ROOT::Math::Functor Class Reference

Documentation for class Functor class.

It is used to wrap in a very simple and convenient way multi-dimensional function objects. It can wrap all the following types:

• any C++ callable object implementation double operator()( const double * )
• a free C function of type double ()(const double * )
• an std::function of type std::function<double (double const *)>
• a member function with the correct signature like Foo::Eval(const double * ). In this case one pass the object pointer and a pointer to the member function (&Foo::Eval)

The function dimension is required when constructing the functor.

Definition at line 49 of file Functor.h.

Public Member Functions
	Functor ()
	Default constructor.
template<class PtrObj , typename MemFn >
	Functor (const PtrObj &p, MemFn memFn, unsigned int dim)
	Construct from a pointer to member function (multi-dim type).
	Functor (std::function< double(double const *)> const &f, unsigned int dim)
	Construct from a callable object of multi-dimension with the right signature (implementing double operator()(const double *x)).
Functor *	Clone () const override
	Clone a function.
unsigned int	NDim () const override
	Retrieve the dimension of the function.
Public Member Functions inherited from ROOT::Math::IBaseFunctionMultiDimTempl< double >
virtual	~IBaseFunctionMultiDimTempl ()=default
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.
virtual void	FdF (const double *x, double &f, double *df) const
	Optimized method to evaluate at the same time the function value and derivative at a point x.
virtual void	Gradient (const double *x, double *grad) const
	Evaluate all the vector of function derivatives (gradient) at a point x.
virtual bool	HasGradient () const
double	operator() (const double *x) const
	Evaluate the function at a point x[].

Private Member Functions
double	DoEval (const double *x) const override
	Implementation of the evaluation function. Must be implemented by derived classes.

Private Attributes
unsigned int	fDim
std::function< double(double const *)	fFunc )

Additional Inherited Members
Public Types inherited from ROOT::Math::IBaseFunctionMultiDimTempl< double >
typedef double	BackendType
typedef IBaseFunctionMultiDimTempl< double >	BaseFunc

#include <Math/Functor.h>

Inheritance diagram for ROOT::Math::Functor:

Constructor & Destructor Documentation

Functor() [1/3]

ROOT::Math::Functor::Functor ( )

inline

Default constructor.

Definition at line 54 of file Functor.h.

Functor() [2/3]

template<class PtrObj , typename MemFn >

ROOT::Math::Functor::Functor ( const PtrObj & p, MemFn memFn, unsigned int dim )

inline

Construct from a pointer to member function (multi-dim type).

Definition at line 58 of file Functor.h.

Functor() [3/3]

ROOT::Math::Functor::Functor ( std::function< double(double const *)> const & f, unsigned int dim )

inline

Construct from a callable object of multi-dimension with the right signature (implementing double operator()(const double *x)).

Definition at line 64 of file Functor.h.

Member Function Documentation

Clone()

Functor * ROOT::Math::Functor::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 67 of file Functor.h.

DoEval()

double ROOT::Math::Functor::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 74 of file Functor.h.

NDim()

unsigned int ROOT::Math::Functor::NDim ( ) const

inlineoverridevirtual

Retrieve the dimension of the function.

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

Definition at line 70 of file Functor.h.

Member Data Documentation

fDim

unsigned int ROOT::Math::Functor::fDim

private

Definition at line 78 of file Functor.h.

fFunc

std::function<double(double const *) ROOT::Math::Functor::fFunc)

private

Definition at line 79 of file Functor.h.

Libraries for ROOT::Math::Functor:

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

• math/mathcore/inc/Math/Functor.h