HISTOGRAM fill

Newbie
1

Hi experts,
How to fill a histogram in which each bin will contain at least 5 counts.
Here is the macro:

  TFile *f1 = new TFile("count.root", "RECREATE");
  TTree *tr = new TTree("ntuple", "data");
  tr->ReadFile("hist_plot.dat", "x");
  TH1F *h1 = new TH1F("h1", "Gaussian Distribution", 20, -2.4, 2.9);
  h1->GetXaxis()->SetTitle("log_{10}(Value)");
  h1->GetYaxis()->SetTitle("Counts (Frequency)");   
  bool checkBins=true;
  int count, sum;
  for( int i=1; i<=20; i++) {
  do {
  if(h1->GetBinContent(i)<5) 
  checkBins=false; 
//    count = h1->GetBinContent(i); 
//   sum = count + h1->GetBinContent(i+1); }
//  else { continue;}
}
  while(checkBins && i <= h1->GetNbinsX());   
  tr->Project("h1", "log10(x)");
  f1->Write();   
  h1->Draw("hist");

However first two bins contain less than 5 counts, other bins are fine. How do I add these two bins to the next bin?

Thanks!!
Anil

2

Hi,
you can try to reduce the number of bins from 20 to 19 or 18.

3

Thank you @Dilicus
If i reduced the number of bins to 18 or 15 or 12 , first two bins contain less than 5 and at 10 only first bin contains 1 count.
However if number of bins reduced to 5, all the bins contain more than 5 counts. In case of gaussian fit to this histogram, should it be relevant?

4

It is not relevant for the fit at all (and you can always set some “xmin” and “xmax” when using the TH1::Fit method).

5

Ok. Thank you @Wile_E_Coyote