ROOT::Minuit2::ParametricFunction Class Reference

Function which has parameters.

For example, one could define a one-dimensional Gaussian, by considering x as an input coordinate for the evaluation of the function, and the mean and the square root of the variance as parameters.

AS OF NOW PARAMETRICFUNCTION INHERITS FROM FCNBASE INSTEAD OF GENERICFUNCTION. THIS IS ONLY BECAUSE NUMERICAL2PGRADIENTCALCULATOR NEEDS AN FCNBASE OBJECT AND WILL BE CHANGED!!!!!!!!!!!!!!!!

Definition at line 43 of file ParametricFunction.h.

Public Member Functions
	ParametricFunction (int nparams)
	Constructor which initializes the ParametricFunction by setting the number of parameters.
	ParametricFunction (std::span< const double > params)
	Constructor which initializes the ParametricFunction with the parameters given as input.
virtual std::vector< double >	GetGradient (std::vector< double > const &x) const
	Member function returning the Gradient of the function with respect to its variables (but without including gradients with respect to its internal parameters).
virtual const std::vector< double > &	GetParameters () const
	Accessor for the state of the parameters.
virtual unsigned int	NumberOfParameters () const
	Accessor for the number of parameters.
double	operator() (std::vector< double > const &x) const override=0
	Evaluates the function with the given coordinates.
virtual double	operator() (std::vector< double > const &x, std::vector< double > const &params) const
	Evaluates the function with the given coordinates and Parameter values.
virtual void	SetParameters (std::vector< double > const &params) const
	Sets the parameters of the ParametricFunction.
Public Member Functions inherited from ROOT::Minuit2::FCNBase
virtual double	ErrorDef () const
	Error definition of the function.
virtual std::vector< double >	G2 (std::vector< double > const &) const
	return second derivatives (diagonal of the Hessian matrix)
virtual std::vector< double >	Gradient (std::vector< double > const &) const
virtual std::vector< double >	GradientWithPrevResult (std::vector< double > const &parameters, double *, double *, double *) const
virtual GradientParameterSpace	gradParameterSpace () const
virtual bool	HasG2 () const
virtual bool	HasGradient () const
virtual bool	HasHessian () const
virtual std::vector< double >	Hessian (std::vector< double > const &) const
	return Hessian
virtual void	SetErrorDef (double)
	add interface to set dynamically a new error definition Re-implement this function if needed.
virtual double	Up () const =0
	Error definition of the function.
Public Member Functions inherited from ROOT::Minuit2::GenericFunction
virtual	~GenericFunction ()

Protected Attributes
std::vector< double >	par
	The vector containing the parameters of the function It is mutable for "historical reasons" as in the hierarchy methods and classes are const and all the implications of changing them back to non-const are not clear.

#include <Minuit2/ParametricFunction.h>

Inheritance diagram for ROOT::Minuit2::ParametricFunction:

Constructor & Destructor Documentation

ParametricFunction() [1/2]

ROOT::Minuit2::ParametricFunction::ParametricFunction ( std::span< const double >  params )

inline

Constructor which initializes the ParametricFunction with the parameters given as input.

Parameters

params

vector containing the initial Parameter values

Definition at line 55 of file ParametricFunction.h.

ParametricFunction() [2/2]

ROOT::Minuit2::ParametricFunction::ParametricFunction ( int  nparams )

inline

Constructor which initializes the ParametricFunction by setting the number of parameters.

Parameters

nparams

number of parameters of the parametric function

Definition at line 66 of file ParametricFunction.h.

Member Function Documentation

GetGradient()

std::vector< double > ROOT::Minuit2::ParametricFunction::GetGradient ( std::vector< double > const &  x ) const

virtual

Member function returning the Gradient of the function with respect to its variables (but without including gradients with respect to its internal parameters).

Parameters

x	vector containing the coordinates of the point where the Gradient is to be calculated.

Returns

the Gradient vector of the function at the given point.

Definition at line 22 of file ParametricFunction.cxx.

GetParameters()

virtual const std::vector< double > & ROOT::Minuit2::ParametricFunction::GetParameters ( ) const

inlinevirtual

Accessor for the state of the parameters.

Returns

vector containing the present Parameter settings

Definition at line 91 of file ParametricFunction.h.

NumberOfParameters()

virtual unsigned int ROOT::Minuit2::ParametricFunction::NumberOfParameters ( ) const

inlinevirtual

Accessor for the number of parameters.

Returns

the number of function parameters

Definition at line 100 of file ParametricFunction.h.

operator()() [1/2]

double ROOT::Minuit2::ParametricFunction::operator() ( std::vector< double > const &  x ) const

overridepure virtual

Evaluates the function with the given coordinates.

Parameters

x	vector containing the input coordinates

Returns

the result of the function evaluation with the given coordinates.

Implements ROOT::Minuit2::FCNBase.

operator()() [2/2]

virtual double ROOT::Minuit2::ParametricFunction::operator() ( std::vector< double > const &  x, std::vector< double > const &  params  ) const

inlinevirtual

Evaluates the function with the given coordinates and Parameter values.

This member function is useful to implement when speed is an issue as it is faster to call only one function instead of two (SetParameters and operator()). The default implementation, provided for convenience, does the latter.

Parameters

x	vector containing the input coordinates
params	vector containing the Parameter values

Returns

the result of the function evaluation with the given coordinates and parameters

Definition at line 135 of file ParametricFunction.h.

SetParameters()

virtual void ROOT::Minuit2::ParametricFunction::SetParameters ( std::vector< double > const &  params ) const

inlinevirtual

Sets the parameters of the ParametricFunction.

Parameters

params

vector containing the Parameter values

Definition at line 76 of file ParametricFunction.h.

Member Data Documentation

par

std::vector<double> ROOT::Minuit2::ParametricFunction::par

mutableprotected

The vector containing the parameters of the function It is mutable for "historical reasons" as in the hierarchy methods and classes are const and all the implications of changing them back to non-const are not clear.

Definition at line 166 of file ParametricFunction.h.

Libraries for ROOT::Minuit2::ParametricFunction:

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

• math/minuit2/inc/Minuit2/ParametricFunction.h
• math/minuit2/src/ParametricFunction.cxx