ROOT::Math::IGradientFunctionOneDim Class Reference

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

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.

Specialized Gradient interface(abstract class) for one dimensional functions It provides a method to evaluate the derivative of the function, Derivative and a method to evaluate at the same time the function and the derivative FdF

Definition at line 254 of file IFunction.h.

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

Public Member Functions
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.
virtual void	FdF (double x, double &f, double &df) const
	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
	Compatibility method with multi-dimensional interface for Gradient.
bool	HasGradient () const override
Public Member Functions inherited from ROOT::Math::IBaseFunctionOneDim
virtual	~IBaseFunctionOneDim ()=default
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.

Private Member Functions
virtual double	DoDerivative (double x) const =0
	Function to evaluate the derivative with respect each coordinate. To be implemented by the derived class.

#include <Math/IFunction.h>

Inheritance diagram for ROOT::Math::IGradientFunctionOneDim:

Member Typedef Documentation

BaseFunc

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

Definition at line 258 of file IFunction.h.

BaseGrad

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

Definition at line 259 of file IFunction.h.

Member Function Documentation

Derivative() [1/2]

double ROOT::Math::IGradientFunctionOneDim::Derivative ( const double *  x ) const

inline

Compatibility method with multi-dimensional interface for partial derivative.

Definition at line 266 of file IFunction.h.

Derivative() [2/2]

double ROOT::Math::IGradientFunctionOneDim::Derivative ( double  x ) const

inline

Return the derivative of the function at a point x Use the private method DoDerivative.

Definition at line 263 of file IFunction.h.

DoDerivative()

virtual double ROOT::Math::IGradientFunctionOneDim::DoDerivative ( double  x ) const

privatepure virtual

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

Implemented in ROOT::Math::WrappedTF1, ROOT::Math::GradFunctor1D, and ROOT::Math::Polynomial.

FdF() [1/2]

void ROOT::Math::IGradientFunctionOneDim::FdF ( const double *  x, double &  f, double *  df  ) const

inline

Compatibility method with multi-dimensional interface for Gradient and function evaluation.

Definition at line 282 of file IFunction.h.

FdF() [2/2]

virtual void ROOT::Math::IGradientFunctionOneDim::FdF ( double  x, double &  f, double &  df  ) const

inlinevirtual

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 in ROOT::Math::WrappedTF1, and ROOT::Math::Polynomial.

Definition at line 275 of file IFunction.h.

Gradient()

void ROOT::Math::IGradientFunctionOneDim::Gradient ( const double *  x, double *  g  ) const

inline

Compatibility method with multi-dimensional interface for Gradient.

Definition at line 269 of file IFunction.h.

HasGradient()

bool ROOT::Math::IGradientFunctionOneDim::HasGradient ( ) const

inlineoverridevirtual

Reimplemented from ROOT::Math::IBaseFunctionOneDim.

Definition at line 284 of file IFunction.h.

Libraries for ROOT::Math::IGradientFunctionOneDim:

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

• math/mathcore/inc/Math/IFunction.h