Re: Obtaining the list of histograms in a root file

From: Laurent Aphecetche (Laurent.Aphecetche@subatech.in2p3.fr)
Date: Wed Jun 02 1999 - 12:51:22 MEST 

Giovanni Organtini wrote:
> 
> Hi,
> I could not find this on the Web pages. I have a root file with several
> histograms. The number and the names of histograms varies from run to run.
> Is there a way to obtain the list of histograms (that I can see with ls())
> and/or directorie names inside a macro? Thank you.

Here's an example macro :

void loop(const char* filein="test.root")
{
  TFile* fin = new TFile(filein) ;

  if (!fin->IsOpen()) {
    printf("<E> Cannot open input file %s\n",filein) ;
    exit(1) ;
  }
  
  TList* list = fin->GetListOfKeys() ;
  if (!list) { printf("<E> No keys found in file\n") ; exit(1) ; }
  TIter next(list) ;
  TKey* key ;
  TObject* obj ;
      
  while ( key = (TKey*)next() ) {
    obj = key->ReadObj() ;
    if (    (strcmp(obj->IsA()->GetName(),"TProfile")!=0)
         && (!obj->InheritsFrom("TH2"))
	 && (!obj->InheritsFrom("TH1")) 
       ) {
      printf("<W> Object %s is not 1D or 2D histogram : "
             "will not be converted\n",obj->GetName()) ;
    }
    printf("Histo name:%s title:%s\n",obj->GetName(),obj->GetTitle());
  }
}

-- 
APHECETCHE Laurent (mailto:Laurent.Aphecetche@subatech.in2p3.fr)       
SUBATECH-Ecole des Mines de Nantes-4 rue Alfred Kastler-44070 NANTES
cedex 03
TEL (+33/0) 2 51 85 84 17 - FAX (+33/0) 2 51 85 84 24
WWW: http://www-subatech.in2p3.fr/~photons

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