{
   TFile* f0   = new TFile("nominal_signalDistributions_20170217.root");
   TF1 *fit = new TF1("fit","gaus");
   FILE *fp = fopen("filename.dat","w");
   if (fp==NULL) return;

   int n = 150;
   TH1F *h;
   for (int i=0; i<10 ; i++) {
      h = (TH1F*)f0->Get(Form("chan_0_hist_%d",n));
      h->Fit(fit);
      for (int i=0;i<fit->GetNpar();i++) {
         Float_t value = fit->GetParameter(i);
         fprintf(fp,"%d %f\n",i,value);
      }
      n = n+50;
   }
}