Hi ,rooters,
I am a new rootfit user, What I want to obtain is a g(x) by integrate variable y of f(x,y), which is too complex to get it by MATHEMATICA or by manual calculation.
And the g(x) is my Pdf.
I would appreciate it if anyone could give me some examples about roofit integrate pdf.

Hi,
What do you mean your function is too complex to be defined in ROOT ?
You should be able to write your function as a class, define it as a functor object and then you can use the Integrator class of ROOT, or use it via the TF1 interface.
So the first step is defining your function as C++ code. Of course it can use an Integrator inside to compute the internal integrals