Home | News | Documentation | Download

RooMixedData (mixing binning and unbinned dataset)


Hello, in RooFIt we have two kind of datasets, unbinned (RooDataSet) or binned (RooDataHist).

In many analyses people are using categories, with very different number of events (~10 in some categories, ~10k in others). It would be nice to have the possibility to mix binned and unbinned data. Presenlty people are solving it using a RooDataSet to mimic the binning: one entry is added at the center of each bin with a weight equal to the number of events. I see that this approach is also using inside Roofit, for example when using genBinned or by the ToyMCSamples.

Is that ok? I guess there should be a small difference between a RooDataHist and a RooDataSet with one entry per bin, since in the computation of the likelihood should be a bit different (considering only the weighted point in the bin center, or the integral in the bin). Is it?

Is there a plan to provide a way to mix proper binned dataset (RooDataHist) and unbinned dataset in a dataset to be used in simultaneous fit?

Is there the possibility to mix binned dataset with different binnings (now people are solving it using several observables, 1 per category, with different binning, but this complicate the generation of toys. By the way why the binning is a property of the RooRealVar and not of the dataset?)?


Hi Ruggero,
this is a question for @moneta (pinging him) :slight_smile:


This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.