Errors on the fit function and not on the parameters

Roofit and RooStats
1

Hi,

In Roofit, or otherwise, after fitting some data with a model/pdf, is it possible to get errors in the “shape” or “height” (and not on the parameters) of the fit result curve?

For example, if I fit (x,y) data with a pdf p, to get a result y = p(x), RooFitResult gives me errors on the parameters. What I wish to calculate is the error in p(x) at some x (which will of course can be estimated from the errors in parameters, but I wish to know if there is some function, which can directly return such an error).

Thanks,
Nikhil

2

Hi,

Or in other words, I need to obtain error on the observable on Y axis for the observable value x on X axis.

cheers,
Nikhil

3

Hi,

You can use FitResult:GetConfidenceIntervals

See root.cern.ch/root/htmldoc/ROOT__ … eIntervals

Lorenzo