RooRombergIntegrator implements an adaptive numerical integration algorithm.

It uses Romberg's method with trapezoids or midpoints. The integrand is approximated by \( 1, 2, 4, 8, \ldots, 2^n \) trapezoids, and Richardson series acceleration is applied to the series. For refinement step \( n \), that is

\[ R(n,m) = \frac{1}{4^m - 1} \left( 4^m R(n, m-1) - R(n-1, m-1) \right) \]

The integrator will evaluate the first six refinements (i.e. 64 points) in one go, apply a five-point series acceleration, and successively add more steps until the desired precision is reached.

Definition at line 36 of file RooRombergIntegrator.h.

Public Types
enum	SummationRule { Trapezoid , Midpoint }

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

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

enum	EDeprecatedStatusBits { kObjInCanvas = (1ULL << ( 3 )) }

enum	EStatusBits { kCanDelete = (1ULL << ( 0 )) , kMustCleanup = (1ULL << ( 3 )) , kIsReferenced = (1ULL << ( 4 )) , kHasUUID = (1ULL << ( 5 )) , kCannotPick = (1ULL << ( 6 )) , kNoContextMenu = (1ULL << ( 8 )) , kInvalidObject = (1ULL << ( 13 )) }

Public Member Functions
	RooRombergIntegrator (const RooAbsFunc &function, const RooNumIntConfig &config, int nDim=1, bool doSegmentation=false)
	Construct integrator on given function binding, using specified configuration object.

	RooRombergIntegrator (const RooAbsFunc &function, double xmin, double xmax, const RooNumIntConfig &config, int nDim=1)
	Construct integrator on given function binding, using specified configuration object and integration range.

	RooRombergIntegrator (const RooAbsFunc &function, double xmin, double xmax, SummationRule rule=Trapezoid, int maxSteps=0, double eps=0)
	Construct integrator on given function binding for given range, using specified summation rule, maximum number of steps and conversion tolerance.

	RooRombergIntegrator (const RooAbsFunc &function, SummationRule rule=Trapezoid, int maxSteps=0, double eps=0)
	Construct integrator on given function binding, using specified summation rule, maximum number of steps and conversion tolerance.

bool	checkLimits () const override
	Check that our integration range is finite and otherwise return false.

double	integral (const double *yvec=nullptr) override

TClass *	IsA () const override

virtual bool	setLimits (double , double )

bool	setLimits (double xmin, double xmax) override
	Change our integration limits.

virtual bool	setLimits (double xmin, double xmax)
	Interface to set limits on integration.

bool	setUseIntegrandLimits (bool flag) override
	Interface function that allows to defer limit definition to integrand definition.

void	Streamer (TBuffer &) override
	Stream an object of class TObject.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

Public Member Functions inherited from RooAbsIntegrator
	RooAbsIntegrator ()

	RooAbsIntegrator (const RooAbsFunc &function, bool printEvalCounter=false)
	Copy constructor.

double	calculate (const double *yvec=nullptr)
	Calculate integral value with given array of parameter values.

const RooAbsFunc *	integrand () const
	Return integrand function binding.

double	integrand (const double x[]) const
	Return value of integrand at given observable values.

bool	isValid () const
	Is integrator in valid state.

bool	printEvalCounter () const

void	setPrintEvalCounter (bool value)

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

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

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 with: `gROOT->SetSelectedPad(c1)`.

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=nullptr)
	Execute method on this object with the given parameter string, e.g.

virtual void	Execute (TMethod method, TObjArray params, Int_t *error=nullptr)
	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)

Bool_t	IsDestructed () const
	IsDestructed.

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 (the base implementation is no-op).

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, void vp)
	Only called by placement new when throwing an exception.

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

void	operator delete[] (void ptr, void vp)
	Only called by placement new[] when throwing an exception.

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.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

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=nullptr, Int_t option=0, Int_t bufsize=0)
	Write this object to the current directory.

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

Static Public Member Functions
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()
	do not persist

static const char *	DeclFileName ()

Static Public Member Functions inherited from RooAbsIntegrator
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

Static Public Member Functions inherited from TObject
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

static Longptr_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 Member Functions
bool	initialize ()
	Initialize the integrator.

double	integral (int iDim, int nSeg, std::span< double > wksp)
	Calculate numeric integral at given set of function binding parameters.

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 ()

Static Protected Member Functions
static void	registerIntegrator (RooNumIntFactory &fact)
	Register integrator plugins, their parameters and capabilities with RooNumIntFactory.

Protected Attributes
bool	_doExtrap = true
	Apply conversion step?

double	_epsAbs
	Absolute convergence tolerance.

double	_epsRel
	Relative convergence tolerance.

int	_fixSteps = 0
	Fixed number of steps.

int	_maxSteps
	Maximum number of steps.

int	_minStepsZero = 999
	Minimum number of steps to declare convergence to zero.

int	_nDim = 1

int	_nSeg = 1
	Number of segments.

SummationRule	_rule

bool	_useIntegrandLimits
	If true limits of function binding are used.

std::vector< double >	_wksp
	! Integrator workspace

std::vector< double >	_x

std::vector< double >	_xmax
	! Upper integration bounds

std::vector< double >	_xmin
	! Lower integration bounds

Protected Attributes inherited from RooAbsIntegrator
const RooAbsFunc *	_function = nullptr
	Pointer to function binding of integrand.

bool	_printEvalCounter = false
	If true print number of function evaluation required for integration.

bool	_valid = false
	Is integrator in valid state?

Friends
class	RooNumIntFactory

Additional Inherited Members
Protected Types inherited from TObject
enum	{ kOnlyPrepStep = (1ULL << ( 3 )) }

#include <RooRombergIntegrator.h>

Inheritance diagram for RooRombergIntegrator:

[legend]

Member Enumeration Documentation

◆ SummationRule

enum RooRombergIntegrator::SummationRule

Enumerator
Trapezoid
Midpoint

Definition at line 39 of file RooRombergIntegrator.h.

Constructor & Destructor Documentation

◆ RooRombergIntegrator() [1/4]

RooRombergIntegrator::RooRombergIntegrator	(	const RooAbsFunc &	function,
		SummationRule	rule = `Trapezoid`,
		int	maxSteps = `0`,
		double	eps = `0`
	)

Construct integrator on given function binding, using specified summation rule, maximum number of steps and conversion tolerance.

The integration limits are taken from the function binding.

Definition at line 309 of file RooRombergIntegrator.cxx.

◆ RooRombergIntegrator() [2/4]

RooRombergIntegrator::RooRombergIntegrator	(	const RooAbsFunc &	function,
		double	xmin,
		double	xmax,
		SummationRule	rule = `Trapezoid`,
		int	maxSteps = `0`,
		double	eps = `0`
	)

Construct integrator on given function binding for given range, using specified summation rule, maximum number of steps and conversion tolerance.

The integration limits are taken from the function binding.

Definition at line 322 of file RooRombergIntegrator.cxx.

◆ RooRombergIntegrator() [3/4]

RooRombergIntegrator::RooRombergIntegrator	(	const RooAbsFunc &	function,
		const RooNumIntConfig &	config,
		int	nDim = `1`,
		bool	doSegmentation = `false`
	)

Construct integrator on given function binding, using specified configuration object.

The integration limits are taken from the function binding

Definition at line 337 of file RooRombergIntegrator.cxx.

◆ RooRombergIntegrator() [4/4]

RooRombergIntegrator::RooRombergIntegrator	(	const RooAbsFunc &	function,
		double	xmin,
		double	xmax,
		const RooNumIntConfig &	config,
		int	nDim = `1`
	)

Construct integrator on given function binding, using specified configuration object and integration range.

Definition at line 371 of file RooRombergIntegrator.cxx.

Member Function Documentation

◆ checkLimits()

bool RooRombergIntegrator::checkLimits ( ) const

overridevirtual

Check that our integration range is finite and otherwise return false.

Update the limits from the integrand if requested.

Reimplemented from RooAbsIntegrator.

Definition at line 448 of file RooRombergIntegrator.cxx.

◆ Class()

static TClass * RooRombergIntegrator::Class ( )

static

Returns: TClass describing this class

◆ Class_Name()

static const char * RooRombergIntegrator::Class_Name ( )

static

Returns: Name of this class

◆ Class_Version()

static constexpr Version_t RooRombergIntegrator::Class_Version ( )

inlinestaticconstexpr

do not persist

Returns: Version of this class

Definition at line 87 of file RooRombergIntegrator.h.

◆ DeclFileName()

static const char * RooRombergIntegrator::DeclFileName ( )

inlinestatic

Returns: Name of the file containing the class declaration

Definition at line 87 of file RooRombergIntegrator.h.

◆ initialize()

bool RooRombergIntegrator::initialize ( )

protected

Initialize the integrator.

Definition at line 395 of file RooRombergIntegrator.cxx.

◆ integral() [1/2]

double RooRombergIntegrator::integral ( const double * yvec = nullptr )

overridevirtual

Implements RooAbsIntegrator.

Definition at line 475 of file RooRombergIntegrator.cxx.

◆ integral() [2/2]

double RooRombergIntegrator::integral	(	int	iDim,
		int	nSeg,
		std::span< double >	wksp
	)

protected

Calculate numeric integral at given set of function binding parameters.

Definition at line 490 of file RooRombergIntegrator.cxx.

◆ IsA()

TClass * RooRombergIntegrator::IsA ( ) const

inlineoverridevirtual

Returns: TClass describing current object

Reimplemented from RooAbsIntegrator.

Definition at line 87 of file RooRombergIntegrator.h.

◆ registerIntegrator()

void RooRombergIntegrator::registerIntegrator ( RooNumIntFactory & fact )

staticprotected

Register integrator plugins, their parameters and capabilities with RooNumIntFactory.

Definition at line 240 of file RooRombergIntegrator.cxx.

◆ setLimits() [1/3]

virtual bool RooAbsIntegrator::setLimits	(	double *	,
		double *
	)

inlinevirtual

Reimplemented from RooAbsIntegrator.

Definition at line 53 of file RooAbsIntegrator.h.

◆ setLimits() [2/3]

bool RooRombergIntegrator::setLimits	(	double *	xmin,
		double *	xmax
	)

overridevirtual

Change our integration limits.

Return true if the new limits are ok, or otherwise false. Always returns false and does nothing if this object was constructed to always use our integrand's limits.

Reimplemented from RooAbsIntegrator.

Definition at line 428 of file RooRombergIntegrator.cxx.

◆ setLimits() [3/3]

bool RooAbsIntegrator::setLimits	(	double	xmin,
		double	xmax
	)

virtual

Interface to set limits on integration.

Reimplemented from RooAbsIntegrator.

Definition at line 54 of file RooAbsIntegrator.cxx.

◆ setUseIntegrandLimits()

bool RooRombergIntegrator::setUseIntegrandLimits ( bool flag )

inlineoverridevirtual

Interface function that allows to defer limit definition to integrand definition.

Reimplemented from RooAbsIntegrator.

Definition at line 55 of file RooRombergIntegrator.h.

◆ Streamer()

void RooRombergIntegrator::Streamer ( TBuffer & R__b )

overridevirtual

Stream an object of class TObject.

Reimplemented from RooAbsIntegrator.

◆ StreamerNVirtual()

void RooRombergIntegrator::StreamerNVirtual ( TBuffer & ClassDef_StreamerNVirtual_b )

inline

Definition at line 87 of file RooRombergIntegrator.h.

Friends And Related Symbol Documentation

◆ RooNumIntFactory

friend class RooNumIntFactory

friend

Definition at line 62 of file RooRombergIntegrator.h.

Member Data Documentation

◆ _doExtrap

bool RooRombergIntegrator::_doExtrap = true

protected

Apply conversion step?

Definition at line 78 of file RooRombergIntegrator.h.

◆ _epsAbs

double RooRombergIntegrator::_epsAbs

protected

Absolute convergence tolerance.

Definition at line 76 of file RooRombergIntegrator.h.

◆ _epsRel

double RooRombergIntegrator::_epsRel

protected

Relative convergence tolerance.

Definition at line 77 of file RooRombergIntegrator.h.

◆ _fixSteps

int RooRombergIntegrator::_fixSteps = 0

protected

Fixed number of steps.

Definition at line 75 of file RooRombergIntegrator.h.

◆ _maxSteps

int RooRombergIntegrator::_maxSteps

protected

Maximum number of steps.

Definition at line 73 of file RooRombergIntegrator.h.

◆ _minStepsZero

int RooRombergIntegrator::_minStepsZero = 999

protected

Minimum number of steps to declare convergence to zero.

Definition at line 74 of file RooRombergIntegrator.h.

◆ _nDim

int RooRombergIntegrator::_nDim = 1

protected

Definition at line 71 of file RooRombergIntegrator.h.

◆ _nSeg

int RooRombergIntegrator::_nSeg = 1

protected

Number of segments.

Definition at line 79 of file RooRombergIntegrator.h.

◆ _rule

SummationRule RooRombergIntegrator::_rule

protected

Definition at line 72 of file RooRombergIntegrator.h.

◆ _useIntegrandLimits

bool RooRombergIntegrator::_useIntegrandLimits

protected

If true limits of function binding are used.

Definition at line 68 of file RooRombergIntegrator.h.

◆ _wksp

std::vector<double> RooRombergIntegrator::_wksp

protected

! Integrator workspace

Definition at line 84 of file RooRombergIntegrator.h.

◆ _x

std::vector<double> RooRombergIntegrator::_x

protected

Definition at line 85 of file RooRombergIntegrator.h.

◆ _xmax

std::vector<double> RooRombergIntegrator::_xmax

protected

! Upper integration bounds

Definition at line 81 of file RooRombergIntegrator.h.

◆ _xmin

std::vector<double> RooRombergIntegrator::_xmin

protected

! Lower integration bounds

Definition at line 80 of file RooRombergIntegrator.h.

Libraries for RooRombergIntegrator:

[legend]

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

roofit/roofitcore/inc/RooRombergIntegrator.h
roofit/roofitcore/src/RooRombergIntegrator.cxx

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Friends

Additional Inherited Members

Member Enumeration Documentation

◆ SummationRule

Constructor & Destructor Documentation

◆ RooRombergIntegrator() [1/4]

◆ RooRombergIntegrator() [2/4]

◆ RooRombergIntegrator() [3/4]

◆ RooRombergIntegrator() [4/4]

Member Function Documentation

◆ checkLimits()

◆ Class()

◆ Class_Name()

◆ Class_Version()

◆ DeclFileName()

◆ initialize()

◆ integral() [1/2]

◆ integral() [2/2]

◆ IsA()

◆ registerIntegrator()

◆ setLimits() [1/3]

◆ setLimits() [2/3]

◆ setLimits() [3/3]

◆ setUseIntegrandLimits()

◆ Streamer()

◆ StreamerNVirtual()

Friends And Related Symbol Documentation

◆ RooNumIntFactory

Member Data Documentation

◆ _doExtrap

◆ _epsAbs

◆ _epsRel

◆ _fixSteps

◆ _maxSteps

◆ _minStepsZero

◆ _nDim

◆ _nSeg

◆ _rule

◆ _useIntegrandLimits

◆ _wksp

◆ _x

◆ _xmax

◆ _xmin