Trend

Gazzelloni F. (2023), Data Visualization: Australia GDP per capita Trend

library(fpp3)
library(tidyverse)
aus_economy <- global_economy |>
  filter(Code == "AUS") |>
  mutate(Pop = Population / 1e6,
         GDP=GDP/Population)

aus_economy |>
autoplot(GDP) +
  labs(y = "Millions", title = "Australian population")

fit <- aus_economy |>
  model(
    AAN = ETS(Pop ~ error("A") + trend("A") + season("N"))
  )

fc <- fit |> forecast(h = 10)

library(fable)
library(tsibbledata)

alpha_range <- seq(0.1, 0.9, by = 0.1)

fits <- list() # create an empty list to store the model fits
for (alpha in alpha_range) {
  fit <- aus_economy %>%
    model(ETS(GDP ~ error("A") +
                trend("A", alpha = alpha) +
                season("N")))
  fits[[as.character(alpha)]] <- fit
  # store the fit in the list using alpha as the key
}

library(purrr)
pred <-
  map2_dfr(fits, 
           alpha_range, 
           ~ as_tibble(.x %>% augment() %>% mutate(alpha = .y))) %>%
  select(Year,GDP,.fitted,alpha)

pred%>%head

Animate

colors=scales::hue_pal(l = 90)(9)
my_colors <- c("#4E79A7", "#F28E2B", "#E15759", "#76B7B2", "#59A14F", "#EDC948", "#B07AA1", "#FF9DA7", "#9C755F")


options(scipen = 999)
library(gganimate)
p <- aus_economy |>
  autoplot(GDP,linewidth=1) +
  geom_line(aes(
    y = .fitted,
    group = alpha,
    col = factor(alpha)
  ),
  linewidth=1,
  data = pred) +  
  geomtextpath::geom_texthline(yintercept = mean(aus_economy$GDP),
                               hjust=0.3,
                               label="Avg value")+
 transition_states(alpha,
                   transition_length = 2,
                   state_length = 1) +
 ease_aes('linear') +
  scale_y_continuous(expand = c(0,0),
                     labels = scales::label_number(suffix = "K", scale = 1e-3))+
  scale_x_continuous(n.breaks = 6)+
  scale_color_manual(values=my_colors)+
  labs(y = "GDP per capita",
       x="Year",
       color="Alpha",
       title="Australia's GDP Exponential Smoothing model\nAlpha {closest_state}",
       caption="#30DayChartChallenge Day 28 Trend | DataSource: {fpp3} global_economy\nDataViz: Federica Gazzelloni")+
  ggthemes::theme_economist_white()+
  theme(text=element_text(family="Roboto Condensed"),
        plot.background = element_rect(color="gold",fill="gold"),
        panel.background = element_rect(color="#efdaa0",fill="#efdaa0"))+
    guides(color="none")

p

anim_save("day28_trend.gif", 
          animate(p, fps = 10, duration = 10))