Class wrapping convolution of two functions.

Class wrapping convolution of two functions: evaluation of \(\int f(x)g(x-t)dx\)

The convolution is performed by default using FFTW if it is available . One can pass optionally the range of the convolution (by default the first function range is used). Note that when using Discrete Fourier Transform (as FFTW), it is a circular transform, so the functions should be approximately zero at the end of the range. If they are significantly different than zero on one side (e.g. the left side) a spill over will occur on the other side (e.g right side). If no function range is given by default the function1 range + 10% is used One should use also a not too small number of points for the DFT (a minimum of 1000). By default 10000 points are used.

Definition at line 20 of file TF1Convolution.h.

Public Member Functions
	TF1Convolution ()
	constructor without arguments

	TF1Convolution (const TF1Convolution &conv)
	Copy constructor (necessary to hold unique_ptr as member variable)

	TF1Convolution (TF1 function1, TF1 function2, Bool_t useFFT=true)
	constructor from the two function pointer and a flag is using FFT

	TF1Convolution (TF1 function1, TF1 function2, Double_t xmin, Double_t xmax, Bool_t useFFT=true)
	Constructor from the two function pointer and the convolution range.

	TF1Convolution (TString formula, Double_t xmin=1., Double_t xmax=0., Bool_t useFFT=true)
	Constructor from a formula expression as f1 * f2 where f1 and f2 are two functions known to ROOT.

	TF1Convolution (TString formula1, TString formula2, Double_t xmin=1., Double_t xmax=0., Bool_t useFFT=true)
	constructor from 2 function names where f1 and f2 are two functions known to ROOT

virtual	~TF1Convolution ()

void	Copy (TObject &obj) const
	Copy this to obj.

Int_t	GetNpar () const

const char *	GetParName (Int_t ipar) const

void	GetRange (Double_t &a, Double_t &b) const

Double_t	GetXmax () const

Double_t	GetXmin () const

Double_t	operator() (const Double_t x, const Double_t p)
	Used in TF1 when doing the fit, will be evaluated at each point.

TF1Convolution &	operator= (const TF1Convolution &rhs)
	Operator =.

void	SetExtraRange (Double_t percentage)

void	SetNofPointsFFT (Int_t n)

void	SetNumConv (Bool_t flag=true)

void	SetParameters (const Double_t *params)

void	SetParameters (Double_t p0, Double_t p1, Double_t p2=0., Double_t p3=0., Double_t p4=0., Double_t p5=0., Double_t p6=0., Double_t p7=0.)

void	SetRange (Double_t a, Double_t b)

void	Update ()
	Update the two component functions of the convolution.

Public Member Functions inherited from TF1AbsComposition
virtual	~TF1AbsComposition ()

Public Member Functions inherited from TObject
	TObject ()
	TObject constructor.

	TObject (const TObject &object)
	TObject copy ctor.

virtual	~TObject ()
	TObject destructor.

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

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

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

ULong_t	CheckedHash ()
	Check and record whether this class has a consistent Hash/RecursiveRemove setup (*) and then return the regular Hash value for this object.

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

virtual void	Clear (Option_t *="")

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

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

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

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

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

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

virtual TObject *	DrawClone (Option_t *option="") const
	Draw a clone of this object in the current selected pad for instance with: `gROOT->SetSelectedPad(gPad)`.

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

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

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.

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

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

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

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

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

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

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

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

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

virtual Option_t *	GetOption () const

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

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

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

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

Bool_t	HasInconsistentHash () const
	Return true is the type of this object is known to have an inconsistent setup for Hash and RecursiveRemove (i.e.

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

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

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

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

void	InvertBit (UInt_t f)

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

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

R__ALWAYS_INLINE Bool_t	IsOnHeap () const

virtual Bool_t	IsSortable () const

R__ALWAYS_INLINE Bool_t	IsZombie () const

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

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).

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

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

void	operator delete (void *ptr)
	Operator delete.

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

void *	operator new (size_t sz)

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

void *	operator new[] (size_t sz)

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

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

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

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

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

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

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

void	ResetBit (UInt_t f)

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

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

void	SetBit (UInt_t f)

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

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

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

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

R__ALWAYS_INLINE Bool_t	TestBit (UInt_t f) const

Int_t	TestBits (UInt_t f) const

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

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

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

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

Private Member Functions
Double_t	EvalFFTConv (Double_t t)

Double_t	EvalNumConv (Double_t t)
	Perform numerical convolution.

void	InitializeDataMembers (TF1 function1, TF1 function2, Bool_t useFFT)
	Use copy instead of Clone.

void	MakeFFTConv ()
	Perform the FFT of the two functions.

Private Attributes
Int_t	fCstIndex
	Index of the constant parameter f the first function.

Bool_t	fFlagFFT
	Choose FFT or numerical convolution.

Bool_t	fFlagGraph = false
	! Tells if the graph is already done or not

std::unique_ptr< TF1 >	fFunction1
	First function to be convolved.

std::unique_ptr< TF1 >	fFunction2
	Second function to be convolved.

std::unique_ptr< TGraph >	fGraphConv
	! Graph of the convolution

Int_t	fNofParams1

Int_t	fNofParams2

Int_t	fNofPoints
	Number of point for FFT array.

std::vector< Double_t >	fParams1

std::vector< Double_t >	fParams2

std::vector< TString >	fParNames
	Parameters' names.

Double_t	fXmax
	Maximal bound of the range of the convolution.

Double_t	fXmin
	Minimal bound of the range of the convolution.

Additional Inherited Members
Public Types inherited from TObject
enum	{ kIsOnHeap = 0x01000000 , kNotDeleted = 0x02000000 , kZombie = 0x04000000 , kInconsistent = 0x08000000 , kBitMask = 0x00ffffff }

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

enum	EDeprecatedStatusBits { kObjInCanvas = BIT(3) }

enum	EStatusBits { kCanDelete = BIT(0) , kMustCleanup = BIT(3) , kIsReferenced = BIT(4) , kHasUUID = BIT(5) , kCannotPick = BIT(6) , kNoContextMenu = BIT(8) , kInvalidObject = BIT(13) }

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

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

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

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

Protected Types inherited from TObject
enum	{ kOnlyPrepStep = BIT(3) }

Protected Member Functions inherited from TObject
virtual void	DoError (int level, const char location, const char fmt, va_list va) const
	Interface to ErrorHandler (protected).

void	MakeZombie ()

#include <TF1Convolution.h>

Inheritance diagram for TF1Convolution:

[legend]

Constructor & Destructor Documentation

◆ TF1Convolution() [1/6]

TF1Convolution::TF1Convolution ( )

constructor without arguments

Definition at line 131 of file TF1Convolution.cxx.

◆ TF1Convolution() [2/6]

TF1Convolution::TF1Convolution	(	TF1 *	function1,
		TF1 *	function2,
		Bool_t	useFFT = `true`
	)

constructor from the two function pointer and a flag is using FFT

Definition at line 139 of file TF1Convolution.cxx.

◆ TF1Convolution() [3/6]

TF1Convolution::TF1Convolution	(	TF1 *	function1,
		TF1 *	function2,
		Double_t	xmin,
		Double_t	xmax,
		Bool_t	useFFT = `true`
	)

Constructor from the two function pointer and the convolution range.

Definition at line 147 of file TF1Convolution.cxx.

◆ TF1Convolution() [4/6]

TF1Convolution::TF1Convolution	(	TString	formula,
		Double_t	xmin = `1.`,
		Double_t	xmax = `0.`,
		Bool_t	useFFT = `true`
	)

Constructor from a formula expression as f1 * f2 where f1 and f2 are two functions known to ROOT.

Definition at line 162 of file TF1Convolution.cxx.

◆ TF1Convolution() [5/6]

TF1Convolution::TF1Convolution	(	TString	formula1,
		TString	formula2,
		Double_t	xmin = `1.`,
		Double_t	xmax = `0.`,
		Bool_t	useFFT = `true`
	)

constructor from 2 function names where f1 and f2 are two functions known to ROOT

if the function names are not known to ROOT, tries to interpret them as TFormula

Definition at line 201 of file TF1Convolution.cxx.

◆ TF1Convolution() [6/6]

TF1Convolution::TF1Convolution ( const TF1Convolution & conv )

Copy constructor (necessary to hold unique_ptr as member variable)

Definition at line 233 of file TF1Convolution.cxx.

◆ ~TF1Convolution()

virtual TF1Convolution::~TF1Convolution ( )

inlinevirtual

Definition at line 55 of file TF1Convolution.h.

Member Function Documentation

◆ Copy()

void TF1Convolution::Copy ( TObject & object ) const

virtual

Copy this to obj.

Implements TF1AbsComposition.

Definition at line 471 of file TF1Convolution.cxx.

◆ EvalFFTConv()

Double_t TF1Convolution::EvalFFTConv ( Double_t t )

private

Definition at line 321 of file TF1Convolution.cxx.

◆ EvalNumConv()

Double_t TF1Convolution::EvalNumConv ( Double_t t )

private

Perform numerical convolution.

Could in principle cache the integral in a Graph as it is done for the FFTW

Definition at line 336 of file TF1Convolution.cxx.

◆ GetNpar()

Int_t TF1Convolution::GetNpar ( ) const

inline

Definition at line 65 of file TF1Convolution.h.

◆ GetParName()

const char * TF1Convolution::GetParName ( Int_t ipar ) const

inline

Definition at line 68 of file TF1Convolution.h.

◆ GetRange()

void TF1Convolution::GetRange	(	Double_t &	a,
		Double_t &	b
	)		const

Definition at line 454 of file TF1Convolution.cxx.

◆ GetXmax()

Double_t TF1Convolution::GetXmax ( ) const

inline

Definition at line 67 of file TF1Convolution.h.

◆ GetXmin()

Double_t TF1Convolution::GetXmin ( ) const

inline

Definition at line 66 of file TF1Convolution.h.

◆ InitializeDataMembers()

void TF1Convolution::InitializeDataMembers	(	TF1 *	function1,
		TF1 *	function2,
		Bool_t	useFFT
	)

private

Use copy instead of Clone.

Definition at line 68 of file TF1Convolution.cxx.

◆ MakeFFTConv()

void TF1Convolution::MakeFFTConv ( )

private

Perform the FFT of the two functions.

Definition at line 251 of file TF1Convolution.cxx.

◆ operator()()

Double_t TF1Convolution::operator()	(	const Double_t *	x,
		const Double_t *	p
	)

virtual

Used in TF1 when doing the fit, will be evaluated at each point.

Implements TF1AbsComposition.

Definition at line 357 of file TF1Convolution.cxx.

◆ operator=()

TF1Convolution & TF1Convolution::operator= ( const TF1Convolution & rhs )

Operator =.

Definition at line 241 of file TF1Convolution.cxx.

◆ SetExtraRange()

void TF1Convolution::SetExtraRange ( Double_t percentage )

Definition at line 421 of file TF1Convolution.cxx.

◆ SetNofPointsFFT()

void TF1Convolution::SetNofPointsFFT ( Int_t n )

Definition at line 371 of file TF1Convolution.cxx.

◆ SetNumConv()

void TF1Convolution::SetNumConv ( Bool_t flag = true )

inline

Definition at line 63 of file TF1Convolution.h.

◆ SetParameters() [1/2]

void TF1Convolution::SetParameters ( const Double_t * params )

virtual

Implements TF1AbsComposition.

Definition at line 381 of file TF1Convolution.cxx.

◆ SetParameters() [2/2]

void TF1Convolution::SetParameters	(	Double_t	p0,
		Double_t	p1,
		Double_t	p2 = `0.`,
		Double_t	p3 = `0.`,
		Double_t	p4 = `0.`,
		Double_t	p5 = `0.`,
		Double_t	p6 = `0.`,
		Double_t	p7 = `0.`
	)

Definition at line 412 of file TF1Convolution.cxx.

◆ SetRange()

void TF1Convolution::SetRange	(	Double_t	a,
		Double_t	b
	)

virtual

Implements TF1AbsComposition.

Definition at line 432 of file TF1Convolution.cxx.

◆ Update()

void TF1Convolution::Update ( )

virtual

Update the two component functions of the convolution.

Implements TF1AbsComposition.

Definition at line 463 of file TF1Convolution.cxx.

Member Data Documentation

◆ fCstIndex

Int_t TF1Convolution::fCstIndex

private

Index of the constant parameter f the first function.

Definition at line 34 of file TF1Convolution.h.

◆ fFlagFFT

Bool_t TF1Convolution::fFlagFFT

private

Choose FFT or numerical convolution.

Definition at line 36 of file TF1Convolution.h.

◆ fFlagGraph

Bool_t TF1Convolution::fFlagGraph = false

private

! Tells if the graph is already done or not

Definition at line 37 of file TF1Convolution.h.

◆ fFunction1

std::unique_ptr<TF1> TF1Convolution::fFunction1

private

First function to be convolved.

Definition at line 21 of file TF1Convolution.h.

◆ fFunction2

std::unique_ptr<TF1> TF1Convolution::fFunction2

private

Second function to be convolved.

Definition at line 22 of file TF1Convolution.h.

◆ fGraphConv

std::unique_ptr<TGraph> TF1Convolution::fGraphConv

private

! Graph of the convolution

Definition at line 23 of file TF1Convolution.h.

◆ fNofParams1

Int_t TF1Convolution::fNofParams1

private

Definition at line 32 of file TF1Convolution.h.

◆ fNofParams2

Int_t TF1Convolution::fNofParams2

private

Definition at line 33 of file TF1Convolution.h.

◆ fNofPoints

Int_t TF1Convolution::fNofPoints

private

Number of point for FFT array.

Definition at line 35 of file TF1Convolution.h.

◆ fParams1

std::vector< Double_t > TF1Convolution::fParams1

private

Definition at line 25 of file TF1Convolution.h.

◆ fParams2

std::vector< Double_t > TF1Convolution::fParams2

private

Definition at line 26 of file TF1Convolution.h.

◆ fParNames

std::vector< TString > TF1Convolution::fParNames

private

Parameters' names.

Definition at line 28 of file TF1Convolution.h.

◆ fXmax

Double_t TF1Convolution::fXmax

private

Maximal bound of the range of the convolution.

Definition at line 31 of file TF1Convolution.h.

◆ fXmin

Double_t TF1Convolution::fXmin

private

Minimal bound of the range of the convolution.

Definition at line 30 of file TF1Convolution.h.

Libraries for TF1Convolution:

[legend]

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

hist/hist/inc/TF1Convolution.h
hist/hist/src/TF1Convolution.cxx

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ TF1Convolution() [1/6]

◆ TF1Convolution() [2/6]

◆ TF1Convolution() [3/6]

◆ TF1Convolution() [4/6]

◆ TF1Convolution() [5/6]

◆ TF1Convolution() [6/6]

◆ ~TF1Convolution()

Member Function Documentation

◆ Copy()

◆ EvalFFTConv()

◆ EvalNumConv()

◆ GetNpar()

◆ GetParName()

◆ GetRange()

◆ GetXmax()

◆ GetXmin()

◆ InitializeDataMembers()

◆ MakeFFTConv()

◆ operator()()

◆ operator=()

◆ SetExtraRange()

◆ SetNofPointsFFT()

◆ SetNumConv()

◆ SetParameters() [1/2]

◆ SetParameters() [2/2]

◆ SetRange()

◆ Update()

Member Data Documentation

◆ fCstIndex

◆ fFlagFFT

◆ fFlagGraph

◆ fFunction1

◆ fFunction2

◆ fGraphConv

◆ fNofParams1

◆ fNofParams2

◆ fNofPoints

◆ fParams1

◆ fParams2

◆ fParNames

◆ fXmax

◆ fXmin