Re: Failure in TTree filling

You can simplify your code as shown below. In your case it looks like you did not create T1 in f1, but you saved T1 via T1->Write() in f1.

Rene Brun

     TFile *f1 = new TFile(...)
     TTree *T1 = new TTree(...)
     T1->Branch...
     ...
     TFile *f2 = new TFile(...)
     TTree *T2 = new TTree(...)
     T2->Branch...
     ...
     fill branches (no need to cd to the file)
     T1->Fill();
     T2->Fill();...

     //save headers (no need to cd() if using Autosave)
     T1->AutoSave();
     T2->Autosave();
     ...
     delete f1;
     delete f2;
     ...

Francois-Xavier Girod wrote:
> Dear rooters,
>
> I am using root version 5.11/06, but the problem also appears on earlier
> versions.
>
> What should I do if I want to write several trees in several files ?
>
> I did
> TFile *f1 = new TFile(...)
> TTree *T1 = new TTree(...)
> T1->Branch...
> ...
> TFile *f2 = new TFile(...)
> TTree *T2 = new TTree(...)
> T2->Branch...
> ...
> ...
> (process stuff and fill variables)
> ...
> f1->cd()
> T1->Fill()
> f2->cd()
> T2->Fill()
> ...
> f1->cd()
> T1->Write()
> f2->cd()
> f2->Write()
>
>
> f2 file is ok, with T2 tree containing its data. However, f1 file contains
> T1 tree, which has correct keys (for instance I can get the number of
> events or the list of leaves) but contains no data. More specifically if I
> try to draw something I get :
>
> Error in <TFile::ReadBuffer>: error reading all requested bytes from file
> outTreeResultDVCS.root, got 0 of 29892
>
> I should add that, this only happens for the analysis of a large number of
> events. When I process a few events, the output is correct.
>
> My guess is that, the way I proceed only the last declared tree is disk
> resident, whereas the previous ones are memory resident.
>
> Thank you for help.
>
> Regards,
> Francois-Xavier
>
> --
>
> Girod Francois-Xavier
>
> CEA Saclay
> DSM / DAPNIA / SPhN
> Orme des Merisiers
> Bat 703 piece 133 C
> 91191 Gif-sur-Yvette
> France
>
> tel : (+33) 1 69 08 74 29
> fax : (+33) 1 69 08 75 84
>
> On Wed, 28 Jun 2006, Rene Brun wrote:
>
>
>> When this message is printed with teh CVS head version, you also get the
>> following print:
>>
>> This error is symptomatic of a Tree created as a memory-resident Tree
>> Instead of doing:
>> TTree *T = new TTree(...)
>> TFile *f = new TFile(...)
>> you should do:
>> TFile *f = new TFile(...)
>> TTree *T = new TTree(...)
>>
>>
>> Rene Brun
>>
>> Alberto Pulvirenti wrote:
>>
>>> Dear rooters,
>>>
>>> sometimes, while filling a TTree, I encountered this message:
>>>
>>> Error in <TTree::Fill>: Failed filling branch:matches.matches, nbytes=-1
>>>
>>> can someone explain me what does it mean? What mistake did I do while
>>> creating the code to fill that TTree?
>>> For completeness I must say that this TTree is filled with a branch
>>> made from a struct of primitive data types.
>>>
>>> Thanks,
>>>
>>> Alberto
>>>
>>> **************************************
>>> ----- Alberto Pulvirenti, Ph. D. -----
>>> Universita' di Catania,
>>> Dipartimento di Fisica e Astronomia
>>> Via Santa Sofia, 64
>>> I-95129, Catania, Italy
>>>
>>> Tel :+39-095-3785286
>>> **************************************
>>>
>>
Received on Fri Jun 30 2006 - 14:29:23 MEST