RootResidualFunction Class Reference

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)
Type_t	Type () const override
ROOT::Math::IMultiGenFunction *	Clone () const override
double	DataElement (const double *pars, unsigned int index, double *gradients=0) const override

Private Member Functions
double	DoEval (const double *pars) const override

Private Attributes
scalar_function_t	m_objective_fun
gradient_function_t	m_gradient_fun
size_t	m_npars
size_t	m_datasize

Detailed Description

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

Definition at line 32 of file RootResidualFunction.h.

Member Typedef Documentation

Type_t

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

Definition at line 35 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

Type()

RootResidualFunction::Type_t RootResidualFunction::Type ( ) const

override

Definition at line 26 of file RootResidualFunction.cpp.

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

Clone()

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

override

Definition at line 31 of file RootResidualFunction.cpp.

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

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

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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 43 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 66 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.

Member Data Documentation

m_objective_fun

scalar_function_t RootResidualFunction::m_objective_fun

private

User function to get value to minimizer.

Definition at line 53 of file RootResidualFunction.h.

Referenced by Clone(), and DoEval().

m_gradient_fun

gradient_function_t RootResidualFunction::m_gradient_fun

private

User function to get residual and gradients.

Definition at line 54 of file RootResidualFunction.h.

Referenced by Clone(), and DataElement().

m_npars

size_t RootResidualFunction::m_npars

private

Definition at line 55 of file RootResidualFunction.h.

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

m_datasize

size_t RootResidualFunction::m_datasize

private

Definition at line 56 of file RootResidualFunction.h.

Referenced by Clone().

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

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