Convolution of two RooFormularVar?

Roofit and RooStats
1

Dear RooFit Experts,

Is it possible to convolute two RooFormulaVar?
I have one RooFormulaVar which is created from the RooProfileLL, and another Gaussian RooFormulaVar, like this:

RooNLLVar nll("nll", "", *fitFunction, *data);
RooProfileLL profile("profile", "", nll, RooArgSet(ratio));
RooFormulaVar pll("pll", "exp(-0.5*@0)", RooArgSet(profile));

RooRealVar mean("mean", "", 0.0);
RooRealVar sigma("sigma", "", sig);
RooFormulaVar gaus("gaus", "exp(-0.5*((@0-@1)/@2)**2)", RooArgSet(ratio, mean, sigma));

So, is there any simple way that I can convolute the two RooFormulaVar, nll and gaus?

Thanks a lot for the helps!

2

Hi,

RooFit can convolute PDFs, but bare formulae were not foreseen (RooFFTConvPdf).
What is the reason for trying to convolve a profileLL with something else? Is it maybe something that could be done using PDFs?

If you need to work with the profile, you could directly do Fourier transforms of the results using
https://root.cern.ch/doc/master/classTVirtualFFT.html

3

Hi,

Thanks a lot for the help!
I need integrate the profileLL after the convolution, I am not sure if I can do it after convert to PDFs.

I will take a look of the TVirtualFFT, thanks a lot!