Definition at line 35 of file TGeoHelix.h.

Public Types
enum	EGeoHelixTypes { kHelixNeedUpdate = BIT(16), kHelixStraigth = BIT(17), kHelixCircle = BIT(18) }

Public Types inherited from TObject
enum	EStatusBits { kCanDelete = BIT(0), kMustCleanup = BIT(3), kObjInCanvas = BIT(3), kIsReferenced = BIT(4), kHasUUID = BIT(5), kCannotPick = BIT(6), kNoContextMenu = BIT(8), kInvalidObject = BIT(13) }

enum	{ kIsOnHeap = 0x01000000, kNotDeleted = 0x02000000, kZombie = 0x04000000, kBitMask = 0x00ffffff }

enum	{ kSingleKey = BIT(0), kOverwrite = BIT(1), kWriteDelete = BIT(2) }

Public Member Functions
	TGeoHelix ()

	TGeoHelix (Double_t curvature, Double_t step, Int_t charge=1)
	Normal constructor. More...

virtual	~TGeoHelix ()
	Destructor. More...

void	InitPoint (Double_t x0, Double_t y0, Double_t z0)
	Initialize coordinates of a point on the helix. More...

void	InitPoint (Double_t *point)
	Set initial point on the helix. More...

void	InitDirection (Double_t dirx, Double_t diry, Double_t dirz, Bool_t is_normalized=kTRUE)
	Initialize particle direction (tangent on the helix in initial point) More...

void	InitDirection (Double_t *dir, Bool_t is_normalized=kTRUE)
	Initialize particle direction (tangent on the helix in initial point) More...

Double_t	ComputeSafeStep (Double_t epsil=1E-6) const
	Compute safe linear step that can be made such that the error between linear-helix extrapolation is less than EPSIL. More...

const Double_t *	GetCurrentPoint () const

const Double_t *	GetCurrentDirection () const

Double_t	GetXYcurvature () const

Double_t	GetStep () const

Double_t	GetTotalCurvature () const
	Compute helix total curvature. More...

Bool_t	IsRightHanded () const

void	ResetStep ()
	Reset current point/direction to initial values. More...

Double_t	StepToPlane (Double_t point, Double_t norm)
	Propagate initial point up to a given Z position in MARS. More...

void	SetCharge (Int_t charge)
	Positive charge means left-handed helix. More...

void	SetXYcurvature (Double_t curvature)
	Set XY curvature: c = 1/Rxy. More...

void	SetField (Double_t bx, Double_t by, Double_t bz, Bool_t is_normalized=kTRUE)
	Initialize particle direction (tangent on the helix in initial point) More...

void	SetHelixStep (Double_t hstep)
	Set Z step of the helix on a complete turn. Positive or null. More...

void	Step (Double_t step)
	Make a step from current point along the helix and compute new point, direction and angle To reach a plane/ shape boundary, one has to: More...

void	UpdateHelix ()
	Update the local helix matrix. More...

Public Member Functions inherited from TObject
	TObject ()

	TObject (const TObject &object)
	TObject copy ctor. More...

TObject &	operator= (const TObject &rhs)
	TObject assignment operator. More...

virtual	~TObject ()
	TObject destructor. More...

virtual void	AppendPad (Option_t *option="")
	Append graphics object to current pad. More...

virtual void	Browse (TBrowser *b)
	Browse object. May be overridden for another default action. More...

virtual const char *	ClassName () const
	Returns name of class to which the object belongs. More...

virtual void	Clear (Option_t *="")

virtual TObject *	Clone (const char *newname="") const
	Make a clone of an object using the Streamer facility. More...

virtual Int_t	Compare (const TObject *obj) const
	Compare abstract method. More...

virtual void	Copy (TObject &object) const
	Copy this to obj. More...

virtual void	Delete (Option_t *option="")
	Delete this object. More...

virtual Int_t	DistancetoPrimitive (Int_t px, Int_t py)
	Computes distance from point (px,py) to the object. More...

virtual void	Draw (Option_t *option="")
	Default Draw method for all objects. More...

virtual void	DrawClass () const
	Draw class inheritance tree of the class to which this object belongs. More...

virtual TObject *	DrawClone (Option_t *option="") const
	Draw a clone of this object in the current pad. More...

virtual void	Dump () const
	Dump contents of object on stdout. More...

virtual void	Execute (const char method, const char params, Int_t *error=0)
	Execute method on this object with the given parameter string, e.g. More...

virtual void	Execute (TMethod method, TObjArray params, Int_t *error=0)
	Execute method on this object with parameters stored in the TObjArray. More...

virtual void	ExecuteEvent (Int_t event, Int_t px, Int_t py)
	Execute action corresponding to an event at (px,py). More...

virtual TObject *	FindObject (const char *name) const
	Must be redefined in derived classes. More...

virtual TObject *	FindObject (const TObject *obj) const
	Must be redefined in derived classes. More...

virtual Option_t *	GetDrawOption () const
	Get option used by the graphics system to draw this object. More...

virtual UInt_t	GetUniqueID () const
	Return the unique object id. More...

virtual const char *	GetName () const
	Returns name of object. More...

virtual const char *	GetIconName () const
	Returns mime type name of object. More...

virtual Option_t *	GetOption () const

virtual char *	GetObjectInfo (Int_t px, Int_t py) const
	Returns string containing info about the object at position (px,py). More...

virtual const char *	GetTitle () const
	Returns title of object. More...

virtual Bool_t	HandleTimer (TTimer *timer)
	Execute action in response of a timer timing out. More...

virtual ULong_t	Hash () const
	Return hash value for this object. More...

virtual Bool_t	InheritsFrom (const char *classname) const
	Returns kTRUE if object inherits from class "classname". More...

virtual Bool_t	InheritsFrom (const TClass *cl) const
	Returns kTRUE if object inherits from TClass cl. More...

virtual void	Inspect () const
	Dump contents of this object in a graphics canvas. More...

virtual Bool_t	IsFolder () const
	Returns kTRUE in case object contains browsable objects (like containers or lists of other objects). More...

virtual Bool_t	IsEqual (const TObject *obj) const
	Default equal comparison (objects are equal if they have the same address in memory). More...

virtual Bool_t	IsSortable () const

Bool_t	IsOnHeap () const

Bool_t	IsZombie () const

virtual Bool_t	Notify ()
	This method must be overridden to handle object notification. More...

virtual void	ls (Option_t *option="") const
	The ls function lists the contents of a class on stdout. More...

virtual void	Paint (Option_t *option="")
	This method must be overridden if a class wants to paint itself. More...

virtual void	Pop ()
	Pop on object drawn in a pad to the top of the display list. More...

virtual void	Print (Option_t *option="") const
	This method must be overridden when a class wants to print itself. More...

virtual Int_t	Read (const char *name)
	Read contents of object with specified name from the current directory. More...

virtual void	RecursiveRemove (TObject *obj)
	Recursively remove this object from a list. More...

virtual void	SaveAs (const char filename="", Option_t option="") const
	Save this object in the file specified by filename. More...

virtual void	SavePrimitive (std::ostream &out, Option_t *option="")
	Save a primitive as a C++ statement(s) on output stream "out". More...

virtual void	SetDrawOption (Option_t *option="")
	Set drawing option for object. More...

virtual void	SetUniqueID (UInt_t uid)
	Set the unique object id. More...

virtual void	UseCurrentStyle ()
	Set current style settings in this object This function is called when either TCanvas::UseCurrentStyle or TROOT::ForceStyle have been invoked. More...

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0)
	Write this object to the current directory. More...

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0) const
	Write this object to the current directory. More...

void *	operator new (size_t sz)

void *	operator new[] (size_t sz)

void *	operator new (size_t sz, void *vp)

void *	operator new[] (size_t sz, void *vp)

void	operator delete (void *ptr)
	Operator delete. More...

void	operator delete[] (void *ptr)
	Operator delete []. More...

void	SetBit (UInt_t f, Bool_t set)
	Set or unset the user status bits as specified in f. More...

void	SetBit (UInt_t f)

void	ResetBit (UInt_t f)

Bool_t	TestBit (UInt_t f) const

Int_t	TestBits (UInt_t f) const

void	InvertBit (UInt_t f)

virtual void	Info (const char method, const char msgfmt,...) const
	Issue info message. More...

virtual void	Warning (const char method, const char msgfmt,...) const
	Issue warning message. More...

virtual void	Error (const char method, const char msgfmt,...) const
	Issue error message. More...

virtual void	SysError (const char method, const char msgfmt,...) const
	Issue system error message. More...

virtual void	Fatal (const char method, const char msgfmt,...) const
	Issue fatal error message. More...

void	AbstractMethod (const char *method) const
	Use this method to implement an "abstract" method that you don't want to leave purely abstract. More...

void	MayNotUse (const char *method) const
	Use this method to signal that a method (defined in a base class) may not be called in a derived class (in principle against good design since a child class should not provide less functionality than its parent, however, sometimes it is necessary). More...

void	Obsolete (const char method, const char asOfVers, const char *removedFromVers) const
	Use this method to declare a method obsolete. More...

Private Member Functions
	TGeoHelix (const TGeoHelix &)

TGeoHelix &	operator= (const TGeoHelix &)

Private Attributes
Double_t	fC

Double_t	fS

Double_t	fStep

Double_t	fPhi

Double_t	fPointInit [3]

Double_t	fDirInit [3]

Double_t	fPoint [3]

Double_t	fDir [3]

Double_t	fB [3]

Int_t	fQ

TGeoHMatrix *	fMatrix

Additional Inherited Members
Static Public Member Functions inherited from TObject
static Long_t	GetDtorOnly ()
	Return destructor only flag. More...

static void	SetDtorOnly (void *obj)
	Set destructor only flag. More...

static Bool_t	GetObjectStat ()
	Get status of object stat flag. More...

static void	SetObjectStat (Bool_t stat)
	Turn on/off tracking of objects in the TObjectTable. More...

Protected Member Functions inherited from TObject
void	MakeZombie ()

virtual void	DoError (int level, const char location, const char fmt, va_list va) const
	Interface to ErrorHandler (protected). More...

#include <TGeoHelix.h>

Inheritance diagram for TGeoHelix:

Collaboration diagram for TGeoHelix:

Member Enumeration Documentation

enum TGeoHelix::EGeoHelixTypes

Enumerator
kHelixNeedUpdate
kHelixStraigth
kHelixCircle

Definition at line 53 of file TGeoHelix.h.

Constructor & Destructor Documentation

TGeoHelix::TGeoHelix ( const TGeoHelix & )

private

TGeoHelix::TGeoHelix ( )

TGeoHelix::TGeoHelix	(	Double_t	curvature,
		Double_t	step,
		Int_t	charge = `1`
	)

Normal constructor.

Definition at line 73 of file TGeoHelix.cxx.

TGeoHelix::~TGeoHelix ( )

virtual

Destructor.

Definition at line 95 of file TGeoHelix.cxx.

Member Function Documentation

Double_t TGeoHelix::ComputeSafeStep ( Double_t epsil = 1E-6 ) const

Compute safe linear step that can be made such that the error between linear-helix extrapolation is less than EPSIL.

Definition at line 104 of file TGeoHelix.cxx.

Referenced by StepToPlane().

const Double_t* TGeoHelix::GetCurrentDirection ( ) const

inline

Definition at line 71 of file TGeoHelix.h.

const Double_t* TGeoHelix::GetCurrentPoint ( ) const

inline

Definition at line 70 of file TGeoHelix.h.

Double_t TGeoHelix::GetStep ( ) const

inline

Definition at line 73 of file TGeoHelix.h.

Double_t TGeoHelix::GetTotalCurvature ( ) const

Compute helix total curvature.

Definition at line 156 of file TGeoHelix.cxx.

Referenced by ComputeSafeStep().

Double_t TGeoHelix::GetXYcurvature ( ) const

inline

Definition at line 72 of file TGeoHelix.h.

void TGeoHelix::InitDirection	(	Double_t	dirx,
		Double_t	diry,
		Double_t	dirz,
		Bool_t	is_normalized = `kTRUE`
	)

Initialize particle direction (tangent on the helix in initial point)

Definition at line 134 of file TGeoHelix.cxx.

Referenced by InitDirection().

void TGeoHelix::InitDirection	(	Double_t *	dir,
		Bool_t	is_normalized = `kTRUE`
	)

Initialize particle direction (tangent on the helix in initial point)

Definition at line 148 of file TGeoHelix.cxx.

void TGeoHelix::InitPoint	(	Double_t	x0,
		Double_t	y0,
		Double_t	z0
	)

Initialize coordinates of a point on the helix.

Definition at line 115 of file TGeoHelix.cxx.

Referenced by InitPoint().

void TGeoHelix::InitPoint ( Double_t * point )

Set initial point on the helix.

Definition at line 126 of file TGeoHelix.cxx.

Bool_t TGeoHelix::IsRightHanded ( ) const

inline

Definition at line 75 of file TGeoHelix.h.

TGeoHelix& TGeoHelix::operator= ( const TGeoHelix & )

private

void TGeoHelix::ResetStep ( )

Reset current point/direction to initial values.

Definition at line 225 of file TGeoHelix.cxx.

Referenced by StepToPlane().

void TGeoHelix::SetCharge ( Int_t charge )

Positive charge means left-handed helix.

Definition at line 182 of file TGeoHelix.cxx.

Referenced by TGeoHelix().

void TGeoHelix::SetField	(	Double_t	bx,
		Double_t	by,
		Double_t	bz,
		Bool_t	is_normalized = `kTRUE`
	)

Initialize particle direction (tangent on the helix in initial point)

Definition at line 197 of file TGeoHelix.cxx.

void TGeoHelix::SetHelixStep ( Double_t hstep )

Set Z step of the helix on a complete turn. Positive or null.

Definition at line 211 of file TGeoHelix.cxx.

Referenced by TGeoHelix().

void TGeoHelix::SetXYcurvature ( Double_t curvature )

Set XY curvature: c = 1/Rxy.

Definition at line 165 of file TGeoHelix.cxx.

Referenced by TGeoHelix().

void TGeoHelix::Step ( Double_t step )

Make a step from current point along the helix and compute new point, direction and angle To reach a plane/ shape boundary, one has to:

Compute the safety to the plane/boundary
Define / update a helix according local field and particle state (position, direction, charge)
Compute the magnetic safety (maximum distance for which the field can be considered constant)
Call TGeoHelix::Step() having as argument the minimum between 1. and 3.
Repeat from 1. until the step to be made is small enough.
Add to the total step the distance along a straigth line from the last point to the plane/shape boundary

Definition at line 243 of file TGeoHelix.cxx.

Referenced by StepToPlane().