1、安装

install.packages("gganimate")
library(gganimate)

提示安装gifski和av包，否则后台无法渲染。No renderer backend detected. gganimate will default to writing frames to separate files.

2、警告和错误信息提示

install.packages(c("gifski", "av"))

p <- ggplot(iris, aes(x = Petal.Width, y = Petal.Length)) +geom_point()

anim <- p + transition_states(Species, transition_length = 2, state_length = 1)

animate(anim)

仍无法渲染，警告信息：file_renderer failed to copy frames to the destination directory.

> anim_save("1.gif", animation=anim)

Error: The animation object does not specify a save_animation method                          
In addition: Warning message:
file_renderer failed to copy frames to the destination directory

也无法正常保存为gif。

3、解决办法

> animate(anim, renderer = gifski_renderer())
          
Inserting image 100 at 9.90s (100%)...
Encoding to gif... done!

> pa <- animate(anim, render = gifski_renderer()
> print(pa)
> anim_save("pa.gif", animation=pa)

animate()正常显示，必须调用render=gifski_renderer()
anim_save()正常保存，必须先返回plot对象，然后print(),最后保存为gif。

4、一种更简单的方法

安装ImageMagick, 让animate()自行调用ImageMagick来显示动画。
ImageMagick为Windows应用程序。如果自行安装的话，在调用ImageMagick很容易出错，所以推荐在RStudio里面安装。

install.packages("installr")
installr::install.ImageMagick

以管理员身份运行RStudio

library(ggplot2)
library(gganimate)
p <- ggplot(iris, aes(x = Petal.Width, y = Petal.Length)) 
     + geom_point()
anim <- p + transition_states(Species, 
        transition_length = 2, state_length = 1)
animate(anim)