Hi Angela,
As you noted changing the return type from double to Double_t work around
the problem. In the current release of ROOT, the TTree::Draw method can
only use method that returns type like Int_t, Double_t, etc. (and NOT int,
double or float!).
This will be fixed in the next release.
Philippe Canal.
> -----Original Message-----
> From: owner-roottalk@pcroot.cern.ch
> [mailto:owner-roottalk@pcroot.cern.ch]On Behalf Of Angela Biselli
> Sent: Monday, July 31, 2000 1:32 PM
> To: roottalk@pcroot.cern.ch
> Subject: [ROOT] problem with a tree with my own class branch
>
>
> Dear Rooters
> I'm sorry if what I'm asking has been discussed already but I could not
> find any useful hint in the roottalk messages and the documentation
> I wrote two classes V3 and V4 and I managed to create the dictionary and
> the so library.I then wrote a small program that create a tree with a
> single branch that is a V3 object(split=0).
>
> Int_t split = 0;
> Int_t bsize = 256000;
> V3 *angela = new V3;
> TFile *f = new TFile("A.root","recreate");
> TTree *tree = new TTree("T","An example of ROOT tree");
> tree->Branch("angela","V3",&angela,bsize,split);
> for (Int_t i=0;i<10;i++) {
> angela->SetV3(1.,2.,3.);
> tree->Fill();
> }
> tree->Print();
> tree->Write();
> f->Write();
> f->Close();
>
> When I try to draw any variable I always get a plot with the right number
> of events but all zeros
>
> gSystem->Load("libVector.so")
> TFile *f=new TFile("A.root");
> T->Draw("angela.GetZ()")
>
> Am I doing something wrong or am I trying to do something that is not
> possible
> I attached all the classes file,the Makefile and the main program
>
> Any help would be appreciated
>
> thanks
>
> Angela
>
> --
> Angela Biselli homepage : http://ignatz.phys.rpi.edu/~biselli
> Graduate Student e-mail:biselli@angel.phys.rpi.edu
> Office TEL.518-276-2050
>
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