Fitting problem

myself davinder from delhi University from India
i am fitting the histogram with user defined function par[0]TMath::exp(-0.5arg*arg)
where arg is arg = (x[0])-par[1])/par[2] this function fits the data points with fitted parameters p0,p1,p2 which ate the polynimial coefficients but when i plot the polynomo\al with these coefficient i am not getting the gaussian like function what should i do

post the shortest possible RUNNING script reproducing your problem