Hi Volker,
Volker Hejny wrote:
>
> Hi Rene,
>
> On Mon, Jan 21, 2002 at 08:42:45AM +0000, Rene Brun wrote:
>
> > In 3.02, I introduced a branch constructor supporting a collection in input.
> > See : http://root.cern.ch/root/html302/src/TTree.cxx.html#TTree:Branch
> > Branch(TCollection *list, Int_t bufsize, Int_t splitlevel, const char *name)
>
> Yes, I know. Maybe I have overlooked something, but the objects in
> the collections are stored as top-level branches, aren't they? I'd
> like to have this structure available in the tree, i.e. when browsing
> through it. And, as far as I know, an automatic reconstruction of the
> collection hierachy on read is not implemented so far.
Suppose a TList *list containing objects A,B,C and D.
Calling tree.Branch("event",list)
This will create 4 top branches. In turn, if classes A,B,C or D have subobjects
or pointers to TClonesArray, this will be split using the usual split rules.
When reading the Tree, you still have to set the branch addresses for A,B,C,D.
I could implement a special SetBranchAddress taking a list as input.
>
> > If you run in compression mode (default), elements that do not change from
> > event to event will be highly compressed. See the result with TTree::Print.
>
> My concern is not disk space, it's rather speed. This would mean writing
> two or three TString variables every time and to compress the buffer
> every time. Writing is already a time consuming part.
>
It will take more time if you have many variables of this type. I would be
curious to know the difference in time in your particular case.
You can always have a RUN object and do RUN.Write() at the time when
you do tree.Write().
Rene Brun
> Best regards,
> Volker
>
> --
> Dr. Volker Hejny Tel: 02461/616853 **
> Institut f. Kernphysik Fax: 02461/613930 **
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