How to include min and max value pf a particular variable in r ggplot

Question

I have tried many things but was not able to include the min and maximum value of GDP in each countries line graph.

Answer 1

There already are maximum and minimum values of GDP in your plot. Or are you just trying to recreate this plot? If so, the following code gets you very close:

library(gapminder)
library(tidyverse)

gapminder %>%
  filter(country %in% c("Canada", "Japan", "Jordan", "United States")) %>%
  filter(year %in% c(1962, 1982, 2002)) %>%
  ggplot(aes(factor(year), gdpPercap, color = country, group = country)) +
  geom_line(size = 2, alpha = 0.8) +
  geom_point(size = 5, alpha = 0.8) +
  geom_text(data = . %>% filter(year == 2002), hjust = 0, nudge_x = 0.1,
            size = 5, key_glyph = draw_key_blank,
            aes(label = scales::dollar(round(gdpPercap)))) +
  geom_text(data = . %>% filter(year == 1962), hjust = 1, nudge_x = -0.1,
            size = 5, key_glyph = draw_key_blank,
            aes(label = scales::dollar(round(gdpPercap)))) +
  scale_color_brewer(palette = "Set2") +
  labs(title = "A comparison of GDP", 
       subtitle = "GDP per capita change 1962 - 2002",
       caption = "Source: Gapminder dataset") +
  theme_void(base_size = 16) +
  theme(panel.grid.major.y = element_line(size = 0.05),
        axis.text.x = element_text(),
        plot.margin = margin(20, 20, 20, 20),
        plot.title = element_text(face = 2),
        plot.subtitle =  element_text(face = 2, margin = margin(10, 0, 50, 0)),
        plot.caption =  element_text(face = 2, margin = margin(30, 30, 30, 30)))