Twelth order polynomials do seem extreme, but without being an expert in the context they used it, I cannot determine its appropriateness. As an extreme, let u

Twelth order polynomials do seem extreme, but without being an expert in the context they used it, I cannot determine its appropriateness. As an extreme, let us suppose that we know that there are 6 sources of noise spread out over the x-axis, and that the power of the noise will decrease x units away from each source. In that case, you might suspect that noise function needs a 12th order polynomial to fit the undulation pattern, just to get the necessary number of humps.