The base class of the dynamic arrays is TTable ROOT class.
Cheers, Valeri
> -----Original Message-----
> From: owner-roottalk@pcroot.cern.ch
[mailto:owner-roottalk@pcroot.cern.ch]
> On Behalf Of Carlos Muņoz Camacho
> Sent: Friday, January 31, 2003 1:26 PM
> To: Arthur E. Snyder
> Cc: roottalk@pcroot.cern.ch
> Subject: Re: [ROOT] Streaming an array whose size is a non-const
parameter
>
> On Fri, 31 Jan 2003, Arthur E. Snyder wrote:
>
> >Maybe you could use an stl vector instead?
>
> I can, but then I need to call the push_back method every time I
add an
> element. As the size of the array is constant and known, I want to
> allocate memory only once (and eventually re-use it for the next
event)
>
> Carlos
>
> >
> >#include <vector>
> >
> >//declare
> >std::vector<Float_t> array;
> >
> >//add next element
> >array.push_back(aFloat);
> >
> >Int_t size=array.size();
> >
> >stl vectors should at least work in compiled code. I'm not sure if
> they're
> >implemented in intrepreter.
> >
> >
> >
> >
> >
> >
> >A.E. Snyder, Group EC \!c*p?/
> >SLAC Mail Stop #95 ((. .))
> >Box 4349 |
> >Stanford, Ca, USA, 94309 '\|/`
> >e-mail:snyder@slac.stanford.edu o
> >phone:650-926-2701 _
> >http://www.slac.stanford.edu/~snyder BaBar
> >FAX:650-926-2657 Collaboration
> >
> >
> >
> >On Fri, 31 Jan 2003, Carlos Muņoz Camacho wrote:
> >
> >>
> >> Hi,
> >>
> >> I have a class similar to Event.h with an array of Float_t as a
> member.
> >> I want the dimension of the array to be a non-const parameter (as
it
> will
> >> be read from an input file). The parameter is a static member of an
> >> inherited class, but this can change. The important thing is I
don't
> want
> >> to hardcode the value of the parameter, because it is read from a
file.
> >>
> >> The solution I found in the documentation is to allocate it
> dynamically
> >> via a pointer and tell the streamer the size of the array in the
> >> commentary field : //[fSize] . However, fSize needs to be a data
member
> of
> >> the class. Obviously, I don't want to save this data member to file
> >> because it is constant for all the events. If I use fSize //! to
avoid
> >> writing it, I get an Error in <TStreamerInfo::Build>. Below is a
short
> >> example which reproduces the problem.
> >>
> >> Is there a way around this?
> >>
> >> ROOT 3.03/08 on a RH 7.2
> >>
> >>
> >> File: class.C
> >> ______________________________________________________
> >>
> >> #include "TObject.h"
> >>
> >> class TEvent : public TObject {
> >>
> >> private :
> >>
> >> Int_t fSize; //!
> >> Float_t* fBlocks; //[fSize]
> >>
> >> ClassDef(TEvent,1)
> >>
> >> };
> >> _______________________________________________
> >>
> >> Result:
> >>
> >> CINT/ROOT C/C++ Interpreter version 5.15.53, Aug 15 2002
> >> Type ? for help. Commands must be C++ statements.
> >> Enclose multiple statements between { }.
> >> root [0] .L class.C+
> >> Info in <TUnixSystem::ACLiC>: creating shared library
> >> /dsm/phnpcd232/local/home/cmunoz/./class_C.so
> >> root [1] TEvent *ev=new TEvent();
> >> root [2] TTree t("t","My tree");
> >> root [3] t.Branch("event","TEvent",&ev,16000,99);
> >> Error in <TStreamerInfo::Build>: TEvent, discarding: Float_t*
fBlocks,
> >> illegal [fSize]
> >>
> >>
> >>
> >> Carlos Munoz Camacho
> >> SPhN/CEA-Saclay
> >>
> >>
> >
This archive was generated by hypermail 2b29 : Thu Jan 01 2004 - 17:50:09 MET