// @(#)root/mathcore:$Id$
// Author: L. Moneta Thu Sep 21 16:21:29 2006

/**********************************************************************
 *                                                                    *
 * Copyright (c) 2006  LCG ROOT Math Team, CERN/PH-SFT                *
 *                                                                    *
 *                                                                    *
 **********************************************************************/

// Header file for class FitConfig

#ifndef ROOT_Fit_FitConfig
#define ROOT_Fit_FitConfig


#ifndef ROOT_Fit_ParameterSettings
#include "Fit/ParameterSettings.h"
#endif

#ifndef ROOT_Math_MinimizerOptions
#include "Math/MinimizerOptions.h"
#endif

#ifndef ROOT_Math_IParamFunctionfwd
#include "Math/IParamFunctionfwd.h"
#endif


#include <vector>

namespace ROOT { 

   namespace Math { 

      class Minimizer;
      class MinimizerOptions; 
   }

   namespace Fit { 

      class FitResult;

//___________________________________________________________________________________
/** 
   Class describing the configuration of the fit, options and parameter settings
   using the ROOT::Fit::ParameterSettings class 

   @ingroup FitMain
*/ 
class FitConfig {

public: 

   /** 
      Default constructor
   */ 
   FitConfig (unsigned int npar = 0); 


   /*
     Copy constructor 
    */
   FitConfig(const FitConfig & rhs);

   /** 
      Destructor 
   */ 
   ~FitConfig ();  

   /*
     Assignment operator 
   */
   FitConfig & operator= (const FitConfig & rhs);


   /**
      get the parameter settings for the i-th parameter (const method)
   */
   const ParameterSettings & ParSettings(unsigned int i) const { return fSettings.at(i); }

   /**
      get the parameter settings for the i-th parameter (non-const method)
   */
   ParameterSettings & ParSettings(unsigned int i) { return fSettings.at(i); }

   /**
      get the vector of parameter settings  (const method)
   */
   const std::vector<ROOT::Fit::ParameterSettings> & ParamsSettings() const { return fSettings; }

   /**
      get the vector of parameter settings  (non-const method)
   */
   std::vector<ROOT::Fit::ParameterSettings> & ParamsSettings() { return fSettings; }

   /**
      number of parameters settings 
    */
   unsigned int NPar() const { return fSettings.size(); }

   /**
      set the parameter settings from a model function. 
      Create always new parameter setting list from a given model function  
   */
   void CreateParamsSettings(const ROOT::Math::IParamMultiFunction & func); 

   /**
      set the parameter settings from number of parameters and a vector of values and optionally step values. If there are not existing or number of parameters does not match existing one, create a new parameter setting list. 
   */
   void SetParamsSettings(unsigned int npar, const double * params, const double * vstep = 0); 

   /*
     Set the parameter settings from a vector of parameter settings
   */
   void SetParamsSettings (const std::vector<ROOT::Fit::ParameterSettings>& pars ) { 
      fSettings = pars;
   }


   /*
     Set the parameter settings from a fit Result
   */
   void SetFromFitResult (const FitResult & rhs);



   /**
      create a new minimizer according to chosen configuration
   */
   ROOT::Math::Minimizer * CreateMinimizer(); 



   /**
      access to the minimizer  control parameter (non const method) 
   */
   ROOT::Math::MinimizerOptions & MinimizerOptions()  { return fMinimizerOpts; } 


#ifndef __CINT__   // this method fails on Windows
   /**
      set all the minimizer options using class MinimizerOptions
    */
   void SetMinimizerOptions(const ROOT::Math::MinimizerOptions & minopt); 
#endif

   
   /**
      set minimizer type 
   */
   void SetMinimizer(const char * type, const char * algo = 0) { 
      if (type) fMinimizerOpts.SetMinimizerType(type); 
      if (algo) fMinimizerOpts.SetMinimizerAlgorithm(algo); 
   } 

   /**
      return type of minimizer package
   */
   const std::string & MinimizerType() const { return fMinimizerOpts.MinimizerType(); } 

   /**
      return type of minimizer algorithms 
   */
   const std::string & MinimizerAlgoType() const { return fMinimizerOpts.MinimizerAlgorithm(); }  


   /**
      flag to check if resulting errors are be normalized according to chi2/ndf 
   */
   bool NormalizeErrors() const { return fNormErrors; } 

   ///do analysis for parabolic errors
   bool ParabErrors() const { return fParabErrors; }

   ///do minos errros analysis on the  parameters
   bool MinosErrors() const { return fMinosErrors; }

   ///Update configuration after a fit using the FitResult
   bool UpdateAfterFit() const { return fUpdateAfterFit; } 

   ///Apply Weight correction for error matrix computation
   bool UseWeightCorrection() const { return fWeightCorr; }


   /// return vector of parameter indeces for which the Minos Error will be computed
   const std::vector<unsigned int> & MinosParams() const { return fMinosParams; }

   /**
      set the option to normalize the error on the result  according to chi2/ndf
   */
   void SetNormErrors(bool on = true) { fNormErrors= on; }

   ///set parabolic erros
   void SetParabErrors(bool on = true) { fParabErrors = on; } 

   ///set Minos erros computation to be performed after fitting
   void SetMinosErrors(bool on = true) { fMinosErrors = on; } 

   ///apply the weight correction for error matric computation
   void SetWeightCorrection(bool on = true) { fWeightCorr = on; }

   /// set parameter indeces for running Minos
   /// this can be used for running Minos on a subset of parameters - otherwise is run on all of them 
   /// if MinosErrors() is set 
   void SetMinosErrors(const std::vector<unsigned int> & paramInd ) { 
      fMinosErrors = true; 
      fMinosParams = paramInd; 
   }

   ///Update configuration after a fit using the FitResult
   void SetUpdateAfterFit(bool on = true) { fUpdateAfterFit = on; } 


   /**
      static function to control default minimizer type and algorithm
   */
   static void SetDefaultMinimizer(const char * type, const char * algo = 0); 

 


protected: 


private: 

   bool fNormErrors;       // flag for error normalization
   bool fParabErrors;      // get correct parabolic errors estimate (call Hesse after minimizing)  
   bool fMinosErrors;      // do full error analysis using Minos
   bool fUpdateAfterFit;   // update the configuration after a fit using the result
   bool fWeightCorr;       // apply correction to errors for weights fits 

   std::vector<ROOT::Fit::ParameterSettings> fSettings;  // vector with the parameter settings
   std::vector<unsigned int> fMinosParams;               // vector with the parameter indeces for running Minos

   ROOT::Math::MinimizerOptions fMinimizerOpts;   //minimizer control parameters including name and algo type

}; 

   } // end namespace Fit

} // end namespace ROOT


#endif /* ROOT_Fit_FitConfig */
