On Mon, 8 Nov 1999, Pascal Perrodo wrote: Hi Pascal, I think you should use TTree for that (see Root Howtos and examples in $ROOTSYS/test). Ntuples are: A simple tree restricted to a list of float variables only. Cheers Otto > > Hi, > > I would like to know how to declare arrays in ntuples (as in PAW ntuples). > That is, instead of using px,py,pz, use p[3]. > I tried to develop a short example below but it doesn't behave as > expected. > > In the same spirit, how to declare arrays with more than 1 dimensions: > e.g. x[3][5][10]. > > Many thanks in advance, > Cheers. > Pascal Perrodo. > > +-------------------------------------------------------------------------+ > | Tel : 04 50 09 16 32 (from France), 00 33 4 50 09 16 32 (from abroad) | > | FAX : 04 50 27 94 95 (from France), 00 33 4 50 27 94 95 (from abroad) | > | | > | LAPP, Chemin de Bellevue, BP 110, F-74941 Annecy-le-Vieux CEDEX | > +-------------------------------------------------------------------------+ > > // > // create an ntuple > // > { > > gROOT->Reset(); > > > TFile *fout; > > fout = new TFile("ntuple.root","RECREATE","simple essai"); > > TNtuple *nt = new TNtuple("h99","h99","x[2]:y:i:j"); > > > Float_t x[2]; > Float_t y; > Int_t i; > Int_t j; > > for ( Int_t n=0 ; n<1000 ; n++ ) > { > > x[0] = (Float_t) n; > x[1] = 2.*x[0]; > y = 3.*x[0]; > i = 4*n; > j = 5*n; > > nt->Fill(x[0],x[1],y,i,j); > > } > > fout->Write(); > > fout->Close(); > > } // end > > ---------------------------------------------------------------------------- Otto Schaile Sektion Physik der LMU Muenchen Phone: (+49 89)289 14070 Am Coulombwall 1, D-85748 Garching, Germany FAX: (+49 89)289 14072 EMail: Otto.Schaile@Physik.Uni-Muenchen.DE
This archive was generated by hypermail 2b29 : Tue Jan 04 2000 - 00:43:42 MET