template<class FunctionType>
class ROOT::Math::BasicFitMethodFunction< FunctionType >

FitMethodFunction class Interface for objective functions (like chi2 and likelihood used in the fit) In addition to normal function interface provide interface for calculating each data contribution to the function which is required by some algorithm (like Fumili)

Definition at line 38 of file FitMethodFunction.h.

Public Types
typedef FunctionType::BaseFunc	BaseFunction

enum	Type_t { kUndefined = 0 , kLeastSquare , kLogLikelihood , kPoissonLikelihood }
	enumeration specifying the possible fit method types More...

Public Member Functions
	BasicFitMethodFunction (int dim, int npoint)

	~BasicFitMethodFunction () override
	Virtual Destructor (no operations)

virtual double	DataElement (const double x, unsigned int i, double g=nullptr, double *h=nullptr, bool fullHessian=false) const =0
	method returning the data i-th contribution to the fit objective function For example the residual for the least square functions or the pdf element for the likelihood functions.

virtual bool	G2 (const double , double ) const
	Computes the Second derivatives.

virtual bool	HasHessian () const

virtual bool	Hessian (const double x, double hess) const
	Computes the full Hessian.

bool	IsAGradFCN ()

virtual unsigned int	NCalls () const
	return the total number of function calls (override if needed)

unsigned int	NDim () const override
	Number of dimension (parameters) .

virtual unsigned int	NPoints () const
	return the number of data points used in evaluating the function

virtual void	ResetNCalls ()
	reset number of function calls

virtual Type_t	Type () const
	return the type of method, override if needed

virtual void	UpdateNCalls () const
	update number of calls

Static Public Member Functions
static bool	IsAGradFCN ()
	Static function to indicate if a function is supporting gradient.

Private Attributes
unsigned int	fNCalls

unsigned int	fNDim

unsigned int	fNPoints

#include <Math/FitMethodFunction.h>

Inheritance diagram for ROOT::Math::BasicFitMethodFunction< FunctionType >:

[legend]

Member Typedef Documentation

◆ BaseFunction

template<class FunctionType >

typedef FunctionType::BaseFunc ROOT::Math::BasicFitMethodFunction< FunctionType >::BaseFunction

Definition at line 43 of file FitMethodFunction.h.

Member Enumeration Documentation

◆ Type_t

template<class FunctionType >

enum ROOT::Math::BasicFitMethodFunction::Type_t

enumeration specifying the possible fit method types

Enumerator
kUndefined
kLeastSquare
kLogLikelihood
kPoissonLikelihood

Definition at line 46 of file FitMethodFunction.h.

Constructor & Destructor Documentation

◆ BasicFitMethodFunction()

template<class FunctionType >

ROOT::Math::BasicFitMethodFunction< FunctionType >::BasicFitMethodFunction	(	int	dim,
		int	npoint
	)

inline

Definition at line 49 of file FitMethodFunction.h.

◆ ~BasicFitMethodFunction()

template<class FunctionType >

ROOT::Math::BasicFitMethodFunction< FunctionType >::~BasicFitMethodFunction ( )

inlineoverride

Virtual Destructor (no operations)

Definition at line 58 of file FitMethodFunction.h.

Member Function Documentation

◆ DataElement()

template<class FunctionType >

virtual double ROOT::Math::BasicFitMethodFunction< FunctionType >::DataElement	(	const double *	x,
		unsigned int	i,
		double *	g = `nullptr`,
		double *	h = `nullptr`,
		bool	fullHessian = `false`
	)		const

pure virtual

method returning the data i-th contribution to the fit objective function For example the residual for the least square functions or the pdf element for the likelihood functions.

Estimating also the gradient of the data element if the passed pointer is not null and the Hessian. The flag fullHessian is set when one needs to compute the full Hessian (not the approximated one) and should be used when the full second derivatives of the model functions are available

Implemented in ROOT::Fit::PoissonLikelihoodFCN< DerivFunType, ModelFunType >, ROOT::Fit::Chi2FCN< DerivFunType, ModelFunType >, and ROOT::Fit::LogLikelihoodFCN< DerivFunType, ModelFunType >.

◆ G2()

template<class FunctionType >

virtual bool ROOT::Math::BasicFitMethodFunction< FunctionType >::G2	(	const double *	,
		double *
	)		const

inlinevirtual

Computes the Second derivatives.

Return false if this is not supported

Definition at line 104 of file FitMethodFunction.h.

◆ HasHessian()

template<class FunctionType >

virtual bool ROOT::Math::BasicFitMethodFunction< FunctionType >::HasHessian ( ) const

inlinevirtual

Reimplemented in ROOT::Fit::BasicFCN< DerivFunType, ModelFunType, DataType >, ROOT::Fit::BasicFCN< DerivFunType, ROOT::Math::IParamMultiFunction, BinData >, and ROOT::Fit::BasicFCN< DerivFunType, ROOT::Math::IParamMultiFunction, UnBinData >.

Definition at line 76 of file FitMethodFunction.h.

◆ Hessian()

template<class FunctionType >

virtual bool ROOT::Math::BasicFitMethodFunction< FunctionType >::Hessian	(	const double *	x,
		double *	hess
	)		const

inlinevirtual

Computes the full Hessian.

Return false if Hessian is not supported

Definition at line 81 of file FitMethodFunction.h.

◆ IsAGradFCN() [1/2]

template<class FunctionType >

static bool ROOT::Math::BasicFitMethodFunction< FunctionType >::IsAGradFCN ( )

inlinestatic

Static function to indicate if a function is supporting gradient.

Definition at line 135 of file FitMethodFunction.h.

◆ IsAGradFCN() [2/2]

bool ROOT::Math::BasicFitMethodFunction< ROOT::Math::IMultiGradFunction >::IsAGradFCN ( )

inline

Definition at line 149 of file FitMethodFunction.h.

◆ NCalls()

template<class FunctionType >

virtual unsigned int ROOT::Math::BasicFitMethodFunction< FunctionType >::NCalls ( ) const

inlinevirtual

return the total number of function calls (override if needed)

Definition at line 119 of file FitMethodFunction.h.

◆ NDim()

template<class FunctionType >

unsigned int ROOT::Math::BasicFitMethodFunction< FunctionType >::NDim ( ) const

inlineoverride

Number of dimension (parameters) .

From IGenMultiFunction interface

Definition at line 63 of file FitMethodFunction.h.

◆ NPoints()

template<class FunctionType >

virtual unsigned int ROOT::Math::BasicFitMethodFunction< FunctionType >::NPoints ( ) const

inlinevirtual

return the number of data points used in evaluating the function

Definition at line 109 of file FitMethodFunction.h.

◆ ResetNCalls()

template<class FunctionType >

virtual void ROOT::Math::BasicFitMethodFunction< FunctionType >::ResetNCalls ( )

inlinevirtual

reset number of function calls

Definition at line 129 of file FitMethodFunction.h.

◆ Type()

template<class FunctionType >

virtual Type_t ROOT::Math::BasicFitMethodFunction< FunctionType >::Type ( ) const

inlinevirtual

return the type of method, override if needed

Reimplemented in ROOT::Fit::Chi2FCN< DerivFunType, ModelFunType >, ROOT::Fit::LogLikelihoodFCN< DerivFunType, ModelFunType >, and ROOT::Fit::PoissonLikelihoodFCN< DerivFunType, ModelFunType >.

Definition at line 114 of file FitMethodFunction.h.

◆ UpdateNCalls()

template<class FunctionType >

virtual void ROOT::Math::BasicFitMethodFunction< FunctionType >::UpdateNCalls ( ) const

inlinevirtual

update number of calls

Definition at line 124 of file FitMethodFunction.h.

Member Data Documentation

◆ fNCalls

template<class FunctionType >

unsigned int ROOT::Math::BasicFitMethodFunction< FunctionType >::fNCalls

mutableprivate

Definition at line 143 of file FitMethodFunction.h.

◆ fNDim

template<class FunctionType >

unsigned int ROOT::Math::BasicFitMethodFunction< FunctionType >::fNDim

private

Definition at line 141 of file FitMethodFunction.h.

◆ fNPoints

template<class FunctionType >

unsigned int ROOT::Math::BasicFitMethodFunction< FunctionType >::fNPoints

private

Definition at line 142 of file FitMethodFunction.h.

math/mathcore/inc/Fit/Fitter.h

math/mathcore/inc/Math/FitMethodFunction.h

Public Types

Public Member Functions

Static Public Member Functions

Private Attributes

Member Typedef Documentation

◆ BaseFunction

Member Enumeration Documentation

◆ Type_t

Constructor & Destructor Documentation

◆ BasicFitMethodFunction()

◆ ~BasicFitMethodFunction()

Member Function Documentation

◆ DataElement()

◆ G2()

◆ HasHessian()

◆ Hessian()

◆ IsAGradFCN() [1/2]

◆ IsAGradFCN() [2/2]

◆ NCalls()

◆ NDim()

◆ NPoints()

◆ ResetNCalls()

◆ Type()

◆ UpdateNCalls()

Member Data Documentation

◆ fNCalls

◆ fNDim

◆ fNPoints