#include "Fit/BinData.h"
#include "Fit/UnBinData.h"
#include "Math/WrappedTF1.h"
#include "Math/WrappedMultiTF1.h"
#include "Math/Minimizer.h"
#include "Fit/Fitter.h"
#include "Fit/Chi2FCN.h"
#include "TMath.h"
#include "Math/Functor.h" 

void forcheck()
{
  TH1D* h_data = new TH1D("h_data","",31,0,31);
  TF1* f_fit  = new TF1("f_fit","[0]+[1]*x+[2]*x*x",0,31);
  for (int i = 0; i < 20;i++)
    {
      for (int j = 0; j < 31;j++)
	{
	  h_data->SetBinContent(j+1,j);
	}
      ROOT::Math::WrappedMultiTF1 fitFunction(*f_fit, 3 ); //f_fit is a TF1
      ROOT::Fit::BinData data(31,1);
      ROOT::Fit::FillData(data,h_data); //h_data is a histogram of data filled earlier
      ROOT::Fit::Chi2Function *EPChi2 = new ROOT::Fit::Chi2Function(data, fitFunction);
      ROOT::Fit::Fitter fitter;
      double params[] = {0,2,0};
      fitter.Config().MinimizerOptions().SetMinimizerType("GSLMultiFit");
      fitter.Config().SetParamsSettings(3,params); 
      fitter.FitFCN(*EPChi2,0,data.Size(),true);
      delete EPChi2;
    }
}