Re: [ROOT] Fetching TTree by Title

From: Rene Brun (Rene.Brun@cern.ch)
Date: Tue Jan 09 2001 - 15:45:36 MET


Hi Doug,
Here is a simple example FindTitle.C

TObject *FindTitle(TDirectory *dir, const char *title)
{
   //find an object with title in the current directory on disk
   //and import this object in memory
   
   TKey *key;
   TIter next(dir->GetListOfKeys());
   while ((key = (TKey *) next())) {
     if (strcmp(title,key->GetTitle()) == 0) return key->ReadObj();
   }
   return 0;
}

Example of use:
root > .L FindTitle.C
root > TFile *f = new TFile("myfile.root");
root > FindTitle(f,"some title")->Draw();


Rene Brun

Douglas Roberts wrote:
> 
> Hi,
>   Does anyone know of a good (and easy) way to find a TTree based on its
> title instead of by its name?  Something like FindObject that takes the
> title as an argument.
>   The specific application I'm trying to solve is taking h2root-ed hbook
> files that, depending on the job configuration, can assign varying ID
> numbers to ntuples but the titles stay the same.  So, the object name
> generated by h2root can vary from job to job.
> 
> Any help would be appreciated,
> Doug
> 
> Douglas Roberts
> Department of Physics
> University of Maryland
> College Park, MD 20742
> Office: Physics 4308
> Phone: (301)405-6067
> FAX: (301)699-9195



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