Re: [ROOT] reading ntuple contents

From: Rene Brun (Rene.Brun@cern.ch)
Date: Fri Apr 16 2004 - 16:45:04 MEST


Andi,

I have the impression that you should

TH1F* myHist = (TH1F* )f.Get("signif/t3333");
instead of
TH1F* myHist = (TH1F* )f.Get("t3333/signif");

where "signif" is teh directory name and "t3333" is your ntuple.

Rene Brun

Andreas WILDAUER wrote:
> 
> Hi all,
> 
> I have the following problem:
> 
> I want to read some ntuple variable and create a histo out of it.
> I do the following:
> 
> TFile f("myFile.root")
> 
> The ntuple variable is in the dir/key: t3333 and is called signif
> 
> so I do:
> 
> TH1F* myHist = (TH1F* )f.Get("t3333/signif");
> 
> this results in the error:
> Error in <TFile::cd>: Object t3333 is not a directory
> 
> but all the ntuple variables are in this directory/key. (I can see that in
> TBrowser)
> 
> I tried certain combinations which worked in the past:
> 
> t3333;1/signif -> no error right away but myHisto->Draw() crashes
> t3333/signif/1 -> same error as above
> ...
> 
> Does anyone know how this works?
> Thanks in advance
> Andi
> 
> =======================================================================
> Andreas Wildauer
>     CERN/PH ATC, mailbox E25310, CH-1211 Geneva 23, Switzerland
>     office 40 3-D06
>     email  Andreas.Wildauer@cern.ch
>     tel    +41 22 76 71779
> =======================================================================



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