Dear colleagues, I want to solve the following problem using Roofit. I have N datasets for different observables, each in forms of a RooDataHist, and for each I construct a PDF from a template; the PDF is in form of a RooHistPDF. Each PDF is convoluted with a Gaussian PDF of unknown sigma, and then…

Hi Andrea, Thank you for your question. @jonas , could you please have a look?

Hi @siliataider , thanks for pinging @jonas - let’s see the reply!

Dear @andrea.celentano , sorry for the late reply! What you are doing should work. I think the reason why it doesn’t is that the way the model is formulated it not really consistent. Your pdf depends on the E variables, and the data contains x variables. Then you have Q_f depending on x, but there…

Dear @jonas , thanks for your guidance. Indeed, I confirm what you say: my pdf depends on E, and the data on x. The connection between these two happens in RooFFTConvPDF, using the constructor you pointed out. My idea was to follow the example in rf210_angularconv tutorial. I have a RooDataHist and…

Dear @jonas , to possibly facilitate the analysis of this problem I attach to this message the full code I am using, as well as the two ROOT files containing the data to be fit and the MC-derived histogram from which I extract the PDF. To run it, python3 ana_globalFit.py 1 (1 is for “period_1.root”)…

Thank you very much! If it worked in the past on a single dataset, it should work. I’ll look at your reproducer and try to understand what’s happening

Ok, indeed I can reproduce the problem and this should not happen! I have opened a GitHub issue about it to remind myself to fix it for the next release: [RF] RooFFTConvPdf inside RooSimultaneous doesn't work in some cases opened 10:39PM -…

Hi @jonas , thanks for confirming this. I’ll then wait till next release to check this :slight_smile:

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Roofit - multiple fit different datasets using different PDFs with some shared parameters

Roofit and RooStats