LSResidualFunc class description.

Internal class used for accessing the residuals of the Least Square function and their derivates which are estimated numerically using GSL numerical derivation. The class contains a pointer to the fit method function and an index specifying the i-th residual and wraps it in a multi-dim gradient function interface ROOT::Math::IGradientFunctionMultiDim. The class is used by ROOT::Math::GSLNLSMinimizer (GSL non linear least square fitter)

Definition at line 77 of file GSLNLSMinimizer.h.

Public Member Functions
	LSResidualFunc ()

	LSResidualFunc (const ROOT::Math::FitMethodFunction &func, unsigned int i)

	LSResidualFunc (const LSResidualFunc &rhs)

LSResidualFunc &	operator= (const LSResidualFunc &rhs)

IMultiGenFunction *	Clone () const
	Clone a function. More...

unsigned int	NDim () const
	Retrieve the dimension of the function. More...

void	Gradient (const double x, double g) const
	Evaluate all the vector of function derivatives (gradient) at a point x. More...

void	FdF (const double x, double &f, double g) 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::IGradientFunctionMultiDim
virtual	~IGradientFunctionMultiDim ()
	Virtual Destructor (no operations) More...

Public Member Functions inherited from ROOT::Math::IBaseFunctionMultiDim
	IBaseFunctionMultiDim ()

virtual	~IBaseFunctionMultiDim ()
	virtual destructor More...

double	operator() (const double *x) const
	Evaluate the function at a point x[]. More...

Public Member Functions inherited from ROOT::Math::IGradientMultiDim
virtual	~IGradientMultiDim ()
	virual destructor More...

double	Derivative (const double *x, unsigned int icoord=0) const
	Return the partial derivative with respect to the passed coordinate. More...

Private Member Functions
double	DoEval (const double *x) const
	Implementation of the evaluation function. More...

double	DoDerivative (const double *x, unsigned int icoord) const
	function to evaluate the derivative with respect each coordinate. More...

Private Attributes
unsigned int	fIndex

const ROOT::Math::FitMethodFunction *	fChi2

std::vector< double >	fX2

Additional Inherited Members
Public Types inherited from ROOT::Math::IGradientFunctionMultiDim
typedef IBaseFunctionMultiDim	BaseFunc

typedef IGradientMultiDim	BaseGrad

Public Types inherited from ROOT::Math::IBaseFunctionMultiDim
typedef IBaseFunctionMultiDim	BaseFunc

#include <Math/GSLNLSMinimizer.h>

Inheritance diagram for ROOT::Math::LSResidualFunc:

[legend]

Constructor & Destructor Documentation

ROOT::Math::LSResidualFunc::LSResidualFunc ( )

inline

Definition at line 81 of file GSLNLSMinimizer.h.

Referenced by Clone().

ROOT::Math::LSResidualFunc::LSResidualFunc	(	const ROOT::Math::FitMethodFunction &	func,
		unsigned int	i
	)

inline

Definition at line 85 of file GSLNLSMinimizer.h.

ROOT::Math::LSResidualFunc::LSResidualFunc ( const LSResidualFunc & rhs )

inline

Definition at line 93 of file GSLNLSMinimizer.h.

Member Function Documentation

IMultiGenFunction* ROOT::Math::LSResidualFunc::Clone ( ) const

inlinevirtual

Clone a function.

Each derived class must implement their version of the Clone method

Implements ROOT::Math::IBaseFunctionMultiDim.

Definition at line 109 of file GSLNLSMinimizer.h.

double ROOT::Math::LSResidualFunc::DoDerivative	(	const double *	x,
		unsigned int	icoord
	)		const

inlineprivatevirtual

function to evaluate the derivative with respect each coordinate.

To be implemented by the derived class

Implements ROOT::Math::IGradientMultiDim.

Definition at line 139 of file GSLNLSMinimizer.h.

double ROOT::Math::LSResidualFunc::DoEval ( const double * x ) const

inlineprivatevirtual

Implementation of the evaluation function.

Must be implemented by derived classes

Implements ROOT::Math::IBaseFunctionMultiDim.

Definition at line 135 of file GSLNLSMinimizer.h.

Referenced by DoDerivative(), and FdF().

void ROOT::Math::LSResidualFunc::FdF	(	const 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 from ROOT::Math::IGradientFunctionMultiDim.

Definition at line 120 of file GSLNLSMinimizer.h.

Referenced by Gradient().