TTree::UnbinnedFit help

Hello All,

I am a bit unsure how to perform a TTree::UnbinnedFit. The documentation says “For the fit to be meaningful, the function must be self-normalized”. I am unsure how to do this.

What should my fit function look like if, for example, when binned, the histogram looks like a Gaussian sitting on a flat DC background:

A*NormailsedGausssian + DC

is not “self-normalized”