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Reference Guide
ROOT::Math::IGradientFunctionOneDim Class Reference

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 381 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

virtual ~IGradientFunctionOneDim ()
 Virtual Destructor (no operations) More...
 
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. More...
 
- Public Member Functions inherited from ROOT::Math::IBaseFunctionOneDim
 IBaseFunctionOneDim ()
 
virtual ~IBaseFunctionOneDim ()
 virtual destructor More...
 
virtual IBaseFunctionOneDimClone () const =0
 Clone a function. More...
 
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. More...
 
double operator() (const double *x) const
 Evaluate the function at a point x[]. More...
 
- Public Member Functions inherited from ROOT::Math::IGradientOneDim
virtual ~IGradientOneDim ()
 virtual destructor More...
 
double Derivative (double x) const
 Return the derivative of the function at a point x Use the private method DoDerivative. More...
 
double Derivative (const double *x) const
 Compatibility method with multi-dimensional interface for partial derivative. More...
 
void FdF (const double *x, double &f, double *df) const
 Compatibility method with multi-dimensional interface for Gradient and function evaluation. More...
 
void Gradient (const double *x, double *g) const
 Compatibility method with multi-dimensional interface for Gradient. More...
 

#include <Math/IFunction.h>

Inheritance diagram for ROOT::Math::IGradientFunctionOneDim:
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Member Typedef Documentation

◆ BaseFunc

◆ BaseGrad

Constructor & Destructor Documentation

◆ ~IGradientFunctionOneDim()

virtual ROOT::Math::IGradientFunctionOneDim::~IGradientFunctionOneDim ( )
inlinevirtual

Virtual Destructor (no operations)

Definition at line 395 of file IFunction.h.

Member Function Documentation

◆ FdF()

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

Implements ROOT::Math::IGradientOneDim.

Definition at line 405 of file IFunction.h.

Libraries for ROOT::Math::IGradientFunctionOneDim:
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The documentation for this class was generated from the following file: