I’d like to write a pdf for a discrete random variable X.
As a concrete example, I’d like to write the pdf of X (otucomes are 0,1,2,3) under the form :
= p_0(a,b,c) if x=0,
= p_1(a,b,c) if x=1,
= p_2(a,b,c) if x=2,
= p_3(a,b,c) if x=3.
where a,b,c are some parameters and p_i, functions that I know analytically. (In fact, p_i is the sum of two pdfs (one for signal and one for background let’s say weighted with a factor f // (1-f) that represents the fraction of signal/background respectively.)
The main aim is to estimate a,b,c and f using a maximum likelihood estimation.
For performing a MLE, I guess that I can use the different tutorials/macros provided with RooFit, unless there are some subtleties I should be aware of. If this is the case, could you also let me know.
Many thanks in advance for your help.