Animation time with gganimate

Question

I want to make a plot animate. I need that the points appear and disappear, but only make that the movements of points.

set.seed(1)
library(tidyverse)
library(gganimate)
df <- tibble(
  x = rnorm(100)
  , y = rnorm(100)
  , size = rep(c(2, 3, 4, 5), 25)
  , cl = sample(c("a", "b"), 100, T)
  , time = rep(1:10, 10) #|> lubridate::year()
)
p2 <-
  df |>
  ggplot() +
  aes(x, y, size = size, color = cl) +
  geom_point() +
  scale_size(range = c(5, 12)) +
  transition_reveal(time) +
  #enter_fade()
  #transition_manual(time) +
  shadow_mark(past = F, future = T)
animate(p2, renderer = gifski_renderer("sa.gif"))

Answer 1

If you don't want to animate by rows or by variable, just all at once, you can use any of the enter states and transition_layers. It won't show the final transition, but it will only animate the entrance. I added enter_fade() so you would see the entrance.

p2 <-
  df |>
  ggplot() +
  aes(x, y, size = size, color = cl) +
  geom_point() +
  scale_size(range = c(5, 12)) +
  theme_bw() +
  transition_layers(layer_length = 2, 
                    transition_length = 2) +
  enter_fade() 

---

Update:

---

In your comment, you asked if you could first should the group a, then group b. I assume this is what you're looking for.

p3 <- ggplot() +
  geom_point(data = filter(df, cl == "a"),
             aes(x, y, color = cl, size = size)) + 
  geom_point(data = filter(df, cl == "b"),
             aes(x, y, color = cl, size = size)) +
  scale_size(range = c(5, 12)) +
  theme_bw() +
  transition_layers(layer_length = 2, 
                    transition_length = 2) +
  enter_fade()

p3