void fit1()
{
  TCanvas *c1; 
  TFile fData("data.root");  //data
   TH1D* hist;
   fData.GetObject("h5",hist);
   hist->SetDirectory(0);
   hist->Draw("hist");
	   
   TFile f4He("4He.root");  //
   TH1D* hist4He;
   f4He.GetObject("h1",hist4He);
   hist4He->SetDirectory(0);
  // hist4He->Draw();
   
   TFile f5He("5He.root"); //
   TH1D* hist5He;
   f5He.GetObject("h2",hist5He);
   hist5He->SetDirectory(0);
 //  hist5He->Draw();   
   
   TFile f6He("6He.root"); //
   TH1D* hist6He;
   f6He.GetObject("h3",hist6He);
   hist6He->SetDirectory(0);
  // hist6He->Draw();   
   
   TFile f7He("7He.root"); //
   TH1D* hist7He;
   f7He.GetObject("h4",hist7He);
   hist7He->SetDirectory(0);
  // hist7He->Draw();

   //TFile f8He("8He.root"); //
   //TH1D* hist8He;
   //f8He.GetObject("Argon",hist8He);
   //hist8He->SetDirectory(0);
  // hist8He->Draw();
     
     

  
   TObjArray *mc = new TObjArray(4);

   mc->Add(hist4He);
   mc->Add(hist5He);
   mc->Add(hist6He);
   mc->Add(hist7He);
  // mc->Add(hist8He);
   TFractionFitter* fit = new TFractionFitter(hist,mc);
   fit->Constrain(0,0.0,1.0);
   fit->Constrain(1,0.0,1.0);
   fit->Constrain(2,0.0,1.0);
   fit->Constrain(3,0.0,1.0);
  // fit->Constrain(4,0.0,1.0);
   fit->SetRangeX(1,45);
   Int_t status = fit->Fit();
   std::cout<<"fit status"<< status << std::endl;
   if (status == 0) {
	   TH1F* result = (TH1F*) fit->GetPlot(); 
	    hist->Draw("PE");
	  result->SetDirectory(0);
   }
   
}