Simulation::VertexBeamCondPositioner Class Reference

This AthenaTool computes geometrical shifts for the initial GenEvent vertices. More...

#include <VertexBeamCondPositioner.h>

Inheritance diagram for Simulation::VertexBeamCondPositioner:

Collaboration diagram for Simulation::VertexBeamCondPositioner:

Public Member Functions
	VertexBeamCondPositioner (const std::string &t, const std::string &n, const IInterface *p)
	Constructor with parameters.
	~VertexBeamCondPositioner ()=default
	Destructor.
StatusCode	initialize () override final
	Athena algtool's Hooks.
StatusCode	finalize () override final
	Athena algtool's Hooks.
CLHEP::HepLorentzVector *	generate (const EventContext &ctx) const override final
	computes the vertex displacement

Private Attributes
SG::ReadCondHandleKey< InDet::BeamSpotData >	m_beamSpotKey { this, "BeamSpotKey", "BeamSpotData", "SG key for beam spot" }
ServiceHandle< IAthRNGSvc >	m_rndGenSvc {this, "RandomSvc", "AthRNGSvc"}
ATHRNG::RNGWrapper *m_randomEngine	ATLAS_THREAD_SAFE {}
	Slot-local RNG.
Gaudi::Property< std::string >	m_randomEngineName {this, "RandomStream", "VERTEX"}
	Name of the random number stream.
Gaudi::Property< bool >	m_timeSmearing {this, "SimpleTimeSmearing", false}
	Do time smearing.
Gaudi::Property< float >	m_timeWidth {this, "TimeWidth", 0.}
	Width of time for smearing.

Detailed Description

This AthenaTool computes geometrical shifts for the initial GenEvent vertices.

based on: https://svnweb.cern.ch/trac/atlasoff/browser/Simulation/G4Atlas/G4AtlasUtilities/trunk/src/VertexPositioner.cxx

Author

Andreas.Salzburger -at- cern.ch , Elmar.Ritsch -at- cern.ch

Definition at line 33 of file VertexBeamCondPositioner.h.

Constructor & Destructor Documentation

VertexBeamCondPositioner()

Simulation::VertexBeamCondPositioner::VertexBeamCondPositioner	(	const std::string &	t,
		const std::string &	n,
		const IInterface *	p )

Constructor with parameters.

Constructor.

Definition at line 25 of file VertexBeamCondPositioner.cxx.

    : base_class(t,n,p)
  {
  }

~VertexBeamCondPositioner()

Simulation::VertexBeamCondPositioner::~VertexBeamCondPositioner ( )

default

Destructor.

Member Function Documentation

finalize()

StatusCode Simulation::VertexBeamCondPositioner::finalize ( )

finaloverride

Athena algtool's Hooks.

Definition at line 50 of file VertexBeamCondPositioner.cxx.

  {
    ATH_MSG_VERBOSE("Finalizing ...");
    return StatusCode::SUCCESS;
  }

generate()

CLHEP::HepLorentzVector * Simulation::VertexBeamCondPositioner::generate ( const EventContext & ctx ) const

finaloverride

computes the vertex displacement

Definition at line 57 of file VertexBeamCondPositioner.cxx.

  {
    // Prepare the random engine
    m_randomEngine->setSeed( name(), ctx );
    CLHEP::HepRandomEngine* randomEngine(m_randomEngine->getEngine(ctx));
    SG::ReadCondHandle<InDet::BeamSpotData> beamSpotHandle { m_beamSpotKey, ctx };
    // See jira issue ATLASSIM-497 for an explanation of why calling
    // shoot outside the CLHEP::HepLorentzVector constructor is
    // necessary/preferable.
    float vertexX = CLHEP::RandGaussZiggurat::shoot(randomEngine)*beamSpotHandle->beamSigma(0);
    float vertexY = CLHEP::RandGaussZiggurat::shoot(randomEngine)*beamSpotHandle->beamSigma(1);
    float vertexZ = CLHEP::RandGaussZiggurat::shoot(randomEngine)*beamSpotHandle->beamSigma(2);
    // calculate the vertexSmearing
    CLHEP::HepLorentzVector *vertexSmearing =
      new CLHEP::HepLorentzVector( vertexX, vertexY, vertexZ, 0. );
 
    // (1) code from: Simulation/G4Atlas/G4AtlasUtilities/VertexPositioner.cxx
    const double tx = tan( beamSpotHandle->beamTilt(1) );
    const double ty = tan( beamSpotHandle->beamTilt(0) );
 
    const double sqrt_abc = sqrt(1. + tx*tx + ty*ty);
    const double sqrt_fgh = sqrt(1. + ty*ty);
 
    const double a = ty/sqrt_abc;
    const double b = tx/sqrt_abc;
    const double c = 1./sqrt_abc;
 
    HepGeom::Point3D<double> from1(0,0,1);
    HepGeom::Point3D<double> to1(a,b,c);
 
    const double f = 1./sqrt_fgh;
    const double g = 0.;
    const double h = -(ty)/sqrt_fgh;
 
    HepGeom::Point3D<double> from2(1,0,0);
    HepGeom::Point3D<double> to2(f,g,h);
 
    // first rotation, then translation
    HepGeom::Transform3D transform(
        HepGeom::Rotate3D(from1, from2, to1, to2).getRotation(),
        CLHEP::Hep3Vector( beamSpotHandle->beamPos().x(),
                           beamSpotHandle->beamPos().y(),
                           beamSpotHandle->beamPos().z() )
        );
 
    // FIXME: don't use endl in MsgStream printouts
    ATH_MSG_VERBOSE("BeamSpotSvc reported beam position as " << beamSpotHandle->beamPos() << std::endl
                    << "\tWidth is (" << beamSpotHandle->beamSigma(0)
                    << ", " << beamSpotHandle->beamSigma(1) << ", "
                    << beamSpotHandle->beamSigma(2) << ")" << std::endl
            << "\tTime smearing is " << (m_timeSmearing ? "on" : "off") << " with width " << m_timeWidth << std::endl
                    << "\tTilts are " << beamSpotHandle->beamTilt(0) << " and " << beamSpotHandle->beamTilt(1) << std::endl
                    << "\tVertex Position before transform: " << *vertexSmearing);
 
    // update with the tilt
    *vertexSmearing = transform * HepGeom::Point3D<double>(*vertexSmearing);
 
    float vertexT = m_timeSmearing ? CLHEP::RandGaussZiggurat::shoot(randomEngine)*m_timeWidth*Gaudi::Units::c_light : 0.;
    vertexSmearing->setT(vertexT);
 
    // and return it
    return vertexSmearing;
  }

initialize()

StatusCode Simulation::VertexBeamCondPositioner::initialize ( )

finaloverride

Athena algtool's Hooks.

Definition at line 33 of file VertexBeamCondPositioner.cxx.

  {
    ATH_MSG_VERBOSE("Initializing ...");
 
    // retrieve the random number service
    ATH_CHECK(m_rndGenSvc.retrieve());
    m_randomEngine = m_rndGenSvc->getEngine(this, m_randomEngineName);
    if (!m_randomEngine) {
      ATH_MSG_ERROR("Could not get random number engine from RandomNumberService. Abort.");
      return StatusCode::FAILURE;
    }
    ATH_CHECK(m_beamSpotKey.initialize());
    // everything set up properly
    return StatusCode::SUCCESS;
  }

Member Data Documentation

ATLAS_THREAD_SAFE

ATHRNG::RNGWrapper* m_randomEngine Simulation::VertexBeamCondPositioner::ATLAS_THREAD_SAFE {}

private

Slot-local RNG.

Definition at line 54 of file VertexBeamCondPositioner.h.

{};  

m_beamSpotKey

SG::ReadCondHandleKey<InDet::BeamSpotData> Simulation::VertexBeamCondPositioner::m_beamSpotKey { this, "BeamSpotKey", "BeamSpotData", "SG key for beam spot" }

private

Definition at line 52 of file VertexBeamCondPositioner.h.

{ this, "BeamSpotKey", "BeamSpotData", "SG key for beam spot" };

m_randomEngineName

Gaudi::Property<std::string> Simulation::VertexBeamCondPositioner::m_randomEngineName {this, "RandomStream", "VERTEX"}

private

Name of the random number stream.

Definition at line 56 of file VertexBeamCondPositioner.h.

{this, "RandomStream", "VERTEX"};         

m_rndGenSvc

ServiceHandle<IAthRNGSvc> Simulation::VertexBeamCondPositioner::m_rndGenSvc {this, "RandomSvc", "AthRNGSvc"}

private

Definition at line 53 of file VertexBeamCondPositioner.h.

{this, "RandomSvc", "AthRNGSvc"};

m_timeSmearing

Gaudi::Property<bool> Simulation::VertexBeamCondPositioner::m_timeSmearing {this, "SimpleTimeSmearing", false}

private

Do time smearing.

Definition at line 57 of file VertexBeamCondPositioner.h.

{this, "SimpleTimeSmearing", false}; 

m_timeWidth

Gaudi::Property<float> Simulation::VertexBeamCondPositioner::m_timeWidth {this, "TimeWidth", 0.}

private

Width of time for smearing.

Definition at line 58 of file VertexBeamCondPositioner.h.

{this, "TimeWidth", 0.}; 

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

• VertexBeamCondPositioner.h
• VertexBeamCondPositioner.cxx