Issue with gganimate and (sometimes) empty facets
问题 I'm observing some behavior in gganimate that I cannot explain, and I would like to understand what I am doing wrong (or whether it is a bug). For example, here is a very simple dataset and a plot of it: library(dplyr) # dplyr_0.7.8 library(tidyr) # tidyr_0.8.2 crossing(p = 1:2, t = seq(0, 1, len = 30), s = c(0, .5)) %>% mutate(x = t, y = t^p) %>% filter(t > s) -> Z library(ggplot2) # ggplot2_3.1.0 Z %>% ggplot(aes(x,y)) + facet_wrap(~s) + geom_point() As expected the second facet (s=0.5)