Create a branch from inheritance classes

[eddymaoui]

I am trying to create a branche based on inhritence classe.(the code based on makeclass method)

1.class Track :public Vec3D
2.class Vec3D {
3. fChain->Branch(“TrackList_”, &TrackList_)/*how i am creating the branch */

what i am looking

> Blockquote

TrackList_:
                id_    
                E_                  
                t_                    
                valid_
                vec:
                                 x
                                 y
                                 z

this is the message i got .

 Warning in <TStreamerInfo::Build>: Track: base class Vec3D has no streamer or dictionary it will not be saved
(analyse) @0x2b53550

you will find the codes used below

analyse.C (1.5 KB) analyse.h (6.3 KB) Track.h (337 Bytes) Vec3D.h (190 Bytes)

[EVTO]

Hi. Have you tried to make your class inherit from TObject (class Vec3D :public TObject {…)? I think this way you would use the “ROOT defined” streamer for input/output
I hope this fix the problem

[eddymaoui]

Hi @EVTO
first of all i would thanks you for your reply .
i try to do same changes in my code but i get this message
1-class Track : public Vec3D{
2-class Vec3D : public TObject {

Error in <TTree::Branch>: The actual class (TObject) of the object provided for the definition of the branch "TrackList_" does not inherit from Track
(analyse2) @0xec6c30

[EVTO]

Maybe I have an idea but I don’t want to say something stupid so I will try on my laptop first and if it works I will tell you then

[Axel]

ROOT needs to know how to store your classes. That info is called “a dictionary”. You can get it simply by running .L analyse.C+ (note the trailing +), and putting

#ifdef __CLING__
#pragma link C++ class Vec3D+;
#endif

into analyse.C. If you build your own binary etc, please check https://root.cern/manual/integrate_root_into_my_cmake_project/

Cheers, Axel.

[eddymaoui]

Hi @Axel
thanks for your answer
i got the same message iven if i add this code in the Linkdef.h file

#ifdef __CLING__
#pragma link C++ class Vec3D+;
#endif

could you please explain more details
thanks

[eddymaoui]

Hi @Axel @EVTO
i have a question
it is the right command line to create a branch from inheritance class ? :

   TfChain->Branch("TrackList_", &TrackList_,2,32000);

and this is the class

#ifndef Track_h
#define Track_h
#include "TObject.h"
#include "TObjArray.h"
#include "Vec3D.h"

class Track : public Vec3D{

public: 
   unsigned int id_;         ///< Unique identifier
   double       E_;                    ///< Energy
   double       t_;                    ///< time  o
   bool         valid_;                ///< Boolean to ev.
   Vec3D        position_;
  }TrackList_;

#endif

thsnks

[EVTO]

Hi @eddymaoui. I think this way you create a branch with a buffer of 2 bytes and 32000 splitting of the branch. Maybe you want the opposite, (… , … ,32000, 2)?

[Axel]

Plus you need to generate the dictionary for the type of the data you want to store - so Track, I guess?

#ifdef __CLING__
#pragma link C++ class Vec3D+;
#pragma link C++ class Track+;
#endif

should help. What do you do with your Linkdef.h file, is that passed to rootcling? Can you share the dictionary source file that’s generated?

[eddymaoui]

Hi @Axel
Sorry for the delay
i am generating the dictionnaire with :

rootcling -f MyDictionary.cxx analyse2.h Hit.h Neutrino.h Track.h Vec3D.h LinkDef.h

when a look to the output via new TBrowser i find the track inherit from the vec 3D
but it still gives me this warning :

Warning in <TStreamerInfo::Build>: Track: base class Vec3D has no streamer or dictionary it will not be saved
(analyse2) @0x27edb40

MyDictionary.cxx (9.7 KB)
Thanks