These are internal helpers for extracting and inserting data into a data.frame of tweened states.
.get_last_frame(data).get_first_frame(data)
.with_prior_frames(prior, new_tween, nframes)
.with_later_frames(later, new_tween, nframes)
.has_frames(data)
A data.frame. If a .frame
column exists it will be interpreted
as a data.frame containing multiple states
The result of a tweening
A data.frame