Re: TTree Draw 5 variables

From: Rene Brun <Rene.Brun_at_cern.ch>
Date: Fri, 1 Oct 2010 15:32:36 +0200


Andrea,

You are right. Currently you have to do something like:   T.Draw("x:y:z:u:v","","para goff");
   T.GetVal(4);

Hoping that we can improve this soon.

Rene Brun

Andrea Massironi wrote:
> Dear Rooters,
> I'm wondering if it's possible to use the "Draw" of a TTree with 5
> variables with the "goff" option and then get the results with
> "GetVal(Int_i i)", like in the following example.
>
> I get the following error:
>
> Error in <TSelectorDraw::Begin>: Too many variables. Use the
> option "para", "gl5d" or "candle" to display more than 4 variables.
>
> even if in http://root.cern.ch/root/html/TTree.html I read
> "Giving more than 4 variables without the option=para or
> option=candle or option=goff will produce an error."
>
> But "goff" seems to be an available option.
>
>
> Thanks,
> Andrea
>
>
>
> TTree* myTree = new TTree("myTree","myTree");
>
> double x,y,z,t,w;
>
> myTree->Branch("x",&x,"x/D");
> myTree->Branch("y",&x,"y/D");
> myTree->Branch("z",&x,"z/D");
> myTree->Branch("t",&x,"t/D");
> myTree->Branch("w",&x,"w/D");
>
>
> for (int i=0; i<100; i++){
> x = i;
> y = i+1;
> z = i+2;
> t = i+3;
> w = i+4;
> myTree->Fill();
> }
>
>
> myTree->Draw("x:y:z:t:w","","goff");
>
> Double_t *vX = myTree->GetVal(0);
> Double_t *vY = myTree->GetVal(1);
> Double_t *vZ = myTree->GetVal(2);
> Double_t *vT = myTree->GetVal(3);
> Double_t *vW = myTree->GetVal(4);
>
>
Received on Fri Oct 01 2010 - 15:32:42 CEST

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