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title: "Differencing"
output: html_document
---

## Differencing to obtain stationarity

Simulate a non-stationary time series by adding a straight line to a simulated stationary ARMA model.

- Confirm that it looks non-stationary by plotting the times series and the acf
- Find the process of differences, i.e. $y_t = x_t-x_{t-1}$ - does this look more stationary?