Reading LUND files

 #include <math.h>
 #include <TRandom3.h>

void ReadLUND()
{
        struct evt_t
        {
                Int_t event;
                Float_t FnlMom[3], MolMom[3];
                Float_t dontcare[10];
                Float_t stilldontcare[14];
                Float_t Px,Py,Pz,E,M,X,Y,Z;
                Float_t px,py,pz,e,m,x,y,z;
        };

        ifstream in;
        in.open("LUND_spread.LUND");
        evt_t evt;
        Int_t nlines=0;

        TLorentzVector Fnl_e_Lab_4Mom;
        TLorentzVector Fnl_Mol_Lab_4Mom;
        TLorentzVector Fnl_e_CM_4Mom;
        TLorentzVector Mol_CM_4Mom;
        TLorentzVector CMS;


        TFile *f = new TFile("CheckLUND_1.root","RECREATE");
        TTree *tree = new TTree("Moller","Moller data from ascii file");
        while(in.good())
        {
                evt.event=nlines;
                in >> evt.dontcare[0] >> evt.dontcare[1] >> evt.dontcare[2] >> evt.dontcare[3] >> evt.dontcare[4] >> evt.dontcare[5] >> evt.dontcare[6]                        
                        >> evt.dontcare[7] >> evt.dontcare[8] >> evt.dontcare[9] ;

 
                nlines++;
         
                in >> evt.stilldontcare[0] >> evt.stilldontcare[1] >> evt.stilldontcare[2] >> evt.stilldontcare[3] >> evt.stilldontcare[4]
                        >> evt.stilldontcare[5] >> evt.Px >> evt.Py >> evt.Pz >> evt.E >> evt.M >> evt.X >> evt.Y >> evt.Z;
                
                nlines++;
                
                in >> evt.stilldontcare[6] >> evt.stilldontcare[7] >> evt.stilldontcare[8] >> evt.stilldontcare[9] >> evt.stilldontcare[10]
                        >> evt.stilldontcare[11] >> evt.px >> evt.py >> evt.pz >> evt.e >> evt.m >> evt.x >> evt.y >> evt.z;

                nlines++;
                tree->Fill();
        
                //Define using Final Moller momentum

                        //Define 4 vector
                                Fnl_Mol_Lab_4Mom.SetPxPyPzE(evt.px,evt.py,evt.pz,evt.e);
        
        
                //Find 4 Momentum vector componets for Final Lab frame scattered electron
                        //Define 4vector

                                Fnl_e_Lab_4Mom.SetPxPyPzE(evt.Px,evt.Py,evt.Pz,evt.E);
        

                        //Fill Final Lab Histograms
                                        MolMomLab->Fill(Fnl_Mol_Lab_4Mom.P(),evt.dontcare[5]);
                                        MolThetaLab->Fill(Fnl_Mol_Lab_4Mom.Theta()*180/3.14159265359,evt.dontcare[5]);
        
        
                        //Boost vectors
                                CMS=Fnl_e_Lab_4Mom+Fnl_Mol_Lab_4Mom;
                        //Boost to CM Frame
                                Fnl_e_Lab_4Mom.Boost(-CMS.BoostVector());
                                Fnl_Mol_Lab_4Mom.Boost(-CMS.BoostVector());
        
                        //Write to 1D final CM histograms
                                        MolMomCM->Fill(Fnl_Mol_Lab_4Mom.P(),evt.dontcare[5]);
                                        MolThetaCM->Fill(Fnl_Mol_Lab_4Mom.Theta()*180/3.14159265359,evt.dontcare[5]);
        
        
        
                }//End input loop
        
        in.close();
        tree->Print();
        tree->Write();
        f->Write();        
        delete tree;
        delete f;
}//End main