#ifndef TEST_H 
#define TEST_H 

#include <vector> 
#include <map> 
#include <set> 
#include <algorithm> 
#include <ctime> 
#include <fstream> 
#include <sstream> 
#include <iostream> 
#include <TObject.h> 
#include <TString.h> 
#include <math.h> 
#include "Minuit2/Minuit2Minimizer.h" 
#include "Math/Functor.h" 

const double pionmass = 0.1349766; 

class Test  : public TObject   { 
private: 
  // Variables 
  int                               m_vars; 
  int                               m_nEntries; 
  ROOT::Minuit2::Minuit2Minimizer*  gMinuit; 
   ROOT::Math::IMultiGenFunction * fFunc;
  double fcn( const double* ); 
public: 
  // Constructors and configuration 

  Test() : gMinuit(0), fFunc(0) {}

  virtual ~Test() { if (gMinuit) delete gMinuit; if (fFunc) delete fFunc; } 
  void configureMinuit( const int ); 
  int  addVar( const int varNum , const TString varName , const float initialValue ); 
  int minimize(); 
  ClassDef( Test , 1 ); 
}; 

#endif

//#include "Test.h" 

#if !defined( __CINT__ ) 
  ClassImp( Test ); 
#endif 

void Test::configureMinuit( const int nVars ){ 
  gMinuit = new ROOT::Minuit2::Minuit2Minimizer( ROOT::Minuit2::kMigrad ); 
  //ROOT::Math::Functor f( this , &Test::fcn , nVars ); 
  // need to have the function object available during the minimization
  fFunc = new ROOT::Math::Functor ( this , &Test::fcn , nVars ); 
  m_vars = nVars; 
  //gMinuit->SetFunction( f ); 
  gMinuit->SetFunction( *fFunc ); 
  // Setting value of UP parameter 
  gMinuit->SetErrorDef( 1.0 ); 
  gMinuit->SetMaxFunctionCalls(10000000); 
  gMinuit->SetMaxIterations(100000); 
  gMinuit->SetTolerance(10); 
} 

int Test::addVar( const int varNum , const TString varName , const float initialValue ){ 
  gMinuit->SetLimitedVariable( varNum , varName.Data() , initialValue , 0.01 , 0.80 , 1.20 );    
  return 1; 
} 

int Test::minimize(){ 
  time_t tstart, tend; 
  tstart = time(0); 
  gMinuit->Minimize(); 
  tend = time(0); 
  std::cout << "The calibration took " << difftime( tend, tstart ) << " seconds" << std::endl; 
  return 1; 
} 

double Test::fcn( const double *par ){ 
  return par[0]*par[0]; 
}