recob::PFParticle Class Reference

Hierarchical representation of particle flow. More...

#include <PFParticle.h>

Public Member Functions
	PFParticle ()
	Default constructor necessary for gccxml - not really for public use. More...
	PFParticle (int pdgCode, size_t self, size_t parent, const std::vector< size_t > &daughters)
	Primary constructor. More...
	PFParticle (int pdgCode, size_t self, size_t parent, std::vector< size_t > &&daughters)
	~PFParticle ()=default
	Destructor definition. More...
	PFParticle (const PFParticle &other)=default
	Copy constructor (using defaults) More...
	PFParticle (PFParticle &&other)=default
PFParticle &	operator= (const PFParticle &other)=default
	Copy assignment operator (using defaults) More...
PFParticle &	operator= (PFParticle &&other)=default
Accessors
int	PdgCode () const
	Return the type of particle as a PDG ID. More...
bool	IsPrimary () const
	Returns whether the particle is the root of the flow. More...
int	NumDaughters () const
	Returns the number of daughter particles flowing from this one. More...
size_t	Self () const
	Returns the index of this particle. More...
size_t	Parent () const
size_t	Daughter (size_t idx) const
	Returns the ID of the specified daughter. More...
const std::vector< size_t > &	Daughters () const
	Returns the collection of daughter particles. More...

Static Public Attributes
static constexpr size_t	kPFParticlePrimary = std::numeric_limits<size_t>::max()
	Define index to signify primary particle. More...

Private Attributes
int	fPdgCode
	A preliminary estimate of the PFParticle type using the PDG code. More...
size_t	fSelf
	Self reference. More...
size_t	fParent
	Index into PFParticle collection for parent. More...
std::vector< size_t >	fDaughters
	Vector of indices into PFParticle Collection for daughters. More...

Friends
std::ostream &	operator<< (std::ostream &o, const PFParticle &c)
bool	operator< (const PFParticle &a, const PFParticle &b)

Detailed Description

Hierarchical representation of particle flow.

The "Particle Flow" Particle is an object connecting to others of the same type to define a hierarchy of a single parent generating multiple daughter particles.

This structure was originally proposed to accommodate the information produced by Pandora. The PFParticle is a small entity that is expected to be associated with recob::Track, recob::Cluster, recob::Hit, recob::Vertex and also recob::Seed to describe all the reconstructed quantities related to it.

The parentage relationships are expressed by indices in the collection all the particles belong to. This requires additional care when creating that collection, since each relation is defined in the particles with indices pointing to a collection that does not yet exist when the particle is created. The relation is expressed as one parent and many daughters. For "primary" particles, which have no parent, the special parent value recob::PFParticle::kPFParticlePrimary must be used.

Note that the parentage relation can not be expressed as simple art associations, which can't express relations between two objects of the same type.

Definition at line 44 of file PFParticle.h.

Constructor & Destructor Documentation

recob::PFParticle::PFParticle

(

)

Default constructor necessary for gccxml - not really for public use.

Definition at line 17 of file PFParticle.cxx.

                           :
        fPdgCode(0), fSelf(0), fParent(PFParticle::kPFParticlePrimary)
    {}

recob::PFParticle::PFParticle	(	int	pdgCode,
		size_t	self,
		size_t	parent,
		const std::vector< size_t > &	daughters
	)

Primary constructor.

Definition at line 21 of file PFParticle.cxx.

                                                                                                      :
        fPdgCode(pdgCode),
        fSelf(self),
        fParent(parent),
        fDaughters(daughters)
    {}

recob::PFParticle::PFParticle	(	int	pdgCode,
		size_t	self,
		size_t	parent,
		std::vector< size_t > &&	daughters
	)

Definition at line 28 of file PFParticle.cxx.

                                                                                                 :
        fPdgCode(pdgCode),
        fSelf(self),
        fParent(parent),
        fDaughters(std::move(daughters))
    {}

recob::PFParticle::~PFParticle ( )

default

Destructor definition.

recob::PFParticle::PFParticle ( const PFParticle &  other )

default

Copy constructor (using defaults)

recob::PFParticle::PFParticle ( PFParticle &&  other )

default

Member Function Documentation

size_t recob::PFParticle::Daughter ( size_t  idx ) const

inline

Returns the ID of the specified daughter.

Parameters

idx	index of the daughter to be queried (0 to NumDaughters()-1)

Returns

the ID of the specified daughter

Exceptions

std::out_of_range

if the requested daughter does not exist

The returned value describes the ID of the idx-th daughter of this PFParticle. Note that this is not the same as the index of that PFParticle in the data product or PFParticle collection.

This function checks the validity of the index (idx). For unchecked access, use Daughters()[idx] instead.

Definition at line 111 of file PFParticle.h.

{return Daughters().at(idx);}

const std::vector<size_t>& recob::PFParticle::Daughters ( ) const

inline

Returns the collection of daughter particles.

Definition at line 114 of file PFParticle.h.

{return fDaughters;}

bool recob::PFParticle::IsPrimary ( ) const

inline

Returns whether the particle is the root of the flow.

Definition at line 86 of file PFParticle.h.

{return fParent == PFParticle::kPFParticlePrimary;}

int recob::PFParticle::NumDaughters ( ) const

inline

Returns the number of daughter particles flowing from this one.

Definition at line 89 of file PFParticle.h.

{return fDaughters.size();}

PFParticle& recob::PFParticle::operator= ( const PFParticle &  other )

default

Copy assignment operator (using defaults)

PFParticle& recob::PFParticle::operator= ( PFParticle &&  other )

default

size_t recob::PFParticle::Parent ( ) const

inline

Returns the index of the parent particle (PFParticle::kPFParticlePrimary if primary).

Definition at line 96 of file PFParticle.h.

{return fParent;}

int recob::PFParticle::PdgCode ( void  ) const

inline

Return the type of particle as a PDG ID.

Definition at line 83 of file PFParticle.h.

{return fPdgCode;}

size_t recob::PFParticle::Self ( ) const

inline

Returns the index of this particle.

Definition at line 92 of file PFParticle.h.

{return fSelf;}

Friends And Related Function Documentation

bool operator< ( const PFParticle &  a, const PFParticle &  b  )

friend

Definition at line 50 of file PFParticle.cxx.

  {
    return a.Self() < b.Self();
  }

std::ostream& operator<< ( std::ostream &  o, const PFParticle &  c  )

friend

Definition at line 38 of file PFParticle.cxx.

  {
    o << std::setiosflags(std::ios::fixed)  << std::setprecision(2);
    o << "PFParticle hypothesis PDG Code "    << std::setw(8)  << std::right       << c.PdgCode()
      << ", is primary = " << c.IsPrimary()
      << ", # Daughters "  << std::setw(5)  << std::right    << c.NumDaughters() << std::endl;

    return o;
  }

Member Data Documentation

std::vector<size_t> recob::PFParticle::fDaughters

private

Vector of indices into PFParticle Collection for daughters.

Definition at line 55 of file PFParticle.h.

size_t recob::PFParticle::fParent

private

Index into PFParticle collection for parent.

Definition at line 54 of file PFParticle.h.

int recob::PFParticle::fPdgCode

private

A preliminary estimate of the PFParticle type using the PDG code.

Definition at line 52 of file PFParticle.h.

size_t recob::PFParticle::fSelf

private

Self reference.

Definition at line 53 of file PFParticle.h.

constexpr size_t recob::PFParticle::kPFParticlePrimary = std::numeric_limits<size_t>::max()

static

Define index to signify primary particle.

Definition at line 61 of file PFParticle.h.

---

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

• lardataobj/lardataobj/RecoBase/PFParticle.h
• lardataobj/lardataobj/RecoBase/PFParticle.cxx