I am trying to fit the function:
Revenuei(time) = A0/(1+exp(-A1*(time-A2))) + B*Costsi

I have 5,000 observations of Revenue and Costs for 8 time periods (time = 0,1,...7).

A0, A1, A2, and B are constants that I am trying to fit.

I am unsure of how to fit this function in Stata using the nl command.

Does anybody have suggestions?