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
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.

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
	Return the gradient vector of the function at the given parameter point.

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	~FCNBase ()=default

virtual double	ErrorDef () const
	Error definition of the function.

virtual std::vector< double >	G2 (std::vector< double > const &) const
	Return the diagonal elements of the Hessian (second derivatives).

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.

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