I am currently using RooFit to do some fittings. And using the chiSquare() from RooPlot to calculate the chi2 of the fitting function, such as frame->chiSqure(“pdf”, “data”). And later I realize that in my “data” data set, there is some data point with no entries, i.e, the data point is at 0± 0, so I wonder if this 0 data point will affect the chi2 calculation, or the RooFit will ignore automatically?
Looking at the code of RooCurve::chiSquare being called, it only includes (and counts) bins with y!=0. But check the note in the documentation of RooPlot::chiSquare and see whether you want this chiSquare.