I have a variable with sales data over time. It is very noisy at a disaggregate level but if you look at it as a whole, you can see a smoothing curve that follows a polynomial pattern. Is there a way to fit such curve and actually generate values of it over time in the dataset?
I tried many different options here including a moving average (which leaves a lot of noise still); I tried
lowess smoother in Stata, which is on the opposite side - too neutral and leaves out important curve patterns. I also tried fitting a nonlinear function
nl but to no avail.
The original goal of this task is to determine any infection points that the curve can have. In my mind, I am looking for a curve that would run in the middle of all the noise.