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.
>
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>
> //
> // 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
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