Dear experts,

I have two P.D.F.s , ZSig and ZBkg. ZSig is a gaussian and ZBkg is a polynomial. I add parametric extended likelihood to them (RooExtendPdf()) and add them (RooAddPdf). I then plot them in a frame (RooPlot).

I would like to find the minimum of the polynomial pdf (ZBkg) and subtract from ZSig at every point.

When I use getCurve->GetMinimum(), to find the minimum, I get always -1111. which I know is wrong.

Please let me know where I go wrong and how I can do what I described above (finding the min and subtracting from ZSig at each point)?

Many thanks in advance,

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