template<class Func>
class ROOT::Math::LSResidualFunc< Func >

LSResidualFunc class description.

Internal class used for accessing the residuals of the Least Square function and their derivatives which are estimated numerically using GSL numerical derivation. The class contains a pointer to the fit method function and an index specifying the i-th residual and wraps it in a multi-dim gradient function interface ROOT::Math::IGradientFunctionMultiDim. The class is used by ROOT::Math::GSLNLSMinimizer (GSL non linear least square fitter)

Definition at line 135 of file GSLNLSMinimizer.cxx.

Public Types
typedef double	BackendType
typedef IBaseFunctionMultiDimTempl< double >	BaseFunc

Public Member Functions
	LSResidualFunc (const Func &func, unsigned int i)
	LSResidualFunc (const LSResidualFunc< Func > &rhs)
IMultiGenFunction *	Clone () const override
	Clone a function.
double	Derivative (const double x, unsigned int icoord, double previous_grad, double previous_g2, double previous_gstep) const
	In some cases, the derivative algorithm will use information from the previous step, these can be passed in with this overload.
double	Derivative (const double *x, unsigned int icoord=0) const
	Return the partial derivative with respect to the passed coordinate.
void	FdF (const double x, double &f, double g) const override
	Optimized method to evaluate at the same time the function value and derivative at a point x.
void	Gradient (const double x, double g) const override
	Evaluate all the vector of function derivatives (gradient) at a point x.
bool	HasGradient () const override
bool	IsLSType () const
unsigned int	NDim () const override
	Retrieve the dimension of the function.
double	operator() (const double *x) const
	Evaluate the function at a point x[].
LSResidualFunc< Func > &	operator= (const LSResidualFunc< Func > &rhs)

Private Member Functions
double	DoDerivative (const double *, unsigned int) const override
	Function to evaluate the derivative with respect each coordinate. To be implemented by the derived class.
virtual double	DoDerivativeWithPrevResult (const double x, unsigned int icoord, double , double , double ) const
	In some cases, the derivative algorithm will use information from the previous step, these can be passed in with this overload.
double	DoEval (const double *x) const override
	Implementation of the evaluation function. Must be implemented by derived classes.

Private Attributes
const Func *	fChi2
unsigned int	fIndex

Inheritance diagram for ROOT::Math::LSResidualFunc< Func >:

Member Typedef Documentation

◆ BackendType

typedef double ROOT::Math::IBaseFunctionMultiDimTempl< double >::BackendType

inherited

Definition at line 67 of file IFunction.h.

◆ BaseFunc

typedef IBaseFunctionMultiDimTempl<double> ROOT::Math::IBaseFunctionMultiDimTempl< double >::BaseFunc

inherited

Definition at line 68 of file IFunction.h.

Constructor & Destructor Documentation

◆ LSResidualFunc() [1/2]

template<class Func>

ROOT::Math::LSResidualFunc< Func >::LSResidualFunc	(	const Func &	func,
		unsigned int	i )

inline

Definition at line 137 of file GSLNLSMinimizer.cxx.

◆ LSResidualFunc() [2/2]

template<class Func>

ROOT::Math::LSResidualFunc< Func >::LSResidualFunc ( const LSResidualFunc< Func > & rhs )

inline

Definition at line 140 of file GSLNLSMinimizer.cxx.

Member Function Documentation

◆ Clone()

template<class Func>

IMultiGenFunction * ROOT::Math::LSResidualFunc< Func >::Clone ( ) const

inlineoverridevirtual

Clone a function.

Each derived class must implement their version of the Clone method.

Implements ROOT::Math::IBaseFunctionMultiDimTempl< double >.

Definition at line 150 of file GSLNLSMinimizer.cxx.

◆ Derivative() [1/2]

double ROOT::Math::IBaseFunctionMultiDimTempl< double >::Derivative	(	const double *	x,
		unsigned int	icoord,
		double *	previous_grad,
		double *	previous_g2,
		double *	previous_gstep ) const

inlineinherited

In some cases, the derivative algorithm will use information from the previous step, these can be passed in with this overload.

The previous_* arrays can also be used to return second derivative and step size so that these can be passed forward again as well at the call site, if necessary.

Definition at line 120 of file IFunction.h.

◆ Derivative() [2/2]

double ROOT::Math::IBaseFunctionMultiDimTempl< double >::Derivative	(	const double *	x,
		unsigned int	icoord = 0 ) const

inlineinherited

Return the partial derivative with respect to the passed coordinate.

Definition at line 115 of file IFunction.h.

◆ DoDerivative()

template<class Func>

double ROOT::Math::LSResidualFunc< Func >::DoDerivative	(	const double *	,
		unsigned int	) const

inlineoverrideprivatevirtual

Function to evaluate the derivative with respect each coordinate. To be implemented by the derived class.

Reimplemented from ROOT::Math::IBaseFunctionMultiDimTempl< double >.

Definition at line 167 of file GSLNLSMinimizer.cxx.

◆ DoDerivativeWithPrevResult()

virtual double ROOT::Math::IBaseFunctionMultiDimTempl< double >::DoDerivativeWithPrevResult	(	const double *	x,
		unsigned int	icoord,
		double *	,
		double *	,
		double *	) const

inlineprivatevirtualinherited

In some cases, the derivative algorithm will use information from the previous step, these can be passed in with this overload.

The previous_* arrays can also be used to return second derivative and step size so that these can be passed forward again as well at the call site, if necessary.

Definition at line 136 of file IFunction.h.

◆ DoEval()

template<class Func>

double ROOT::Math::LSResidualFunc< Func >::DoEval ( const double * x ) const

inlineoverrideprivatevirtual

Implementation of the evaluation function. Must be implemented by derived classes.

Implements ROOT::Math::IBaseFunctionMultiDimTempl< double >.

Definition at line 165 of file GSLNLSMinimizer.cxx.

◆ FdF()

template<class Func>

void ROOT::Math::LSResidualFunc< Func >::FdF	(	const double *	x,
		double &	f,
		double *	df ) const

inlineoverridevirtual

Optimized method to evaluate at the same time the function value and derivative at a point x.

Often both value and derivatives are needed and it is often more efficient to compute them at the same time. Derived class should implement this method if performances play an important role and if it is faster to evaluate value and derivative at the same time

Reimplemented from ROOT::Math::IBaseFunctionMultiDimTempl< double >.

Definition at line 162 of file GSLNLSMinimizer.cxx.

◆ Gradient()

template<class Func>

void ROOT::Math::LSResidualFunc< Func >::Gradient	(	const double *	x,
		double *	grad ) const

inlineoverridevirtual

Evaluate all the vector of function derivatives (gradient) at a point x.

Derived classes must re-implement it if more efficient than evaluating one at a time

Reimplemented from ROOT::Math::IBaseFunctionMultiDimTempl< double >.

Definition at line 154 of file GSLNLSMinimizer.cxx.

◆ HasGradient()

bool ROOT::Math::IGradientFunctionMultiDimTempl< double >::HasGradient ( ) const

inlineoverridevirtualinherited

Reimplemented from ROOT::Math::IBaseFunctionMultiDimTempl< double >.

Definition at line 243 of file IFunction.h.

◆ IsLSType()

template<class Func>

bool ROOT::Math::LSResidualFunc< Func >::IsLSType ( ) const

inline

Definition at line 160 of file GSLNLSMinimizer.cxx.

◆ NDim()

template<class Func>

unsigned int ROOT::Math::LSResidualFunc< Func >::NDim ( ) const

inlineoverridevirtual

Retrieve the dimension of the function.

Implements ROOT::Math::IBaseFunctionMultiDimTempl< double >.

Definition at line 152 of file GSLNLSMinimizer.cxx.

◆ operator()()

double ROOT::Math::IBaseFunctionMultiDimTempl< double >::operator() ( const double * x ) const

inlineinherited

Evaluate the function at a point x[].

Use the pure virtual private method DoEval which must be implemented by the sub-classes.

Definition at line 81 of file IFunction.h.

◆ operator=()

template<class Func>

LSResidualFunc< Func > & ROOT::Math::LSResidualFunc< Func >::operator= ( const LSResidualFunc< Func > & rhs )

inline

Definition at line 143 of file GSLNLSMinimizer.cxx.

Member Data Documentation

◆ fChi2

template<class Func>

const Func* ROOT::Math::LSResidualFunc< Func >::fChi2

private

Definition at line 175 of file GSLNLSMinimizer.cxx.

◆ fIndex

template<class Func>

unsigned int ROOT::Math::LSResidualFunc< Func >::fIndex

private

Definition at line 174 of file GSLNLSMinimizer.cxx.

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

math/mathmore/src/GSLNLSMinimizer.cxx

Public Types

Public Member Functions

Private Member Functions

Private Attributes

Member Typedef Documentation

◆ BackendType

◆ BaseFunc

Constructor & Destructor Documentation

◆ LSResidualFunc() [1/2]

◆ LSResidualFunc() [2/2]

Member Function Documentation

◆ Clone()

◆ Derivative() [1/2]

◆ Derivative() [2/2]

◆ DoDerivative()

◆ DoDerivativeWithPrevResult()

◆ DoEval()

◆ FdF()

◆ Gradient()

◆ HasGradient()

◆ IsLSType()

◆ NDim()

◆ operator()()

◆ operator=()

Member Data Documentation

◆ fChi2

◆ fIndex