I am making a histogram for the particle multiplicity as shown in the code(attached a link to download). I wanted to fill the color in the histogram for the different centrality bins 0-5%, 5-10%,… 90-100%. I don’t know how can I do it in the function named “void Draw_MultiplicityHistogram(){}” I have defined in the code.

void Draw_MultiplicityHistogram(TH1F* histogram, const TString& xTitle, const TString& yTitle, bool logY = false) {

```
TCanvas* canvas = new TCanvas("", " ", 800, 600);
//canvas->SetFillColor(kWhite); // Set canvas background color
histogram->GetXaxis()->SetTitle(xTitle);
histogram->GetYaxis()->SetTitle(yTitle);
if (logY) {
canvas->SetLogy(); // Set logarithmic Y axis
}
double Total_Entries = histogram->GetEntries();
cout << "Total Entries / Integral is : " << Total_Entries << endl;
Int_t NofBins = histogram->GetNbinsX();
cout << "Total bin content is : " << NofBins << endl;
// Define percentile ranges
Double_t Percentiles[] = {0, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100};
Double_t Nof_Percent_Range = sizeof(Percentiles) / sizeof(Percentiles[0]);
cout << "Total percentile : " << Nof_Percent_Range << endl;
cout << "Percentile Ranges:" << endl;
// Loop through each percentile range
for (Int_t i = 0; i < Nof_Percent_Range - 1; ++i) {
Double_t Start = Percentiles[i];
Double_t End = Percentiles[i + 1];
Double_t RangeDifference = End - Start;
Double_t ThresholdEntries = RangeDifference * (Total_Entries / 100.0);
cout << "Percent : " << " " << End << " - " << Start << " = " << RangeDifference << " Threshold
Entries: " << ThresholdEntries << endl;
Double_t integral = 0;
Int_t binIndex = NofBins;
// Calculate integral in reverse order until it fulfills threshold
while (binIndex >= 0 && integral < ThresholdEntries) {
Double_t binContent = histogram->GetBinContent(binIndex);
if (binContent > 0) {
integral += binContent;
}
binIndex--;
}
cout << "Integral: " << integral << endl;
// Check if integral matches the threshold entries
if (integral >= ThresholdEntries) {
histogram->SetFillColor(i + 2);
histogram->Draw();
}
}
canvas->Update();
```

}

download link:

https://drive.google.com/drive/folders/1TZsDKZhiWEHBphI-GhdvyLYl4C3H5qwO?usp=sharing