[ROOT] TTree trouble - cannot distinguish element by the branch name

From: AOKI Kazuya (aoki@nh.scphys.kyoto-u.ac.jp)
Date: Thu Nov 27 2003 - 05:47:57 MET 

Dear ROOT experts,

I have trouble with TTree,
Can experts look at this , please?

I created two branches

tree->Branch("north","TEvent",&north);
tree->Branch("south","TEvent",&south);

   ( same class but different branch names )
   ( TEvent class  has a single valuable named "val" )

When I tried to Scan them , I did like this,

  tree->Scan("north.val")
  tree->Scan("south.val")

but the "north." "south." didn't work.
these commands always return "north.val" value.

with tree->SetBranchAddress and tree->GetEntry,
I can get correct values.
only Draw and Scan functions failed to distinguish
these valuables which has exactly the same name but 
different branch names.

Best Regards,
Kazuya

------------------------------
I'm using ROOT Version   3.05/07     8 August 2003 

The following are the source files.
  TEvent.h
  TEvent.C
  TEventLinkDef.h
  Makefile
  test.C
  rootlogon.C

------------------------------- SCREEN SHOT
root [0] .x test.C
root [1] tree->Scan("north.val")
************************
*    Row   * north.val *
************************
*        0 *         1 *
*        1 *         1 *
*        2 *         1 *
************************
(Int_t)3
root [2] tree->Scan("south.val")
************************
*    Row   * south.val *
************************
*        0 *         1 *
*        1 *         1 *
*        2 *         1 *
************************
(Int_t)3
----------------------------------- END OF SCREEN SHOT

-----TEvent.h-----

#ifndef __TEVENT_H
#define __TEVENT_H

#ifndef __CINT__
#include "TObject.h"
#endif

class TObject;

class TEvent : public TObject
{
  int val;
public:
  TEvent(){}
  ~TEvent(){}
  void SetVal(int _val) { val = _val; }
  int GetVal(){return val;}

  ClassDef( TEvent , 1 )
};

#endif

---- TEvent.C ----

#include "TEvent.h"

ClassImp( TEvent )

----- test.C ----
TTree *tree;
TEvent *south;
TEvent *north;

void test()
{
  TEvent t;
  north = new TEvent();
  south = new TEvent();
  tree = new TTree("testtree","testtree");
  tree->Branch("north","TEvent",&north,3200,99);
  tree->Branch("south","TEvent",&south,3200,99);
  north->SetVal(1);
  south->SetVal(0);
  tree->Fill();
  tree->Fill();
  tree->Fill();
}

------ rootlogon.C ----
{
gSystem->Load("libTEvent.so");
}

---- TEventLinkDef.h ---
#ifdef __CINT__
#pragma link off all globals;
#pragma link off all classes;
#pragma link off all functions;
#pragma link C++ class TEvent;
#endif

--- Makefile ---

ROOTCFLAGS   := $(shell root-config --cflags)
ROOTLIBS     := $(shell root-config --libs)
ROOTGLIBS    := $(shell root-config --glibs)

CXXFLAGS      = $(ROOTCFLAGS)
LD            = g++
PACKAGE = TEvent

ROOTLIBS = $(shell root-config --libs)

LDFLAGS       = -O
SOFLAGS       = -shared

HDRFILES = TEvent.h

ADDITIONAL_SOURCES = TEventDict.C

SO = lib$(PACKAGE).so

$(SO) : $(PACKAGE).C $(ADDITIONAL_SOURCES) $(HDRFILES)
        $(CXX) $(CXXFLAGS) -g -o $@ -shared  $<  $(ADDITIONAL_SOURCES) $(LDFLAGS) 

.PHONY: clean

TEventDict.C:  TEvent.h TEventLinkDef.h
        @echo "Generating ROOT Dictionnary ..."
        rootcint -f $@ -c $(CINTINCS) $^

clean: 
        rm -f $(SO) *Dict*

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