Fitting to signal and background functions excluding regions

I’m trying to figure out the best way of fitting a background and signal function to a histogram.

In the “good ol’ days” of mn_fit, I’d:

  • exclude the signal region
  • fit the background function
  • fix the background function parameters
  • fit the signal region with the signal + background function
  • release the background parameters and fit everywhere

There seem to be two impedements in Root to doing this:

  • releasing parameters
  • excluding regions

As for the former, I can use ‘SetParamLimits’ to release the parameter, but is there an easy way to do this from my TF1 without enforcing a range?

As for the latter, you can write a special function that ignores certain regions, but is there a way you can use the built in functions and just tell the fitting to ignore (temporarily) a region?


p.s. If you currently can’t do either of what I asked, would it be possible to put it on the list for future upgrades?