#include "Fit/Chi2FCN.h"

#include "Fit/Chi2FCN.h"

class MyFCN: public ROOT::Fit::Chi2Function{
  public:
    MyFCN(const ROOT::Fit::BinData&  data, const ROOT::Fit::Chi2Function::IModelFunction&  func): ROOT::Fit::Chi2Function(data,func) {}
    ~MyFCN(){}

   virtual ROOT::Fit::Chi2Function::BaseFunction * Clone() const { 
      return new MyFCN( Data(), ModelFunction() );
   }
    private:
    virtual double  DoEval(const double* x) const{
       // N.B. this will work only in CINT not in a compiled C++ Program 
       // since Chi2Function::DoEval is private
       double ret = ROOT::Fit::Chi2Function::DoEval(x);
       std::cout << "MyFCN::DoEval" << ret << std::endl;
        assert(0);
        return ret;
    }
};