ROOT::Math::IGradientFunctionMultiDimTempl< T > Class Template Reference

Description

template<class T>
class ROOT::Math::IGradientFunctionMultiDimTempl< T >

Interface (abstract class) for multi-dimensional functions providing a gradient calculation. It implements both the ROOT::Math::IBaseFunctionMultiDimTempl and ROOT::Math::IGradientMultiDimTempl interfaces. The method ROOT::Math::IFunction::Gradient calculates the full gradient vector, ROOT::Math::IFunction::Derivative calculates the partial derivative for each coordinate and ROOT::Math::Fdf calculates the gradient and the function value at the same time. The pure private virtual method DoDerivative() must be implemented by the derived classes, while Gradient and FdF are by default implemented using DoDerivative, butthey can be overloaded by the derived classes to improve the efficiency in the derivative calculation.

Definition at line 326 of file IFunction.h.

Inheritance diagram for ROOT::Math::IGradientFunctionMultiDimTempl< T >:

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Public Types
typedef T	BackendType
typedef IBaseFunctionMultiDimTempl< T >	BaseFunc
typedef IGradientMultiDimTempl< T >	BaseGrad

Public Member Functions
virtual	~IGradientFunctionMultiDimTempl ()
virtual IBaseFunctionMultiDimTempl< T > *	Clone () const =0
T	Derivative (const T *x, unsigned int icoord=0) const
virtual void	FdF (const T *x, T &f, T *df) const
virtual void	Gradient (const T *x, T *grad) const
virtual unsigned int	NDim () const =0
virtual unsigned int	NDim () const=0
T	operator() (const T *x) const

Private Member Functions
virtual T	DoDerivative (const T *x, unsigned int icoord) const =0
virtual T	DoEval (const T *x) const =0

Member Typedef Documentation

BackendType

template<class T >

typedef T ROOT::Math::IBaseFunctionMultiDimTempl< T >::BackendType

inherited

Definition at line 66 of file IFunction.h.

BaseFunc

template<class T >

typedef IBaseFunctionMultiDimTempl<T> ROOT::Math::IGradientFunctionMultiDimTempl< T >::BaseFunc

Definition at line 330 of file IFunction.h.

BaseGrad

template<class T >

typedef IGradientMultiDimTempl<T> ROOT::Math::IGradientFunctionMultiDimTempl< T >::BaseGrad

Definition at line 331 of file IFunction.h.

Constructor & Destructor Documentation

~IGradientFunctionMultiDimTempl()

template<class T >

virtual ROOT::Math::IGradientFunctionMultiDimTempl< T >::~IGradientFunctionMultiDimTempl ( )

inlinevirtual

Virtual Destructor (no operations)

Definition at line 336 of file IFunction.h.

{}

Member Function Documentation

Clone()

template<class T >

virtual IBaseFunctionMultiDimTempl<T>* ROOT::Math::IBaseFunctionMultiDimTempl< T >::Clone ( ) const

pure virtualinherited

Clone a function. Each derived class must implement their version of the Clone method

Implemented in ROOT::Math::WrappedParamFunctionGen< FuncPtr >, ROOT::Math::WrappedParamFunction< FuncPtr >, ROOT::Math::WrappedMemMultiFunction< FuncObj, MemFuncPtr >, ROOT::Math::WrappedMultiFunction< Func >, ROOT::Math::MultiNumGradFunction, ROOT::Math::MinimTransformFunction, ROOT::Math::LSResidualFunc, ROOT::Math::GradFunctor, ROOT::Math::Functor, and ROOT::Fit::FcnAdapter.

Referenced by ROOT::Math::MultiNumGradFunction::Clone().

Derivative()

template<class T >

T ROOT::Math::IGradientMultiDimTempl< T >::Derivative ( const T *  x, unsigned int  icoord = 0  ) const

inlineinherited

Return the partial derivative with respect to the passed coordinate

Definition at line 217 of file IFunction.h.

{ return DoDerivative(x, icoord); }

References ROOT::Math::IGradientMultiDimTempl< T >::DoDerivative().

Referenced by ROOT::Math::MinimTransformFunction::DoDerivative(), and ROOT::Math::IGradientFunctionMultiDimTempl< T >::Gradient().

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DoDerivative()

template<class T >

virtual T ROOT::Math::IGradientMultiDimTempl< T >::DoDerivative ( const T *  x, unsigned int  icoord  ) const

privatepure virtualinherited

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

Referenced by ROOT::Math::IGradientMultiDimTempl< T >::Derivative().

DoEval()

template<class T >

virtual T ROOT::Math::IBaseFunctionMultiDimTempl< T >::DoEval ( const T *  x ) const

privatepure virtualinherited

Implementation of the evaluation function. Must be implemented by derived classes

Implemented in ROOT::Math::IParametricGradFunctionMultiDimTempl< T >, and ROOT::Math::IParametricFunctionMultiDimTempl< T >.

Referenced by ROOT::Math::IBaseFunctionMultiDimTempl< T >::operator()().

FdF()

template<class T >

virtual void ROOT::Math::IGradientFunctionMultiDimTempl< T >::FdF ( const T *  x, T &  f, T *  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::IGradientMultiDimTempl< T >.

Definition at line 357 of file IFunction.h.

         {
            f = BaseFunc::operator()(x);
            Gradient(x, df);
         }

References ROOT::Math::IGradientFunctionMultiDimTempl< T >::Gradient(), and ROOT::Math::IBaseFunctionMultiDimTempl< T >::operator()().

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Gradient()

template<class T >

virtual void ROOT::Math::IGradientFunctionMultiDimTempl< T >::Gradient ( const T *  x, T *  grad  ) const

inlinevirtual

Evaluate all the vector of function derivatives (gradient) at a point x. Derived classes must re-implement it if more efficient than evaluting one at a time

Implements ROOT::Math::IGradientMultiDimTempl< T >.

Definition at line 342 of file IFunction.h.

         {
            unsigned int ndim = NDim();
            for (unsigned int icoord  = 0; icoord < ndim; ++icoord)
               grad[icoord] = BaseGrad::Derivative(x, icoord);
         }

References ROOT::Math::IGradientMultiDimTempl< T >::Derivative(), and ROOT::Math::IGradientFunctionMultiDimTempl< T >::NDim().

Referenced by ROOT::Math::IGradientFunctionMultiDimTempl< T >::FdF().

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NDim() [1/2]

template<class T >

virtual unsigned int ROOT::Math::IBaseFunctionMultiDimTempl< T >::NDim ( ) const

pure virtualinherited

Retrieve the dimension of the function

Implemented in ROOT::Math::WrappedParamFunctionGen< FuncPtr >, ROOT::Math::WrappedParamFunction< FuncPtr >, ROOT::Math::WrappedMemMultiFunction< FuncObj, MemFuncPtr >, ROOT::Math::WrappedMultiFunction< Func >, ROOT::Math::MultiNumGradFunction, ROOT::Math::MinimTransformFunction, ROOT::Math::LSResidualFunc, ROOT::Math::GradFunctor, ROOT::Math::Functor, and ROOT::Fit::FcnAdapter.

NDim() [2/2]

template<class T >

virtual unsigned int ROOT::Math::IBaseFunctionMultiDimTempl< T >::NDim

Retrieve the dimension of the function

Referenced by ROOT::Math::IGradientFunctionMultiDimTempl< T >::Gradient(), ROOT::Math::MinimTransformFunction::NTot(), and ROOT::Math::GSLMultiMinimizer::Set().

operator()()

template<class T >

T ROOT::Math::IBaseFunctionMultiDimTempl< T >::operator() ( const T *  x ) const

inlineinherited

Evaluate the function at a point x[]. Use the pure virtual private method DoEval which must be implemented by the sub-classes

Definition at line 92 of file IFunction.h.

         {
            return DoEval(x);
         }

References ROOT::Math::IBaseFunctionMultiDimTempl< T >::DoEval().

Referenced by ROOT::Math::IGradientFunctionMultiDimTempl< T >::FdF().

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

• /home/build/builds/o5h8MZZm/0/mlz/bornagain/Fit/3rdparty/RootMinimizers/mathcore/Math/IFunction.h