Generate particles isotrop in space around origine (0,0,0) More...

#include <Geant4IsotropeGenerator.h>

Inheritance diagram for dd4hep::sim::Geant4IsotropeGenerator:

Public Member Functions
	Geant4IsotropeGenerator ()=delete
	Inhibit default constructor. More...

	Geant4IsotropeGenerator (const Geant4IsotropeGenerator &copy)=delete
	Inhibit copy constructor. More...

	Geant4IsotropeGenerator (Geant4Context *context, const std::string &name)
	Standard constructor. More...

virtual	~Geant4IsotropeGenerator ()
	Default destructor. More...

Public Member Functions inherited from dd4hep::sim::Geant4ParticleGenerator
	Geant4ParticleGenerator (Geant4Context *context, const std::string &name)
	Standard constructor. More...

virtual	~Geant4ParticleGenerator ()
	Default destructor. More...

virtual void	operator() (G4Event *event) override
	Callback to generate primary particles. More...

Public Member Functions inherited from dd4hep::sim::Geant4GeneratorAction
	Geant4GeneratorAction (Geant4Context *context, const std::string &name)
	Standard constructor. More...

virtual	~Geant4GeneratorAction ()
	Default destructor. More...

Public Member Functions inherited from dd4hep::sim::Geant4Action
	Geant4Action (Geant4Context *context, const std::string &nam)
	Standard constructor. More...

long	addRef ()
	Increase reference count. More...

long	release ()
	Decrease reference count. Implicit destruction. More...

Geant4Context *	context () const
	Access the context. More...

virtual void	updateContext (Geant4Context *ctxt)
	Set or update client context. More...

virtual void	configureFiber (Geant4Context *thread_context)
	Set or update client for the use in a new thread fiber. More...

const std::string &	name () const
	Access name of the action. More...

const char *	c_name () const
	Access name of the action. More...

void	setName (const std::string &new_name)
	Set the object name. More...

PropertyManager &	properties ()
	Access to the properties of the object. More...

PrintLevel	outputLevel () const
	Access the output level. More...

PrintLevel	setOutputLevel (PrintLevel new_level)
	Set the output level; returns previous value. More...

Geant4UIMessenger *	control () const
	Access to the UI messenger. More...

virtual void	enableUI ()
	Enable and install UI messenger. More...

template<typename T >
Geant4Action &	declareProperty (const std::string &nam, T &val)
	Declare property. More...

template<typename T >
Geant4Action &	declareProperty (const char *nam, T &val)
	Declare property. More...

bool	hasProperty (const std::string &name) const
	Check property for existence. More...

Property &	property (const std::string &name)
	Access single property. More...

virtual void	installMessengers ()
	Install property control messenger if wanted. More...

virtual void	installCommandMessenger ()
	Install command control messenger if wanted. More...

virtual void	installPropertyMessenger ()
	Install property control messenger if wanted. More...

void	print (const char *fmt,...) const
	Support for messages with variable output level using output level. More...

void	printM1 (const char *fmt,...) const
	Support for messages with variable output level using output level-1. More...

void	printM2 (const char *fmt,...) const
	Support for messages with variable output level using output level-2. More...

void	printP1 (const char *fmt,...) const
	Support for messages with variable output level using output level+1. More...

void	printP2 (const char *fmt,...) const
	Support for messages with variable output level using output level+2. More...

void	always (const char *fmt,...) const
	Support of always printed messages. More...

void	debug (const char *fmt,...) const
	Support of debug messages. More...

void	info (const char *fmt,...) const
	Support of info messages. More...

void	warning (const char *fmt,...) const
	Support of warning messages. More...

void	error (const char *fmt,...) const
	Support of error messages. More...

bool	return_error (bool return_value, const char *fmt,...) const
	Action to support error messages. More...

void	fatal (const char *fmt,...) const
	Support of fatal messages. Throws exception. More...

void	except (const char *fmt,...) const
	Support of exceptions: Print fatal message and throw runtime_error. More...

void	abortRun (const std::string &exception, const char *fmt,...) const
	Abort Geant4 Run by throwing a G4Exception with type RunMustBeAborted. More...

Geant4RunActionSequence &	runAction () const
	Access to the main run action sequence from the kernel object. More...

Geant4EventActionSequence &	eventAction () const
	Access to the main event action sequence from the kernel object. More...

Geant4SteppingActionSequence &	steppingAction () const
	Access to the main stepping action sequence from the kernel object. More...

Geant4TrackingActionSequence &	trackingAction () const
	Access to the main tracking action sequence from the kernel object. More...

Geant4StackingActionSequence &	stackingAction () const
	Access to the main stacking action sequence from the kernel object. More...

Geant4GeneratorActionSequence &	generatorAction () const
	Access to the main generator action sequence from the kernel object. More...

Protected Member Functions
void	initHalton (Geant4Random &rnd) const
	Initialize Cranley-Patterson shifts using rnd; set m_haltonIndex = m_haltonOffset. More...

double	haltonScrambled (uint64_t index, unsigned int dim) const
	Return the scrambled Halton sample for dimension dim (0=phi,1=theta,2=momentum) More...

std::function< double(unsigned int)>	makeSampler (Geant4Random &rnd) const
	Build a per-particle sampler: PRNG or Halton depending on m_halton. More...

void	sampleMomentum (double h, double &momentum) const
	Sample momentum from [m_momentumMin, m_momentumMax] using a pre-computed [0,1) value h. More...

virtual void	getParticleDirection (int num, ROOT::Math::XYZVector &direction, double &momentum) const override
	Particle modification. Caller presets defaults to: ( direction = m_direction, momentum = [m_momentumMin, m_momentumMax]) More...

void	getParticleDirectionFFbar (int num, ROOT::Math::XYZVector &direction, double &momentum) const
	e+e- --> ffbar particle distribution ~ 1 + cos^2(theta) (PRNG only; incompatible with Halton) More...

void	getParticleDirectionEta (int num, const std::function< double(unsigned int)> &sample, ROOT::Math::XYZVector &direction, double &momentum) const
	Flat pseudorapidity (eta) distribution. More...

void	getParticleDirectionCosTheta (int num, const std::function< double(unsigned int)> &sample, ROOT::Math::XYZVector &direction, double &momentum) const
	Particle distribution ~ cos(theta) More...

void	getParticleDirectionUniform (int num, const std::function< double(unsigned int)> &sample, ROOT::Math::XYZVector &direction, double &momentum) const
	Uniform particle distribution. More...

Protected Member Functions inherited from dd4hep::sim::Geant4ParticleGenerator
virtual void	getParticleMultiplicity (int &multiplicity) const
	Particle modification. Caller presets defaults to: (multiplicity=m_multiplicity) More...

virtual void	getVertexPosition (ROOT::Math::XYZVector &position) const
	Particle's vertex modification. Caller presets defaults to: (multiplicity=m_multiplicity) More...

void	getParticleMomentumUniform (double &momentum) const
	Uniform particle momentum. More...

virtual void	printInteraction (int mask) const
	Print single particle interaction identified by its mask. More...

virtual void	printInteraction (Geant4PrimaryInteraction *inter) const
	Print single particle interaction identified by its reference. More...

Protected Member Functions inherited from dd4hep::sim::Geant4GeneratorAction
	DDG4_DEFINE_ACTION_CONSTRUCTORS (Geant4GeneratorAction)
	Define standard assignments and constructors. More...

Protected Member Functions inherited from dd4hep::sim::Geant4Action
	DDG4_DEFINE_ACTION_CONSTRUCTORS (Geant4Action)
	Define standard assignments and constructors. More...

virtual	~Geant4Action ()
	Default destructor. More...

Static Protected Member Functions
static double	haltonValue (uint64_t index, int base)
	Compute the radical inverse of index in the given base (standard Halton value) More...

Protected Attributes
std::string	m_distribution
	Property: Distribution name. Default: "uniform". Allowed: "uniform", "cos(theta)", "ffbar", "eta". More...

double	m_phiMin
	Property: Minimal phi angular value. More...

double	m_phiMax
	Property: Maximal phi angular value. More...

double	m_thetaMin
	Property: Minimal theta angular value. More...

double	m_thetaMax
	Property: Maximal theta angular value. More...

bool	m_halton
	Property: Enable scrambled Halton sequence sampling (RQMC mode) More...

uint64_t	m_haltonOffset
	Property: Starting index in the Halton sequence (use for parallel-job partitioning) More...

uint64_t	m_haltonIndex
	Current Halton sequence index (incremented per generated particle) More...

std::array< double, 3 >	m_haltonShift
	Per-dimension additive scramble shifts in [0,1), sampled from Geant4Random on first use. More...

std::once_flag	m_haltonOnce
	Ensures initHalton() runs exactly once across all events. More...

Protected Attributes inherited from dd4hep::sim::Geant4ParticleGenerator
ROOT::Math::XYZVector	m_direction
	Property: Shooting direction of the gun. More...

ROOT::Math::XYZVector	m_position
	Property: Position of the gun in space. More...

std::string	m_particleName
	Property: Particle name. More...

G4ParticleDefinition *	m_particle
	Pointer to geant4 particle definition. More...

double	m_energy
	Property: Fixed momentum value, overwrites momentumMin and momentumMax if set. More...

double	m_momentumMin
	Property: Minimal momentum value. More...

double	m_momentumMax
	Property: Maximal momentum value. More...

int	m_multiplicity
	Property: Desired multiplicity of the particles to be shot. More...

int	m_mask
	Property: User mask passed to all particles in the generated interaction. More...

Protected Attributes inherited from dd4hep::sim::Geant4GeneratorAction
Callback	m_calls

Protected Attributes inherited from dd4hep::sim::Geant4Action
Geant4Context *	m_context { nullptr }
	Reference to the Geant4 context. More...

Geant4UIMessenger *	m_control { nullptr }
	Control directory of this action. More...

int	m_outputLevel { 3 }
	Default property: Output level. More...

bool	m_needsControl { false }
	Default property: Flag to create control instance. More...

std::string	m_name { }
	Action name. More...

PropertyManager	m_properties { }
	Property pool. More...

long	m_refCount { 1 }
	Reference count. Initial value: 1. More...

Additional Inherited Members
Public Types inherited from dd4hep::sim::Geant4GeneratorAction
typedef Geant4SharedGeneratorAction	shared_type

Detailed Description

Generate particles isotrop in space around origine (0,0,0)

Supports both standard PRNG-based sampling and Randomized Quasi-Monte Carlo sampling via scrambled Halton sequences (Cranley-Patterson rotation).

When Halton mode is enabled (property "Halton" = true), the three sampling dimensions use low-discrepancy Halton sequences in bases 2 (phi), 3 (theta), and 5 (momentum), each additively scrambled by a per-dimension shift derived from the Geant4Random seed. This provides superior phase-space coverage relative to a PRNG while remaining reproducible and independent across jobs (using different seeds or "HaltonOffset" values).

Note: the "ffbar" distribution is incompatible with Halton mode because its acceptance-rejection loop cannot be driven by a fixed per-particle Halton point.

Author: M.Frank

Version: 1.0

Definition at line 54 of file Geant4IsotropeGenerator.h.

Constructor & Destructor Documentation

◆ Geant4IsotropeGenerator() [1/3]

dd4hep::sim::Geant4IsotropeGenerator::Geant4IsotropeGenerator ( )

delete

Inhibit default constructor.

◆ Geant4IsotropeGenerator() [2/3]

dd4hep::sim::Geant4IsotropeGenerator::Geant4IsotropeGenerator ( const Geant4IsotropeGenerator & copy )

delete

Inhibit copy constructor.

◆ Geant4IsotropeGenerator() [3/3]

Geant4IsotropeGenerator::Geant4IsotropeGenerator	(	Geant4Context *	context,
		const std::string &	name
	)

Standard constructor.

Definition at line 23 of file Geant4IsotropeGenerator.cpp.

◆ ~Geant4IsotropeGenerator()

Geant4IsotropeGenerator::~Geant4IsotropeGenerator ( )

virtual

Default destructor.

Definition at line 39 of file Geant4IsotropeGenerator.cpp.

Member Function Documentation

◆ getParticleDirection()

void Geant4IsotropeGenerator::getParticleDirection	(	int	num,
		ROOT::Math::XYZVector &	direction,
		double &	momentum
	)		const

overrideprotectedvirtual

Particle modification. Caller presets defaults to: ( direction = m_direction, momentum = [m_momentumMin, m_momentumMax])

Particle modification. Caller presets defaults to: ( direction = m_direction, momentum = [mMin, mMax])

Use this function to implement isotrop guns, multiple guns etc. User must return a UNIT vector, which gets scaled with momentum.

Reimplemented from dd4hep::sim::Geant4ParticleGenerator.

Reimplemented in dd4hep::sim::Geant4ParticleGun.

Definition at line 156 of file Geant4IsotropeGenerator.cpp.

◆ getParticleDirectionCosTheta()

void Geant4IsotropeGenerator::getParticleDirectionCosTheta	(	int	num,
		const std::function< double(unsigned int)> &	sample,
		ROOT::Math::XYZVector &	direction,
		double &	momentum
	)		const

protected

Particle distribution ~ cos(theta)

Definition at line 102 of file Geant4IsotropeGenerator.cpp.

◆ getParticleDirectionEta()

void Geant4IsotropeGenerator::getParticleDirectionEta	(	int	num,
		const std::function< double(unsigned int)> &	sample,
		ROOT::Math::XYZVector &	direction,
		double &	momentum
	)		const

protected

Flat pseudorapidity (eta) distribution.

Particle distribution flat in eta (pseudo rapidity)

Definition at line 112 of file Geant4IsotropeGenerator.cpp.

◆ getParticleDirectionFFbar()

void Geant4IsotropeGenerator::getParticleDirectionFFbar	(	int	num,
		ROOT::Math::XYZVector &	direction,
		double &	momentum
	)		const

protected

e+e- --> ffbar particle distribution ~ 1 + cos^2(theta) (PRNG only; incompatible with Halton)

Definition at line 131 of file Geant4IsotropeGenerator.cpp.

◆ getParticleDirectionUniform()

void Geant4IsotropeGenerator::getParticleDirectionUniform	(	int	num,
		const std::function< double(unsigned int)> &	sample,
		ROOT::Math::XYZVector &	direction,
		double &	momentum
	)		const

protected

Uniform particle distribution.

Definition at line 93 of file Geant4IsotropeGenerator.cpp.

◆ haltonScrambled()

double Geant4IsotropeGenerator::haltonScrambled	(	uint64_t	index,
		unsigned int	dim
	)		const

protected

Return the scrambled Halton sample for dimension dim (0=phi,1=theta,2=momentum)

Cranley-Patterson scrambled Halton sample for dimension dim (0=phi, 1=theta, 2=momentum)

Definition at line 62 of file Geant4IsotropeGenerator.cpp.

◆ haltonValue()

double Geant4IsotropeGenerator::haltonValue	(	uint64_t	index,
		int	base
	)

staticprotected

Compute the radical inverse of index in the given base (standard Halton value)

Compute the radical inverse of index in the given base (Halton value in [0,1))

Definition at line 50 of file Geant4IsotropeGenerator.cpp.

◆ initHalton()

void Geant4IsotropeGenerator::initHalton ( Geant4Random & rnd ) const

protected

Initialize Cranley-Patterson shifts using rnd; set m_haltonIndex = m_haltonOffset.

Initialize Cranley-Patterson shifts using rnd; set m_haltonIndex = m_haltonOffset.

Definition at line 44 of file Geant4IsotropeGenerator.cpp.

◆ makeSampler()

std::function< double(unsigned int)> Geant4IsotropeGenerator::makeSampler ( Geant4Random & rnd ) const

protected

Build a per-particle sampler: PRNG or Halton depending on m_halton.

Build and return a per-particle sampler: either PRNG or Halton, depending on m_halton. For Halton mode, advances m_haltonIndex by one.

Definition at line 71 of file Geant4IsotropeGenerator.cpp.

◆ sampleMomentum()

void Geant4IsotropeGenerator::sampleMomentum	(	double	h,
		double &	momentum
	)		const

protected

Sample momentum from [m_momentumMin, m_momentumMax] using a pre-computed [0,1) value h.

Definition at line 81 of file Geant4IsotropeGenerator.cpp.

Member Data Documentation

◆ m_distribution

std::string dd4hep::sim::Geant4IsotropeGenerator::m_distribution

protected

Property: Distribution name. Default: "uniform". Allowed: "uniform", "cos(theta)", "ffbar", "eta".

Definition at line 57 of file Geant4IsotropeGenerator.h.

◆ m_halton

bool dd4hep::sim::Geant4IsotropeGenerator::m_halton

protected

Property: Enable scrambled Halton sequence sampling (RQMC mode)

Definition at line 67 of file Geant4IsotropeGenerator.h.

◆ m_haltonIndex

uint64_t dd4hep::sim::Geant4IsotropeGenerator::m_haltonIndex

mutableprotected

Current Halton sequence index (incremented per generated particle)

Definition at line 71 of file Geant4IsotropeGenerator.h.

◆ m_haltonOffset

uint64_t dd4hep::sim::Geant4IsotropeGenerator::m_haltonOffset

protected

Property: Starting index in the Halton sequence (use for parallel-job partitioning)

Definition at line 69 of file Geant4IsotropeGenerator.h.

◆ m_haltonOnce

std::once_flag dd4hep::sim::Geant4IsotropeGenerator::m_haltonOnce

mutableprotected

Ensures initHalton() runs exactly once across all events.

Definition at line 75 of file Geant4IsotropeGenerator.h.

◆ m_haltonShift

std::array<double,3> dd4hep::sim::Geant4IsotropeGenerator::m_haltonShift

mutableprotected

Per-dimension additive scramble shifts in [0,1), sampled from Geant4Random on first use.

Definition at line 73 of file Geant4IsotropeGenerator.h.

◆ m_phiMax

double dd4hep::sim::Geant4IsotropeGenerator::m_phiMax

protected

Property: Maximal phi angular value.

Definition at line 61 of file Geant4IsotropeGenerator.h.

◆ m_phiMin

double dd4hep::sim::Geant4IsotropeGenerator::m_phiMin

protected

Property: Minimal phi angular value.

Definition at line 59 of file Geant4IsotropeGenerator.h.

◆ m_thetaMax

double dd4hep::sim::Geant4IsotropeGenerator::m_thetaMax

protected

Property: Maximal theta angular value.

Definition at line 65 of file Geant4IsotropeGenerator.h.

◆ m_thetaMin

double dd4hep::sim::Geant4IsotropeGenerator::m_thetaMin

protected

Property: Minimal theta angular value.

Definition at line 63 of file Geant4IsotropeGenerator.h.

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

DDG4/include/DDG4/Geant4IsotropeGenerator.h
DDG4/src/Geant4IsotropeGenerator.cpp

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Geant4IsotropeGenerator() [1/3]

◆ Geant4IsotropeGenerator() [2/3]

◆ Geant4IsotropeGenerator() [3/3]

◆ ~Geant4IsotropeGenerator()

Member Function Documentation

◆ getParticleDirection()

◆ getParticleDirectionCosTheta()

◆ getParticleDirectionEta()

◆ getParticleDirectionFFbar()

◆ getParticleDirectionUniform()

◆ haltonScrambled()

◆ haltonValue()

◆ initHalton()

◆ makeSampler()

◆ sampleMomentum()

Member Data Documentation

◆ m_distribution

◆ m_halton

◆ m_haltonIndex

◆ m_haltonOffset

◆ m_haltonOnce

◆ m_haltonShift

◆ m_phiMax

◆ m_phiMin

◆ m_thetaMax

◆ m_thetaMin