G4BFieldIntegrationDriver Class Reference

G4BFieldIntegrationDriver is specialised integration driver for pure magnetic field. More...

#include <G4BFieldIntegrationDriver.hh>

Inheritance diagram for G4BFieldIntegrationDriver:

Public Member Functions
	G4BFieldIntegrationDriver (std::unique_ptr< G4VIntegrationDriver > smallStepDriver, std::unique_ptr< G4VIntegrationDriver > largeStepDriver)
	~G4BFieldIntegrationDriver () override=default
	G4BFieldIntegrationDriver (const G4BFieldIntegrationDriver &)=delete
const G4BFieldIntegrationDriver &	operator= (const G4BFieldIntegrationDriver &)=delete
G4double	AdvanceChordLimited (G4FieldTrack &track, G4double hstep, G4double eps, G4double chordDistance) override
G4bool	AccurateAdvance (G4FieldTrack &track, G4double hstep, G4double eps, G4double hinitial=0) override
G4bool	DoesReIntegrate () const override
void	SetEquationOfMotion (G4EquationOfMotion *equation) override
G4EquationOfMotion *	GetEquationOfMotion () override
G4MagIntegratorStepper *	GetStepper () override
G4double	ComputeNewStepSize (G4double errMaxNorm, G4double hstepCurrent) override
void	SetVerboseLevel (G4int level) override
G4int	GetVerboseLevel () const override
void	OnComputeStep (const G4FieldTrack *track) override
void	OnStartTracking () override
void	StreamInfo (std::ostream &os) const override
void	PrintStatistics () const
void	GetDerivatives (const G4FieldTrack &track, G4double dydx[]) const override
void	GetDerivatives (const G4FieldTrack &track, G4double dydx[], G4double field[]) const override
const G4MagIntegratorStepper *	GetStepper () const override
Public Member Functions inherited from G4VIntegrationDriver
virtual	~G4VIntegrationDriver ()=default
virtual void	RenewStepperAndAdjust (G4MagIntegratorStepper *pItsStepper)
virtual G4bool	QuickAdvance (G4FieldTrack &, const G4double[], G4double, G4double &, G4double &)

Additional Inherited Members
Static Protected Attributes inherited from G4VIntegrationDriver
static constexpr G4double	max_stepping_increase = 5
static constexpr G4double	max_stepping_decrease = 0.1

Detailed Description

G4BFieldIntegrationDriver is specialised integration driver for pure magnetic field.

Definition at line 48 of file G4BFieldIntegrationDriver.hh.

Constructor & Destructor Documentation

G4BFieldIntegrationDriver() [1/2]

G4BFieldIntegrationDriver::G4BFieldIntegrationDriver	(	std::unique_ptr< G4VIntegrationDriver >	smallStepDriver,
		std::unique_ptr< G4VIntegrationDriver >	largeStepDriver )

Constructor for the integrator driver.

Parameters

[in]	smallStepDriver	Pointer to driver for small steps.
[in]	largeStepDriver	Pointer to driver for large steps.

Definition at line 61 of file G4BFieldIntegrationDriver.cc.

    : fSmallStepDriver(std::move(smallStepDriver)),
      fLargeStepDriver(std::move(largeStepDriver)),
      fCurrDriver(fSmallStepDriver.get()),
      fEquation(toMagneticEquation(fCurrDriver->GetEquationOfMotion()))
{
  if (fSmallStepDriver->GetEquationOfMotion()
     != fLargeStepDriver->GetEquationOfMotion())
  {
    G4Exception("G4BFieldIntegrationDriver Constructor:",
                "GeomField1001", FatalException, "different EoM");  
  }
}

Referenced by G4BFieldIntegrationDriver(), and operator=().

~G4BFieldIntegrationDriver()

G4BFieldIntegrationDriver::~G4BFieldIntegrationDriver ( )

overridedefault

Default Destructor.

G4BFieldIntegrationDriver() [2/2]

G4BFieldIntegrationDriver::G4BFieldIntegrationDriver ( const G4BFieldIntegrationDriver & )

delete

Copy constructor and assignment operator not allowed.

Member Function Documentation

AccurateAdvance()

G4bool G4BFieldIntegrationDriver::AccurateAdvance ( G4FieldTrack & track, G4double hstep, G4double eps, G4double hinitial = 0 )

inlineoverridevirtual

Integrates ODE from current s (s=s0) to s=s0+h with accuracy eps.

Parameters

[in,out]	track	The current track in field.
[in]	hstep	Proposed step length.
[in]	eps	Requested accuracy, y_err/hstep.
[in]	hinitial	Initial minimum integration step.

Returns

true if integration succeeds.

Implements G4VIntegrationDriver.

AdvanceChordLimited()

G4double G4BFieldIntegrationDriver::AdvanceChordLimited ( G4FieldTrack & track, G4double hstep, G4double eps, G4double chordDistance )

overridevirtual

Computes the step to take, based on chord limits.

Parameters

[in,out]	track	The current track in field.
[in]	hstep	Proposed step length.
[in]	eps	Requested accuracy, y_err/hstep.
[in]	chordDistance	Maximum sagitta distance.

Returns

The length of step taken.

Implements G4VIntegrationDriver.

Definition at line 77 of file G4BFieldIntegrationDriver.cc.

{
  const G4double radius = CurvatureRadius(yCurrent);
 
  G4VIntegrationDriver* driver = nullptr;
  if (chordDistance < 2 * radius)
  {
    stepMax = std::min(stepMax, twopi * radius);
    driver = fSmallStepDriver.get();
    ++fSmallDriverSteps;
  }
  else
  {
    driver = fLargeStepDriver.get();
    ++fLargeDriverSteps;
  }
 
  if (driver != fCurrDriver)
  {
    driver->OnComputeStep();
  }
 
  fCurrDriver = driver;
 
  return fCurrDriver->AdvanceChordLimited(yCurrent, stepMax,
                                          epsStep, chordDistance);
}

ComputeNewStepSize()

G4double G4BFieldIntegrationDriver::ComputeNewStepSize ( G4double errMaxNorm, G4double hstepCurrent )

inlineoverridevirtual

Computes a step size for the next step, taking the last step's normalised error 'errMaxNorm'.

Parameters

[in]	errMaxNorm	The normalised error on last step.
[in]	hstepCurrent	The current proposed step.

Returns

The step size for the next step.

Implements G4VIntegrationDriver.

DoesReIntegrate()

G4bool G4BFieldIntegrationDriver::DoesReIntegrate ( ) const

inlineoverridevirtual

Checks whether the driver implements re-integration.

Returns

true if driver Recalculates when AccurateAdvance() is called.

Implements G4VIntegrationDriver.

GetDerivatives() [1/2]

void G4BFieldIntegrationDriver::GetDerivatives ( const G4FieldTrack & track, G4double dydx[] ) const

inlineoverridevirtual

[[deprecated("will be removed")]]

Implements G4VIntegrationDriver.

GetDerivatives() [2/2]

void G4BFieldIntegrationDriver::GetDerivatives ( const G4FieldTrack & track, G4double dydx[], G4double field[] ) const

inlineoverridevirtual

[[deprecated("will be removed")]]

Implements G4VIntegrationDriver.

GetEquationOfMotion()

G4EquationOfMotion * G4BFieldIntegrationDriver::GetEquationOfMotion ( )

inlineoverridevirtual

Implements G4VIntegrationDriver.

Referenced by G4BFieldIntegrationDriver().

GetStepper() [1/2]

const G4MagIntegratorStepper * G4BFieldIntegrationDriver::GetStepper ( ) const

inlineoverridevirtual

[[deprecated("use GetEquationOfMotion() instead of GetStepper()->GetEquationOfMotion()")]]

Implements G4VIntegrationDriver.

GetStepper() [2/2]

G4MagIntegratorStepper * G4BFieldIntegrationDriver::GetStepper ( )

inlineoverridevirtual

Returns a pointer to the integrator stepper.

Implements G4VIntegrationDriver.

GetVerboseLevel()

G4int G4BFieldIntegrationDriver::GetVerboseLevel ( ) const

inlineoverridevirtual

Implements G4VIntegrationDriver.

OnComputeStep()

void G4BFieldIntegrationDriver::OnComputeStep ( const G4FieldTrack * track )

inlineoverridevirtual

Dispatch interface method for computing step.

Implements G4VIntegrationDriver.

OnStartTracking()

void G4BFieldIntegrationDriver::OnStartTracking ( )

inlineoverridevirtual

Dispatch interface method for initialisation/reset of driver.

Implements G4VIntegrationDriver.

operator=()

const G4BFieldIntegrationDriver & G4BFieldIntegrationDriver::operator= ( const G4BFieldIntegrationDriver & )

delete

PrintStatistics()

void G4BFieldIntegrationDriver::PrintStatistics

(

)

const

Prints out statistics of the integrator driver.

Definition at line 148 of file G4BFieldIntegrationDriver.cc.

{
  const auto totSteps = fSmallDriverSteps + fLargeDriverSteps;
  const auto toFraction = [&](double value) { return value / totSteps * 100; };
 
  G4cout << "============= G4BFieldIntegrationDriver statistics ===========\n"
         << "total steps " << totSteps << " "
         << "smallDriverSteps " << toFraction(fSmallDriverSteps) << " "
         << "largeDriverSteps " << toFraction(fLargeDriverSteps) << "\n"
         << "======================================\n";
}

SetEquationOfMotion()

void G4BFieldIntegrationDriver::SetEquationOfMotion ( G4EquationOfMotion * equation )

overridevirtual

Setter and getter for the equation of motion.

Implements G4VIntegrationDriver.

Definition at line 109 of file G4BFieldIntegrationDriver.cc.

{
  fEquation = toMagneticEquation(equation);
  fSmallStepDriver->SetEquationOfMotion(equation);
  fLargeStepDriver->SetEquationOfMotion(equation);
}

SetVerboseLevel()

void G4BFieldIntegrationDriver::SetVerboseLevel ( G4int level )

inlineoverridevirtual

Setter and getter for verbosity.

Implements G4VIntegrationDriver.

StreamInfo()

void G4BFieldIntegrationDriver::StreamInfo ( std::ostream & os ) const

inlineoverridevirtual

Writes out to stream the parameters/state of the driver.

Implements G4VIntegrationDriver.

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

• G4BFieldIntegrationDriver.hh
• G4BFieldIntegrationDriver.cc