fitting many TGraphAsymmErrors

Hello,

I have a function (a vN cross section as a function of various params) that I want to fit to a quite large number of cross section measurements. Since these measurements come from different experiments I would like to allow them to 'float' with respect to each other as a way to handle unknown relative differences in flux normalizations.

So, technically I have a TF1 and a list of TGraphAsymmErrors (each one includes all the data points from a single experiment). In total, I am trying to fit *Nm* parameters related with a physics model + 1 parameter for each of the *Nd* experiments included in the fit.

I need to fit the function to all graphs in the list *simultaneously*.

Is there a simpler way to do this other than implementing by myself the Fit() method in TMultiGraph?

cheers,

       Costas

-- 
Dr. Constantinos Andreopoulos, CCLRC - Rutherford Lab.
http://hepunx.rl.ac.uk/~candreop