Backward compatible implementation of TVirtualFitter.

Backward compatible implementation of TVirtualFitter using the class ROOT::Fit::Fitter. This class is created after fitting an histogram (TH1), TGraph or TTree and provides in addition to the methods of the TVirtualFitter hooks to access the fit result class (ROOT::Fit::FitResult), the fit configuration (ROOT::Fit::FitConfig) or the fit data (ROOT::Fit::FitData) using

TBackCompFitter * fitter = (TBackCompFitter *) TVirtualFitter::GetFitter();
ROOT::Fit::FitResult & result = fitter->GetFitResult();
result.Print(std::cout);

Methods for getting the confidence level or contours are also provided. Note that after a new calls to TH1::Fit (or similar) the class will be deleted and all reference to the FitResult, FitConfig or minimizer will be invalid. One could eventually copying the class before issuing a new fit to avoid deleting this information.

Definition at line 37 of file TBackCompFitter.h.

Public Types
enum	EStatusBits { kCanDeleteLast = BIT(9) }

Public Types inherited from TVirtualFitter
typedef void(*	FCNFunc_t) (Int_t &npar, Double_t gin, Double_t &f, Double_t u, Int_t flag)

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) }

Public Member Functions
	TBackCompFitter ()
	Constructor needed by TVirtualFitter interface.

	TBackCompFitter (const std::shared_ptr< ROOT::Fit::Fitter > &fitter, const std::shared_ptr< ROOT::Fit::FitData > &data)
	Constructor used after having fit using directly ROOT::Fit::Fitter will create a dummy fitter copying configuration and parameter settings.

virtual	~TBackCompFitter ()
	Destructor - delete the managed objects.

virtual Double_t	Chisquare (Int_t npar, Double_t *params) const
	Do chisquare calculations in case of likelihood fits Do evaluation a the minimum only.

virtual void	Clear (Option_t *option="")
	Clear resources for consecutive fits.

bool	Contour (unsigned int ipar, unsigned int jpar, TGraph *gr, double confLevel=0.683)
	Create a 2D contour around the minimum for the parameter ipar and jpar if a minimum does not exist or is invalid it will return false on exit a TGraph is filled with the contour points the number of contour points is determined by the size of the TGraph.

virtual Int_t	ExecuteCommand (const char command, Double_t args, Int_t nargs)
	Execute the command (Fortran Minuit compatible interface)

virtual void	FixParameter (Int_t ipar)
	Fix the parameter.

virtual void	GetConfidenceIntervals (Int_t n, Int_t ndim, const Double_t x, Double_t ci, Double_t cl=0.95)
	Computes point-by-point confidence intervals for the fitted function.

virtual void	GetConfidenceIntervals (TObject *obj, Double_t cl=0.95)
	Computes confidence intervals at level cl.

virtual Double_t *	GetCovarianceMatrix () const
	Get the error matrix in a pointer to a NxN array.

virtual Double_t	GetCovarianceMatrixElement (Int_t i, Int_t j) const
	Get error matrix element (return all zero if matrix is not available)

virtual Int_t	GetErrors (Int_t ipar, Double_t &eplus, Double_t &eminus, Double_t &eparab, Double_t &globcc) const
	Get fit errors.

ROOT::Fit::FitConfig &	GetFitConfig ()

const ROOT::Fit::FitData &	GetFitData () const

const ROOT::Fit::FitResult &	GetFitResult () const

ROOT::Math::Minimizer *	GetMinimizer () const
	Return a pointer to the minimizer.

virtual Int_t	GetNumberFreeParameters () const

virtual Int_t	GetNumberTotalParameters () const
	Number of total parameters.

ROOT::Math::IMultiGenFunction *	GetObjFunction () const
	Return a pointer to the objective function (FCN) If fitting directly using TBackCompFitter the pointer is managed by the class, which has been set previously when calling SetObjFunction or SetFCN Otherwise if the class is used in the backward compatible mode (e.g.

virtual Double_t	GetParameter (Int_t ipar) const
	Parameter value.

virtual Int_t	GetParameter (Int_t ipar, char *name, Double_t &value, Double_t &verr, Double_t &vlow, Double_t &vhigh) const
	Get all parameter info (name, value, errors)

virtual Double_t	GetParError (Int_t ipar) const
	Parameter error.

virtual const char *	GetParName (Int_t ipar) const
	Return name of parameter ipar.

virtual Int_t	GetStats (Double_t &amin, Double_t &edm, Double_t &errdef, Int_t &nvpar, Int_t &nparx) const
	Get fit statistical information.

virtual Double_t	GetSumLog (Int_t i)
	Sum of log (un-needed)

TFitResult *	GetTFitResult () const
	Return a new copy of the TFitResult object which needs to be deleted later by the user.

virtual Bool_t	IsFixed (Int_t ipar) const
	Query if parameter ipar is fixed.

virtual void	PrintResults (Int_t level, Double_t amin) const
	Print the fit result.

void	ReCreateMinimizer ()
	Recreate a minimizer instance using the function and data set objective function in minimizers function to re-create FCN from stored data object and fit options.

virtual void	ReleaseParameter (Int_t ipar)
	Release a fit parameter.

bool	Scan (unsigned int ipar, TGraph *gr, double xmin=0, double xmax=0)
	Scan parameter ipar between value of xmin and xmax A graph must be given which will be on return filled with the scan resul If the graph size is zero, a default size n = 40 will be used.

virtual void	SetFCN (void(fcn)(Int_t &, Double_t , Double_t &f, Double_t *, Int_t))
	Override setFCN to use the Adapter to Minuit2 FCN interface To set the address of the minimization function.

virtual void	SetFitMethod (const char *name)
	Set fit method (chi2 or likelihood).

virtual void	SetMethodCall (TMethodCall *m)

virtual void	SetObjFunction (ROOT::Math::IMultiGenFunction *f)
	Set the objective function for fitting Needed if fitting directly using TBackCompFitter class The class clones a copy of the function and manages it.

virtual Int_t	SetParameter (Int_t ipar, const char *parname, Double_t value, Double_t verr, Double_t vlow, Double_t vhigh)
	Set (add) a new fit parameter passing initial value, step size (verr) and parameter limits if vlow > vhigh the parameter is unbounded if the stepsize (verr) == 0 the parameter is treated as fixed.

Public Member Functions inherited from TVirtualFitter
	TVirtualFitter ()
	Default constructor.

virtual	~TVirtualFitter ()
	Cleanup virtual fitter.

virtual FCNFunc_t	GetFCN ()

virtual Foption_t	GetFitOption () const

TMethodCall *	GetMethodCall () const

virtual TObject *	GetObjectFit () const

virtual TObject *	GetUserFunc () const

virtual Int_t	GetXfirst () const

virtual Int_t	GetXlast () const

virtual Int_t	GetYfirst () const

virtual Int_t	GetYlast () const

virtual Int_t	GetZfirst () const

virtual Int_t	GetZlast () const

virtual Double_t *	SetCache (Int_t npoints, Int_t psize)
	Initialize the cache array npoints is the number of points to be stored (or already stored) in the cache psize is the number of elements per point.

virtual void	SetFitOption (Foption_t option)

virtual void	SetObjectFit (TObject *obj)

virtual void	SetUserFunc (TObject *userfunc)

virtual void	SetXfirst (Int_t first)

virtual void	SetXlast (Int_t last)

virtual void	SetYfirst (Int_t first)

virtual void	SetYlast (Int_t last)

virtual void	SetZfirst (Int_t first)

virtual void	SetZlast (Int_t last)

Public Member Functions inherited from TNamed
	TNamed ()

	TNamed (const char name, const char title)

	TNamed (const TNamed &named)
	TNamed copy ctor.

	TNamed (const TString &name, const TString &title)

virtual	~TNamed ()
	TNamed destructor.

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 two TNamed objects.

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

virtual void	FillBuffer (char *&buffer)
	Encode TNamed into output buffer.

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

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

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

virtual Bool_t	IsSortable () const

virtual void	ls (Option_t *option="") const
	List TNamed name and title.

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

virtual void	Print (Option_t *option="") const
	Print TNamed name and title.

virtual void	SetName (const char *name)
	Set the name of the TNamed.

virtual void	SetNameTitle (const char name, const char title)
	Set all the TNamed parameters (name and title).

virtual void	SetTitle (const char *title="")
	Set the title of the TNamed.

virtual Int_t	Sizeof () const
	Return size of the TNamed part of the TObject.

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	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 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 UInt_t	GetUniqueID () const
	Return the unique object id.

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

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

R__ALWAYS_INLINE Bool_t	IsZombie () const

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 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.

Protected Member Functions
void	DoSetDimension ()
	Private method to set dimension in objective function.

bool	ValidParameterIndex (int ipar) const
	Check if ipar is a valid parameter index.

Protected Member Functions inherited from TVirtualFitter
	TVirtualFitter (const TVirtualFitter &tvf)
	copy constructor

TVirtualFitter &	operator= (const TVirtualFitter &tvf)
	assignment operator

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 ()

Private Attributes
std::vector< double >	fCovar

std::shared_ptr< ROOT::Fit::FitData >	fFitData

std::shared_ptr< ROOT::Fit::Fitter >	fFitter
	data of the fit

ROOT::Math::Minimizer *	fMinimizer
	pointer to fitter object

ROOT::Math::IParamMultiFunction *	fModelFunc

ROOT::Math::IMultiGenFunction *	fObjFunc

Additional Inherited Members
Static Public Member Functions inherited from TVirtualFitter
static TVirtualFitter *	Fitter (TObject *obj, Int_t maxpar=25)
	Static function returning a pointer to the current fitter.

static const char *	GetDefaultFitter ()
	static: return the name of the default fitter

static Double_t	GetErrorDef ()
	static: Return the Error Definition

static TVirtualFitter *	GetFitter ()
	static: return the current Fitter

static Int_t	GetMaxIterations ()
	static: Return the maximum number of iterations actually max number of function calls

static Double_t	GetPrecision ()
	static: Return the fit relative precision

static void	SetDefaultFitter (const char *name="")
	static: set name of default fitter

static void	SetErrorDef (Double_t errdef=1)
	static: Set the Error Definition (default=1) For Minuit this is the value passed with the "SET ERR" command (see https://cern-tex.web.cern.ch/cern-tex/minuit/node18.html)

static void	SetFitter (TVirtualFitter *fitter, Int_t maxpar=25)
	Static function to set an alternative fitter.

static void	SetMaxIterations (Int_t niter=5000)
	static: Set the maximum number of function calls for the minimization algorithm For example for MIGRAD this is the maxcalls value passed as first argument (see https://cern-tex.web.cern.ch/cern-tex/minuit/node18.html )

static void	SetPrecision (Double_t prec=1e-6)
	static: Set the tolerance used in the minimization algorithm For example for MIGRAD this is tolerance value passed as second argument (see https://cern-tex.web.cern.ch/cern-tex/minuit/node18.html )

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 Attributes inherited from TVirtualFitter
Double_t *	fCache

Int_t	fCacheSize

void(*	fFCN )(Int_t &npar, Double_t gin, Double_t &f, Double_t u, Int_t flag)

TMethodCall *	fMethodCall

Int_t	fNpoints

TObject *	fObjectFit

Foption_t	fOption

Int_t	fPointSize

TObject *	fUserFunc

Int_t	fXfirst

Int_t	fXlast

Int_t	fYfirst

Int_t	fYlast

Int_t	fZfirst

Int_t	fZlast

Protected Attributes inherited from TNamed
TString	fName

TString	fTitle

#include <TBackCompFitter.h>

Inheritance diagram for TBackCompFitter:

[legend]

Member Enumeration Documentation

◆ EStatusBits

enum TBackCompFitter::EStatusBits

Enumerator
kCanDeleteLast

Definition at line 52 of file TBackCompFitter.h.

Constructor & Destructor Documentation

◆ TBackCompFitter() [1/2]

TBackCompFitter::TBackCompFitter ( )

Constructor needed by TVirtualFitter interface.

Same behavior as default constructor. initialize setting name and the global pointer

Definition at line 77 of file TBackCompFitter.cxx.

◆ TBackCompFitter() [2/2]

TBackCompFitter::TBackCompFitter	(	const std::shared_ptr< ROOT::Fit::Fitter > &	fitter,
		const std::shared_ptr< ROOT::Fit::FitData > &	data
	)

Constructor used after having fit using directly ROOT::Fit::Fitter will create a dummy fitter copying configuration and parameter settings.

Definition at line 89 of file TBackCompFitter.cxx.

◆ ~TBackCompFitter()

TBackCompFitter::~TBackCompFitter ( )

virtual

Destructor - delete the managed objects.

Definition at line 102 of file TBackCompFitter.cxx.

Member Function Documentation

◆ Chisquare()

Double_t TBackCompFitter::Chisquare	(	Int_t	npar,
		Double_t *	params
	)		const

virtual

Do chisquare calculations in case of likelihood fits Do evaluation a the minimum only.

bool TBackCompFitter::Contour	(	unsigned int	ipar,
		unsigned int	jpar,
		TGraph *	gr,
		double	confLevel = `0.683`
	)

n	number of points
ndim	dimensions of points
x	points, at which to compute the intervals, for ndim > 1 should be in order: (x0,y0, x1, y1, ... xn, yn)
ci	computed intervals are returned in this array
cl	confidence level, default=0.95

Fitted object	Passed object
TGraph	TGraphErrors, TH1
TGraphErrors, AsymmErrors	TGraphErrors, TH1
TH1	TGraphErrors, TH1
TGraph2D	TGraph2DErrors, TH2
TGraph2DErrors	TGraph2DErrors, TH2
TH2	TGraph2DErrors, TH2
TH3	TH3

bool TBackCompFitter::Scan	(	unsigned int	ipar,
		TGraph *	gr,
		double	xmin = `0`,
		double	xmax = `0`
	)

Public Types

Public Member Functions

Protected Member Functions

Private Attributes

Additional Inherited Members

Member Enumeration Documentation

◆ EStatusBits

Constructor & Destructor Documentation

◆ TBackCompFitter() [1/2]

◆ TBackCompFitter() [2/2]

◆ ~TBackCompFitter()

Member Function Documentation

◆ Chisquare()

◆ Clear()

◆ Contour()

◆ DoSetDimension()

◆ ExecuteCommand()

◆ FixParameter()

◆ GetConfidenceIntervals() [1/2]

◆ GetConfidenceIntervals() [2/2]

◆ GetCovarianceMatrix()

◆ GetCovarianceMatrixElement()

◆ GetErrors()

◆ GetFitConfig()

◆ GetFitData()

◆ GetFitResult()

◆ GetMinimizer()

◆ GetNumberFreeParameters()

◆ GetNumberTotalParameters()

◆ GetObjFunction()

◆ GetParameter() [1/2]

◆ GetParameter() [2/2]

◆ GetParError()

◆ GetParName()

◆ GetStats()

◆ GetSumLog()

◆ GetTFitResult()

◆ IsFixed()

◆ PrintResults()

◆ ReCreateMinimizer()

◆ ReleaseParameter()

◆ Scan()

◆ SetFCN()

◆ SetFitMethod()

◆ SetMethodCall()

◆ SetObjFunction()

◆ SetParameter()

◆ ValidParameterIndex()

Member Data Documentation

◆ fCovar

◆ fFitData

◆ fFitter

◆ fMinimizer

◆ fModelFunc

◆ fObjFunc