Pythia6.cc.

{
/// Add one entry to the event record, i.e. either a parton or a
/// particle. 
///
///  IP:   normally line number for the parton/particle. There are two
///        exceptions:
/// 
///        If IP = 0: line number 1 is used and PYEXEC is called. 
///        If IP < 0: line -IP is used, with status code K(-IP,2)=2
///                   rather than 1; thus a parton system may be built
///                   up by filling all but the last parton of the
///                   system with IP < 0.   
///  KF:   parton/particle flavour code (PDG code)
///  PE:   parton/particle energy. If PE is smaller than the mass,
///        the parton/particle is taken to be at rest.  
///  THETA:
///  PHI:  polar and azimuthal angle for the momentum vector of the
///        parton/particle. 
 
   py1ent(ip, kf, pe, theta, phi);
}

ImportParticles() [1/2]

ParticleVector * Pythia6::ImportParticles

(

)

ImportParticles() [2/2]

int Pythia6::ImportParticles	(	ParticleVector *	particles,
		const char *	option = ""
	)

Default primary creation method. It reads the /HEPEVT/ common block which has been filled by the GenerateEvent method. If the event generator does not use the HEPEVT common block, This routine has to be overloaded by the subclasses. The function loops on the generated particles and store them in the TClonesArray pointed by the argument particles. The default action is to store only the stable particles (ISTHEP = 1) This can be demanded explicitly by setting the option = "Final" If the option = "All", all the particles are stored.

Definition at line 217 of file Pythia6.cc.

{
///  Default primary creation method. It reads the /HEPEVT/ common block which
///  has been filled by the GenerateEvent method. If the event generator does
///  not use the HEPEVT common block, This routine has to be overloaded by
///  the subclasses.
///  The function loops on the generated particles and store them in
///  the TClonesArray pointed by the argument particles.
///  The default action is to store only the stable particles (ISTHEP = 1)
///  This can be demanded explicitly by setting the option = "Final"
///  If the option = "All", all the particles are stored.
 
   if ( particles == 0 ) return 0;
   
   ParticleVector::const_iterator it;
   for ( it = particles->begin(); it != particles->end(); it++ )
     delete  *it;
   particles->clear();
   
   int numpart = fPyjets->N;
   int nparts=0;
   if (!strcmp(option,"") || !strcmp(option,"Final")) {
      for (int i = 0; i<numpart; i++) {
 
        if (fPyjets->K[0][i] == 1) {
          //
          //  Use the common block values for the TParticle constructor
          //
          particles->push_back(
            new Pythia6Particle(
                            fPyjets->K[0][i] ,
                            fPyjets->K[1][i] ,
                            fPyjets->K[2][i] ,
                            fPyjets->K[3][i] ,
                            fPyjets->K[4][i] ,
                            fPyjets->P[0][i] ,
                            fPyjets->P[1][i] ,
                            fPyjets->P[2][i] ,
                            fPyjets->P[3][i] ,
                            fPyjets->P[4][i] ,
                            fPyjets->V[0][i] ,
                            fPyjets->V[1][i] ,
                            fPyjets->V[2][i] ,
                            fPyjets->V[3][i] ,
                            fPyjets->V[4][i]));
 
          //     if(gDebug) printf("%d %d %d! ",i,fPyjets->K[1][i],numpart);
          nparts++;
       }
     }
   } 
   else if (!strcmp(option,"All")) {
      for (int i = 0; i<numpart; i++) {
          particles->push_back(
            new Pythia6Particle(
                            fPyjets->K[0][i] ,
                            fPyjets->K[1][i] ,
                            fPyjets->K[2][i] ,
                            fPyjets->K[3][i] ,
                            fPyjets->K[4][i] ,
                            fPyjets->P[0][i] ,
                            fPyjets->P[1][i] ,
                            fPyjets->P[2][i] ,
                            fPyjets->P[3][i] ,
                            fPyjets->P[4][i] ,
                            fPyjets->V[0][i] ,
                            fPyjets->V[1][i] ,
                            fPyjets->V[2][i] ,
                            fPyjets->V[3][i] ,
                            fPyjets->V[4][i]));
      }
      nparts=numpart;
   }
 
   return nparts;
}

SetMSTJ()

void Pythia6::SetMSTJ ( int  i, int  m  )

inline

Definition at line 181 of file Pythia6.hh.

{ fPydat1->MSTJ[i-1] = m; }

GetMDCY()

int Pythia6::GetMDCY ( int  i, int  j  )

inline

Definition at line 185 of file Pythia6.hh.

{ return fPydat3->MDCY[j-1][i-1]; }

GetKFDP()

int Pythia6::GetKFDP ( int  i, int  j  )

inline

Definition at line 186 of file Pythia6.hh.

{ return fPydat3->KFDP[j-1][i-1]; }

SetMDCY()

void Pythia6::SetMDCY ( int  i, int  j, int  m  )

inline

Definition at line 187 of file Pythia6.hh.

{ fPydat3->MDCY[j-1][i-1] = m; }

SetMDME()

void Pythia6::SetMDME ( int  i, int  j, int  m  )

inline

Definition at line 188 of file Pythia6.hh.

{ fPydat3->MDME[j-1][i-1] = m; }

Member Data Documentation

fgInstance

Pythia6 * Pythia6::fgInstance = 0

staticprivate

Definition at line 191 of file Pythia6.hh.

fParticles

ParticleVector* Pythia6::fParticles

private

Definition at line 193 of file Pythia6.hh.

fPyjets

Pyjets_t* Pythia6::fPyjets

private

Definition at line 194 of file Pythia6.hh.

fPydat1

Pydat1_t* Pythia6::fPydat1

private

Definition at line 195 of file Pythia6.hh.

fPydat3

Pydat3_t* Pythia6::fPydat3

private

Definition at line 196 of file Pythia6.hh.

---

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

• .doxygen/Doxymodules_eventgenerator.h
• extended/eventgenerator/pythia/decayer6/include/Pythia6.hh
• extended/eventgenerator/pythia/decayer6/src/Pythia6.cc