 ROOT   6.08/07 Reference Guide
ROOT::Math::LSResidualFunc Class Reference

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)

IMultiGenFunctionClone () const
Clone a function. 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...

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

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

LSResidualFuncoperator= (const LSResidualFunc &rhs) Public Member Functions inherited from ROOT::Math::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
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 DoDerivative (const double *x, unsigned int icoord) const
function to evaluate the derivative with respect each coordinate. More...

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

## Private Attributes

const ROOT::Math::FitMethodFunctionfChi2

unsigned int fIndex

std::vector< double > fX2 Public Types inherited from ROOT::Math::IGradientFunctionMultiDim
typedef IBaseFunctionMultiDim BaseFunc Public Types inherited from ROOT::Math::IBaseFunctionMultiDim
typedef IBaseFunctionMultiDim BaseFunc

#include <Math/GSLNLSMinimizer.h>

Inheritance diagram for ROOT::Math::LSResidualFunc:
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## ◆ LSResidualFunc() [1/3]

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

Definition at line 81 of file GSLNLSMinimizer.h.

## ◆ LSResidualFunc() [2/3]

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

Definition at line 85 of file GSLNLSMinimizer.h.

## ◆ LSResidualFunc() [3/3]

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

Definition at line 93 of file GSLNLSMinimizer.h.

## ◆ Clone()

 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.

## ◆ DoDerivative()

 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

Definition at line 139 of file GSLNLSMinimizer.h.

## ◆ DoEval()

 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.

## ◆ 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

Definition at line 120 of file GSLNLSMinimizer.h.

 void ROOT::Math::LSResidualFunc::Gradient ( const double * x, double * 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

Definition at line 115 of file GSLNLSMinimizer.h.

## ◆ NDim()

 unsigned int ROOT::Math::LSResidualFunc::NDim ( ) const
inlinevirtual

Retrieve the dimension of the function.

Implements ROOT::Math::IBaseFunctionMultiDim.

Definition at line 113 of file GSLNLSMinimizer.h.

## ◆ operator=()

 LSResidualFunc& ROOT::Math::LSResidualFunc::operator= ( const LSResidualFunc & rhs )
inline

Definition at line 101 of file GSLNLSMinimizer.h.

## ◆ fChi2

 const ROOT::Math::FitMethodFunction* ROOT::Math::LSResidualFunc::fChi2
private

Definition at line 148 of file GSLNLSMinimizer.h.

## ◆ fIndex

 unsigned int ROOT::Math::LSResidualFunc::fIndex
private

Definition at line 147 of file GSLNLSMinimizer.h.

## ◆ fX2

 std::vector ROOT::Math::LSResidualFunc::fX2
mutableprivate

Definition at line 149 of file GSLNLSMinimizer.h.

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