Convolution of Gaussian with Breit-Wigner?


  1. Does ROOT provide implementation of convolution of Gaussian with Breit-Wigner?

For example, there is implementation of convolution of Gaussian with Lorentzian (TMath::Voigt).

  1. Is it possible to use integration in TF1 created with a formula? I.e. in the “formula” of the following constructor:
TF1(const char* name, const char* formula, Double_t xmin = 0, Double_t xmax = 1)

Thank you,


  1. The Voigt functions is the convolution of a Gaussian with a Lorentzian (also called Breit-Wigner or Cauchy) distribution.
    We have three implementations in ROOT, the one in TMath::Voigt and two in RooFit usable with the class
    RooVoigtian (see ).
    One of the RooFit implementation is based on a Cernlib implementation of the complex error function
    (see … lexErrFunc%1 )
    while the other one is a faster implementation based on a look up table.

  2. Given a TF1 class created using whatever constructor you can integrate it always using TF1::Integral. If you have any problem with it please let me know

Best Regards,