In tdhock/animint2: Animated Interactive Grammar of Graphics

The code below shows a minimal example of the animint package: an interactive animation can be defined as a list of ggplots with showSelected and clickSelects aesthetics.

library(animint2)
data(worldPop)
## Linked bar and line plots of world population by subcontinent,
## inspired by polychartjs.
animint(
  bars=ggplot()+
    geom_bar(aes(
      x=subcontinent, y=population),
      clickSelects="subcontinent", showSelected="year",
      data=worldPop, stat="identity", position="identity")+
    ## This make_text creates a geom_text that shows the current
    ## selected value of the year variable.
    make_text(worldPop, 1, 3e6, "year")+
    coord_flip(),
  lines=ggplot()+
    ## This make_tallrect tiles the background of the lineplot with
    ## rects that can be clicked to select the year variable.
    make_tallrect(worldPop, "year")+
    ## This geom_point does not have aes(clickSelects) so its alpha
    ## transparency behaves normally: all points have alpha=1/4.
    geom_point(aes(
      year, population, colour=type),
      data=worldPop, size=4, alpha=1/4)+
    ## This geom_line DOES have aes(clickSelects) so only the
    ## selected line has the specified alpha=3/4. The other
    ## unselected lines have 0.5 less (alpha=1/4).
    geom_line(aes(
      year, population, group=subcontinent),
      clickSelects="subcontinent",
      data=worldPop, size=4, alpha=3/4),
  time=list(variable="year", ms=2000),
  duration=list(year=1000))