Basically seasonality prior scale is setting the standard deviation for the normal distribution . Higher seasonality prior scale means we are setting a wider normal distribution when sampling for the 2*n terms for our fourier. At the end, the yearly components will be simply the fourier generated dot beta.
Read moreHow does Prophet forecasting work?
At its core, the Prophet procedure is an additive regression model with four main components: A piecewise linear or logistic growth curve trend. Prophet automatically detects changes in trends by selecting changepoints from the data . A yearly seasonal component modeled using Fourier series.
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