Chapter 7: Trend Changepoints
During the development of Prophet, the engineering team recognized that real-world time series will frequently exhibit abrupt changes in their trajectories. As a fundamentally linear regression model, Prophet would not be capable of capturing these changes without special care being taken. You may have noticed in the previous chapters, however, that when we plotted the forecast components in our examples, the trend line was not always perfectly straight. Clearly, the Prophet team has developed a way for Prophet to capture these bends in the linear model. The locations of these bends are called changepoints.
Prophet will automatically identify these changepoints and allow the trend to adapt appropriately. However, there are several tools you can use to control this behavior if Prophet is underfitting or overfitting these rate changes. In this chapter, we'll look at Prophet's automatic changepoint detection to provide you with an understanding...
