ISF::TruthPreselectionTool Class Reference

#include <TruthPreselectionTool.h>

Inheritance diagram for ISF::TruthPreselectionTool:

Collaboration diagram for ISF::TruthPreselectionTool:

Public Member Functions
	TruthPreselectionTool (const std::string &t, const std::string &n, const IInterface *p)
	Constructor with parameters. More...
virtual	~TruthPreselectionTool ()=default
	Destructor. More...
virtual StatusCode	initialize () override final
	Athena algorithm's interface method initialize() More...
virtual std::unique_ptr< HepMC::GenEvent >	filterGenEvent (const HepMC::GenEvent &inputEvent) const override final
	IGenEventFilter interface. More...

Private Member Functions
bool	passesFilters (HepMC::ConstGenParticlePtr part, const ToolHandleArray< IGenParticleFilter > &filters) const
	check if the given particle passes all filters More...
bool	identifiedQuasiStableParticleForSim (HepMC::ConstGenParticlePtr part) const
bool	hasQuasiStableAncestorParticle (HepMC::ConstGenParticlePtr part) const
bool	isPostQuasiStableParticleVertex (HepMC::ConstGenVertexPtr vtx) const

Private Attributes
ToolHandleArray< IGenParticleFilter >	m_genParticleFilters {this, "GenParticleFilters", {}, "Tools for filtering out GenParticles"}
	Filter passes if a difference between the decision of m_genParticleOldFilters and m_genParticleNewFilters is found. More...
ToolHandle< IGenParticleFilter >	m_quasiStableFilter {this, "QuasiStableParticleFilter", "", "Tools for finding quasi-stable particles"}

Detailed Description

Definition at line 21 of file TruthPreselectionTool.h.

Constructor & Destructor Documentation

TruthPreselectionTool()

ISF::TruthPreselectionTool::TruthPreselectionTool	(	const std::string &	t,
		const std::string &	n,
		const IInterface *	p
	)

Constructor with parameters.

Definition at line 15 of file TruthPreselectionTool.cxx.

                                                                                                             :
  base_class( t, n, p )
{
}

~TruthPreselectionTool()

virtual ISF::TruthPreselectionTool::~TruthPreselectionTool ( )

virtualdefault

Destructor.

Member Function Documentation

filterGenEvent()

std::unique_ptr< HepMC::GenEvent > ISF::TruthPreselectionTool::filterGenEvent ( const HepMC::GenEvent &  inputEvent ) const

finaloverridevirtual

IGenEventFilter interface.

Definition at line 126 of file TruthPreselectionTool.cxx.

                                                                                                           {
#ifdef HEPMC3
   std::unique_ptr<HepMC::GenEvent>  outputEvent = std::make_unique<HepMC::GenEvent>(inputEvent);
   if (inputEvent.run_info()) {
     outputEvent->set_run_info(std::make_shared<HepMC3::GenRunInfo>(*(inputEvent.run_info().get())));
   }
   if (inputEvent.heavy_ion()) {
     outputEvent->set_heavy_ion(std::make_shared<HepMC::GenHeavyIon>(*(inputEvent.heavy_ion())));
   }
   HepMC::fillBarcodesAttribute(outputEvent.get());
 
   // First loop: flag the particles which should be passed to simulation
   for (auto& particle: outputEvent->particles()) {
       HepMC::ConstGenParticlePtr cparticle = particle;
       if (passesFilters(cparticle, m_genParticleFilters)) {
       // Particle to be simulated
       const int shadowId = particle->id();
       // Version 1 Use the Id
       particle->add_attribute("ShadowParticleId",
                               std::make_shared<HepMC3::IntAttribute>(shadowId));
       // Version 2 Directly save the ConstGenParticlePtr - needs to link to a version of the GenEvent after zero-lifetime positioner as been applied.
       // HepMC::ConstGenParticlePtr& shadow = inputEvent.particles().at(shadowId);
       // particle->add_attribute("ShadowParticle",
       //                         std::make_shared<HepMC::ShadowParticle>(particle));
     }
   }
   // Second loop(s): flag particles (and vertices) to be removed (i.e. those
   // with ancestor particle flagged to be passed to simulation).
   for (;;) {
     std::vector<HepMC::GenParticlePtr> p_to_remove;
     std::vector<HepMC::GenVertexPtr> v_to_remove;
     for (auto& particle: outputEvent->particles()) {
       HepMC::ConstGenParticlePtr cparticle = particle;
       if (hasQuasiStableAncestorParticle(cparticle)) {
         p_to_remove.push_back(particle);
       }
     }
     for (auto& particle: p_to_remove) outputEvent->remove_particle(particle);
     for (auto& vertex: outputEvent->vertices()) {
       HepMC::ConstGenVertexPtr cvertex = vertex;
       if (isPostQuasiStableParticleVertex(cvertex)) {
         v_to_remove.push_back(vertex);
       }
     }
     for (auto& vertex: v_to_remove) outputEvent->remove_vertex(vertex);
     if (p_to_remove.empty() && v_to_remove.empty()) break;
   }
#else
 
  std::unique_ptr<HepMC::GenEvent> outputEvent = std::make_unique<HepMC::GenEvent>(inputEvent.signal_process_id(),
                                                                                   inputEvent.event_number());
 
  outputEvent->set_mpi                  ( inputEvent.mpi() );
  outputEvent->set_event_scale          ( inputEvent.event_scale() );
  outputEvent->set_alphaQCD             ( inputEvent.alphaQCD() );
  outputEvent->set_alphaQED             ( inputEvent.alphaQED() );
  if ( inputEvent.cross_section() ) {
    outputEvent->set_cross_section        ( *inputEvent.cross_section());
  }
  if (inputEvent.heavy_ion()) {
    outputEvent->set_heavy_ion(*(inputEvent.heavy_ion()));
  }
  if (inputEvent.pdf_info()) {
    outputEvent->set_pdf_info(*(inputEvent.pdf_info()));
  }
  outputEvent->define_units( inputEvent.momentum_unit(), inputEvent.length_unit() );
 
  // 1. create a NEW copy of all vertices from inputEvent
  //    taking care to map new vertices onto the vertices being copied
  //    and add these new vertices to this event.
  //    We do not use GenVertex::operator= because that would copy
  //    the attached particles as well.
  std::map<const HepMC::GenVertex*,HepMC::GenVertex*> inputEvtVtxToOutputEvtVtx;
  HepMC::GenEvent::vertex_const_iterator currentVertexIter(inputEvent.vertices_begin());
  const HepMC::GenEvent::vertex_const_iterator endOfCurrentListOfVertices(inputEvent.vertices_end());
  ATH_MSG_VERBOSE( "Starting a vertex loop ... " );
  for (; currentVertexIter != endOfCurrentListOfVertices; ++currentVertexIter) {
    const HepMC::GenVertex *pCurrentVertex(*currentVertexIter);
    if (isPostQuasiStableParticleVertex(pCurrentVertex)) {
      continue; // skip vertices created by the simulation
    }
    std::unique_ptr<HepMC::GenVertex> copyOfGenVertex =std::make_unique<HepMC::GenVertex>(pCurrentVertex->position(), pCurrentVertex->id(), pCurrentVertex->weights() );
    copyOfGenVertex->suggest_barcode( HepMC::barcode(pCurrentVertex) );
    inputEvtVtxToOutputEvtVtx[pCurrentVertex] = copyOfGenVertex.get();
    outputEvent->add_vertex( copyOfGenVertex.release() );
  } //vertex loop
 
  // 2. copy the signal process vertex info.
  if ( inputEvent.signal_process_vertex() ) {
    outputEvent->set_signal_process_vertex( inputEvtVtxToOutputEvtVtx[inputEvent.signal_process_vertex()] );
  }
  else {
    outputEvent->set_signal_process_vertex( nullptr );
  }
  //
  // 3. create a NEW copy of all particles from inputEvent
  //    taking care to attach them to the appropriate vertex
  HepMC::GenParticle* beam1{};
  HepMC::GenParticle* beam2{};
  for ( HepMC::GenEvent::particle_const_iterator particleIter = inputEvent.particles_begin();
        particleIter != inputEvent.particles_end(); ++particleIter ) {
    const HepMC::GenParticle* currentParticle = *particleIter;
    if (hasQuasiStableAncestorParticle(currentParticle)) { // TODO Consider making the threshold for this check configurable.
      continue; // skip particles created by the simulation
    }
    std::unique_ptr<HepMC::GenParticle> copyOfGenParticle = std::make_unique<HepMC::GenParticle>(*currentParticle);
    const bool isBeamParticle1(currentParticle == inputEvent.beam_particles().first);
    const bool isBeamParticle2(currentParticle == inputEvent.beam_particles().second);
    // There may (will) be particles which had end vertices added by
    // the simulation (inputEvent). Those vertices will not be copied
    // to the outputEvent, so we should not try to use them here.
    const bool shouldAddProdVertex(currentParticle->production_vertex() && inputEvtVtxToOutputEvtVtx[ currentParticle->production_vertex() ]);
    const bool shouldAddEndVertex(currentParticle->end_vertex() && inputEvtVtxToOutputEvtVtx[ currentParticle->end_vertex() ]);
    if ( isBeamParticle1 || isBeamParticle2 || shouldAddProdVertex || shouldAddEndVertex ) {
      HepMC::GenParticle* particleCopy = copyOfGenParticle.release();
      if ( isBeamParticle1 ) {
        beam1 = particleCopy;
      }
      if ( isBeamParticle2 ) {
        beam2 = particleCopy;
      }
      if ( shouldAddProdVertex || shouldAddEndVertex ) {
        if ( shouldAddEndVertex  ) {
          inputEvtVtxToOutputEvtVtx[ currentParticle->end_vertex() ]->
            add_particle_in(particleCopy);
        }
        if ( shouldAddProdVertex ) {
          inputEvtVtxToOutputEvtVtx[ currentParticle->production_vertex() ]->
            add_particle_out(particleCopy);
        }
      }
      else {
        ATH_MSG_WARNING ( "Found GenParticle with no production or end vertex! \n" << *currentParticle);
      }
    }
  }
  outputEvent->set_beam_particles( beam1, beam2 );
  //
  // 4. now that vtx/particles are copied, copy weights and random states
  outputEvent->set_random_states( inputEvent.random_states() );
  outputEvent->weights() = inputEvent.weights();
#endif
  return outputEvent;
}

hasQuasiStableAncestorParticle()

bool ISF::TruthPreselectionTool::hasQuasiStableAncestorParticle ( HepMC::ConstGenParticlePtr  part ) const

private

Definition at line 80 of file TruthPreselectionTool.cxx.

{
  // TODO: investigate making this more efficient
#ifdef HEPMC3
  // Recursively loop over ancestral particles looking for a quasi-stable particle
  if (!part->production_vertex() || part->production_vertex()->particles_in().empty()) { return false; }
  for ( auto ancestor: part->production_vertex()->particles_in() ) {
    // Check ancestor particle for Attribute
    if ( ancestor->attribute<HepMC3::IntAttribute>("ShadowParticleId") ) { return true; }
#else
  if (!part->production_vertex() || part->production_vertex()->particles_in_size()==0) { return false; }
  // Recursively loop over ancestral particles looking for a quasi-stable particle
  auto  firstParent = part->production_vertex()->particles_begin(HepMC::parents);
  auto lastParent  = part->production_vertex()->particles_end(HepMC::parents);
  for (auto  pitr = firstParent; pitr != lastParent; ++pitr ) {
    HepMC::ConstGenParticlePtr ancestor = *pitr;
    if (identifiedQuasiStableParticleForSim(ancestor)) { return true; }
#endif
    if (hasQuasiStableAncestorParticle(ancestor)) { return true; }
  }
  return false;
}

identifiedQuasiStableParticleForSim()

bool ISF::TruthPreselectionTool::identifiedQuasiStableParticleForSim ( HepMC::ConstGenParticlePtr  part ) const

private

Definition at line 61 of file TruthPreselectionTool.cxx.

{
  bool b_sim = false;
#ifdef HEPMC3
  if (m_quasiStableFilter->pass(part)) {
    b_sim = passesFilters(part, m_genParticleFilters);
  }
#else
  if (m_quasiStableFilter->pass(*part)) {
    b_sim = passesFilters(part, m_genParticleFilters);
  }
#endif
  return b_sim;
}

initialize()

StatusCode ISF::TruthPreselectionTool::initialize ( )

finaloverridevirtual

Athena algorithm's interface method initialize()

Definition at line 22 of file TruthPreselectionTool.cxx.

{
  ATH_MSG_VERBOSE ( "Initializing TruthPreselectionTool Algorithm" );
 
  if (!m_genParticleFilters.empty()) ATH_CHECK(m_genParticleFilters.retrieve());
  ATH_CHECK(m_quasiStableFilter.retrieve());
 
  // intialziation successful
  return StatusCode::SUCCESS;
}

isPostQuasiStableParticleVertex()

bool ISF::TruthPreselectionTool::isPostQuasiStableParticleVertex ( HepMC::ConstGenVertexPtr  vtx ) const

private

Definition at line 112 of file TruthPreselectionTool.cxx.

{
  // Recursively loop over ancestral particles looking for a quasi-stable particle
  auto  firstParent = vtx->particles_in_const_begin();
  auto lastParent  = vtx->particles_in_const_end();
  for (auto  pitr = firstParent; pitr != lastParent; ++pitr ) {
    HepMC::ConstGenParticlePtr ancestor = *pitr;
    if (identifiedQuasiStableParticleForSim(ancestor)) { return true; }
    if (hasQuasiStableAncestorParticle(ancestor)) { return true; }
  }
  return false;
}

passesFilters()

bool ISF::TruthPreselectionTool::passesFilters ( HepMC::ConstGenParticlePtr  part, const ToolHandleArray< IGenParticleFilter > &  filters  ) const

private

check if the given particle passes all filters

Definition at line 37 of file TruthPreselectionTool.cxx.

{
  // TODO: implement this as a std::find_if with a lambda function
  for ( const auto& filter : filters ) {
    // determine if the particle passes current filter
#ifdef HEPMC3
    bool passFilter = filter->pass(part);
#else
    bool passFilter = filter->pass(*part);
#endif
    ATH_MSG_VERBOSE("Filter '" << filter.typeAndName() << "' returned: "
                    << (passFilter ? "true, will keep particle."
                        : "false, will remove particle."));
 
    if (!passFilter) return false;
  }
 
  return true;
}

Member Data Documentation

m_genParticleFilters

ToolHandleArray<IGenParticleFilter> ISF::TruthPreselectionTool::m_genParticleFilters {this, "GenParticleFilters", {}, "Tools for filtering out GenParticles"}

private

Filter passes if a difference between the decision of m_genParticleOldFilters and m_genParticleNewFilters is found.

m_genParticleCommonFilters is applied before to select relevant particles. If only m_genParticleCommonFilters is specified, filter passes if any particle passes this one HepMC::GenParticle filters for both selections

Definition at line 52 of file TruthPreselectionTool.h.

m_quasiStableFilter

ToolHandle<IGenParticleFilter> ISF::TruthPreselectionTool::m_quasiStableFilter {this, "QuasiStableParticleFilter", "", "Tools for finding quasi-stable particles"}

private

Definition at line 53 of file TruthPreselectionTool.h.

---

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

• TruthPreselectionTool.h
• TruthPreselectionTool.cxx