Plot of the exponential growth of temples by The Church of Jesus Christ of Latter-day Saints

temples_exponential.R

# install.packages(pacman)
pacman::p_load(tidyverse, rvest, lubridate, magick)

# Times that temples were opened
temple_time <- "https://churchofjesuschristtemples.org/statistics/milestones/" %>% 
  read_html() %>% 
  html_nodes("table") %>% 
  html_table() %>% .[[2]] %>%
  rename_all(str_to_lower) %>%
  mutate(announcement = dmy(announcement), groundbreaking = dmy(groundbreaking),
         dedication = dmy(dedication))

growth <- temple_time %>%
  mutate(year_announce = year(announcement)) %>%
  arrange(year_announce) %>%
  count(year_announce) 

growth <- tibble(year_announce = 1830:2019) %>%
  left_join(growth) %>%
  replace_na(list(n=0)) %>%
  mutate(cum = cumsum(n)) 

temple <- magick::image_read("https://d3ewd3ysu1dfsj.cloudfront.net/images/stories/large/35030.jpg?1487202042") %>% 
  image_border(color = "black") %>%
  as.raster()

y_lines <- tibble(x.end = c(1912, 1952, 1980, 1990, 2000, 2019), x = -Inf, y = c(6, 12, 25, 50, 100, 200))

growth %>%
  ggplot(aes(x = year_announce, y = cum)) +
  geom_segment(data = y_lines, aes(x = x, y = y, yend = y, xend = x.end), color = "darkgrey") +
  geom_col(color = "white", fill = "black", size = .1) +
  coord_cartesian(x = c(1910, 2019)) +
  scale_y_continuous(breaks = y_lines$y) +
  scale_x_continuous(breaks = y_lines$x.end) +
  theme_bw() +
  theme(panel.grid.minor = element_blank(), panel.grid.major = element_blank()) +
  labs(x = "Year (Doubling time ~25 years)", y = "Number of temples built or announced", title = "Exponential growth of temple announcements", 
       subtitle = "The Church of Jesus Christ of Latter-day Saints") +
  annotate("text", x = 1935, y = 175, label = "This is not the only temple we shall build; there will be hundreds of them built and dedicated to the Lord.\nThis temple will be known as the first temple built in the mountains by the Latter-day Saints.\n - Discourses of Brigham Young, p.395 -", hjust = 0, vjust = 1) +
  annotation_raster(temple, 1910, 1930, 130, 190)

ggsave("exponential_growth_temples.png", width = 12, height = 8)