The idea is to add an additional aesthetics called transition_..() that provides a frame variable. For each value of the variable, a step on the chart will be drawn. Here, transition_time() is used since the frame variable is numeric.
Note that the gganimate automatically performs a transition between state. Several options are available, set using the ease_aes() function.
library(ggplot2)
library(gganimate)
theme_set(theme_bw())
library(gapminder)
head(gapminder)## # A tibble: 6 x 6
## country continent year lifeExp pop gdpPercap
## <fct> <fct> <int> <dbl> <int> <dbl>
## 1 Afghanistan Asia 1952 28.8 8425333 779.
## 2 Afghanistan Asia 1957 30.3 9240934 821.
## 3 Afghanistan Asia 1962 32.0 10267083 853.
## 4 Afghanistan Asia 1967 34.0 11537966 836.
## 5 Afghanistan Asia 1972 36.1 13079460 740.
## 6 Afghanistan Asia 1977 38.4 14880372 786.p <- ggplot(
gapminder,
aes(x = gdpPercap, y=lifeExp, size = pop, colour = country)
) +
geom_point(show.legend = FALSE, alpha = 0.7) +
scale_color_viridis_d() +
scale_size(range = c(2, 12)) +
scale_x_log10() +
labs(x = "GDP per capita", y = "Life expectancy")
p + transition_time(year) +
labs(title = "Year: {frame_time}")
## # A tibble: 5 x 2
## Month Temp
## <int> <dbl>
## 1 5 65.5
## 2 6 79.1
## 3 7 83.9
## 4 8 84.0
## 5 9 76.9