hey tim,
thanks a lot. i think i have it working now. however, i had to make a couple modifications to what you sent me:
Float_t p;
(if t is you ntuple)
t->SetBranchAddress("leafp",&p);
Int_t nentries = t->GetEntries();
Int_t nbytes = 0;
Int_t i;
for ( i=0; i<nentries;i++)
{
t->GetEntry(i);
cout << p << endl;
}
so i'm a little confused about what you meant to do with 'nbytes'. anyway, thanks a lot for your help (oh, thanks to chi too.)
have fun,
jason
Timothy Smith wrote:
Hello Jason,It looks to me as if you root file is just a simple ntuple?
If that is true then, I think, you read it like you can loops
through an ntuple.Float_t p;
(if t is you ntuple)
t->SetBranchAddress("leafp",&p);
Int_t nentries = n->GetEntries();
Int_t nbytes = 0;
Int_t i;
for ( i=0; i<nentries;i++) {
nbytes->GetEntry(i);
cout << p << endl;
}Tim
On Fri, 6 Sep 2002, Jason Seely wrote:> hi eveyone,
>
> how's it going? i'm trying to figure out how to get the numerical value
> of a leaf in a chain for a particular event. This seems like it should
> be straightforward, but i can't find a member that does it. i would like
> to be able to do something like this:
>
> TChain *t = new TChain("ntp");
> t->Add("rootfile.root");
>
> Float_t p = t->GetValue("leafp",eventindex);
>
> does any one know an easy way to do this?
>
> thanks,
>
> jason
>
> --
> --------------------------------------------------------------------
> jason seely
> 26.650.b
> massachusetts institute of technology
> 77 massachusetts avenue
> cambridge, ma 02139-4307
>
> email: seely@mit.edu
> phone: 617.253.4772/6734
> html: web.mit.edu/seely/www
> --------------------------------------------------------------------
>
>--
____________________________________________________________________
Timothy Paul Smith Assistant Research Professor
still using my MIT email for now -> tim_smith@mit.edu
no voice mail yet -> tel: (603) 646-9346
Dartmouth College
Department of Physics and Astronomy
6127 Wilder Lab.
Hanover, New Hampshire 03755
-- -------------------------------------------------------------------- jason seely 26.650.b massachusetts institute of technology 77 massachusetts avenue cambridge, ma 02139-4307 email: seely@mit.edu phone: 617.253.4772/6734 html: web.mit.edu/seely/www --------------------------------------------------------------------
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