Thomas,
Your question is not clear. Do you mean "can" or "cannot" ?
Any collection of objects can be written to a file
(see TCollection::Write method). You have two ways
-single key (all objects are serialized in teh same buffer)
-one key per object in the collection (default).
Obviously, each object in the collection must be streamable (have a
dictionary).
See for example this session:
root [4] TObjArray a(3)
root [5] a.Add(hpx)
root [6] a.Add(hprof)
root [7] a.Add(hpxpy)
root [8] TFile f("junk.root","recreate")
root [9] a.Write("a")
(Int_t)4644
root [10] .ls
TFile** junk.root
TFile* junk.root
KEY: TH2F a;3 py vs px
KEY: TProfile a;2 Profile of pz versus px
KEY: TH1F a;1 This is the px distribution
root [11] a.Write("as",TObject::kSingleKey)
(Int_t)4381
root [12] .ls
TFile** junk.root
TFile* junk.root
KEY: TH2F a;3 py vs px
KEY: TProfile a;2 Profile of pz versus px
KEY: TH1F a;1 This is the px distribution
KEY: TObjArray as;1 An array of objects
Rene Brun
On Wed, 15
Sep
2004, Thomas Bretz wrote:
> Hi,
>
> is it possible that a TObjArray cannot be written to a file? I cannot
> find anything about this in the documenation...
>
> Thomas.
>
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