Seasonality and trends

14:15-15:00

Date

17 September 2023

Lab sessions

Lab Session 8

  1. Produce the following decomposition

    canadian_gas |>
  STL(Volume ~ season(window=7) + trend(window=11)) |>
  autoplot()

  2. What happens as you change the values of the two window arguments?

  3. How does the seasonal shape change over time? [Hint: Try plotting the seasonal component using gg_season.]

  4. Can you produce a plausible seasonally adjusted series? [Hint: season_adjust is one of the variables returned by STL.]