G4CachedMagneticField Class Reference

G4CachedMagneticField is a specialisation of G4MagneticField and is used to cache the Magnetic Field value, for fields whose evaluation is expensive. More...

#include <G4CachedMagneticField.hh>

Inheritance diagram for G4CachedMagneticField:

Public Member Functions
	G4CachedMagneticField (G4MagneticField *pMagField, G4double distance)
	~G4CachedMagneticField () override=default
	G4CachedMagneticField (const G4CachedMagneticField &r)
G4CachedMagneticField &	operator= (const G4CachedMagneticField &p)
void	GetFieldValue (const G4double Point[4], G4double *Bfield) const override
G4double	GetConstDistance () const
void	SetConstDistance (G4double dist)
G4int	GetCountCalls () const
G4int	GetCountEvaluations () const
void	ClearCounts ()
void	ReportStatistics ()
G4Field *	Clone () const override
Public Member Functions inherited from G4MagneticField
	G4MagneticField ()
	~G4MagneticField () override=default
	G4MagneticField (const G4MagneticField &r)
G4MagneticField &	operator= (const G4MagneticField &p)
G4bool	DoesFieldChangeEnergy () const override
G4FieldType	GetFieldType () const override
Public Member Functions inherited from G4Field
	G4Field (G4bool gravityOn=false)
virtual	~G4Field ()=default
	G4Field (const G4Field &p)=default
G4Field &	operator= (const G4Field &p)
G4bool	IsGravityActive () const
void	SetGravityActive (G4bool OnOffFlag)

Protected Attributes
G4int	fCountCalls = 0
G4int	fCountEvaluations = 0

Additional Inherited Members
Static Public Attributes inherited from G4Field
static constexpr G4int	MAX_NUMBER_OF_COMPONENTS = 24

Detailed Description

G4CachedMagneticField is a specialisation of G4MagneticField and is used to cache the Magnetic Field value, for fields whose evaluation is expensive.

Definition at line 47 of file G4CachedMagneticField.hh.

Constructor & Destructor Documentation

G4CachedMagneticField() [1/2]

G4CachedMagneticField::G4CachedMagneticField	(	G4MagneticField *	pMagField,
		G4double	distance )

Constructor for G4CachedMagneticField.

Parameters

[in]	pMagField	Pointer to the original magnetic field.
[in]	distance	Distance for field evaluation, within which the field does not change.

Definition at line 33 of file G4CachedMagneticField.cc.

  : fpMagneticField(pMagField), fDistanceConst(distance),
    fLastLocation(DBL_MAX,DBL_MAX,DBL_MAX), fLastValue(DBL_MAX,DBL_MAX,DBL_MAX)
{
  ClearCounts(); 
}

Referenced by Clone(), G4CachedMagneticField(), operator=(), and ~G4CachedMagneticField().

~G4CachedMagneticField()

G4CachedMagneticField::~G4CachedMagneticField ( )

overridedefault

Default Destructor.

G4CachedMagneticField() [2/2]

G4CachedMagneticField::G4CachedMagneticField

(

const G4CachedMagneticField &

r

)

Copy constructor and assignment operator.

Definition at line 61 of file G4CachedMagneticField.cc.

  : G4MagneticField(rightCMF)
{
  fpMagneticField= rightCMF.fpMagneticField;  // NOTE: sharing pointer here!
  fDistanceConst = rightCMF.fDistanceConst;
  fLastLocation  = rightCMF.fLastLocation;
  fLastValue     = rightCMF.fLastValue;
  ClearCounts(); 
}

Member Function Documentation

ClearCounts()

void G4CachedMagneticField::ClearCounts ( )

inline

Resets counters.

Definition at line 93 of file G4CachedMagneticField.hh.

{ fCountCalls = 0; fCountEvaluations=0; }

Referenced by G4CachedMagneticField(), G4CachedMagneticField(), and operator=().

Clone()

G4Field * G4CachedMagneticField::Clone ( ) const

overridevirtual

Returns a pointer of an allocated clone of the field.

Reimplemented from G4Field.

Definition at line 41 of file G4CachedMagneticField.cc.

{
  // Cannot use copy constructor: need to clone the associated magnetic field
 
  auto aF = static_cast<G4MagneticField*>(fpMagneticField->Clone());
  auto cloned = new G4CachedMagneticField(aF, fDistanceConst);
 
  cloned->fLastLocation = fLastLocation;
  cloned->fLastValue = fLastValue;
  return cloned;
}

GetConstDistance()

G4double G4CachedMagneticField::GetConstDistance ( ) const

inline

Getter and setter for the distance within which field is constant.

Definition at line 81 of file G4CachedMagneticField.hh.

{ return fDistanceConst; } 

GetCountCalls()

G4int G4CachedMagneticField::GetCountCalls ( ) const

inline

Accessors.

Definition at line 87 of file G4CachedMagneticField.hh.

{ return fCountCalls; }

GetCountEvaluations()

G4int G4CachedMagneticField::GetCountEvaluations ( ) const

inline

Definition at line 88 of file G4CachedMagneticField.hh.

{ return fCountEvaluations; } 

GetFieldValue()

void G4CachedMagneticField::GetFieldValue ( const G4double Point[4], G4double * Bfield ) const

overridevirtual

Returns the value of the field at the give 'Point'.

Parameters

[in]	Point	The given position time vector (x,y,z,t).
[out]	Bfield	The returned field array.

Implements G4MagneticField.

Definition at line 86 of file G4CachedMagneticField.cc.

{
  G4ThreeVector newLocation( Point[0], Point[1], Point[2] );
 
  G4double      distSq= (newLocation-fLastLocation).mag2();
  ++fCountCalls;
  if( distSq < fDistanceConst*fDistanceConst )
  { 
     Bfield[0] = fLastValue.x();
     Bfield[1] = fLastValue.y();
     Bfield[2] = fLastValue.z();
  }
  else
  {
     fpMagneticField->GetFieldValue( Point, Bfield );
     ++fCountEvaluations;
     fLastLocation = G4ThreeVector( Point[0],  Point[1],  Point[2] );
     fLastValue    = G4ThreeVector( Bfield[0], Bfield[1], Bfield[2] );
  }
}

operator=()

G4CachedMagneticField & G4CachedMagneticField::operator=

(

const G4CachedMagneticField &

p

)

Definition at line 73 of file G4CachedMagneticField.cc.

{
  if (&p == this) { return *this; }
  G4MagneticField::operator=(p);
  fpMagneticField= p.fpMagneticField;  // NOTE: sharing pointer here!
  fDistanceConst = p.fDistanceConst;
  fLastLocation  = p.fLastLocation;
  fLastValue     = p.fLastValue;
  ClearCounts(); 
  return *this;
}

ReportStatistics()

void G4CachedMagneticField::ReportStatistics

(

)

Streams on standard output the values of counters.

Definition at line 54 of file G4CachedMagneticField.cc.

{
  G4cout << " Cached field: " << G4endl
         << "   Number of calls:        " << fCountCalls << G4endl
         << "   Number of evaluations : " << fCountEvaluations << G4endl;                     
}

SetConstDistance()

void G4CachedMagneticField::SetConstDistance ( G4double dist )

inline

Definition at line 82 of file G4CachedMagneticField.hh.

{ fDistanceConst = dist;}

Member Data Documentation

fCountCalls

G4int G4CachedMagneticField::fCountCalls = 0

mutableprotected

Definition at line 107 of file G4CachedMagneticField.hh.

Referenced by ClearCounts(), GetCountCalls(), GetFieldValue(), and ReportStatistics().

fCountEvaluations

G4int G4CachedMagneticField::fCountEvaluations = 0

protected

Definition at line 107 of file G4CachedMagneticField.hh.

Referenced by ClearCounts(), GetCountEvaluations(), GetFieldValue(), and ReportStatistics().

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

• G4CachedMagneticField.hh
• G4CachedMagneticField.cc