How to save frames of gif created using gganimate package

问题

I will use the gapminder data as an example. Let's say I create this animation:

library(gapminder)
library(ggplot2)
theme_set(theme_bw())
p <- ggplot(gapminder, aes(gdpPercap, lifeExp, size = pop, color = 
continent, frame = year)) +
  geom_point() +
  scale_x_log10()

library(gganimate)

gganimate(p)

gganimate(p, "output.gif")

Now, I want to have access to the individual images (frames) that constitute the gif. Is there a way to do this in gganimate or do I need to use the animation package?

回答1:

gganimate has changed a lot since this question was asked. In the current version (0.9.9.9999), there is a way to store each frame as its own file.

First, I need to create the animation, which looks a bit different with the new version of the package:

p <- ggplot(gapminder, aes(gdpPercap, lifeExp, size = pop, color = continent)) +
      geom_point() +
      scale_x_log10() +
      transition_states(year, 1, 5)

The animation can then be shown using

animate(p)

The rendering is taken care of by so called renderers. To store the animation in a single animated gif, you can use

animate(p, nframes = 24, renderer = gifski_renderer("gganim.gif"))

Note that I have manually set the number of frames to be created. By default, 100 frames are used and I chose a smaller number here. Picking the right number of frames can be a bit tricky at times and if you get weird results, try using more frames.

Alternatively, you can use a file_renderer() to write each frame to its own file

animate(p, nframes = 24, device = "png",
        renderer = file_renderer("~/gganim", prefix = "gganim_plot", overwrite = TRUE))

This will write files named gganim_plot0001.png, gganim_plot0002.png, etc. to the directory ~/gganim. Modify the values for prefix and device if you want different file names or different file types. (I set them to the defaults.)

来源：https://stackoverflow.com/questions/49155038/how-to-save-frames-of-gif-created-using-gganimate-package

标签

gganimate