The GenEvent class is the core of HepMC. More...

#include <GenEvent.h>

Classes
class	particle_const_iterator
	const particle iterator More...

class	particle_iterator
	non-const particle iterator More...

class	vertex_const_iterator
	const vertex iterator More...

class	vertex_iterator
	non-const vertex iterator More...

Public Member Functions
	GenEvent (int signal_process_id=0, int event_number=0, GenVertex *signal_vertex=0, const WeightContainer &weights=std::vector< double >(), const std::vector< long > &randomstates=std::vector< long >(), Units::MomentumUnit=Units::default_momentum_unit(), Units::LengthUnit=Units::default_length_unit())
	default constructor creates null pointers to HeavyIon, PdfInfo, and GenCrossSection More...

	GenEvent (int signal_process_id, int event_number, GenVertex *signal_vertex, const WeightContainer &weights, const std::vector< long > &randomstates, const HeavyIon &ion, const PdfInfo &pdf, Units::MomentumUnit=Units::default_momentum_unit(), Units::LengthUnit=Units::default_length_unit())
	explicit constructor that takes HeavyIon and PdfInfo More...

	GenEvent (Units::MomentumUnit, Units::LengthUnit, int signal_process_id=0, int event_number=0, GenVertex *signal_vertex=0, const WeightContainer &weights=std::vector< double >(), const std::vector< long > &randomstates=std::vector< long >())
	constructor requiring units - all else is default More...

	GenEvent (Units::MomentumUnit, Units::LengthUnit, int signal_process_id, int event_number, GenVertex *signal_vertex, const WeightContainer &weights, const std::vector< long > &randomstates, const HeavyIon &ion, const PdfInfo &pdf)
	explicit constructor with units first that takes HeavyIon and PdfInfo More...

	GenEvent (const GenEvent &inevent)
	deep copy More...

GenEvent &	operator= (const GenEvent &inevent)
	make a deep copy More...

virtual	~GenEvent ()
	deletes all vertices/particles in this evt More...

void	swap (GenEvent &other)
	swap

void	print (std::ostream &ostr=std::cout) const
	dumps to ostr More...

void	print_version (std::ostream &ostr=std::cout) const
	dumps release version to ostr

GenParticle *	barcode_to_particle (int barCode) const
	assign a barcode to a particle More...

GenVertex *	barcode_to_vertex (int barCode) const
	assign a barcode to a vertex More...

int	signal_process_id () const
	unique signal process id More...

int	event_number () const
	event number

int	mpi () const
	number of multi parton interactions More...

double	event_scale () const
	energy scale, see hep-ph/0109068

double	alphaQCD () const
	QCD coupling, see hep-ph/0109068.

double	alphaQED () const

GenVertex *	signal_process_vertex () const
	pointer to the vertex containing the signal process More...

bool	valid_beam_particles () const
	test to see if we have two valid beam particles

std::pair< HepMC::GenParticle , HepMC::GenParticle >	beam_particles () const
	pair of pointers to the two incoming beam particles

bool	is_valid () const

WeightContainer &	weights ()
	direct access to WeightContainer More...

const WeightContainer &	weights () const
	direct access to WeightContainer

GenCrossSection const *	cross_section () const
	access the GenCrossSection container if it exists

GenCrossSection *	cross_section ()

HeavyIon const *	heavy_ion () const
	access the HeavyIon container if it exists

HeavyIon *	heavy_ion ()

PdfInfo const *	pdf_info () const
	access the PdfInfo container if it exists

PdfInfo *	pdf_info ()

const std::vector< long > &	random_states () const
	vector of integers containing information about the random state More...

int	particles_size () const
	how many particle barcodes exist?

bool	particles_empty () const
	return true if there are no particle barcodes

int	vertices_size () const
	how many vertex barcodes exist?

bool	vertices_empty () const
	return true if there are no vertex barcodes

void	write_units (std::ostream &os=std::cout) const

void	write_cross_section (std::ostream &ostr=std::cout) const

Units::MomentumUnit	momentum_unit () const
	Units used by the GenParticle momentum FourVector.

Units::LengthUnit	length_unit () const
	Units used by the GenVertex position FourVector.

std::ostream &	write (std::ostream &)

std::istream &	read (std::istream &)

bool	add_vertex (GenVertex *vtx)
	adds to evt and adopts More...

bool	remove_vertex (GenVertex *vtx)
	erases vtx from evt More...

void	clear ()
	empties the entire event More...

void	set_signal_process_id (int id)
	set unique signal process id

void	set_event_number (int eventno)
	set event number

void	set_mpi (int)
	set number of multi parton interactions More...

void	set_event_scale (double scale)
	set energy scale

void	set_alphaQCD (double a)
	set QCD coupling

void	set_alphaQED (double a)
	set QED coupling

void	set_signal_process_vertex (GenVertex *)
	set pointer to the vertex containing the signal process

bool	set_beam_particles (GenParticle , GenParticle )
	set incoming beam particles More...

bool	set_beam_particles (std::pair< HepMC::GenParticle , HepMC::GenParticle > const &)
	use a pair of GenParticle*'s to set incoming beam particles More...

void	set_random_states (const std::vector< long > &randomstates)
	provide random state information

void	set_cross_section (const GenCrossSection &)
	provide a pointer to the GenCrossSection container

void	set_heavy_ion (const HeavyIon &ion)
	provide a pointer to the HeavyIon container

void	set_pdf_info (const PdfInfo &p)
	provide a pointer to the PdfInfo container

void	use_units (Units::MomentumUnit, Units::LengthUnit)

void	use_units (std::string &, std::string &)

void	define_units (Units::MomentumUnit, Units::LengthUnit)

void	define_units (std::string &, std::string &)

GenEventVertexRange	vertex_range ()
	vertex range

ConstGenEventVertexRange	vertex_range () const
	vertex range

GenEventParticleRange	particle_range ()
	particle range

ConstGenEventParticleRange	particle_range () const
	particle range

vertex_const_iterator	vertices_begin () const
	begin vertex iteration

vertex_const_iterator	vertices_end () const
	end vertex iteration

vertex_iterator	vertices_begin ()
	begin vertex iteration

vertex_iterator	vertices_end ()
	end vertex iteration

particle_const_iterator	particles_begin () const
	begin particle iteration

particle_const_iterator	particles_end () const
	end particle iteration

particle_iterator	particles_begin ()
	begin particle iteration

particle_iterator	particles_end ()
	end particle iteration

Protected Member Functions
bool	set_barcode (GenParticle *p, int suggested_barcode=false)
	set the barcode - intended for use by GenParticle

bool	set_barcode (GenVertex *v, int suggested_barcode=false)
	set the barcode - intended for use by GenVertex

void	remove_barcode (GenParticle *p)
	intended for use by GenParticle

void	remove_barcode (GenVertex *v)
	intended for use by GenVertex

void	delete_all_vertices ()
	delete all vertices owned by this event More...

Friends
class	GenParticle

class	GenVertex

class	vertex_const_iterator

class	vertex_iterator

class	particle_const_iterator

class	particle_iterator

Detailed Description

The GenEvent class is the core of HepMC.

HepMC::GenEvent contains information about generated particles. GenEvent is structured as a set of vertices which contain the particles.

Definition at line 155 of file GenEvent.h.

Constructor & Destructor Documentation

HepMC::GenEvent::GenEvent	(	int	signal_process_id = `0`,
		int	event_number = `0`,
		GenVertex *	signal_vertex = `0`,
		const WeightContainer &	weights = `std::vector<double>()`,
		const std::vector< long > &	randomstates = `std::vector<long>()`,
		Units::MomentumUnit	mom = `Units::default_momentum_unit()`,
		Units::LengthUnit	len = `Units::default_length_unit()`
	)

default constructor creates null pointers to HeavyIon, PdfInfo, and GenCrossSection

This constructor only allows null pointers to HeavyIon and PdfInfo

note: default values for m_event_scale, m_alphaQCD, m_alphaQED are as suggested in hep-ph/0109068, "Generic Interface..."

Definition at line 22 of file GenEvent.cc.

HepMC::GenEvent::GenEvent	(	int	signal_process_id,
		int	event_number,
		GenVertex *	signal_vertex,
		const WeightContainer &	weights,
		const std::vector< long > &	randomstates,
		const HeavyIon &	ion,
		const PdfInfo &	pdf,
		Units::MomentumUnit	mom = `Units::default_momentum_unit()`,
		Units::LengthUnit	len = `Units::default_length_unit()`
	)

explicit constructor that takes HeavyIon and PdfInfo

GenEvent makes its own copy of HeavyIon and PdfInfo

note: default values for m_event_scale, m_alphaQCD, m_alphaQED are as suggested in hep-ph/0109068, "Generic Interface..."

Definition at line 55 of file GenEvent.cc.

HepMC::GenEvent::GenEvent	(	Units::MomentumUnit	mom,
		Units::LengthUnit	len,
		int	signal_process_id = `0`,
		int	event_number = `0`,
		GenVertex *	signal_vertex = `0`,
		const WeightContainer &	weights = `std::vector<double>()`,
		const std::vector< long > &	randomstates = `std::vector<long>()`
	)

constructor requiring units - all else is default

constructor requiring units - all else is default This constructor only allows null pointers to HeavyIon and PdfInfo

note: default values for m_event_scale, m_alphaQCD, m_alphaQED are as suggested in hep-ph/0109068, "Generic Interface..."

Definition at line 88 of file GenEvent.cc.

HepMC::GenEvent::GenEvent	(	Units::MomentumUnit	mom,
		Units::LengthUnit	len,
		int	signal_process_id,
		int	event_number,
		GenVertex *	signal_vertex,
		const WeightContainer &	weights,
		const std::vector< long > &	randomstates,
		const HeavyIon &	ion,
		const PdfInfo &	pdf
	)

explicit constructor with units first that takes HeavyIon and PdfInfo

explicit constructor with units first that takes HeavyIon and PdfInfo GenEvent makes its own copy of HeavyIon and PdfInfo

note: default values for m_event_scale, m_alphaQCD, m_alphaQED are as suggested in hep-ph/0109068, "Generic Interface..."

Definition at line 122 of file GenEvent.cc.

HepMC::GenEvent::GenEvent ( const GenEvent & inevent )

deep copy

deep copy - makes a copy of all vertices!

Definition at line 156 of file GenEvent.cc.

References add_vertex(), beam_particles(), HepMC::GenParticle::end_vertex(), particles_begin(), particles_end(), HepMC::GenParticle::production_vertex(), random_states(), set_beam_particles(), set_random_states(), set_signal_process_vertex(), signal_process_vertex(), HepMC::GenVertex::suggest_barcode(), vertices_begin(), vertices_end(), and weights().

HepMC::GenEvent::~GenEvent ( )

virtual

deletes all vertices/particles in this evt

Deep destructor. deletes all vertices/particles in this GenEvent deletes the associated HeavyIon and PdfInfo

Definition at line 258 of file GenEvent.cc.

References delete_all_vertices().

Member Function Documentation

bool HepMC::GenEvent::add_vertex ( GenVertex * vtx )

adds to evt and adopts

returns true if successful - generally will only return false if the inserted vertex is already included in the event.

Definition at line 334 of file GenEvent.cc.

References HepMC::GenVertex::barcode(), HepMC::GenVertex::parent_event(), remove_vertex(), and HepMC::GenVertex::set_parent_event_().

Referenced by HepMC::IO_HEPEVT::build_end_vertex(), HepMC::IO_HERWIG::build_end_vertex(), HepMC::IO_HEPEVT::build_production_vertex(), HepMC::IO_HERWIG::build_production_vertex(), Photospp::PhotosHepMCParticle::createSelfDecayVertex(), HepMC::IO_HEPEVT::fill_next_event(), HepMC::IO_HERWIG::fill_next_event(), GenEvent(), read(), set_signal_process_vertex(), Photospp::PhotosHepMCParticle::setDaughters(), Tauolapp::TauolaHepMCParticle::setDaughters(), Photospp::PhotosHepMCParticle::setMothers(), and Tauolapp::TauolaHepMCParticle::setMothers().

double HepMC::GenEvent::alphaQED ( ) const

inline

QED coupling, see hep-ph/0109068

Definition at line 692 of file GenEvent.h.

Referenced by print(), write(), and HepMC::IO_AsciiParticles::write_event().

GenParticle * HepMC::GenEvent::barcode_to_particle ( int barCode ) const

inline

assign a barcode to a particle

Each vertex or particle has a barcode, which is just an integer which uniquely identifies it inside the event (i.e. there is a one to one mapping between particle memory addresses and particle barcodes... and the same applied for vertices).

The value of a barcode has NO MEANING and NO ORDER! For the user's convenience, when an event is read in via an IO_method from an indexed list (like the HEPEVT common block), then the index will become the barcode for that particle.

Particle barcodes are always positive integers. The barcodes are chosen and set automatically when a vertex or particle comes under the ownership of an event (i.e. it is contained in an event).

Please note that the barcodes are intended for internal use within HepMC as a unique identifier for the particles and vertices. Using the barcode to encode extra information is an abuse of the barcode data member and causes confusion among users.

Definition at line 798 of file GenEvent.h.

Referenced by StarEvtGenDecayer::ImportParticles().

GenVertex * HepMC::GenEvent::barcode_to_vertex ( int barCode ) const

inline

assign a barcode to a vertex

Each vertex or particle has a barcode, which is just an integer which uniquely identifies it inside the event (i.e. there is a one to one mapping between particle memory addresses and particle barcodes... and the same applied for vertices).

The value of a barcode has NO MEANING and NO ORDER! For the user's convenience, when an event is read in via an IO_method from an indexed list (like the HEPEVT common block), then the index will become the barcode for that particle.

Vertex barcodes are always negative integers. The barcodes are chosen and set automatically when a vertex or particle comes under the ownership of an event (i.e. it is contained in an event).

Please note that the barcodes are intended for internal use within HepMC as a unique identifier for the particles and vertices. Using the barcode to encode extra information is an abuse of the barcode data member and causes confusion among users.

Definition at line 823 of file GenEvent.h.

Referenced by read().

void HepMC::GenEvent::clear ( void )

empties the entire event

remove all information from the event deletes all vertices/particles in this evt

Definition at line 365 of file GenEvent.cc.

References delete_all_vertices().

Referenced by HepMC::IO_GenEvent::fill_next_event(), and read().

void HepMC::GenEvent::define_units	(	Units::MomentumUnit	new_m,
		Units::LengthUnit	new_l
	)

inline

set the units using enums This method will NOT convert momentum and position data

Definition at line 866 of file GenEvent.h.

void HepMC::GenEvent::define_units	(	std::string &	new_m,
		std::string &	new_l
	)

set the units using strings the string must match the enum exactly This method will NOT convert momentum and position data

Definition at line 665 of file GenEvent.cc.

void HepMC::GenEvent::delete_all_vertices ( )

protected

delete all vertices owned by this event

deletes all vertices in the vertex container (i.e. all vertices owned by this event) The vertices are the "owners" of the particles, so as we delete the vertices, the vertex desctructors are automatically deleting their particles.

Definition at line 403 of file GenEvent.cc.

References particles_empty(), and vertices_empty().

Referenced by clear(), and ~GenEvent().

bool HepMC::GenEvent::is_valid ( ) const

check GenEvent for validity A GenEvent is presumed valid if it has particles and/or vertices.

A GenEvent is presumed valid if it has both associated particles and vertices. No other information is checked.

Definition at line 677 of file GenEvent.cc.

References particles_empty(), and vertices_empty().

Referenced by HepMC::IO_GenEvent::fill_next_event().

int HepMC::GenEvent::mpi ( ) const

inline

number of multi parton interactions

Returns the number of multi parton interactions in the event. This number is -1 if it is not set.

Definition at line 686 of file GenEvent.h.

Referenced by write().

GenEvent & HepMC::GenEvent::operator= ( const GenEvent & inevent )

make a deep copy

best practices implementation

Definition at line 269 of file GenEvent.cc.

References swap().

void HepMC::GenEvent::print ( std::ostream & ostr = std::cout ) const

dumps to ostr

dumps the content of this event to ostr to dump to cout use: event.print(); if you want to write this event to file outfile.txt you could use: std::ofstream outfile("outfile.txt"); event.print( outfile );

Definition at line 277 of file GenEvent.cc.

References alphaQCD(), alphaQED(), HepMC::GenVertex::barcode(), beam_particles(), event_number(), event_scale(), particles_size(), HepMC::WeightContainer::print(), signal_process_id(), signal_process_vertex(), HepMC::WeightContainer::size(), vertices_begin(), vertices_end(), vertices_size(), weights(), write_cross_section(), and write_units().

Referenced by StarEvtGenDecayer::ImportParticles(), and Photospp::PhotosHepMCEvent::print().

const std::vector< long > & HepMC::GenEvent::random_states ( ) const

inline

vector of integers containing information about the random state

Vector of integers which specify the random number generator's state for this event. It is left to the generator to make use of this. We envision a vector of RndmStatesTags to be included with a run class which would specify the meaning of the random_states.

Definition at line 727 of file GenEvent.h.

Referenced by GenEvent(), and HepMC::IO_AsciiParticles::write_event().

std::istream & HepMC::GenEvent::read ( std::istream & is )

read a GenEvent from streaming input

Definition at line 155 of file GenEventStreamIO.cc.

Referenced by HepMC::operator>>().

bool HepMC::GenEvent::remove_vertex ( GenVertex * vtx )

erases vtx from evt

this removes vtx from the event but does NOT delete it. returns True if an entry vtx existed in the table and was erased

Definition at line 357 of file GenEvent.cc.

References HepMC::GenVertex::barcode(), HepMC::GenVertex::parent_event(), and HepMC::GenVertex::set_parent_event_().

Referenced by add_vertex().

bool HepMC::GenEvent::set_beam_particles	(	GenParticle *	bp1,
		GenParticle *	bp2
	)

set incoming beam particles

construct the beam particle information using pointers to GenParticle returns false if either GenParticle* is null

Definition at line 586 of file GenEvent.cc.

Referenced by HepMC::IO_HEPEVT::fill_next_event(), HepMC::IO_HERWIG::fill_next_event(), GenEvent(), read(), and set_beam_particles().

bool HepMC::GenEvent::set_beam_particles ( std::pair< HepMC::GenParticle *, HepMC::GenParticle * > const & bp )

use a pair of GenParticle*'s to set incoming beam particles

construct the beam particle information using a std::pair of pointers to GenParticle returns false if either GenParticle* is null

Definition at line 595 of file GenEvent.cc.

References set_beam_particles().

void HepMC::GenEvent::set_mpi ( int nmpi )

inline

set number of multi parton interactions

Use this to set the number of multi parton interactions in each event.

Definition at line 737 of file GenEvent.h.

int HepMC::GenEvent::signal_process_id ( ) const

inline

unique signal process id

The integer ID that uniquely specifies this signal process, i.e. MSUB in Pythia. It is necessary to package this with each event rather than with the run because many processes may be generated within one run.

Definition at line 679 of file GenEvent.h.

Referenced by print(), write(), and HepMC::IO_AsciiParticles::write_event().

GenVertex * HepMC::GenEvent::signal_process_vertex ( ) const

inline

pointer to the vertex containing the signal process

returns a (mutable) pointer to the signal process vertex

Definition at line 694 of file GenEvent.h.

Referenced by GenEvent(), print(), read(), write(), and HepMC::IO_AsciiParticles::write_event().

void HepMC::GenEvent::use_units	(	Units::MomentumUnit	new_m,
		Units::LengthUnit	new_l
	)

inline

set the units using enums This method will convert momentum and position data if necessary

Definition at line 856 of file GenEvent.h.

Referenced by read(), and Tauolapp::TauolaHepMCEvent::TauolaHepMCEvent().

void HepMC::GenEvent::use_units	(	std::string &	new_m,
		std::string &	new_l
	)

inline

set the units using strings the string must match the enum exactly This method will convert momentum and position data if necessary

Definition at line 861 of file GenEvent.h.

WeightContainer & HepMC::GenEvent::weights ( )

inline

direct access to WeightContainer

direct access to the weights container is allowed. Thus you can use myevt.weights()[2]; to access element 2 of the weights. or use myevt.weights().push_back( mywgt ); to add an element. and you can set the weights with myevt.weights() = myvector;

Definition at line 699 of file GenEvent.h.

Referenced by GenEvent(), print(), write(), and HepMC::IO_AsciiParticles::write_event().

std::ostream & HepMC::GenEvent::write ( std::ostream & os )

Writes evt to an output stream.

Definition at line 72 of file GenEventStreamIO.cc.

References alphaQCD(), alphaQED(), beam_particles(), event_number(), event_scale(), HepMC::StreamInfo::finished_first_event(), HepMC::get_stream_info(), heavy_ion(), length_unit(), momentum_unit(), mpi(), pdf_info(), HepMC::StreamInfo::set_finished_first_event(), signal_process_id(), signal_process_vertex(), HepMC::WeightContainer::size(), vertices_begin(), vertices_end(), vertices_size(), weights(), and HepMC::GenCrossSection::write().