TH1D* MakeHistoFromFile(TString filename, TString hname, TString title)
{
   ifstream inp;
   double x,x1,x2,xp,y,bw;
   inp.open(filename.Data());
   int i = 0;
   while (inp >> x >> y) {
      if (i == 0) {
         x1 = x;
         xp = x;
      } else {
        bw = x - xp;
        xp = x;
      }
      i++;
   }
   x2 = x;
   inp.close();
   printf("Computed bin width = %g\n", bw);
   if (TMath::Abs(1-bw) < 0.001 ) bw = 1.;
   printf("Bin width = %g \n", bw);

   int nb = i+1; // Number of bins
   auto h = new TH1D(hname.Data(),title.Data(),nb,x1-bw/2.,x2+bw/2.);
   h->GetXaxis()->SetTitle("Energy (keV)");
   h->GetYaxis()->SetTitle("Count");
   inp.open(filename.Data());
   while (inp >> x >> y) {
      h->Fill(x,y);
   }
   inp.close();
   return h;
}

void Devices() {
   auto C = new TCanvas("C","C",600,600);
   C->Divide(1,2);

   auto h1 = MakeHistoFromFile("Device-1-005.txt","h1", "Device 1");
   C->cd(1); h1->Draw("hist"); h1->SetFillColor(kRed);
   auto h2 = MakeHistoFromFile("Device-2-005.txt","h2", "Device 2");
   C->cd(2); h2->Draw("hist"); h2->SetFillColor(kBlue);

   h1->Add(h2);
}