ROOT   Reference Guide
ROOT::Minuit2::FumiliStandardChi2FCN Class Reference

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.

FumiliChi2FCN

Definition at line 40 of file FumiliStandardChi2FCN.h.

## Public Member Functions

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

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

~FumiliStandardChi2FCN () override

std::vector< doubleElements (const std::vector< double > &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. More...

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

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

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

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

~FumiliChi2FCN () override

virtual std::vector< doubleElements (const std::vector< double > &par) const =0
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. More...

virtual const std::vector< double > & GetMeasurement (int Index) const =0
Accessor to the parameters of a given measurement. More...

virtual int GetNumberOfMeasurements () const =0
Accessor to the number of measurements used for calculating the present figure of merit. More...

const ParametricFunctionModelFunction () const
Returns the model function used for the data. More...

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

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

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

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

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

~FumiliFCNBase () override

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

virtual void EvaluateAll (const std::vector< double > &par)=0
Evaluate function Value, Gradient and Hessian using Fumili approximation, for values of parameters p The resul is cached inside and is return from the FumiliFCNBase::Value , FumiliFCNBase::Gradient and FumiliFCNBase::Hessian methods. More...

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

virtual double Hessian (unsigned int row, unsigned int col) const
Return Value of the i-th j-th element of the Hessian matrix estimated previously using the FumiliFCNBase::EvaluateAll method. More...

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

Public Member Functions inherited from ROOT::Minuit2::FCNBase
~FCNBase () override

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

double operator() (const std::vector< double > &v) const override=0
The meaning of the vector of parameters is of course defined by the user, who uses the values of those parameters to calculate their function Value. More...

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

virtual double Up () const =0
Error definition of the function. More...

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

virtual double operator() (const std::vector< double > &x) const =0
Evaluates the function using the vector containing the input values. More...

## Private Attributes

std::vector< doublefInvErrors

std::vector< doublefMeasurements

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

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 More...

void SetFCNValue (double value)

#include <Minuit2/FumiliStandardChi2FCN.h>

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## ◆ FumiliStandardChi2FCN() [1/2]

 ROOT::Minuit2::FumiliStandardChi2FCN::FumiliStandardChi2FCN ( const ParametricFunction & modelFCN, const std::vector< double > & meas, const std::vector< double > & pos, const std::vector< 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 60 of file FumiliStandardChi2FCN.h.

## ◆ FumiliStandardChi2FCN() [2/2]

 ROOT::Minuit2::FumiliStandardChi2FCN::FumiliStandardChi2FCN ( const ParametricFunction & modelFCN, const std::vector< double > & meas, const std::vector< std::vector< double > > & pos, const std::vector< 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 101 of file FumiliStandardChi2FCN.h.

## ◆ ~FumiliStandardChi2FCN()

 ROOT::Minuit2::FumiliStandardChi2FCN::~FumiliStandardChi2FCN ( )
inlineoverride

Definition at line 122 of file FumiliStandardChi2FCN.h.

## ◆ Elements()

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

Evaluate function Value, Gradient and Hessian using Fumili approximation, for values of parameters p The resul 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.

## ◆ fInvErrors

 std::vector ROOT::Minuit2::FumiliStandardChi2FCN::fInvErrors
private

Definition at line 182 of file FumiliStandardChi2FCN.h.

## ◆ fMeasurements

 std::vector ROOT::Minuit2::FumiliStandardChi2FCN::fMeasurements
private

Definition at line 179 of file FumiliStandardChi2FCN.h.

## ◆ fPositions

 std::vector > ROOT::Minuit2::FumiliStandardChi2FCN::fPositions
private

Definition at line 181 of file FumiliStandardChi2FCN.h.

Libraries for ROOT::Minuit2::FumiliStandardChi2FCN:
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The documentation for this class was generated from the following files: