Axel Schwank wrote:
>
> Dear Nick,
> I read about your problem with equally named data members in a ROOT TTree.
> I wonder if it really turns out to be a problem. Have you tried this out?
> I use a TTree built of TClonesArrays in split mode. Probably you would use
> the approach to build the tree directly of your classes. But then, each
> class would go into a separate branch and thus each subbranch would be
> uniquely named, e.g.
> Track_fEnergy and Jet_fEnergy.
> If I understand you well, that's how you build your Tree.
> Or do I misunderstand something here?
> Could you spare the time and tell me how your Tree is organized and where
> the branches collide?
>
> Thank you in advance,
> Axel
>
> ********************************
>
> Axel Schwank
>
> DESY H1-F22
> Notkestrasse 85
> D-22607 Hamburg
>
> Rm. 1b/269
> Tel (+49 40) 8998-3560
> Fax (+49 40) 8998-4385
>
> e-mail schwank@mail.desy.de
> Quix 0165-6-2705109
>
> ********************************
>
> On 13 Aug 1998, Nick van Eijndhoven wrote:
>
> >
> > Dear ROOTers,
> > In setting up some classes for data analysis of events concerning
> > heavy-ion collisions I wonder about the following :
> >
> > I have a class Track and a class Jet and my event data consists
> > of a ROOT Tree in which there is a branch for tracks and a branch
> > for jets of a certain event.
> > Both Track and Jet contain a data member float fEnergy
> > In case I have the libs containing the Track and Jet classes
> > available in my ROOT environment there clearly is no problem,
> > since I can just use the Track and Jet member functions to investigate
> > e.g. the fEnergy of both of them and even plot one against the other.
> > However, in case I don't have the libs, I would use the MakeCode()
> > facility to be able to analyse the Tree.
> > As far as I can see this now gives a problem, since the fEnergy
> > would be related to both classes.
> > Question : Am I right here that the produced code can't work ?
> > Or does MakeCode properly take care of the problem ?
> >
> > Obviously a way out would be to define fTrackEnergy and fJetEnergy,
> > but as far as I can see this is no solution once one thinks of
> > (re)using code of other related experiments.
> >
> > Suggestion : In case MakeCode encounters the same variable name
> > in different branches, could then on each additional
> > occurence of that variable some suffix be added auto-
> > matically be MakeCode ?
> >
> > In case of the above situation this would result in e.g. :
> >
> > fEnergy and fEnergy_2
> >
> > In case the problems I expect in the above are real, the latter
> > is just a suggestion and in case someone has a better solution
> > please let me know.
> > --
> >
> > Cheers,
> >
> > _/_/ _/ _/ _/_/_/_/ _/ _/
> > _/ _/ _/ _/ _/ _/ _/
> > _/ _/ _/ _/ _/ _/_/
> > _/ _/_/ _/ _/ _/ _/
> > _/ _/ _/ _/_/_/_/ _/ _/
> >
> >
> > *----------------------------------------------------------------------*
> > Dr. Nick van Eijndhoven Department of Subatomic Physics
> > email : nick@phys.uu.nl Utrecht University / NIKHEF
> > tel. +31-30-2532331 (direct) P.O. Box 80.000
> > tel. +31-30-2531492 (secr.) NL-3508 TA Utrecht
> > fax. +31-30-2518689 The Netherlands
> > WWW : http://www.phys.uu.nl/~nick Office : Ornstein lab. 172
> > ----------------------------------------------------------------------
> > tel. +41-22-7679751 (direct) CERN PPE Division / ALICE exp.
> > tel. +41-22-7675857 (secr.) CH-1211 Geneva 23
> > fax. +41-22-7679480 Switzerland
> > CERN beep : 13+7294 Office : B 160 1-012
> > *----------------------------------------------------------------------*
> >
> >
Hi Axel,
First of all : I didn't try things out yet, it was just something which
came to my mind when I started thinking about it (yes I know, thinking
may be dangerous !).
Indeed I plan to build the tree directly from my classes and if indeed
every branch creates a prefix like Track_fEnergy and Jet_fEnergy
automatically
from just the fEnergy and fEnergy data members which I had in my Track
and Jet
classes, everything seems to be fine to me.
However, I have my doubts here, since when I use h2root to convert a
column
wise ntuple into a ROOT tree, the docs say that each ntuple variable
becomes
a separate branch, but the variable names still come out the same as
they were
in the ntuple. It could be of course that our ROOT friends play some
tricks
in between here, but that's not clear to me. This is why I posed the
question
to the mailing list.
The other thing is of course, will it also work when NO split mode is
used ?
I hope that soon I will have a spare moment to try things out, but
clearly
I would welcome all experience of other people in this.
--
Cheers,
_/_/ _/ _/ _/_/_/_/ _/ _/
_/ _/ _/ _/ _/ _/ _/
_/ _/ _/ _/ _/ _/_/
_/ _/_/ _/ _/ _/ _/
_/ _/ _/ _/_/_/_/ _/ _/
*----------------------------------------------------------------------*
Dr. Nick van Eijndhoven Department of Subatomic Physics
email : nick@phys.uu.nl Utrecht University / NIKHEF
tel. +31-30-2532331 (direct) P.O. Box 80.000
tel. +31-30-2531492 (secr.) NL-3508 TA Utrecht
fax. +31-30-2518689 The Netherlands
WWW : http://www.phys.uu.nl/~nick Office : Ornstein lab. 172
----------------------------------------------------------------------
tel. +41-22-7679751 (direct) CERN PPE Division / ALICE exp.
tel. +41-22-7675857 (secr.) CH-1211 Geneva 23
fax. +41-22-7679480 Switzerland
CERN beep : 13+7294 Office : B 160 1-012
*----------------------------------------------------------------------*
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