Time axis for histograms

couet · January 13, 2010, 11:00am

{  
   // Define the lowest histogram limit as 2010, January 10th 00:00
   TDatime T1(2010,01,10,00,00,00);
   Double_t X1 = T1.Convert();
 
   // Define the lowest histogram limit as 2010, January 10th 05:00
   TDatime T2(2010,01,10,05,00,00);
   Double_t X2 = T2.Convert();
   
   TH1F * h1 = new TH1F("h1","test",100,X1,X2);
   
   TRandom r;
   for (Int_t i=0;i<30000;i++) {
      Double_t noise = r.Gaus(0.5*(X1+X2),0.1*(X2-X1));
      h1->Fill(noise);
   }
   
   h1->GetXaxis()->SetTimeDisplay(1); 
   h1->GetXaxis()->SetLabelSize(0.03);
   h1->GetXaxis()->SetTimeFormat("%H:%M");  
   h1->GetXaxis()->SetTimeOffset(0, "gmt");
   h1->Draw();
}