What xframe->pullHist() does in roofit?

ROOT
1

Dear Experts,

I am doing Invariant mass fit In data in roofit. There I want to check pull distribution of the fit. I found something like

data->plotOn(xframe);
model->plotOn(xframe);
RooHist* hMasspll = xframe->pullHist() ;
MassframePll->addPlotable(hMasspll,“P”) ;
MassframePll->Draw();

So, I am not sure what it does. I want to check when I call xframe->pullHist(), how it is calculating the pull distribution ?

Kind Regards
Chandi

2

Dear Chandi,

The code calculating the pull distribution is in RooHist::makeResidHist . See
https://root.cern.ch/doc/v608/RooHist_8cxx_source.html
line 701.
This is the standard definition, i.e. (y_i - y_i_fit) / erry_i .

Hope it helps,

G Ganis