01-intro.R

source("before-each-chapter.R")

## ----beer, fig.cap='Australian quarterly beer production: 2000Q1–2010Q2, with two years of forecasts.', echo=FALSE, message=FALSE----
ausbeer2 <- aus_production %>%
  filter(year(Quarter) >= 2000)
ausbeer2 %>%
  model(ETS(Beer)) %>%
  forecast() %>%
  autoplot(ausbeer2) +
  labs(y = "Megalitres", title = "Australian beer production")

## ----austa1, echo=FALSE, message=FALSE, warning=FALSE, fig.cap="Total international visitors to Australia (1980-2015) along with ten possible futures."----
austa <- readr::read_csv("https://OTexts.com/fpp3/extrafiles/austa.csv") %>%
  as_tsibble(index = Year)
sim <- austa %>%
  model(ETS()) %>%
  generate(h = 10, times = 10) %>%
  mutate(replicate = factor(.rep, levels = 1:10, labels = paste("Future", 1:10)))
p1 <- ggplot(austa, aes(x = Year)) +
  geom_line(aes(y = Visitors, colour = "Data")) +
  geom_line(aes(y = .sim, colour = replicate), data = sim) +
  labs(y = "Visitors (millions)",
       title = "Total international arrivals to Australia") +
  scale_colour_manual(
    values = c("#000000", rainbow(10)),
    breaks = c("Data", paste("Future", 1:10)),
    name = " "
  )
p2 <- austa %>%
  model(ETS = ETS(Visitors)) %>%
  forecast(h = "10 years") %>%
  autoplot(austa) +
  labs(y = "Visitors (millions)",
       title = "Forecasts of total international arrivals to Australia")
aligned_plots <- patchwork::align_plots(p1,p2)
aligned_plots[[1]]

## ----austa2, dependson="austa1", echo=FALSE, message=FALSE, warning=FALSE, fig.cap="(ref:figcapausta2)"----
aligned_plots[[2]]