#include <iostream>
#include <TFile.h>
#include <TH1F.h>
#include <TTree.h>



void  Fitterfinal1()

{
TFile* file5 = new TFile("data.root");
TH1F* data = (TH1F*)file5->Get("data");
TH1F * Data1 = (TH1F*) data->Clone(); 
int nBins1 = data->GetNbinsX(); // get the number of bins in the x-axis
std::cout << "Number of bins: " << nBins1 << std::endl;


TFile* file1 = new TFile("silver_background.root");
TH1F* h2 = (TH1F*)file1->Get("h2");
TH1F * BKG1 = (TH1F*) h2->Clone("BKG1");
int nBins2 = h2->GetNbinsX(); // get the number of bins in the x-axis
std::cout << "Number of bins: " << nBins2 << std::endl;


TFile* file2 = new TFile("7He.root");
TH1F* mc00 = (TH1F*)file2->Get("mc00");
TH1F *mc000 = (TH1F*) mc00->Clone();
int nBins3 = mc00->GetNbinsX(); // get the number of bins in the x-axis
std::cout << "Number of bins: " << nBins3 << std::endl;

TFile* file3 = new TFile("6He.root");
TH1F* mc01 = (TH1F*)file3->Get("mc01");
TH1F * mc001 = (TH1F*) mc01->Clone();
int nBins4 = mc01->GetNbinsX(); // get the number of bins in the x-axis
std::cout << "Number of bins: " << nBins4 << std::endl;

TFile* file4 = new TFile("4He.root");
TH1F* mc02 = (TH1F*)file4->Get("mc02");
TH1F * mc002 = (TH1F*) mc02->Clone();
int nBins5 = mc02->GetNbinsX(); // get the number of bins in the x-axis
std::cout << "Number of bins: " << nBins5 << std::endl;
 
//TFile* file6 = new TFile("5He.root");
//TH1F* mc03 = (TH1F*)file6->Get("mc03");
//TH1F * mc003 = (TH1F*) mc03->Clone();
//int nBins6 = mc03->GetNbinsX(); // get the number of bins in the x-axis
//std::cout << "Number of bins: " << nBins6 << std::endl;
 
TFile* file6 = new TFile("r1.root");
TH1F* h9 = (TH1F*)file6->Get("h9");
TH1F * mc003 = (TH1F*) h9->Clone();
int nBins6 = h9->GetNbinsX(); // get the number of bins in the x-axis
std::cout << "Number of bins: " << nBins6 << std::endl;
 


 
  
TH1F* h3 = (TH1F*) Data1->Clone("h3");

TH1F* h4 = (TH1F*) BKG1->Clone("h4");
int nBins7 = h4->GetNbinsX(); // get the number of bins in the x-axis
std::cout << "Number of bins: " << nBins7 << std::endl;
  h4->Scale(2.31);
TH1F *h5 = (TH1F*) h4->Clone("h5");
int nBins8 = h5->GetNbinsX(); // get the number of bins in the x-axis
std::cout << "Number of bins: " << nBins8 << std::endl;
h3->Add(h4,-1);
   //Draw the histograms and save them to a PDF file
TCanvas *c = new TCanvas("c", "Data and MC Histograms",1600,1600);
  h3->Draw("");
  
  h4->Draw("SAME");
  h4->SetLineColor(kBlack);

  mc000->Draw("same");
  mc000->SetLineColor(kRed);
  
  mc001->Draw("same");
  mc001->SetLineColor(kGreen);
  
  mc002->Draw("same");
  mc002->SetLineColor(kBlue);

  mc003->Draw("same");
  mc003->SetLineColor(kOrange);
  //mc04->Draw("same");
  //mc04->SetLineColor(kOrange);
  //mc05->Draw("same");
  //mc05->SetLineColor(kPink);
  
  c->Print("data_and_mc_histograms.pdf");
  
 // retrieve histograms
   TObjArray *mc = new TObjArray(4);        // MC histograms are put in this array
   mc->Add(mc000);
   mc->Add(mc001);
   mc->Add(mc002);
   mc->Add(mc003);
   
   TFractionFitter* fit = new TFractionFitter(h3, mc); // initialise
   fit->Constrain(0,0,1.0);               // constrain fraction 1 to be between 0 and 1
   fit->Constrain(1,0,1.0);               // constrain fraction 2 to be between 0 and 1
   fit->Constrain(2,0,1.0); 
   fit->Constrain(3,0,1.0);               // constrain fraction 3 to be between 0 and 1
   fit->SetRangeX(0,60);                    // use only the first 15 bins in the fit for mc0                   // use only the first 15 bins in the fit  for mc2
   Int_t status = fit->Fit();               // perform the fit
   std::cout << "fit status: " << status << std::endl;
   if (status == 0) {                       // check on fit status
     TH1F* result = (TH1F*) fit->GetPlot();
     h3->Draw("Ep");
     result->Draw("same");
     Double_t chi2 = fit->GetChisquare();

// Get the number of degrees of freedom
Int_t ndf = fit->GetNDF();

// Print the result
std::cout << "Chi-square = " << chi2 << std::endl;
    std::cout << "Number of degrees of freedom = " << ndf << std::endl;
    double chiSquareNDF = chi2 / ndf;
    std::cout << "Chi-square / ndf = " << chiSquareNDF << std::endl;
   }




}