Tadeusz Pytlos wrote:
>
> On Wed, 12 Aug 1998, Rene Brun wrote:
>
> > >2) Is it possible to write TGraph object into root file?
> >
> > Yes, this is possible, like for any TObject derived class.
> > You can do:
> > mygraph->Write("graphname"); // if graph has no name
> > or
> > mygraph->SetName("graphname");
> > mygraph->Write();
> >
> > Rene Brun
> >
> >
> Hello Rene,
> Thank you for your answer, but it doesn't work for me.
> Below is slightly modified gerrors.C, which produces root file with
> 1) in browser only info and error
> root [0]
> Processing gerrors.C...
> root [1] Warning in <MakeDefCanvas>: creating a default canvas with name
> inspect
> Error in <TClass::GetMethod>:
> Did not find matching TMethod <GetOption> with "" for TGraph
>
> 2) in interactive mode
> root [0] TFile *fin=new TFile("graph.root")
> root [1] gr->Draw()
> only one line.
> What happens with my graph or what I'm doing wrong?
> I'm using ROOT v.2.00/10 under LInux RedHat 5.0.
>
> // gerrors.C
> {
> gROOT->Reset();
> TFile *fout=new TFile("graph.root","recreate");
> c1 = new TCanvas("c1","A Simple Graph with error bars",200,10,700,500);
>
> c1->SetFillColor(42);
> c1->SetGrid();
> c1->GetFrame()->SetFillColor(21);
> c1->GetFrame()->SetBorderSize(12);
>
> Int_t n = 10;
> Float_t x[n] = {-0.22, 0.05, 0.25, 0.35, 0.5,0.61,0.7,0.85,0.89,0.95};
> Float_t y[n] = {1,2.9,5.6,7.4,9,9.6,8.7,6.3,4.5,1};
> Float_t ex[n] = {.05,.1,.07,.07,.04,.05,.06,.07,.08,.05};
> Float_t ey[n] = {.8,.7,.6,.5,.4,.4,.5,.6,.7,.8};
> gr = new TGraphErrors(n,x,y,ex,ey);
> gr->SetTitle("TGraphErrors Example");
> gr->SetMarkerColor(4);
> gr->SetMarkerStyle(21);
> gr->Draw("ALP");
> gr->Write("gr");
>
> c1->Update();
> delete fout;
> }
Tadeusz,
When you redraw the TGraph object in the second session from the file,
you should specify a draw option (like in your original macro)
and it will work.
Try
gr->Draw("alp")
Rene Brun
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