Hello, I have a 2D histogram (scatter plot) which is the occupancy of my detector (see attached plot). I need to parameterize the shape of the histogram, but there is no a model to describe it. I was thinking the TMultiDimFit could be the right choice. I had a look at the $ROOTSYS/tutorials/multidimfit.C example, but I don’t know if I can “fit” my histogram or not…
Can somebody help me?
Thanks a lot!
Regards, Davide

No TMultiDim is not appropriate for this job (when starting from a binned histogram). You should use a model function and fit it.
You could try TMultidimFit starting from the original unbinned data and using the Chebyschev polynomials option, but no guarantee.