Fitting multiple data sets with the same function

Hello to everybody,

I’m not yet a real ROOT-expert at all, and I write here to ask for your support concerning the following issue.
My problem is that I would like to use the same TF1 to fit different data sets at the same time, getting at the end a unique set of parameters as resulting output.

Could someone give me some indications or tips how to face this issue?

Thank you,

[url]Fit multiple histograms with the same function