Hi Bernard,
Bernard Andrieu wrote:
>
> Hello,
>
> I have several questions about Chains. I use e.g. 2 files each
> containing the Tree "Global":
> TChain mychain("Global")
> mychain.Add("file1.root")
> mychain.Add("file2.root")
>
> 1)
> When I do:
> Global.Print()
> I get a description of all Branches of the Tree, which is nice, but for
> each File, which is very unconvenient. Is this normal? How to avoid it?
>
This is normal. If you use TChain::Print, you get the equivalent of TTree::Print
for each element of the chain. One could add an option to cumulate the
statistics
of all Trees in one single sheet: to be implemented.
> 2)
> Where can I find the description of the options of Print()? If I go on
> the "Root Clas Categories" web page -> "Tree and Ntuple Classes"
> ->"TChain" ->"Print", or directly to the following adress:
> http://root.cern.ch/root/html/TChain.html#TChain:Print
> I get this:
> void Print(Option_t *option) const
> but I don't see what options can be given, and what do they mean.
>
see http://root.cern.ch/root/htmldoc/TChain.html#TChain:Print
http://root.cern.ch/root/htmldoc/TTree.html#TTree:Print
> 3)
> Is there a way of printing only the Branches which have been selected by
> using Global->SetBranchStatus("*",0)
> Global->SetBranchStatus("branchname",1)?
>
This should work. Only active branches are printed, unless you use an old
version.
> 4)
> Last remark about what can be called not a bug, but an "unconvenient
> feature", of SetBranchStatus. If I do:
> Global->SetBranchStatus("*",0)
> Global->SetBranchStatus("cal",1)
> Global->SetBranchStatus("cal",0)
> //Correct misspelling: the name of the Branch is CAL in capital letters
> Global->SetBranchStatus("CAL",1)
> Global.Draw("ncal")
>
> I get the following error messages
> Error in <TTree::SetBranchStatus>: unknown branch -> cal
> Error in <TTree::SetBranchStatus>: unknown branch -> cal
>
I disagree. An error should be reported in this case.
Rene Brun
> and I cannot get rid of these messages even if I do:
> Global->SetBranchStatus("*",0)
> Is there a way to turnaround this problem?
>
> Thank you,
> Bernard Andrieu
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