ProofPythia.C: The class definition in ProofPythia.h has been generated automatically

#define ProofPythia_cxx
// The class definition in ProofPythia.h has been generated automatically
// by the ROOT utility TTree::MakeSelector(). This class is derived
// from the ROOT class TSelector. For more information on the TSelector
// framework see $ROOTSYS/README/README.SELECTOR or the ROOT User Manual.

// The following methods are defined in this file:
//    Begin():        called everytime a loop on the tree starts,
//                    a convenient place to create your histograms.
//    SlaveBegin():   called after Begin(), when on PROOF called only on the
//                    slave servers.
//    Process():      called for each event, in this function you decide what
//                    to read and fill your histograms.
//    SlaveTerminate: called at the end of the loop on the tree, when on PROOF
//                    called only on the slave servers.
//    Terminate():    called at the end of the loop on the tree,
//                    a convenient place to draw/fit your histograms.
//
// To use this file, try the following session on your Tree T:
//
// Root > T->Process("ProofPythia.C")
// Root > T->Process("ProofPythia.C","some options")
// Root > T->Process("ProofPythia.C+")
//

//based on 

#include <TCanvas.h>
#include <TFrame.h>
#include <TPaveText.h>
#include <TFormula.h>
#include <TF1.h>
#include <TH1F.h>
#include <TMath.h>
#include <TString.h>
#include <TStyle.h>
#include <TSystem.h>
#include <TParameter.h>
#include "TClonesArray.h"
#include "TParticle.h"

#include "ProofPythia.h"
#include "TPythia8.h"

//_____________________________________________________________________________
ProofPythia::ProofPythia()
{
   // Constructor

   fHist = 0;
   fPt = 0;
   fEta = 0;
   fPythia = 0;
   fP = 0;
}

//_____________________________________________________________________________
ProofPythia::~ProofPythia()
{
   // Destructor

   SafeDelete(fPythia);
   SafeDelete(fP);
}

//_____________________________________________________________________________
void ProofPythia::Begin(TTree * /*tree*/)
{
   // The Begin() function is called at the start of the query.
   // When running with PROOF Begin() is only called on the client.
   // The tree argument is deprecated (on PROOF 0 is passed).

   TString option = GetOption();
}

//_____________________________________________________________________________
void ProofPythia::SlaveBegin(TTree * /*tree*/)
{
   // The SlaveBegin() function is called after the Begin() function.
   // When running with PROOF SlaveBegin() is called on each slave server.
   // The tree argument is deprecated (on PROOF 0 is passed).

   TString option = GetOption();

   // Histograms
   fTot = new TH1F("histo1", "total multiplicity", 25, 0.5, 2500.5);
   fHist = new TH1F("histo2", "charged multiplicity", 20, 0.5, 500.5);
   fPt = new TH1F("histo3", "particles pT", 100, 0., 10);
   fEta = new TH1F("histo4", "particles Eta", 100, -10., 10);
   fTot->SetFillColor(kBlue);
   fHist->SetFillColor(kRed);
   fOutput->Add(fTot);
   fOutput->Add(fHist);
   fOutput->Add(fPt);
   fOutput->Add(fEta);

   fPythia = new TPythia8();
   // Configure
   fPythia->SetName("pythia8");
   fPythia->ReadConfigFile("pythia8/main03.cmnd");

   // Initialize
   fPythia->Initialize( 2212, 2212, 14000.);
   fP = new TClonesArray("TParticle", 1000);

}

//_____________________________________________________________________________
Bool_t ProofPythia::Process(Long64_t entry)
{
   // Main event loop  

   fPythia->GenerateEvent();
   if (entry < 2)
      fPythia->EventListing();
   fPythia->ImportParticles(fP, "All");
   Int_t nTot = fPythia->GetN();
   fPythia->ImportParticles(fP, "All");
   Int_t np = fP->GetEntriesFast();
   // Particle loop
   Int_t nCharged = 0;
   for (Int_t ip = 0; ip < np; ip++) {
      TParticle* part = (TParticle*) fP->At(ip);
      Int_t ist = part->GetStatusCode();
      Int_t pdg = part->GetPdgCode();
      if (ist != 1) continue;
      Float_t charge = TDatabasePDG::Instance()->GetParticle(pdg)->Charge();
      if (charge == 0.) continue;
      nCharged++;
      Float_t eta = part->Eta();
      Float_t pt  = part->Pt();
      if (pt > 0.) fPt->Fill(pt);
      if ((eta > -10) && (eta < 10)) fEta->Fill(eta);
   }
   fHist->Fill(nCharged);
   fTot->Fill(nTot);

   return kTRUE;
}

//_____________________________________________________________________________
void ProofPythia::SlaveTerminate()
{
   // The SlaveTerminate() function is called after all entries or objects
   // have been processed. When running with PROOF SlaveTerminate() is called
   // on each slave server.
}

//_____________________________________________________________________________
void ProofPythia::Terminate()
{
   // The Terminate() function is the last function to be called during
   // a query. It always runs on the client, it can be used to present
   // the results graphically or save the results to file.

   fOutput->ls();

   //
   // Create canvas
   //
   TCanvas *c1 = new TCanvas("c1","Proof ProofPythia canvas",200,10,700,700);
   c1->Divide(2, 2);

   if ((fTot = dynamic_cast<TH1F *>(fOutput->FindObject("histo1")))) {
      c1->cd(1);
      fTot->Draw("h");
   }

   if ((fHist = dynamic_cast<TH1F *>(fOutput->FindObject("histo2")))) {
      c1->cd(2);
      fHist->Draw("h");
   }

   if ((fPt = dynamic_cast<TH1F *>(fOutput->FindObject("histo3")))) {
      c1->cd(3);
      fPt->Draw("h");
   }

   if ((fEta = dynamic_cast<TH1F *>(fOutput->FindObject("histo4")))) {
      c1->cd(4);
      fEta->Draw("h");
   }

   // Final update
   c1->cd();
   c1->Update();
}