Weighted histogram may be rounding off

ROOT
1

I tried to use weighting method in histogram.
I did the following:

histo->Sumw2(); histo->Fill( value, weight)
and to get bin content and error;

histoname(pointer)->GetBincontent(bin) and ->GetBinError(bin) to get total entries,

->GetSumOfWeights().
I didn’t find the numbers of bin content exactly same what I get manually, even not closer. Is there a rounding off issue ? or is there a separate way to deal the weighted histogram to get bin content, error and so on?
Thanks
Pramod

2

Hi Pramod,

If you have some data that close to the edge of the bins, it is indeed likely to be a numerical issue. Since you did not quantify the difference it is hard to tell whether it is just a rounding off issue or not. Also some of the routines (check the documentation) includes the data that is ‘out-of-range’ and some do not.

If you still have issues related to this, you may want to restart a new post in the Math and Stats forum.

Cheers,
Philippe.