Class implementing the standard chi square function, which is the sum of the squares of the figures-of-merit calculated for each measurement point, the individual figures-of-merit being: (the Value predicted by the model-measured Value)/standard deviation.

Author: Andras Zsenei and Lorenzo Moneta, Creation date: 31 Aug 2004

See also: FumiliChi2FCN

Definition at line 43 of file FumiliStandardChi2FCN.h.

Public Member Functions
	FumiliStandardChi2FCN (const ParametricFunction &modelFCN, std::span< const double > meas, std::span< const double > pos, std::span< const double > mvar)
	Constructor which initializes chi square function for one-dimensional model function.

	FumiliStandardChi2FCN (const ParametricFunction &modelFCN, std::span< const double > meas, std::span< const std::vector< double > > pos, std::span< const double > mvar)
	Constructor which initializes the multi-dimensional model function.

std::vector< double >	Elements (std::vector< double > const &par) const override
	Evaluates the model function for the different measurement points and the Parameter values supplied, calculates a figure-of-merit for each measurement and returns a vector containing the result of this evaluation.

void	EvaluateAll (std::vector< double > const &par) override
	Evaluate function Value, Gradient and Hessian using Fumili approximation, for values of parameters p The result is cached inside and is return from the FumiliFCNBase::Value , FumiliFCNBase::Gradient and FumiliFCNBase::Hessian methods.

const std::vector< double > &	GetMeasurement (int Index) const override
	Accessor to the position of the measurement (x coordinate).

int	GetNumberOfMeasurements () const override
	Accessor to the number of measurements used for calculating the chi-square.

Public Member Functions inherited from ROOT::Minuit2::FumiliChi2FCN
	FumiliChi2FCN ()

	~FumiliChi2FCN () override

const ParametricFunction *	ModelFunction () const
	Returns the model function used for the data.

double	operator() (std::vector< double > const &par) const override
	Calculates the sum of Elements squared, ie the chi-square.

void	SetModelFunction (const ParametricFunction &modelFCN)
	Sets the model function for the data (for example gaussian+linear for a peak)

double	Up () const override
	!!!!!!!!!!!! to be commented

Public Member Functions inherited from ROOT::Minuit2::FumiliFCNBase
	FumiliFCNBase ()
	Default Constructor.

	FumiliFCNBase (unsigned int npar)
	Constructor which initializes the class with the function provided by the user for modeling the data.

	~FumiliFCNBase () override

virtual unsigned int	Dimension ()
	return number of function variable (parameters) , i.e.

virtual const std::vector< double > &	Gradient () const
	Return cached Value of function Gradient estimated previously using the FumiliFCNBase::EvaluateAll method.

std::vector< double >	Gradient (std::vector< double > const &) const override

bool	HasGradient () const override

std::vector< double >	Hessian (std::vector< double > const &) const override
	Return Value of the i-th j-th element of the Hessian matrix estimated previously using the FumiliFCNBase::EvaluateAll method.

virtual double	Hessian (unsigned int row, unsigned int col) const

virtual double	Value () const
	Return cached Value of objective function estimated previously using the FumiliFCNBase::EvaluateAll method.

Public Member Functions inherited from ROOT::Minuit2::FCNBase
virtual double	ErrorDef () const
	Error definition of the function.

virtual std::vector< double >	G2 (std::vector< double > const &) const
	return second derivatives (diagonal of the Hessian matrix)

virtual std::vector< double >	GradientWithPrevResult (std::vector< double > const &parameters, double , double , double *) const

virtual GradientParameterSpace	gradParameterSpace () const

virtual bool	HasG2 () const

virtual bool	HasHessian () const

virtual void	SetErrorDef (double)
	add interface to set dynamically a new error definition Re-implement this function if needed.

Public Member Functions inherited from ROOT::Minuit2::GenericFunction
virtual	~GenericFunction ()

Private Attributes
std::vector< double >	fInvErrors

std::vector< double >	fMeasurements

std::vector< std::vector< double > >	fPositions

Additional Inherited Members
Protected Member Functions inherited from ROOT::Minuit2::FumiliFCNBase
std::vector< double > &	Gradient ()

std::vector< double > &	Hessian ()

virtual void	InitAndReset (unsigned int npar)
	initialize and reset values of gradien and Hessian

void	SetFCNValue (double value)

#include <Minuit2/FumiliStandardChi2FCN.h>

Inheritance diagram for ROOT::Minuit2::FumiliStandardChi2FCN:

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Constructor & Destructor Documentation

◆ FumiliStandardChi2FCN() [1/2]

ROOT::Minuit2::FumiliStandardChi2FCN::FumiliStandardChi2FCN	(	const ParametricFunction &	modelFCN,
		std::span< const double >	meas,
		std::span< const double >	pos,
		std::span< const double >	mvar
	)

inline

Constructor which initializes chi square function for one-dimensional model function.

Parameters

modelFCN	the model function used for describing the data.
meas	vector containing the measured values.
pos	vector containing the x values corresponding to the measurements
mvar	vector containing the variances corresponding to each measurement (where the variance equals the standard deviation squared). If the variances are zero, a Value of 1 is used (as it is done in ROOT/PAW)

Definition at line 63 of file FumiliStandardChi2FCN.h.

◆ FumiliStandardChi2FCN() [2/2]

ROOT::Minuit2::FumiliStandardChi2FCN::FumiliStandardChi2FCN	(	const ParametricFunction &	modelFCN,
		std::span< const double >	meas,
		std::span< const std::vector< double > >	pos,
		std::span< const double >	mvar
	)

inline

Constructor which initializes the multi-dimensional model function.

Parameters

modelFCN	the model function used for describing the data.
meas	vector containing the measured values.
pos	vector containing the x values corresponding to the measurements
mvar	vector containing the variances corresponding to each measurement (where the variance equals the standard deviation squared). If the variances are zero, a Value of 1 is used (as it is done in ROOT/PAW)

Definition at line 104 of file FumiliStandardChi2FCN.h.

Member Function Documentation

◆ Elements()

std::vector< double > ROOT::Minuit2::FumiliStandardChi2FCN::Elements ( std::vector< double > const & par ) const

overridevirtual

Evaluates the model function for the different measurement points and the Parameter values supplied, calculates a figure-of-merit for each measurement and returns a vector containing the result of this evaluation.

The figure-of-merit is (Value predicted by the model function-measured Value)/standard deviation.

Parameters

par	vector of Parameter values to feed to the model function.

Returns: A vector containing the figures-of-merit for the model function evaluated for each set of measurements.

Implements ROOT::Minuit2::FumiliChi2FCN.

Definition at line 19 of file FumiliStandardChi2FCN.cxx.

◆ EvaluateAll()

void ROOT::Minuit2::FumiliStandardChi2FCN::EvaluateAll ( std::vector< double > const & par )

overridevirtual

Evaluate function Value, Gradient and Hessian using Fumili approximation, for values of parameters p The result is cached inside and is return from the FumiliFCNBase::Value , FumiliFCNBase::Gradient and FumiliFCNBase::Hessian methods.

Parameters

par	vector of parameters

Implements ROOT::Minuit2::FumiliFCNBase.

Definition at line 57 of file FumiliStandardChi2FCN.cxx.

◆ GetMeasurement()

const std::vector< double > & ROOT::Minuit2::FumiliStandardChi2FCN::GetMeasurement ( int Index ) const

overridevirtual

Accessor to the position of the measurement (x coordinate).

Parameters

Index Index of the measuerement the position of which to return.

Returns: the position of the measurement.

Implements ROOT::Minuit2::FumiliChi2FCN.

Definition at line 45 of file FumiliStandardChi2FCN.cxx.

◆ GetNumberOfMeasurements()

int ROOT::Minuit2::FumiliStandardChi2FCN::GetNumberOfMeasurements ( ) const

overridevirtual

Accessor to the number of measurements used for calculating the chi-square.

Returns: the number of measurements.

Implements ROOT::Minuit2::FumiliChi2FCN.

Definition at line 51 of file FumiliStandardChi2FCN.cxx.

Member Data Documentation

◆ fInvErrors

std::vector<double> ROOT::Minuit2::FumiliStandardChi2FCN::fInvErrors

private

Definition at line 183 of file FumiliStandardChi2FCN.h.

◆ fMeasurements

std::vector<double> ROOT::Minuit2::FumiliStandardChi2FCN::fMeasurements

private

Definition at line 180 of file FumiliStandardChi2FCN.h.

◆ fPositions

std::vector<std::vector<double> > ROOT::Minuit2::FumiliStandardChi2FCN::fPositions

private

Definition at line 182 of file FumiliStandardChi2FCN.h.

Libraries for ROOT::Minuit2::FumiliStandardChi2FCN:

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

math/minuit2/inc/Minuit2/FumiliStandardChi2FCN.h
math/minuit2/src/FumiliStandardChi2FCN.cxx

Public Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ FumiliStandardChi2FCN() [1/2]

◆ FumiliStandardChi2FCN() [2/2]

Member Function Documentation

◆ Elements()

◆ EvaluateAll()

◆ GetMeasurement()

◆ GetNumberOfMeasurements()

Member Data Documentation

◆ fInvErrors

◆ fMeasurements

◆ fPositions