genfit::TGeoMaterialInterface Class Reference

AbsMaterialInterface implementation for use with ROOT's TGeoManager. More...

#include <TGeoMaterialInterface.h>

Inheritance diagram for genfit::TGeoMaterialInterface:

Collaboration diagram for genfit::TGeoMaterialInterface:

Public Member Functions
	TGeoMaterialInterface ()
virtual	~TGeoMaterialInterface ()
bool	initTrack (double posX, double posY, double posZ, double dirX, double dirY, double dirZ)
	Initialize the navigator at given position and with given direction. Returns true if the volume changed.
void	getMaterialParameters (double &density, double &Z, double &A, double &radiationLength, double &mEE)
	Get material parameters in current material.
void	getMaterialParameters (MaterialProperties &parameters)
double	findNextBoundary (const RKTrackRep *rep, const M1x7 &state7, double sMax, bool varField=true)
	Make a step (following the curvature) until step length sMax or the next boundary is reached. After making a step to a boundary, the position has to be beyond the boundary, i.e. the current material has to be that beyond the boundary. The actual step made is returned.
double	findNextBoundaryAndStepStraight (double sMax)
	ClassDef (TGeoMaterialInterface, 1)
	TGeoMaterialInterface ()
virtual	~TGeoMaterialInterface ()
bool	initTrack (double posX, double posY, double posZ, double dirX, double dirY, double dirZ)
	Initialize the navigator at given position and with given direction. Returns true if the volume changed.
void	getMaterialParameters (double &density, double &Z, double &A, double &radiationLength, double &mEE)
	Get material parameters in current material.
void	getMaterialParameters (MaterialProperties &parameters)
double	findNextBoundary (const RKTrackRep *rep, const M1x7 &state7, double sMax, bool varField=true)
	Make a step (following the curvature) until step length sMax or the next boundary is reached. After making a step to a boundary, the position has to be beyond the boundary, i.e. the current material has to be that beyond the boundary. The actual step made is returned.
double	findNextBoundaryAndStepStraight (double sMax)
	ClassDef (TGeoMaterialInterface, 1)
Public Member Functions inherited from genfit::AbsMaterialInterface
	AbsMaterialInterface ()
virtual	~AbsMaterialInterface ()
	AbsMaterialInterface ()
virtual	~AbsMaterialInterface ()

Detailed Description

AbsMaterialInterface implementation for use with ROOT's TGeoManager.

Definition at line 35 of file TGeoMaterialInterface.h.

Constructor & Destructor Documentation

TGeoMaterialInterface() [1/2]

genfit::TGeoMaterialInterface::TGeoMaterialInterface ( )

inline

Definition at line 39 of file TGeoMaterialInterface.h.

{};

~TGeoMaterialInterface() [1/2]

virtual genfit::TGeoMaterialInterface::~TGeoMaterialInterface ( )

inlinevirtual

Definition at line 40 of file TGeoMaterialInterface.h.

{;};

TGeoMaterialInterface() [2/2]

genfit::TGeoMaterialInterface::TGeoMaterialInterface ( )

inline

Definition at line 39 of file TGeoMaterialInterface.h.

{};

~TGeoMaterialInterface() [2/2]

virtual genfit::TGeoMaterialInterface::~TGeoMaterialInterface ( )

inlinevirtual

Definition at line 40 of file TGeoMaterialInterface.h.

{;};

Member Function Documentation

ClassDef() [1/2]

genfit::TGeoMaterialInterface::ClassDef	(	TGeoMaterialInterface	,
		1
	)

ClassDef() [2/2]

genfit::TGeoMaterialInterface::ClassDef	(	TGeoMaterialInterface	,
		1
	)

findNextBoundary() [1/2]

double genfit::TGeoMaterialInterface::findNextBoundary ( const RKTrackRep *  rep, const M1x7 &  state7, double  sMax, bool  varField = true  )

virtual

Make a step (following the curvature) until step length sMax or the next boundary is reached. After making a step to a boundary, the position has to be beyond the boundary, i.e. the current material has to be that beyond the boundary. The actual step made is returned.

Implements genfit::AbsMaterialInterface.

Definition at line 88 of file TGeoMaterialInterface.cc.

{
  const double delta(1.E-2); // cm, distance limit beneath which straight-line steps are taken.
  const double epsilon(1.E-1); // cm, allowed upper bound on arch
                   // deviation from straight line
 
  M1x3 SA;
  M1x7 state7, oldState7;
  memcpy(oldState7, stateOrig, sizeof(state7));
 
  int stepSign(sMax < 0 ? -1 : 1);
 
  double s = 0;  // trajectory length to boundary
 
  const unsigned maxIt = 300;
  unsigned it = 0;
 
  // Initialize the geometry to the current location (set by caller).
  gGeoManager->FindNextBoundary(fabs(sMax) - s);
  double safety = gGeoManager->GetSafeDistance();
  double slDist = gGeoManager->GetStep();
  double step = slDist;
 
  while (1) {
    if (++it > maxIt){
      Exception exc("TGeoMaterialInterface::findNextBoundary ==> maximum number of iterations exceeded",__LINE__,__FILE__);
      exc.setFatal();
      throw exc;
    }
 
    // No boundary in sight?
    if (s + safety > fabs(sMax)) {
      if (debug)
    std::cout << "   next boundary is further away than sMax \n";
      return stepSign*(s + safety); //sMax;
    }
 
    // Are we at the boundary?
    if (slDist < delta) {
      if (debug)
    std::cout << "   very close to the boundary -> return"
          << " stepSign*(s + slDist) = "
          << stepSign << "*(" << s + slDist << ")\n";
      return stepSign*(s + slDist);
    }
 
    // We have to find whether there's any boundary on our path.
 
    // Follow curved arch, then see if we may have missed a boundary.
    // Always propagate complete way from original start to avoid
    // inconsistent extrapolations.
    memcpy(state7, stateOrig, sizeof(state7));
    rep->RKPropagate(state7, NULL, SA, stepSign*(s + step), varField);
 
    // Straight line distance² between extrapolation finish and
    // the end of the previously determined safe segment.
    double dist2 = (pow(state7[0] - oldState7[0], 2)
            + pow(state7[1] - oldState7[1], 2)
            + pow(state7[2] - oldState7[2], 2));
    // Maximal lateral deviation².
    double maxDeviation2 = 0.25*(step*step - dist2);
 
    if (step > safety
    && maxDeviation2 > epsilon*epsilon) {
      // Need to take a shorter step to reliably estimate material,
      // but only if we didn't move by safety.  In order to avoid
      // issues with roundoff we check 'step > safety' instead of
      // 'step != safety'.  If we moved by safety, there couldn't have
      // been a boundary that we missed along the path, but we could
      // be on the boundary.
 
      // Take a shorter step, but never shorter than safety.
      step = std::max(step / 2, safety);
    } else {
      gGeoManager->PushPoint();
      bool volChanged = initTrack(state7[0], state7[1], state7[2],
                  stepSign*state7[3], stepSign*state7[4],
                  stepSign*state7[5]);
 
      if (volChanged) {
    // Move back to start.
    gGeoManager->PopPoint();
 
    // Extrapolation may not take the exact step length we asked
    // for, so it can happen that a requested step < safety takes
    // us across the boundary.  This is then the best estimate we
    // can get of the distance to the boundary with the stepper.
    if (step <= safety)
      return stepSign*(s + step);
 
    // Volume changed during the extrapolation.  Take a shorter
    // step, but never shorter than safety.
    step = std::max(step / 2, safety);
      } else {
    // we're in the new place, the step was safe, advance
    s += step;
 
    memcpy(oldState7, state7, sizeof(state7));
    gGeoManager->PopDummy();  // Pop stack, but stay in place.
 
    gGeoManager->FindNextBoundary(fabs(sMax) - s);
    safety = gGeoManager->GetSafeDistance();
    step = slDist = gGeoManager->GetStep();
      }
    }
  }
}

findNextBoundary() [2/2]

double genfit::TGeoMaterialInterface::findNextBoundary ( const RKTrackRep *  rep, const M1x7 &  state7, double  sMax, bool  varField = true  )

virtual

Make a step (following the curvature) until step length sMax or the next boundary is reached. After making a step to a boundary, the position has to be beyond the boundary, i.e. the current material has to be that beyond the boundary. The actual step made is returned.

Implements genfit::AbsMaterialInterface.

findNextBoundaryAndStepStraight() [1/2]

double genfit::TGeoMaterialInterface::findNextBoundaryAndStepStraight ( double  sMax )

virtual

Implements genfit::AbsMaterialInterface.

Definition at line 201 of file TGeoMaterialInterface.cc.

                                                                  {
 
  gGeoManager->FindNextBoundaryAndStep(sMax);
  return gGeoManager->GetStep();
 
}

findNextBoundaryAndStepStraight() [2/2]

double genfit::TGeoMaterialInterface::findNextBoundaryAndStepStraight ( double  sMax )

virtual

Implements genfit::AbsMaterialInterface.

getMaterialParameters() [1/4]

void genfit::TGeoMaterialInterface::getMaterialParameters ( double &  density, double &  Z, double &  A, double &  radiationLength, double &  mEE  )

virtual

Get material parameters in current material.

Implements genfit::AbsMaterialInterface.

Definition at line 56 of file TGeoMaterialInterface.cc.

                                                           {
 
  TGeoMaterial* mat = gGeoManager->GetCurrentVolume()->GetMedium()->GetMaterial();
 
  density         = mat->GetDensity();
  Z               = mat->GetZ();
  A               = mat->GetA();
  radiationLength = mat->GetRadLen();
  mEE             = MeanExcEnergy_get(mat);
 
}

getMaterialParameters() [2/4]

void genfit::TGeoMaterialInterface::getMaterialParameters ( double &  density, double &  Z, double &  A, double &  radiationLength, double &  mEE  )

virtual

Get material parameters in current material.

Implements genfit::AbsMaterialInterface.

getMaterialParameters() [3/4]

void genfit::TGeoMaterialInterface::getMaterialParameters ( MaterialProperties &  parameters )

virtual

Implements genfit::AbsMaterialInterface.

Definition at line 74 of file TGeoMaterialInterface.cc.

                                                                           {
 
  TGeoMaterial* mat = gGeoManager->GetCurrentVolume()->GetMedium()->GetMaterial();
 
  parameters.setMaterialProperties(mat->GetDensity(),
      mat->GetZ(),
      mat->GetA(),
      mat->GetRadLen(),
      MeanExcEnergy_get(mat));
 
}

getMaterialParameters() [4/4]

void genfit::TGeoMaterialInterface::getMaterialParameters ( MaterialProperties &  parameters )

virtual

Implements genfit::AbsMaterialInterface.

initTrack() [1/2]

bool genfit::TGeoMaterialInterface::initTrack ( double  posX, double  posY, double  posZ, double  dirX, double  dirY, double  dirZ  )

virtual

Initialize the navigator at given position and with given direction. Returns true if the volume changed.

Implements genfit::AbsMaterialInterface.

Definition at line 39 of file TGeoMaterialInterface.cc.

                                                                         {
  #ifdef DEBUG
  std::cout << "TGeoMaterialInterface::initTrack. \n";
  std::cout << "Pos    "; TVector3(posX, posY, posZ).Print();
  std::cout << "Dir    "; TVector3(dirX, dirY, dirZ).Print();
  #endif
 
  // Move to the new point.
  bool result = !gGeoManager->IsSameLocation(posX, posY, posZ, kTRUE);
  // Set the intended direction.
  gGeoManager->SetCurrentDirection(dirX, dirY, dirZ);
  return result;
}

initTrack() [2/2]

bool genfit::TGeoMaterialInterface::initTrack ( double  posX, double  posY, double  posZ, double  dirX, double  dirY, double  dirZ  )

virtual

Initialize the navigator at given position and with given direction. Returns true if the volume changed.

Implements genfit::AbsMaterialInterface.

---

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

• genfit/include/genfit/TGeoMaterialInterface.h
• genfit/trackReps/include/TGeoMaterialInterface.h
• genfit/trackReps/src/TGeoMaterialInterface.cc