Interface (abstract class) for one-dimensional functions providing a gradient calculation.

It implements both the ROOT::Math::IBaseFunctionOneDim and ROOT::Math::IGradientOneDim interfaces. The method ROOT::Math::IFunction::Derivative calculates the derivative and ROOT::Math::Fdf calculates the derivative and the function values at the same time. The pure private virtual method DoDerivative() must be implemented by the derived classes, while FdF is by default implemented using DoDerivative, but it can be overloaded by the derived classes to improve the efficiency in the derivative calculation.

Definition at line 407 of file IFunction.h.

Public Types
typedef IBaseFunctionOneDim	BaseFunc

typedef IGradientOneDim	BaseGrad

Public Types inherited from ROOT::Math::IBaseFunctionOneDim
typedef IBaseFunctionOneDim	BaseFunc

Public Member Functions
	~IGradientFunctionOneDim () override
	Virtual Destructor (no operations)

void	FdF (double x, double &f, double &df) const override
	Optimized method to evaluate at the same time the function value and derivative at a point x.

Public Member Functions inherited from ROOT::Math::IBaseFunctionOneDim
	IBaseFunctionOneDim ()

virtual	~IBaseFunctionOneDim ()
	virtual destructor

virtual IBaseFunctionOneDim *	Clone () const =0
	Clone a function.

double	operator() (const double *x) const
	Evaluate the function at a point x[].

double	operator() (double x) const
	Evaluate the function at a point x Use the a pure virtual private method DoEval which must be implemented by sub-classes.

Public Member Functions inherited from ROOT::Math::IGradientOneDim
virtual	~IGradientOneDim ()
	virtual destructor

double	Derivative (const double *x) const
	Compatibility method with multi-dimensional interface for partial derivative.

double	Derivative (double x) const
	Return the derivative of the function at a point x Use the private method DoDerivative.

void	FdF (const double x, double &f, double df) const
	Compatibility method with multi-dimensional interface for Gradient and function evaluation.

void	Gradient (const double x, double g) const
	Compatibility method with multi-dimensional interface for Gradient.

#include <Math/IFunction.h>

Inheritance diagram for ROOT::Math::IGradientFunctionOneDim:

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Member Typedef Documentation

◆ BaseFunc

typedef IBaseFunctionOneDim ROOT::Math::IGradientFunctionOneDim::BaseFunc

Definition at line 414 of file IFunction.h.

◆ BaseGrad

typedef IGradientOneDim ROOT::Math::IGradientFunctionOneDim::BaseGrad

Definition at line 415 of file IFunction.h.

Constructor & Destructor Documentation

◆ ~IGradientFunctionOneDim()

ROOT::Math::IGradientFunctionOneDim::~IGradientFunctionOneDim ( )

inlineoverride

Virtual Destructor (no operations)

Definition at line 421 of file IFunction.h.

Member Function Documentation

◆ FdF()

void ROOT::Math::IGradientFunctionOneDim::FdF	(	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

Implements ROOT::Math::IGradientOneDim.

Definition at line 431 of file IFunction.h.

Libraries for ROOT::Math::IGradientFunctionOneDim: