Re: [ROOT] Deleting trees.

From: Rene Brun (Rene.Brun@cern.ch)
Date: Tue May 21 2002 - 09:14:15 MEST


Hi Martin,

It is hard to understand this problem without seeing your code.
Could you make a small tar file with the strict minimum to
reproduce the problem and let me know where I can take it?

Rene Brun

Martin Turner wrote:
> 
> What is wrong with the folowing piece of code in a compiled make selector?
> 
> fLambdaBfile = new TFile(output_filename,"update");
> if(fLambdaBfile)  fLambdaB_tree=(TTree*)fLambdaBfile->Get("Jpsi selection");
> if(!fLambdaBfile)  fLambdaBfile = new TFile(output_filename,"recreate");
> if(fLambdaB_tree)  fLambdaB_tree->Delete("all");
> 
> fLambdaB_tree = new TTree("Jpsi selection","jpsi selection tree");
> 
> //fLambdaBfile and fLambdaB_tree are defined in the header file of make
> selector
> 
> It is random wether the script will crash eventually or not. If it will
> crash it will give the following warning:
> 
> R__unzip: error in header
> after the update line.
> Are these four lines carelessly coded? Anyone any suspicions? Is the
> problems elsewhere?
> 
> The goal is to have 3 Tselectors, that make a Lambda Selection, Jpsi
> selection and Kshort selection on a single file. These 3 selections are 3
> trees which are read in to a final LambdaB selector to give a LB or B0
> peak. If I want to update a particular selection then I don't want to
> build all the others, so that's my motivation.
> 
> Thanks in advance,
> Martin



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