void graph4() {
  
   
   TCanvas *c1 = new TCanvas("c1","3 Graphs",200,10,700,500);


   c1->SetGrid();
   c1->SetLogx ();
   c1->SetLogy();
  
   c1->BuildLegend();

   //create the coordinates arrays 

   const Int_t n = 87;

   
		   

   Float_t x1[n]={1.00E-009,
		  1.00E-008,
		  2.53E-008,
		  1.00E-007,
		  2.00E-007,
		  5.00E-007,
		  1.00E-006,
		  2.00E-006,
		  5.00E-006,
		  1.00E-005,
		  2.00E-005,
		  5.00E-005,
		  0.0001,
		  0.0002,
		  0.0005,
		  0.001,
		  0.002,
		  0.005,
		  0.01,
		  0.02,
		  0.03,
		  0.05,
		  0.07,
		  0.1,
		  0.144,
		  0.15,
		  0.2,
		  0.25,
		  0.3,
		  0.5,
		  0.565,
		  0.7,
		  0.9,
		  1,
		  1.2,
		  2,
		  2.5,
		  3,
		  4,
		  5,
		  6,
		  7,
		  8,
		  9,
		  10,
		  12,
		  14,
		  14.8,
		  15,
		  16,
		  18,
		  19,
		  20,
		  25,
		  30,
		  35,
		  40,
		  45,
		  50,
		  55,
		  60,
		  70,
		  80,
		  90,
		  100,
		  120,
		  140,
		  150,
		  160,
		  180,
		  200,
		  250,
		  300,
		  400,
		  500,
		  600,
		  700,
		  800,
		  900,
		  1000,
		  1200,
		  1500,
		  2000,
		  2500,
		  3000,
		  4000,
		  5000};


Float_t y1[n]={1.94E-002,
		2.45E-002,
		2.88E-002,
		4.40E-002,
		5.82E-002,
		7.19E-002,
		8.08E-002,
		9.49E-002,
		1.13E-001,
		1.21E-001,
		1.31E-001,
		1.44E-001,
		1.59E-001,
		1.64E-001,
		1.83E-001,
		2.04E-001,
		2.09E-001,
		2.20E-001,
		2.45E-001,
		2.65E-001,
		2.86E-001,
		3.19E-001,
		3.48E-001,
		3.94E-001,
		4.46E-001,
		4.69E-001,
		5.28E-001,
		5.97E-001,
		6.69E-001,
		8.83E-001,
		9.55E-001,
		1.07E+000,
		1.20E+000,
		1.25E+000,
		1.35E+000,
		1.49E+000,
		1.50E+000,
		1.52E+000,
		1.36E+000,
		1.37E+000,
		1.28E+000,
		1.21E+000,
		1.11E+000,
		1.08E+000,
		1.07E+000,
		1.03E+000,
		1.02E+000,
		1.00E+000,
		1.01E+000,
		9.98E-001,
		1.02E+000,
		1.04E+000,
		1.01E+000,
		9.22E-001,
		9.53E-001,
		9.50E-001,
		9.98E-001,
		1.02E+000,
		1.05E+000,
		1.07E+000,
		1.08E+000,
		1.11E+000,
		1.16E+000,
		1.18E+000,
		1.22E+000,
		1.27E+000,
		1.31E+000,
		1.33E+000,
		1.35E+000,
		1.40E+000,
		1.42E+000,
		1.52E+000,
		1.57E+000,
		1.69E+000,
		1.78E+000,
		1.90E+000,
		1.99E+000,
		2.06E+000,
		2.11E+000,
		2.19E+000,
		2.29E+000,
		2.42E+000,
		2.52E+000,
		2.62E+000,
		2.69E+000,
		2.78E+000,
		2.79E+000};

  

Float_t x2[n]={1.00E-009,
		  1.00E-008,
		  2.53E-008,
		  1.00E-007,
		  2.00E-007,
		  5.00E-007,
		  1.00E-006,
		  2.00E-006,
		  5.00E-006,
		  1.00E-005,
		  2.00E-005,
		  5.00E-005,
		  0.0001,
		  0.0002,
		  0.0005,
		  0.001,
		  0.002,
		  0.005,
		  0.01,
		  0.02,
		  0.03,
		  0.05,
		  0.07,
		  0.1,
		  0.144,
		  0.15,
		  0.2,
		  0.25,
		  0.3,
		  0.5,
		  0.565,
		  0.7,
		  0.9,
		  1,
		  1.2,
		  2,
		  2.5,
		  3,
		  4,
		  5,
		  6,
		  7,
		  8,
		  9,
		  10,
		  12,
		  14,
		  14.8,
		  15,
		  16,
		  18,
		  19,
		  20,
		  25,
		  30,
		  35,
		  40,
		  45,
		  50,
		  55,
		  60,
		  70,
		  80,
		  90,
		  100,
		  120,
		  140,
		  150,
		  160,
		  180,
		  200,
		  250,
		  300,
		  400,
		  500,
		  600,
		  700,
		  800,
		  900,
		  1000,
		  1200,
		  1500,
		  2000,
		  2500,
		  3000,
		  4000,
		  5000};


 Float_t y2[n]={1.88E-002,
		2.44E-002,
		2.92E-002,
		4.37E-002,
		5.73E-002,
		7.22E-002,
		8.19E-002,
		9.50E-002,
		1.13E-001,
		1.21E-001,
		1.31E-001,
		1.43E-001,
		1.59E-001,
		1.64E-001,
		1.84E-001,
		2.03E-001,
		2.07E-001,
		2.20E-001,
		2.46E-001,
		2.66E-001,
		2.85E-001,
		3.22E-001,
		3.49E-001,
		3.96E-001,
		4.46E-001,
		4.69E-001,
		5.27E-001,
		5.99E-001,
		6.70E-001,
		8.83E-001,
		9.54E-001,
		1.07E+000,
		1.20E+000,
		1.25E+000,
		1.34E+000,
		1.49E+000,
		1.48E+000,
		1.53E+000,
		1.36E+000,
		1.36E+000,
		1.29E+000,
		1.21E+000,
		1.11E+000,
		1.07E+000,
		1.09E+000,
		1.05E+000,
		1.01E+000,
		1.01E+000,
		1.01E+000,
		1.01E+000,
		1.03E+000,
		1.04E+000,
		1.11E+000,
		1.09E+000,
		1.14E+000,
		1.18E+000,
		1.23E+000,
		1.27E+000,
		1.31E+000,
		1.34E+000,
		1.37E+000,
		1.45E+000,
		1.52E+000,
		1.58E+000,
		1.62E+000,
		1.77E+000,
		1.82E+000,
		1.85E+000,
		1.88E+000,
		1.92E+000,
		1.95E+000,
		2.09E+000,
		2.13E+000,
		2.31E+000,
		2.56E+000,
		2.91E+000,
		3.09E+000,
		3.27E+000,
		3.41E+000,
		3.59E+000,
		3.80E+000,
		4.14E+000,
		4.62E+000,
		4.92E+000,
		5.17E+000,
		5.64E+000,
		6.10E+000};

 
 

   TGraph*gr1 = new TGraph(n,x1,y1);
   TGraph*gr2 = new TGraph(n,x2,y2);
  
  

   gr1->SetLineColor(4);
   // gr1->SetLineWidth(2);
   gr1->SetMarkerColor(1);
   gr1->SetMarkerStyle(8);
   gr1->SetMarkerSize(0.8);
   gr1->SetTitle("");

   gr1->SetTitle("");
   
   gr1->GetXaxis()->SetTitle("Energie [MeV]");
   gr1->GetXaxis()->CenterTitle();
   // gr1->GetXaxis()->SetRangeUser(90.,355);
   
   gr1->GetYaxis()->SetTitle("Coups par unit#acute{e}  de fluence [cps-cm^{2}]");
   gr1->GetYaxis()->CenterTitle();
   gr1->GetYaxis()->SetRangeUser(1E-03,3E+1);
   gr1->GetYaxis()->SetTitleOffset(1.2);

   gr1->Draw("AP");
		   
   gr2->SetLineColor(2);
   // gr2->SetLineWidth(2);
   gr2->SetMarkerColor(2);
   gr2->SetMarkerStyle(33);
   gr2->SetMarkerSize(0.8);
   gr2->Draw("P");

  
   
 TLegend *leg = new TLegend(0.6,0.6,0.9,0.9);

  
   leg->AddEntry(gr1,"QGSP_BIC_HP","lp");
   leg->AddEntry(gr2,"QGSP_BERT_HP","lp");
  
  
   // leg->SetHeader("The Legend Title");
   leg->Draw();



}