// Author V.Fine 06/12/2001 BNL mailto:[email protected] // This run Pythia using ROOT TPYthia6 interface // Thanks Michael Bussmann <*****@*****.**> for Pythia living example void ReadPythia(const char *fileName="pythia.root") { struct pythia_particle { Int_t status; // status of particle ( LUJETS K[1] ) Int_t pdg_id; // flavour code ( LUJETS K[2] ) Int_t parent; // parrent's id ( LUJETS K[3] ) Int_t firstChild; // id of first child ( LUJETS K[4] ) Int_t lastChild; // id of last child ( LUJETS K[5] ) Float_t momentum[4]; // X.Y,Z,energy momenta [GeV/c]( LUJETS P[1]=P[4] ) Float_t mass; // Mass [Gev/c^2] ( LUJETS P[5] ) Float_t vertex[4]; // X,Y,Z vertex [mm]; time of procuction [mm/c]( LUJETS V[1]-V[4] ) Float_t lifetime; // proper lifetime [mm/c] ( LUJETS V[5] ) }; TFileIter readEvents(fileName); TObject *nextObject = 0; // the number of the object available directly from "MyDataSet.root" Int_t size = readEvents.TotalKeys(); printf(" The total number of the events: %d\n",size); //----------------------------------------------------------------------- // Loop over all events, read them in to memory one by one printf(" -- > Loop over all events, read them in to memory one by one < -- \n"); for( readEvents = 0; int(readEvents) < size; readEvents.SkipObjects() ){ nextObject = *readEvents; printf(" %d bytes of the object \"%s\" of class \"%s\" written with TKey \"%s\" has been read from file\n" ,readEvents.GetObjlen() ,nextObject->GetName() ,nextObject->IsA()->GetName() ,(const char *)readEvents ); TDataSet *event = (TDataSet *)nextObject; event->ls(9); delete nextObject; } }
