RE: [ROOT] Can't strip TChain

From: Salvatore Rappoccio (rappoccio@heplcdf2.harvard.edu)
Date: Fri Nov 19 2004 - 19:44:39 MET


Hi, Philippe,

I put them in both places:



    SetTheAddresses(chain); // set the address of ALL the top branches on the chain an NOT on the tree
    if ( stripTree ) {
      std::cout << "Setting up strip tree" << std::endl;
      histf->cd();
      tskim = (TTree*)chain->GetTree()->CloneTree(0);
    } 
   prevTreeNum=-1;
   //Loop over the events
    for(int ev=firstEvent; ev<nEvents; ev++) { 
      counter++;


    if ( chain->GetTreeNumber() != prevTreeNum ) {
      SetTheAddresses(chain->GetTree());
      prevTreeNum = chain->GetTreeNumber();
      if ( stripTree ) {
	histf->cd();
	tskim->AutoSave();
	tskim = (TTree *)chain->GetTree()->CloneTree(0);
      }

    }


  ....
  }

Thanks,
Sal
 
> Cheers,
> Philippe.
> 
> -----Original Message-----
> From: Salvatore Rappoccio [mailto:rappoccio@heplcdf2.harvard.edu] 
> Sent: Friday, November 19, 2004 12:13 PM
> To: Philippe Canal
> Cc: rappocc@fnal.gov; roottalk@pcroot.cern.ch
> Subject: RE: [ROOT] Can't strip TChain
> 
> Hi, Philippe,
> 
> I tried this, and now it seems that I only get the events from the LAST file
> of the original chain.
> 
> I also tried adding
> 
>     SetTheAddresses(chain); // set the address of ALL the top branches on
> the chain an NOT on the tree
>     if ( stripTree ) {
>       std::cout << "Setting up strip tree" << std::endl;
>       histf->cd();
>       tskim->AutoSave();
>       tskim = (TTree*)chain->GetTree()->CloneTree(0);
>     }
> 
> 
> How do I tell the chain written to histf to pick up the earlier data?
> 
> Thanks,
> Sal
> 
> >  
> > Cheers,
> > Philippe.  
> > 
> > -----Original Message-----
> > From: Salvatore Rappoccio [mailto:rappoccio@heplcdf2.harvard.edu]
> > Sent: Friday, November 19, 2004 10:31 AM
> > To: Philippe Canal
> > Cc: roottalk@pcroot.cern.ch
> > Subject: RE: [ROOT] Can't strip TChain
> > 
> > Hi, Philippe,
> > 
> > I'm using 3.05/07. I'll give this a try.
> > 
> > Thanks!
> > Sal
> > 
> > On Thu, 18 Nov 2004, Philippe Canal wrote:
> > 
> > > Hi Salvatore,
> > > 
> > > Which version of ROOT are using?
> > > 
> > > The problem is that you seemingly are setting the addresses of the 
> > > underlying original tree but not the addresses of the cloned tree:
> > > 
> > >     if ( chain->GetTreeNumber() != prevTreeNum ) {
> > >       SetTheAddresses(chain->GetTree());
> > >       prevTreeNum = chain->GetTreeNumber();
> > >     }
> > > 
> > > In recent version of ROOT, it is sufficient to set the address of 
> > > the original chain (using SetBranchAddress).
> > > 
> > > Cheers,
> > > Philippe.
> > > 
> > > -----Original Message-----
> > > From: owner-roottalk@pcroot.cern.ch 
> > > [mailto:owner-roottalk@pcroot.cern.ch]
> > > On Behalf Of Salvatore Rappoccio
> > > Sent: Thursday, November 18, 2004 2:34 PM
> > > To: roottalk@pcroot.cern.ch
> > > Subject: [ROOT] Can't strip TChain
> > > 
> > > Hi,
> > > 
> > > I am trying to read a subset of the events in my TChain object to 
> > > another file, given some selection criteria.
> > > 
> > > I can write the objects out without complaint, but when I try to 
> > > read back the events that I wrote from the second file of the 
> > > TChain, I get nonsense values.
> > > 
> > > Any ideas?
> > > 
> > > My code is:
> > > 
> > > {
> > >   std::cout << "Getting trees" << std::endl;
> > > 
> > >   TChain * chain = GetChain();
> > >   TTree * tskim = 0;
> > >   int nskim = 0;
> > >   int counter = 0;
> > >   int prevTreeNum = -1;
> > >   int prevRunNum = -1;
> > >   // Load the tree and set the addresses for the second time
> > >   chain->LoadTree(0);
> > >   chain->GetEntry(0);
> > >   
> > >   if ( stripTree ) {
> > >     std::cout << "Setting up strip tree" << std::endl;
> > >     histf->cd();
> > >     tskim = (TTree*)chain->GetTree()->CloneTree(0);
> > >   }
> > > 
> > > 
> > >   prevTreeNum=-1;
> > > 
> > >   //Loop over the events
> > >   for(int ev=firstEvent; ev<nEvents; ev++) { 
> > >     counter++;
> > >     int lflag = -1;
> > >     lflag = chain->LoadTree(ev);
> > > 
> > >     // If this tree hasn't already been set, set the branch addresses
> > >     if ( chain->GetTreeNumber() != prevTreeNum ) {
> > >       SetTheAddresses(chain->GetTree());
> > >       prevTreeNum = chain->GetTreeNumber();
> > >     }
> > > 
> > >     if ( stripTree )
> > >       lflag = chain->GetEntry(ev,1);
> > >     else
> > >       lflag = chain->GetEntry(ev);
> > > 
> > >     if ( lflag < 0 ) {
> > >       cout << "Error in loading trees" << endl;
> > >       return;
> > >     }
> > >     
> > >     // Decide to strip the event or not
> > >     bool stripEvent = false;
> > > 
> > >     
> > >     // If this event passes simple cuts, process the
> > >     // event, returning strip status
> > >     if ( PassCuts( ev, lflag ) ) {
> > >       stripEvent = Process( ev, lflag );
> > >       // If desired, strip this event and write to file
> > >       if ( stripTree ) {
> > > 	tskim->Fill();
> > > 	nskim++;
> > > 	if ( nskim % 10000 == 0 ) {
> > > 	cout << "Writing to strip tree : nskim = " << nskim << endl;
> > > 	tskim->AutoSave();
> > > 	}
> > >       }
> > >     }
> > >   }
> > > 
> > >   // Write stuff to output file
> > >   histf->cd();
> > > 
> > >   // Strip tree
> > >   if ( stripTree ) {
> > >     cout << "Writing to strip tree : nskim = " << nskim << endl;
> > >     tskim->AutoSave();
> > >   }
> > >   histf -> Close();
> > > 
> > > }
> > > 
> > > 
> > > Thanks,
> > > Sal Rappoccio
> > > 
> > > 
> > 
> > 
> > 
> 
> 
> 



This archive was generated by hypermail 2b29 : Sun Jan 02 2005 - 05:50:10 MET