I would like to reproduce chebychev polinomials in the plain root.
To do this I would like to understand how is the parameter works inside RooChebychev function.
If I define a function like following
RooChebychev* bkgch = new RooChebychev(“bkgch”, “Chebychev background”, *(ws->var(“mass”)), RooArgList(p0, p1));
, there are two parameters p0, p1.
And the definition of second order chevychev polinomial is
T2(x) = 2x^2 -1
Then, how the parameters are applied to this function?
T2(x) = 2(x-p0)^2 - 1 + p1?
or some different shape?