Before executing this macro, the file makegeometry.C must have been executed. 
 
   if (n49) {
      TFile na(
"na49.root",
"RECREATE");
 
      na.Write();
   }
}
R__EXTERN TBenchmark * gBenchmark
 
virtual void Start(const char *name)
Starts Benchmark with the specified name.
 
virtual void Show(const char *name)
Stops Benchmark name and Prints results.
 
A ROOT file is a suite of consecutive data records (TKey instances) with a well defined format.
 
virtual TObject * FindObject(const char *name) const
Search object identified by name in the geometry tree.
 
virtual Int_t Write(const char *name=nullptr, Int_t option=0, Int_t bufsize=0)
Write this object to the current directory.
 
- Author
 - Andrei Gheata 
 
Definition in file na49geomfile.C.