Re: 2-D FitPanel

From: Pasha Murat (murat@cdfsga.fnal.gov)
Date: Tue Aug 18 1998 - 17:26:15 MEST


Tadeusz Pytlos writes:
 > 
 > 
 > 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.
 > 

	Seems like this is a problem in TGraph::Draw() and it has nothing to do 
	with I/O. If you were using gr->Draw("ALP") you'd see the whole graph.
	Alternatively if you put gr->Draw() in your macro w/o option parameter,
	you'll see only one line....

					Regards, Pasha.

 > // 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;
 > }
 > 
 > 



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