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ROOT::Math::LSResidualFunc< Func > Class Template Reference

template<class Func>
class ROOT::Math::LSResidualFunc< Func >

LSResidualFunc class description.

Internal class used for accessing the residuals of the Least Square function and their derivatives 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 135 of file GSLNLSMinimizer.cxx.

Public Member Functions

 LSResidualFunc ()
 
 LSResidualFunc (const Func &func, unsigned int i)
 
 LSResidualFunc (const LSResidualFunc< Func > &rhs)
 
IMultiGenFunctionClone () const override
 Clone a function.
 
void FdF (const double *x, double &f, double *g) const override
 Optimized method to evaluate at the same time the function value and derivative at a point x.
 
void Gradient (const double *x, double *g) const override
 Evaluate all the vector of function derivatives (gradient) at a point x.
 
unsigned int NDim () const override
 Retrieve the dimension of the function.
 
LSResidualFunc< Func > & operator= (const LSResidualFunc< Func > &rhs)
 
- Public Member Functions inherited from ROOT::Math::IGradientFunctionMultiDimTempl< double >
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, 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.
 
double Derivative (const double *x, unsigned int icoord=0) const
 Return the partial derivative with respect to the passed coordinate.
 
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 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.
 
bool HasGradient () const
 
bool HasGradient () const
 
virtual bool returnsInMinuit2ParameterSpace () const
 
virtual bool returnsInMinuit2ParameterSpace () const
 
- Public Member Functions inherited from ROOT::Math::IBaseFunctionMultiDimTempl< double >
virtual ~IBaseFunctionMultiDimTempl ()=default
 
virtual ~IBaseFunctionMultiDimTempl ()=default
 
double operator() (const double *x) const
 Evaluate the function at a point x[].
 
double operator() (const double *x) const
 Evaluate the function at a point x[].
 

Private Member Functions

double DoDerivative (const double *, unsigned int) const override
 Function to evaluate the derivative with respect each coordinate. To be implemented by the derived class.
 
double DoEval (const double *x) const override
 Implementation of the evaluation function. Must be implemented by derived classes.
 

Private Attributes

const Func * fChi2
 
unsigned int fIndex
 

Additional Inherited Members

- Public Types inherited from ROOT::Math::IGradientFunctionMultiDimTempl< double >
typedef IBaseFunctionMultiDimTempl< doubleBaseFunc
 
typedef IGradientFunctionMultiDimTempl< doubleBaseGrad
 
- Public Types inherited from ROOT::Math::IBaseFunctionMultiDimTempl< double >
typedef double BackendType
 
typedef IBaseFunctionMultiDimTempl< doubleBaseFunc
 
Inheritance diagram for ROOT::Math::LSResidualFunc< Func >:
[legend]

Constructor & Destructor Documentation

◆ LSResidualFunc() [1/3]

template<class Func>
ROOT::Math::LSResidualFunc< Func >::LSResidualFunc ( )
inline

Definition at line 139 of file GSLNLSMinimizer.cxx.

◆ LSResidualFunc() [2/3]

template<class Func>
ROOT::Math::LSResidualFunc< Func >::LSResidualFunc ( const Func & func,
unsigned int i )
inline

Definition at line 143 of file GSLNLSMinimizer.cxx.

◆ LSResidualFunc() [3/3]

template<class Func>
ROOT::Math::LSResidualFunc< Func >::LSResidualFunc ( const LSResidualFunc< Func > & rhs)
inline

Definition at line 150 of file GSLNLSMinimizer.cxx.

Member Function Documentation

◆ Clone()

template<class Func>
IMultiGenFunction * ROOT::Math::LSResidualFunc< Func >::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 165 of file GSLNLSMinimizer.cxx.

◆ DoDerivative()

template<class Func>
double ROOT::Math::LSResidualFunc< Func >::DoDerivative ( const double * x,
unsigned int icoord ) const
inlineoverrideprivatevirtual

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

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

Definition at line 193 of file GSLNLSMinimizer.cxx.

◆ DoEval()

template<class Func>
double ROOT::Math::LSResidualFunc< Func >::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 189 of file GSLNLSMinimizer.cxx.

◆ FdF()

template<class Func>
void ROOT::Math::LSResidualFunc< Func >::FdF ( const double * x,
double & f,
double * df ) const
inlineoverridevirtual

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::IGradientFunctionMultiDimTempl< double >.

Definition at line 176 of file GSLNLSMinimizer.cxx.

◆ Gradient()

template<class Func>
void ROOT::Math::LSResidualFunc< Func >::Gradient ( const double * x,
double * grad ) const
inlineoverridevirtual

Evaluate all the vector of function derivatives (gradient) at a point x.

Derived classes must re-implement it if more efficient than evaluating one at a time

Reimplemented from ROOT::Math::IGradientFunctionMultiDimTempl< double >.

Definition at line 171 of file GSLNLSMinimizer.cxx.

◆ NDim()

template<class Func>
unsigned int ROOT::Math::LSResidualFunc< Func >::NDim ( ) const
inlineoverridevirtual

Retrieve the dimension of the function.

Reimplemented from ROOT::Math::IGradientFunctionMultiDimTempl< double >.

Definition at line 169 of file GSLNLSMinimizer.cxx.

◆ operator=()

template<class Func>
LSResidualFunc< Func > & ROOT::Math::LSResidualFunc< Func >::operator= ( const LSResidualFunc< Func > & rhs)
inline

Definition at line 158 of file GSLNLSMinimizer.cxx.

Member Data Documentation

◆ fChi2

template<class Func>
const Func* ROOT::Math::LSResidualFunc< Func >::fChi2
private

Definition at line 200 of file GSLNLSMinimizer.cxx.

◆ fIndex

template<class Func>
unsigned int ROOT::Math::LSResidualFunc< Func >::fIndex
private

Definition at line 199 of file GSLNLSMinimizer.cxx.

  • math/mathmore/src/GSLNLSMinimizer.cxx