EXP1803

void check3He()

{

        TFile *fr = new TFile("sim_digi.root");

        TTree *tr = (TTree*)fr->Get("er");

        TClonesArray *tracks = new TClonesArray("ERQTelescopeTrack", 10);

        tr->SetBranchAddress("ERQTelescopeTrack_DoubleSi_SD2_XY_1", &tracks);

        TFile *fw = new TFile("output.root", "RECREATE");

        TTree *tw = new TTree("out","a simple Tree with simple variables");

        Float_t x, y, z, energy;

        TLorentzVector *particle = new TLorentzVector();

//        tw->Branch("x",&x,"x/F");

//        tw->Branch("y",&y,"y/F");

//        tw->Branch("z",&z,"z/F");

        tw->Branch("energy",&energy,"energy/F");

        tw->Branch("particle.", "TLorentzVector", &particle);

        Double_t dE, E;

        //read all entries and fill the histograms

        Long64_t nentries = tr->GetEntriesFast();

//        nentries = 1000;

        for (Long64_t i = 0; i < nentries; i++) {

                tr->GetEntry(i);

                dE = 0;

                E = 0;

                x = 0; y = 0; z = 0;

                particle->SetXYZT(0, 0, 0, 0);

                for (int iPoint = 0; iPoint < tracks->GetEntriesFast(); iPoint++) {

                        ERQTelescopeTrack* t = (ERQTelescopeTrack*)tracks->At(iPoint);

                        if (tracks->GetEntriesFast() == 1) {

                                x = t->fTelescopeX-t->fTargetX;

                                y = t->fTelescopeY-t->fTargetY;

                                z = t->fTelescopeZ-t->fTargetZ;

                                energy = t->fSumEdep;

                                TVector3 p;

                                p.SetXYZ(x, y, z);

                                p.SetMag( TMath::Sqrt( TMath::Power(energy + 2.809,2) - TMath::Power(2.809, 2) ) );

                                particle->SetVect(p);

                                particle->SetE(energy + 2.809);

                        }

                }

                tw->Fill();

        }

        tw->Write();

        fw->Close();

//        if (gROOT->IsBatch())

//                return;

}