RootResidualFunction Class Reference

Minimizer function with access to single data element residuals, required by Fumili2 and GSLMultiMin minimizers. More...

Inheritance diagram for RootResidualFunction:

Collaboration diagram for RootResidualFunction:

Public Types
typedef ROOT::Math::BasicFitMethodFunction< ROOT::Math::IMultiGenFunction >::Type_t	Type_t

Public Member Functions
	RootResidualFunction (scalar_function_t objective_fun, gradient_function_t gradient_fun, size_t npars, size_t ndatasize)
	Constructs RootResidualFunction. More...
ROOT::Math::IMultiGenFunction *	Clone () const override
double	DataElement (const double *pars, unsigned int index, double *gradients=0) const override
	Evaluation of single data element residual. Will be called by ROOT minimizer. More...
Type_t	Type () const override

Private Member Functions
double	DoEval (const double *pars) const override
	evaluation of chi2 More...

Private Attributes
size_t	m_datasize
gradient_function_t	m_gradient_fun
	User function to get residual and gradients. More...
size_t	m_npars
scalar_function_t	m_objective_fun
	User function to get value to minimizer. More...

Detailed Description

Minimizer function with access to single data element residuals, required by Fumili2 and GSLMultiMin minimizers.

Definition at line 37 of file RootResidualFunction.h.

Member Typedef Documentation

Type_t

typedef ROOT::Math::BasicFitMethodFunction<ROOT::Math::IMultiGenFunction>::Type_t RootResidualFunction::Type_t

Definition at line 39 of file RootResidualFunction.h.

Constructor & Destructor Documentation

RootResidualFunction()

RootResidualFunction::RootResidualFunction	(	scalar_function_t	objective_fun,
		gradient_function_t	gradient_fun,
		size_t	npars,
		size_t	ndatasize
	)

Constructs RootResidualFunction.

Definition at line 17 of file RootResidualFunction.cpp.

    : ROOT::Math::FitMethodFunction(static_cast<int>(npars), static_cast<int>(ndatasize))
    , m_objective_fun(objective_fun)
    , m_gradient_fun(gradient_fun)
    , m_npars(npars)
    , m_datasize(ndatasize)
{
}

Referenced by Clone().

Member Function Documentation

Clone()

ROOT::Math::IMultiGenFunction * RootResidualFunction::Clone ( ) const

override

Definition at line 33 of file RootResidualFunction.cpp.

{
    return new RootResidualFunction(m_objective_fun, m_gradient_fun, m_npars, m_datasize);
}

References RootResidualFunction(), m_datasize, m_gradient_fun, m_npars, and m_objective_fun.

Here is the call graph for this function:

DataElement()

double RootResidualFunction::DataElement ( const double *  pars, unsigned int  index, double *  gradients = 0  ) const

override

Evaluation of single data element residual. Will be called by ROOT minimizer.

Returns residual value for given data element index.

Transform call of ancient pointer based function to safer gradient_function_t.

Parameters

pars	array of fit parameter values from the minimizer
index	index of residual element
gradients	if not zero, then array where we have to put gradients

Returns

value of residual for given data element index

Definition at line 45 of file RootResidualFunction.cpp.

{
    std::vector<double> par_values;
    par_values.resize(m_npars, 0.0);
    std::copy(pars, pars + m_npars, par_values.begin());
 
    std::vector<double> par_gradients;
 
    if (gradients)
        par_gradients.resize(m_npars);
 
    // retrieving result from user function
    double result = m_gradient_fun(par_values, index, par_gradients);
 
    // packing result back to minimizer's array
    if (gradients)
        for (size_t i = 0; i < m_npars; ++i)
            gradients[i] = par_gradients[i];
 
    return result;
}

References m_gradient_fun, and m_npars.

DoEval()

double RootResidualFunction::DoEval ( const double *  pars ) const

overrideprivate

evaluation of chi2

Definition at line 68 of file RootResidualFunction.cpp.

{
    std::vector<double> par_values;
    par_values.resize(m_npars, 0.0);
    std::copy(pars, pars + m_npars, par_values.begin());
    return m_objective_fun(par_values);
}

References m_npars, and m_objective_fun.

Type()

RootResidualFunction::Type_t RootResidualFunction::Type ( ) const

override

Definition at line 28 of file RootResidualFunction.cpp.

{
    return ROOT::Math::FitMethodFunction::kLeastSquare;
}

Member Data Documentation

m_datasize

size_t RootResidualFunction::m_datasize

private

Definition at line 60 of file RootResidualFunction.h.

Referenced by Clone().

m_gradient_fun

gradient_function_t RootResidualFunction::m_gradient_fun

private

User function to get residual and gradients.

Definition at line 58 of file RootResidualFunction.h.

Referenced by Clone(), and DataElement().

m_npars

size_t RootResidualFunction::m_npars

private

Definition at line 59 of file RootResidualFunction.h.

Referenced by Clone(), DataElement(), and DoEval().

m_objective_fun

scalar_function_t RootResidualFunction::m_objective_fun

private

User function to get value to minimizer.

Definition at line 57 of file RootResidualFunction.h.

Referenced by Clone(), and DoEval().

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

• /home/www/ba/Fit/Adapter/RootResidualFunction.h
• /home/www/ba/Fit/Adapter/RootResidualFunction.cpp