DerivationFramework::TruthNavigationDecorator Class Reference

#include <TruthNavigationDecorator.h>

Inheritance diagram for DerivationFramework::TruthNavigationDecorator:

Collaboration diagram for DerivationFramework::TruthNavigationDecorator:

Public Member Functions
	TruthNavigationDecorator (const std::string &t, const std::string &n, const IInterface *p)
	~TruthNavigationDecorator ()
StatusCode	initialize ()
virtual StatusCode	addBranches () const

Private Member Functions
void	find_parents (const xAOD::TruthParticle *part, std::vector< ElementLink< xAOD::TruthParticleContainer > > &parents, std::map< int, ElementLink< xAOD::TruthParticleContainer > > &linkMap, std::vector< int > &seen_particles) const
	Helper function for finding all the parents of a particle. More...
void	find_children (const xAOD::TruthParticle *part, std::vector< ElementLink< xAOD::TruthParticleContainer > > &parents, std::map< int, ElementLink< xAOD::TruthParticleContainer > > &linkMap, std::vector< int > &seen_particles) const
	Helper function for finding all the children of a particle. More...

Private Attributes
SG::ReadHandleKeyArray< xAOD::TruthParticleContainer >	m_inputKeys {this, "InputCollections", {}, "Input truth particle collection keys"}
	Parameter: input particle collections. More...
SG::ReadHandleKey< xAOD::TruthEventContainer >	m_truthEventKey {this, "TruthEventKey", "TruthEvents", "SG key for the TruthEvent container"}
SG::WriteDecorHandleKeyArray< xAOD::TruthParticleContainer, std::vector< ElementLink< xAOD::TruthParticleContainer > > >	m_parentLinksDecorKeys {this, "DoNotSet_parentDecorKeys", {}, "WriteHandleKeyArray - set internally but must be property"}
	Decor keys. More...
SG::WriteDecorHandleKeyArray< xAOD::TruthParticleContainer, std::vector< ElementLink< xAOD::TruthParticleContainer > > >	m_childLinksDecorKeys {this, "DoNotSet_childDecorKeys", {}, "WriteHandleKeyArray - set internally but must be property"}

Detailed Description

Definition at line 27 of file TruthNavigationDecorator.h.

Constructor & Destructor Documentation

TruthNavigationDecorator()

DerivationFramework::TruthNavigationDecorator::TruthNavigationDecorator	(	const std::string &	t,
		const std::string &	n,
		const IInterface *	p
	)

Definition at line 18 of file TruthNavigationDecorator.cxx.

                              :
    base_class(t,n,p)
{
}

~TruthNavigationDecorator()

DerivationFramework::TruthNavigationDecorator::~TruthNavigationDecorator

(

)

Definition at line 26 of file TruthNavigationDecorator.cxx.

                                                                       {
}

Member Function Documentation

addBranches()

StatusCode DerivationFramework::TruthNavigationDecorator::addBranches ( ) const

virtual

Definition at line 51 of file TruthNavigationDecorator.cxx.

{
  // Event context 
  const EventContext& ctx = Gaudi::Hive::currentContext();   
 
  // Retrieve the truth collections
  SG::ReadHandle<xAOD::TruthEventContainer> truthEvents(m_truthEventKey, ctx);
  if (!truthEvents.isValid()) {
    ATH_MSG_ERROR("Couldn't retrieve TruthEvent collection with name " << m_truthEventKey);
    return StatusCode::FAILURE;
  }
 
  // Retrieve all the individual particle collections
  std::vector<SG::ReadHandle<xAOD::TruthParticleContainer> > inputParticles;
  inputParticles.reserve(m_inputKeys.size());
  for (const SG::ReadHandleKey<xAOD::TruthParticleContainer>& inputKey : m_inputKeys) {
    inputParticles.push_back(SG::ReadHandle<xAOD::TruthParticleContainer>(inputKey, ctx));
  }  
 
  // Build a dictionary of uniqueIDs and element links
  std::map<int,ElementLink<xAOD::TruthParticleContainer> > linkMap;
  for (auto& coll : inputParticles){
    for (size_t p=0;p<coll.ptr()->size();++p){
      if (!coll.ptr()->at(p)) continue; // Protection against null ptrs
      if (linkMap.find(HepMC::uniqueID(coll.ptr()->at(p))) != linkMap.end()) continue; // Particle in multiple collections
      linkMap[HepMC::uniqueID(coll.ptr()->at(p))] = ElementLink<xAOD::TruthParticleContainer>(*coll,p);
    } // Loop over particles in the collection
  } // Loop over collections
 
  // Now loop over the collections and for each one decorate children and parents
  // The list of particles we keep is small-ish, and the list of particles in the
  // original truth record is large-ish, so I think it will be more efficient to
  // do a loop (O(N)) over the big record and a search (O(Nlog(N))) over the small
  // container.  Future performance optimization is welcome...
 
  // Keep maps, do the decoration last.  This ensures that duplicates all get decorated.
  std::map< int , std::vector<ElementLink<xAOD::TruthParticleContainer> > > parentMap;
  std::map< int , std::vector<ElementLink<xAOD::TruthParticleContainer> > > childMap;
 
  // Loop protection
  std::vector<int> seen_particles(20);
  // As usual, only consider the first truth event
  const xAOD::TruthEvent * event = truthEvents->at(0);
  for (size_t p=0;p<event->nTruthParticles();++p){
    if (!event->truthParticle(p)) continue; // Protection against null ptrs
    if (linkMap.find(HepMC::uniqueID(event->truthParticle(p))) == linkMap.end()) continue; // Not a particle we are interested in
    // Make parent and child lists
    std::vector<ElementLink<xAOD::TruthParticleContainer> > parents;
    std::vector<ElementLink<xAOD::TruthParticleContainer> > children;
    // Populate the lists - include loop protection
    seen_particles.clear();
    find_parents( event->truthParticle(p) , parents , linkMap , seen_particles );
    seen_particles.clear();
    find_children( event->truthParticle(p) , children , linkMap , seen_particles );
    // Set the maps, so that we can decorate later
    parentMap[HepMC::uniqueID(event->truthParticle(p))] = parents;
    childMap[HepMC::uniqueID(event->truthParticle(p))] = children;
  } // Loop over truth particles in the big truth collection
 
  // Now final loop over the collections and setting all the decorators
  auto parent_decorator = m_parentLinksDecorKeys.makeHandles (ctx);
  auto child_decorator  = m_childLinksDecorKeys.makeHandles (ctx);
  unsigned int pCntr{0};
  for (auto coll : inputParticles){
    if (parent_decorator.at(pCntr).isAvailable()) {
      ++pCntr;
      continue;
    }
    for (size_t p=0;p<coll.ptr()->size();++p){
      if (!coll.ptr()->at(p)) continue; // Protection against null ptrs
      parent_decorator.at(pCntr)(*coll.ptr()->at(p)) = parentMap[ HepMC::uniqueID(coll->at(p)) ];
      child_decorator.at(pCntr)(*coll.ptr()->at(p)) = childMap[ HepMC::uniqueID(coll->at(p)) ];
    } // Loop over the particles in each collection
    ++pCntr;
  } // Loop over the collections
 
  return StatusCode::SUCCESS;
}

find_children()

void DerivationFramework::TruthNavigationDecorator::find_children ( const xAOD::TruthParticle *  part, std::vector< ElementLink< xAOD::TruthParticleContainer > > &  parents, std::map< int, ElementLink< xAOD::TruthParticleContainer > > &  linkMap, std::vector< int > &  seen_particles  ) const

private

Helper function for finding all the children of a particle.

Definition at line 152 of file TruthNavigationDecorator.cxx.

                                                                       {
  // Null pointer protection
  if (!part) return;
  // Check if we've seen the particle before, otherwise add it to our list
  if (std::find(seen_particles.begin(),seen_particles.end(),HepMC::uniqueID(part)) != seen_particles.end()) return;
  seen_particles.push_back(HepMC::uniqueID(part));
  // Look through the children and see if we know about them; otherwise iterate through the list
  for (size_t child=0;child<part->nChildren();++child){
    if (!part->child(child)) continue; // Null pointer check
    if (linkMap.find(HepMC::uniqueID(part->child(child))) != linkMap.end()){
      // Hit!  Add it to the list
      children.push_back( linkMap[HepMC::uniqueID(part->child(child))] );
    } else {
      // Not a hit yet, keep iterating
      find_children( part->child(child) , children , linkMap , seen_particles );
    }
  } // Loop over parents
}

find_parents()

void DerivationFramework::TruthNavigationDecorator::find_parents ( const xAOD::TruthParticle *  part, std::vector< ElementLink< xAOD::TruthParticleContainer > > &  parents, std::map< int, ElementLink< xAOD::TruthParticleContainer > > &  linkMap, std::vector< int > &  seen_particles  ) const

private

Helper function for finding all the parents of a particle.

Definition at line 130 of file TruthNavigationDecorator.cxx.

                                                                       {
  // Null pointer protection
  if (!part) return;
  // Check if we've seen the particle before, otherwise add it to our list
  if (std::find(seen_particles.begin(), seen_particles.end(), HepMC::uniqueID(part)) != seen_particles.end()) return;
  seen_particles.push_back(HepMC::uniqueID(part));
  // Loop through the parents and see if we know about them; otherwise iterate through the list
  for (size_t parent=0;parent<part->nParents();++parent){
    if (!part->parent(parent)) continue; // Null pointer check
    if (linkMap.find(HepMC::uniqueID(part->parent(parent))) != linkMap.end()){
      // Hit!  Add it to the list
      parents.push_back( linkMap[HepMC::uniqueID(part->parent(parent))] );
    } else {
      // Not a hit yet, keep iterating
      find_parents( part->parent(parent) , parents , linkMap , seen_particles );
    }
  } // Loop over parents
}

initialize()

StatusCode DerivationFramework::TruthNavigationDecorator::initialize

(

)

Definition at line 30 of file TruthNavigationDecorator.cxx.

                                                                   {
 
  // Initialise input keys
  ATH_CHECK( m_inputKeys.initialize() ); 
  ATH_CHECK( m_truthEventKey.initialize() );  
 
  // Decorations - dependent on the name of the input keys 
  // Loop over the container names provided by the user
  for (auto key : m_inputKeys) {
    m_parentLinksDecorKeys.emplace_back(key.key()+".parentLinks");   
    m_childLinksDecorKeys.emplace_back(key.key()+".childLinks");  
  }
  
  ATH_CHECK( m_parentLinksDecorKeys.initialize() );
  ATH_CHECK( m_childLinksDecorKeys.initialize() );
 
  return StatusCode::SUCCESS;
 
}

Member Data Documentation

m_childLinksDecorKeys

SG::WriteDecorHandleKeyArray<xAOD::TruthParticleContainer, std::vector<ElementLink<xAOD::TruthParticleContainer> > > DerivationFramework::TruthNavigationDecorator::m_childLinksDecorKeys {this, "DoNotSet_childDecorKeys", {}, "WriteHandleKeyArray - set internally but must be property"}

private

Definition at line 43 of file TruthNavigationDecorator.h.

m_inputKeys

SG::ReadHandleKeyArray<xAOD::TruthParticleContainer> DerivationFramework::TruthNavigationDecorator::m_inputKeys {this, "InputCollections", {}, "Input truth particle collection keys"}

private

Parameter: input particle collections.

Definition at line 36 of file TruthNavigationDecorator.h.

m_parentLinksDecorKeys

SG::WriteDecorHandleKeyArray<xAOD::TruthParticleContainer, std::vector<ElementLink<xAOD::TruthParticleContainer> > > DerivationFramework::TruthNavigationDecorator::m_parentLinksDecorKeys {this, "DoNotSet_parentDecorKeys", {}, "WriteHandleKeyArray - set internally but must be property"}

private

Decor keys.

Definition at line 41 of file TruthNavigationDecorator.h.

m_truthEventKey

SG::ReadHandleKey<xAOD::TruthEventContainer> DerivationFramework::TruthNavigationDecorator::m_truthEventKey {this, "TruthEventKey", "TruthEvents", "SG key for the TruthEvent container"}

private

Definition at line 38 of file TruthNavigationDecorator.h.

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

• TruthNavigationDecorator.h
• TruthNavigationDecorator.cxx