Re: Problems with TTrees

From: Pasha Murat (630)840-8237 FNAL (630)859-3463 home (murat@murat.fnal.gov)
Date: Wed Mar 08 2000 - 16:14:21 MET


hi Glen - after you leave `sub' the variables px,py,pz etc... get 
deallocated so you're reading your data into nowhere...

						best, pasha
Glen R. Salo wrote:
> 
> (My apologies if this message appears twice.)
> 
> The following macro demonstrates a problem I'm having with TTrees.  As shown,
> the scripts end with repeated *** Break *** segmentation violation statements.
> The macro can be made to work as shown below.  These solutions, however, are not
> suitable for my application.  Any hints as to why this problem is occurring will
> be greatly appreciated.  I'm running root 2.23.12 under RedHat linux 6.1.
> 
> Thanks,
> 
> Glen
> 
> int main() {
> 
>   TFile f("hsimple.root");
>   TNtuple *n = (TNtuple *)f.Get("ntuple");
>   sub(n,0);                  // works if line is removed
> //   sub(n,n->GetEntries()); // works if above line is replaced with this one
> 
>   n->Scan("*","i<3");
>   n->Scan("*","i<3");
> 
>   return (0);
> 
> }
> 
> void sub(TTree *n, Int_t index) {
> 
>   Float_t px,py,pz,random;
>   Int_t i;
>   n->SetBranchStatus("*",kTRUE);
>   n->SetBranchAddress("px",&px);
>   n->SetBranchAddress("py",&py);
>   n->SetBranchAddress("pz",&pz);
>   n->SetBranchAddress("random",&random);
>   n->SetBranchAddress("i",&i);
> 
> }



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