lar::example::tests::ParticleMaker Class Reference

Creates a collection of simulated particles. More...

Inheritance diagram for lar::example::tests::ParticleMaker:

Classes
struct	Config
struct	ParticleConfig
struct	ParticleSpecs

Public Types
using	Parameters = art::EDProducer::Table< Config >

Public Member Functions
	ParticleMaker (Parameters const &config)
	Constructor; see the class documentation for the configuration. More...
virtual void	produce (art::Event &event) override
	Create and add the particles (the same for all events). More...

Private Attributes
std::vector< ParticleSpecs >	fParticleSpecs
	Settings for particles. More...

Detailed Description

Creates a collection of simulated particles.

A collection of simb::MCParticle is added to the event. The particles are one starting where the previous one ended (starting from the origin). The configuration specifies the number, type and energy of the particles, and their path length.

Configuration parameters

• particles (list of structures, mandatory): each element in the list is a table with entries:
  • length (real, mandatory): particle path length [cm]
  • energy (real, mandatory): particle energy [GeV]
  • type (integer, mandatory): particle type as PDG ID

Definition at line 60 of file ParticleMaker_module.cc.

Member Typedef Documentation

using lar::example::tests::ParticleMaker::Parameters = art::EDProducer::Table<Config>

Definition at line 98 of file ParticleMaker_module.cc.

Constructor & Destructor Documentation

lar::example::tests::ParticleMaker::ParticleMaker ( Parameters const &  config )

explicit

Constructor; see the class documentation for the configuration.

Definition at line 138 of file ParticleMaker_module.cc.

  : EDProducer{config}
{

  auto const& particleSpecs = config().particles();
  fParticleSpecs.assign(particleSpecs.begin(), particleSpecs.end());

  // consumes: nothing

  // produces:
  produces<std::vector<simb::MCParticle>>();

} // lar::example::tests::ParticleMaker::ParticleMaker()

Member Function Documentation

void lar::example::tests::ParticleMaker::produce ( art::Event &  event )

overridevirtual

Create and add the particles (the same for all events).

Definition at line 154 of file ParticleMaker_module.cc.

                                                          {

  //
  // set up
  //

  // container for the data product
  auto particles = std::make_unique<std::vector<simb::MCParticle>>();

  //
  // creation of the particles
  //
  static std::array<TVector3, 6U> const Dirs = {{
    geo::vect::rounded01( geo::Xaxis<TVector3>(), 1e-8),
    geo::vect::rounded01( geo::Yaxis<TVector3>(), 1e-8),
    geo::vect::rounded01( geo::Zaxis<TVector3>(), 1e-8),
    geo::vect::rounded01(-geo::Xaxis<TVector3>(), 1e-8),
    geo::vect::rounded01(-geo::Yaxis<TVector3>(), 1e-8),
    geo::vect::rounded01(-geo::Zaxis<TVector3>(), 1e-8)
  }}; // Dirs

  int trackID = 0;
  TLorentzVector pos;
  for (auto const& specs: fParticleSpecs) {

    int const motherID = trackID - 1;
    if (motherID >= 0) (*particles)[motherID].AddDaughter(trackID);

    particles->emplace_back(
        trackID           // track ID
      , specs.type        // pdg
      , "magic"           // process
      , motherID          // mother
      );
    simb::MCParticle& particle = particles->back();

    auto const& dir = Dirs[trackID % 6];
    TLorentzVector const mom{ specs.energy * dir, specs.energy };
    unsigned int const nSteps = std::ceil(specs.length);
    particle.AddTrajectoryPoint(pos, mom);
    for (unsigned int i = 1; i <= nSteps; ++i) {
      double const stepSize = std::min(specs.length - double(i - 1), 1.0);
      pos += TLorentzVector{ dir * stepSize, 1.0 };
      particle.AddTrajectoryPoint(pos, mom);
    } // for

    ++trackID;

  } // for specs

  //
  // result storage
  //
  mf::LogInfo("ParticleMaker")
    << "Created " << particles->size() << " space points.";

  event.put(std::move(particles));

} // lar::example::tests::ParticleMaker::produce()

Member Data Documentation

std::vector<ParticleSpecs> lar::example::tests::ParticleMaker::fParticleSpecs

private

Settings for particles.

Definition at line 120 of file ParticleMaker_module.cc.

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

• ParticleMaker_module.cc