Re: subbranches

From: chiara zampolli <Chiara.Zampolli_at_bo.infn.it>
Date: Tue, 22 Mar 2005 15:20:24 +0100

Dear Axel,

    Thank you for your answer.
    Francesco and I have tried to write a short macro (see attachment) following your suggestions. After running it, what we find in the prova.root file (exploring it via the TBrowser) is a leaf (fStrips) with two entries, which we suppose to belong to the two plates we have defined in the macro itself. Now, is this correct? Are the histograms stored as we would like them to be, even if we do not see them? If this is the case, could you suggest us how to read/retrieve them?

    Thank you. Cheers,
      chiara & nofero.

Axel Naumann wrote:

> Hi Chiara,
> one way of doing that is by creating an class which represents a
> certain part of your hierarchy. I assume you have several entries of
> (sector1, sector2) pairs, i.e. you'd fill your tree more than once
> (otherwise you probably shouldn't use a TTree), and that you have
> several histos per strip object (otherwise get rid of the TString
> class, and store the list of histos directly in TPlate). In that case
> this should work:
>
> class TStrip: public: TObject {
> ...
> private:
> std::list<TH1*> fHists;
> };
>
> class TPlate: public TObject {
> ...
> private:
> std::list<TStrip> fStrips;
> };
>
> TClonesArray* ca=new TClonesArray("TPlate");
>
> TTree* t=new TTree("ch_nofero", "tree of sectors, plates, and strips");
> t->Branch("sectors", &ca);
>
> You could also create one branch for each strip, named e.g.
> "Sector1Plate4Strip2". This is pretty efficient, but a bit ugly.
>
> Axel.
>
> chiara zampolli wrote:
>
>> Dear rooters,
>>
>> we are trying to create a tree with four levels of subbranches,
>> with the last one made up of histograms (TH1F):
>>
>> LEVEL1: sector1
>> sector2
>>
>> | |
>> /
>> \ / \
>> LEVEL 2: plate1 plate2
>> plate1 plate2
>> |
>> /
>> LEVEL3: strip1 .... .....
>> ....... ......
>> |
>> LEVEL4: histo1
>>
>> and so on. Could you suggest me how to create such a tree? Since we
>> are not able to split more than once the tree we have defined.
>> Till now, we have tried using the TClonesArray class and the
>> TTree->Branch(....) method.
>>
>> Thank you.
>> Cheers,
>> ch & nofero
>>

#include "TFile.h"
#include "TObject.h"
#include "TH1F.h"
#include "TTree.h"
#include <list>
//_____________________________________________________________________________

class TStrip: public TObject {   

public:
  TStrip(const char *name){};
  void pushback(TH1F *histog){fHists.push_back(histog);}; private:
  std:list<TH1F*> fHists;
};

class TPlate: public TObject {   

public:
  TPlate(const char *name){};
  void pushback(TStrip *strip){fStrips.push_back(strip);};   

private:
  std:list<TStrip*> fStrips;   

};

void lista(){   

  // Char_t hnameMEAN[100];
  TH1F *hist[5];
  TTree *fTreeEq;
  fTreeEq = new TTree("TreeEq","Tree of Plates and Sectors");   

  TStrip *Strips[3];
  TPlate *Plate[2];

  TH1F *hist[5];
  TH1F *hist[0] = new TH1F("hist0", "hist0", 100,-1.,1.);
  TH1F *hist[1] = new TH1F("hist1", "hist1", 100,-1.,1.);
  TH1F *hist[2] = new TH1F("hist2", "hist2", 100,-1.,1.);
  TH1F *hist[3] = new TH1F("hist3", "hist3", 100,-1.,1.);
  TH1F *hist[4] = new TH1F("hist4", "hist4", 100,-1.,1.);
  

  char stripname[10];
  char platename[10];

  TClonesArray *ca=new TClonesArray("TPlate");   TClonesArray &aca=*ca;

  for (Int_t k=0; k<2; k++){
    sprintf(platename,"plate%i",k);
    new(aca[k]) TPlate (platename);
    Plate[k] = new TPlate(platename);
    for (Int_t i=0; i<1; i++){

      sprintf(stripname,"strip%i",i);
      Strips[i] = new TStrip(stripname);
      for (Int_t j=0; j<5; j++){
	Strips[i]->pushback(hist[j]);
      }
      Plate[k]->pushback(Strips[i]);

    }
  }   

  TFile *fileout = new TFile("prova.root","recreate");

  fTreeEq->Branch("sectors", &ca);
  fTreeEq->Fill();
  fTreeEq->Write();
  fileout->Close();

} Received on Tue Mar 22 2005 - 15:08:24 MET