FillRandom for the fit

General Chat
1

Hi all,
could you help to recognize what is wrong when I use FillRandom?

I have an original hist and need to ‘simulate’ another ones (based on this ‘original’) with changed statistics in bins in order to study systematic of my fit.

I’m doing
origcont = original->GetSumOfWeights();
and then as many times as I need, I fill another hist to put it to the fit
datamass->FillRandom(original,origcont);

and I see that these randomly generated hists always provide permanently higher yield
of mesons I took from the fit

     thanks in advance,
     Valeri
2

Hi,

This is strange. I would need to see your histograms and your code doing this study.

Cheers

Lorenzo

3

Hi Lorenzo,
it is a couple of root-hist files.
I could put them and a script on public area of AFS.
is it ok for you?
cheers,
Valeri

4

Hi Valeri,
Are you sure that GetSumOfWeights() in your case is the same as GetEntries(),
because the signature of FillRandom is

void FillRandom(TH1* h, Int_t ntimes = 5000)

So, it uses nTimes, but not Sum of weights.

Boris :slight_smile: