void write { TClonesArray * arr = new TClonesArray ( " TVector3 " ); TClonesArray & ar = * arr ; TFile * file = new TFile ( " file.root " , " recreate " ); TTree * tree = new TTree ( " tcl " , " tcl " ); tree -> Branch ( " array " , & arr ); TRandom2 * rand = new TRandom2 ( 1 ); for ( int i = 0 ; i < 100 ; i ++) { arr -> Clear (); for ( int j = 0 ; j < 1000 ; j ++) { double x = rand -> Rndm (); double y = rand -> Rndm (); double z = rand -> Rndm (); new ( ar [ j ]) TVector3 ( x , y , z ); } tree -> Fill (); } file -> Write (); file -> Close (); } void read () { TFile * file = new TFile ( " file.root " ); TTree * tree = ( TTree *) file -> Get ( " tcl " ); TClonesArray * arr = new