// @(#)root/mathcore:$Id: FitMethodFunction.h 21503 2007-12-19 17:34:54Z moneta $ // Author: L. Moneta Thu Aug 16 15:40:28 2007 /********************************************************************** * * * Copyright (c) 2007 LCG ROOT Math Team, CERN/PH-SFT * * * * * **********************************************************************/ // Header file for class FitMethodFunction #ifndef ROOT_Math_FitMethodFunction #define ROOT_Math_FitMethodFunction #ifndef ROOT_Math_IFunction #include "Math/IFunction.h" #endif namespace ROOT { namespace Math { //______________________________________________________________________________________ /** FitMethodFunction class Interface for objective functions (like chi2 and likelihood used in the fit) In addition to normal function interface provide interface for calculating each data contrinution to the function which is required by some algorithm (like Fumili) @ingroup CppFunctions */ template<class FunctionType> class BasicFitMethodFunction : public FunctionType { public: typedef typename FunctionType::BaseFunc BaseFunction; /// enumeration specyfing the possible fit method types enum Type { kUndefined , kLeastSquare, kLogLikelihood }; /** Virtual Destructor (no operations) */ virtual ~BasicFitMethodFunction () {} /** method returning the data i-th contribution to the fit objective function For example the residual for the least square functions or the pdf element for the likelihood functions. Estimating eventually also the gradient of the data element if the passed pointer is not null */ virtual double DataElement(const double *x, unsigned int i, double *g = 0) const = 0; /** return the number of data points used in evaluating the function */ virtual unsigned int NPoints() const = 0; /** return the type of method, override if needed */ virtual Type GetType() const { return kUndefined; } public: protected: private: }; // define the normal and gradient function typedef BasicFitMethodFunction<ROOT::Math::IMultiGenFunction> FitMethodFunction; typedef BasicFitMethodFunction<ROOT::Math::IMultiGradFunction> FitMethodGradFunction; } // end namespace Math } // end namespace ROOT #endif /* ROOT_Math_FitMethodFunction */