RE: [ROOT] saving a graph into a root file

From: Philippe Canal (
Date: Thu Jun 10 2004 - 19:29:40 MEST

Hi Luis,

If you double click in the browser on a TGraph is draw by default using the option "ALP".
The drawing option of the TGraph is not part of the TGraph object but of the Pad and/or
canvas.  If you want to prefer the visual aspect, save the canvas instead of the graph.


-----Original Message-----
[]On Behalf Of Luis March Ruiz
Sent: Thursday, June 10, 2004 9:14 AM
Subject: [ROOT] saving a graph into a root file

  Hi rooters,

  I have created a few graphs that they have been saved into a root file :

  for example,

     c1 = new TCanvas("c1","Graph Example",200,10,700,500);
     gr = new TGraph(n_bin,bin_x,bins_comp);
     gr -> SetTitle("(difference between test and norm ref histos)/sigma");
     gr -> SetMarkerStyle(21);
     gr -> SetMarkerColor(3);
     gr -> SetLineColor(3);
     gr -> SetMarkerSize(0.5);
     gr -> Draw("AP");
     line_1 = new TLine(range_start,0.0,range_end,0.0);
     line_1 -> SetLineWidth(0.5);
     line_1 -> SetLineStyle(3);
     line_1 -> Draw();
     //c1 -> SaveAs("");
     c1 -> Update();
     //c1 -> Modified();

  The problem is when I open the root file ... the graph has been saved 
with other Draw() options ... the graph is plotted with a line between 
dots, as the option Draw("ALP") ... I don't understand it, histograms have 
been saved as well, but they have the Draw() options that I selected, 

  I'm working with an old version, is it a problem ?
  What am I doing wrong ?

  RedHat Linux 7.3 2.96-112, ROOT Version 3.04/02.


  Best regards,


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