Making a .csv file into a histogram

Hello, I have the following problem. I convert the csv files into ROOT histograms using the following algorithm:

TNtuple *t=new TNtuple("Data","title","X:Y");

Then I save the histogram in .ps or .root format. But the binning seems to change in the process (the fluctuations are considerably larger; for comparison, I provide one of my ROOT histograms and the same histogram, done in Excel). Is there any way to change the binning? Or maybe there’s a better way of converting csv’s into histograms?


Where h is a TH1F you booked with the proper binning.