Show preceding frames with gradual falloff

This shadow is meant to draw a small wake after data by showing the latest frames up to the current. You can choose to gradually diminish the size and/or opacity of the shadow. The length of the wake is not given in absolute frames as that would make the animation susceptible to changes in the framerate. Instead it is given as a proportion of the total length of the animation.

shadow_wake(
  wake_length,
  size = TRUE,
  alpha = TRUE,
  colour = NULL,
  fill = NULL,
  falloff = "cubic-in",
  wrap = TRUE,
  exclude_layer = NULL,
  exclude_phase = c("enter", "exit")
)

Arguments

wake_length: A number between 0 and 1 giving the length of the wake, in relation to the total number of frames.
size: Numeric indicating the size the wake should end on. If NULL then size is not modified. Can also be a boolean with TRUE beeing equal 0 and FALSE beeing equal to NULL
alpha: as size but for alpha modification of the wake
colour, fill: colour or fill the wake should end on. If NULL they are not modified.
falloff: An easing function that control how size and/or alpha should change.
wrap: Should the shadow wrap around, so that the first frame will get shadows from the end of the animation.
exclude_layer: Indexes of layers that should be excluded.
exclude_phase: Element phases that should not get a shadow. Possible values are 'enter', 'exit', 'static', 'transition', and 'raw'. If NULL all phases will be included. Defaults to 'enter' and 'exit'

Examples

anim <- ggplot(iris, aes(Petal.Length, Sepal.Length)) +
  geom_point() +
  labs(title = "{closest_state}") +
  transition_states(Species, transition_length = 4, state_length = 1)

# `shadow_wake` can be combined with e.g. `transition_states` to show
# motion of geoms as they are in transition with respect to the selected state.
anim1 <- anim +
  shadow_wake(wake_length = 0.05)

# Different qualities can be manipulated by setting a value for it that it
# should taper off to
anim2 <- anim +
  shadow_wake(0.1, size = 10, alpha = FALSE, colour = 'grey92')

# Use `detail` in the `animate()` call to increase the number of calculated
# frames and thus make the wake smoother
if (FALSE) {
animate(anim2, detail = 5)
}

Arguments

See also

Examples