void fit()
{
  TFile *f = TFile::Open("plot.root");
  TFile *file = new TFile("Fit_Res.root","RECREATE");
 
  TCanvas *c = new TCanvas("c","",1);
  ROOT::Math::MinimizerOptions::SetDefaultMaxFunctionCalls( 10000000);

  c->SetLogy();
  
  TH1D *h1 = (TH1D*)f->Get("Hadd_Resolution_HT_total_2"); 
  
  Double_t par[12];
  TF1 *g1    = new TF1("g1","gaus",0.5,0.7);
  TF1 *g2    = new TF1("g2","gaus",0.8,1.1);
  TF1 *g3    = new TF1("g3","gaus",1.1,1.3);
  TF1 *g4    = new TF1("g4","gaus",1.3,1.8);
  TF1 *total = new TF1("total","gaus(0)+gaus(3)+gaus(6)+gaus(9)",0.5,1.8);
  total->SetLineColor(kBlue);
  h1->Fit(g1,"R");
  h1->Fit(g2,"R+");
  h1->Fit(g3,"R+");
  h1->Fit(g4,"R+");
  g1->GetParameters(&par[0]);
  g2->GetParameters(&par[3]);
  g3->GetParameters(&par[6]);
  g4->GetParameters(&par[9]);
  g1->SetLineColor(0);
  g2->SetLineColor(0);
  g3->SetLineColor(0);
     
  total->SetParameter(0,8.20989);
  total->SetParameter(1,0.740543);
  total->SetParameter(2,0.0620681);
  total->SetParameter(3,697.204);
  total->SetParameter(4,1.00438);
  total->SetParameter(5,0.0547298);
  total->SetParameter(6,309.261);
  total->SetParameter(7,1.02128);
  total->SetParameter(8,0.0800669);
  total->SetParameter(9,5.29383);
  total->SetParameter(10,1.3149);
  total->SetParameter(11,0.137413);

  h1->Fit(total,"R+");
   
  
  Double_t chi2 = total->GetChisquare();
  Double_t ndf = total->GetNDF();
  Double_t chi2_ndf = chi2/ndf;
  cout<<" chi2 : "<<chi2<<" ndf : "<<ndf<<" chi2/ndf : "<<chi2_ndf<<endl;
  h1->Draw("");
  
  h1->SetTitle("");	
    
  h1->GetXaxis()->SetMoreLogLabels();
  h1->GetXaxis()->SetNoExponent();
  h1->GetXaxis()->SetLabelSize(0.04);

  h1->SetMarkerStyle(20);
  h1->SetMarkerColor(kBlack);
  h1->SetLineColor(kBlack);
  h1->SetMarkerSize(0.2);
  
  h1->GetYaxis()->SetRangeUser(0.000001,1000000.); 
  h1->GetXaxis()->SetRangeUser(0.3,2.0); 
  h1->GetXaxis()->SetLabelSize(0.03);
  h1->GetXaxis()->SetTitleSize(0.035);
  h1->GetXaxis()->SetTitleOffset(1.19);
  
  c->Draw();
  h1->Write();
  file->Write();
  //file->Close();
}