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 void	GradientWithPrevResult (const double *x, double *grad, double *previous_grad, double *previous_g2, double *previous_gstep) const
	In some cases, the gradient algorithm will use information from the previous step, these can be passed in with this overload.
virtual bool	HasGradient () const
double	operator() (const double *x) const
	Evaluate the function at a point x[].
virtual bool	returnsInMinuit2ParameterSpace () const

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:

---

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

• math/mathcore/inc/Math/Functor.h