using namespace RooFit;

void bruno() 
{

  RooRealVar mass("mass","invariant mass (GeV/c2)",0,12);
    
  //Breit-Wigner for the phi
  
  RooRealVar mean_phi("mean_phi","mean_phi",1.0,0.9,1.1);
  RooRealVar g("sigma_phi","sigma_phi",1,0,2);
  RooBreitWigner *phi_BW = new RooBreitWigner("phi_BW","Breit Wigner PDF",mass,mean_phi,g);
  
  //Crystal ball for the J/psi
  
  RooRealVar mean_jpsi("mean_jpsi","mean_jpsi",3,2.9,3.2);
  RooRealVar sigma_jpsi("sigma_jpsi","sigma_jpsi",0.07,0,0.1);
  RooRealVar alpha("alpha","alpha",1);
  RooRealVar n("n","n",5);
  RooCBShape *jpsi = new RooCBShape("jpsi","crystal ball PDF",mass,mean_jpsi,sigma_jpsi,alpha,n);
  
  //Crystal ball for the psi
  
  RooRealVar mean_psi("mean_psi","mean_psi",3.6,3.4,3.8);
  RooRealVar sigma_psi("sigma_psi","sigma_psi",0.07,0,0.1);
  RooRealVar alpha_psi("alpha","alpha",1.5);
  RooRealVar n_psi("n","n",1);
  RooCBShape *psi = new RooCBShape("psi","crystal ball PDF",mass,mean_psi,sigma_psi,alpha_psi,n_psi);
  
  //Crystal ball for the Upsilon
  
  RooRealVar mean_up("mean_up","mean_up",9.4,9.3,9.5);
  RooRealVar sigma_up("sigma_up","sigma_up",0.07,0,0.1);
  RooRealVar alpha_up("alpha_up","alpha_up",1,0,5);
  RooRealVar n_up("n_up","n_up",1,0,10);
  RooCBShape *upsilon = new RooCBShape("upsilon","crystal ball PDF",mass,mean_up,sigma_up,alpha_up,n_up);
  
  //Exponential background
  
  RooRealVar a("a","a",-0.85,-0.8,-0.9);
  RooExponential bkg("exp","exp",mass,a);
  
  RooRealVar fsig("fsig","signal",0.1,0.,1.);
  RooRealVar fsig2("fsig2","signal2",0.1,0.,1.);
  RooRealVar fsig3("fsig3","signal3",0.1,0.,1.);
  RooRealVar fsig4("fsig4","signal4",0.1,0.,1.);
  
  RooAddPdf sum("sum","sum",RooArgList(*phi_BW,*jpsi,*psi,*upsilon,bkg),RooArgList(fsig,fsig2,fsig3,fsig4),kTRUE);

  
  RooDataSet* data = sum.generate(mass,10000) ;

  sum.getParameters(data)->setAttribAll("Constant",kTRUE) ;
  fsig.setConstant(kFALSE) ;
  
  sum.fitTo(*data,Range(2.2,5));
  
  RooPlot* mframe = mass.frame(Title("Fit of invariant mass"));
  data->plotOn(mframe);
  sum.plotOn(mframe);
  sum.plotOn(mframe,Components(bkg),LineStyle(kDashed));
  
  mframe->Draw();

}