RooMCStudy::plotPull - extracting gaussian fit parameters

this in my first post so I hope I’m posting in the right section.

I’m using class RooMCStudy in order to simulate the reciprocal influences of various backgrounds in my invariant mass region. I would like to study pull distribution of fitting yields, and I would like to extract the parameters ( pullMean and pullSigma ) from the fitted Gaussian distribution of the pull, when I call:

But in the returned frame there are only a RooCurve, a RooHist and a TPaveText (and not a Roo*Pdf) so I don’t know to extract these parameters (as a Double_t for example).

Thank you for your help!
Best regards,

Can you please post a simple running macro showing your problem ?

Thank you


One simple workaround I have been using is to extract the plotted histogram, do a manual fit and extract the parameters. Here’s the example code in python (not tested):


This should be fine or, you can do what is done inside RooMCStudy::plotPull (i.e. using RooFit).
See … tml#l01334
Unfortunately, looking at the code the parameter values are not saved and returned to the user, they are just written in the text box.


Ok, maybe the better solution is to do what is done inside RooMCStudy::plotPull, copying those lines.

Thank you again