RooBernstein Correction

[Jamshid435]

Hi dear experts…! Greetings
I have used the cheybechev polynomial to fit the sideband region of my plot. Now my instructor says that I should replace it with RooBernstein. Does it mean that I should replace the chebychev with the Bernstein polynomial…?? please someone provide me with its structural example…
Thanks

[eguiraud]

Hi,
I think we need the help of @moneta or @StephanH for this one.

Cheers,
Enrico

[moneta]

Hi,
You should be able to just replace RooChebishev with RooBernstein.
The only thing is you might add an extra parameter (the constant term) in RooBernstein, that it should be set as constant.
For example if you want to describe a 1-degree polynomial, you can do:

RooRealVar x("x","x",0,10);
RooRealVar c1("c1","c1", 0.2, 0, 1); 
RooChebychev  cheb_poly("cheb_poly","cheb_poly", x, RooArgList(c1));
// create now Bernstein polynomial
RooRealVar c0("c0","c0", 1);   // extra parameter needed 
RooBernstein bpoly("bpoly","bpoly",x,RooArgList(c1,c0));

Lorenzo

[Jamshid435]

Great Job…Moneta…Thank you so much