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RooRombergIntegrator Class Reference

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 ,
}

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

TClassIsA () 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 RooAbsFuncintegrand () 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.

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 TObjectClone (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 TObjectDrawClone (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 TObjectFindObject (const char *name) const
Must be redefined in derived classes.

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

virtual Option_tGetDrawOption () 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_tGetOption () 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)

TObjectoperator= (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 TClassClass ()

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 TClassClass ()

static const char * Class_Name ()

static constexpr Version_t Class_Version ()

static const char * DeclFileName ()

Static Public Member Functions inherited from TObject
static TClassClass ()

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

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

#include <RooRombergIntegrator.h>

Inheritance diagram for RooRombergIntegrator:
[legend]

## ◆ SummationRule

Enumerator
Trapezoid
Midpoint

Definition at line 39 of file RooRombergIntegrator.h.

## ◆ 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.

## ◆ 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.

## ◆ RooNumIntFactory

 friend class RooNumIntFactory
friend

Definition at line 62 of file RooRombergIntegrator.h.

## ◆ _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 RooRombergIntegrator::_wksp
protected

! Integrator workspace

Definition at line 84 of file RooRombergIntegrator.h.

## ◆ _x

 std::vector RooRombergIntegrator::_x
protected

Definition at line 85 of file RooRombergIntegrator.h.

## ◆ _xmax

 std::vector RooRombergIntegrator::_xmax
protected

! Upper integration bounds

Definition at line 81 of file RooRombergIntegrator.h.

## ◆ _xmin

 std::vector RooRombergIntegrator::_xmin
protected

! Lower integration bounds

Definition at line 80 of file RooRombergIntegrator.h.

Libraries for RooRombergIntegrator:

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