animated pie chart with gganimate

talkingpie.R

library(dplyr)
library(ggplot2)
library(gganimate)

open <- c(.16, 1 - .16)
closed <- c(.02, .98)
colors <- c("#EDD63F", "#4C4C4C") # yellow and dark gray

data <- tibble(
  position = c(open, closed),
  frame = c(1,1,2,2),
  body_part = rep(c("mouth", "head"), 2)
  )

gg <- data %>%
  ggplot(aes(x = 1, y = position, fill = body_part)) +
  geom_col(width = 1) +
  coord_polar(theta = "y", start = 1.2) +
  annotate("text", x = 1.2, y = .93, label = "O", size = 10) +
  scale_fill_manual(values = colors) +
  theme_void() +
  transition_states(frame, 5, 1)

anim_save("ggpietalk1", animate(gg, nframes = 20, fps = 20))