Createprojection problem


I have a multidimensional pdf, and between others it depends on observable k (where k is given by a binned histogram). I would like to integrate this pdf in k and then use the new pdf, non dependant from k anymore, to fit my data, do plots, etc…

To do that I am using createProjection(*k) of the complete pdf. Then, with the new non-k-dependant pdf, I do the fit and plots, and each time (so per each fit and each plot) I get the messages:

INFO:NumericIntegration – RooRealIntegral::init(SPECINT[k_factor_PDF_NORM[k]]_Int[k]) using numeric integrator RooIntegrator1D to calculate Int(k)
[#1] INFO:NumericIntegration – RooRealIntegral::init(SPECINT[k_factor_PDF_NORM[k]_X_t_sig_nprompt_decay_1_kdep_NORM[t]]_Int[k]) using numeric integrator RooIntegrator1D to calculate Int(k)

as if it was repeating the projection on k each time. Is this normal? Or am I maybe using the createprojection in the wrong way? I would have expected it to perform the integration only once, when I call the createProjection method, and then use automatically the integrated pdf, isn’t this the way this method works?

I hope you’ll help me understand this, it’s a quite urgent matter…

Thanks a lot, cheers,

Camilla Maiani.