I don’t know the details of LsqFit.jl, but looking at the documentation of curve_fit and the error you cite, I’d say that its primary cause is that curve_fit needs four arguments, and you are only passing three.
I don’t know the details of LsqFit.jl, but looking at the documentation of curve_fit and the error you cite, I’d say that its primary cause is that curve_fit needs four arguments, and you are only passing three.