Re: Merging TNtuples from different files in one ROOT file

In your version using TChain, could you replace the statement:  ch.Merge("newfile.root")
by
 ch.Merge("newfile.root","fast")

Rene Brun

Matthias Kirsch wrote:
> Dear ROOTers,
>
> I have problems merging several ROOT files into one. Each of the eight
> files contains an TNtuple with approx. 260 variables. They all have
> the same name. I have already tried several methods, TFileMerger,
> hadd, TChain. All these methods work fine, if I only use three or four
> files. But trying to merge all eight files, I get error messages. The
> logfile in the attachment shows two interactive attempts using ROOT
> 5.12/00e. The input files were created with this ROOT version. I also
> tried to merge the files with using the latest version 5.17/04, but
> also without success.
> Is this because of the input size of the files (summed up approx. 80
> MB)? Or because of the number of variables? I have already used the
> same methods to merge more than 100 smaller files successfully. Any
> ideas what might cause this problems?
>
> Thanks for your help!
>
> Cheers,
> Matthias
Received on Tue Oct 23 2007 - 16:24:15 CEST