Animate bar chart error in last plot (gganimate)? - r

Question

I created an animated bar chart but the label value is not right. I don't know why cum_2 in my data is an integer, but in the resulting gif the label text appears as a real number (example: 674.5... instead of 675).
library(tidyverse)
library(gganimate)
df <- data.frame(date = c(rep('2020-07-08',4), rep('2020-07-09',4),
rep('2020-07-10',4), rep('2020-07-11',4),
rep('2020-07-12',4)),
sub = rep(c("PYTHON", "SQL", "VBA", "R"),5),
cum_2 = c(659,609,454,450,659,609,468,450,670,609,478,450,670, 609,486,461,679,609,486,469),
rank = rep(c(1,2,3,4),5))
fill <- c('red','blue','green','orange') # example fill colors
df %>%
ggplot(aes(rank, y = cum_2,
fill = sub)) +
geom_col(alpha = 0.6)+
scale_fill_manual(values = fill) +
geom_text(aes(y = 0,
label = paste(sub, " ")),
vjust = 0.2,
hjust = 1) +
transition_states(states = date,transition_length = 4, state_length = 1) +
geom_text(aes(y = cum_2,
label = round(cum_2,0),
hjust = 0,
size = 12)) +
scale_x_reverse() +
coord_flip(clip = "off", expand = FALSE) +
guides(color = FALSE, fill = FALSE) +
theme(axis.line=element_blank(),
axis.text.x=element_blank(),
axis.text.y=element_blank(),
axis.ticks=element_blank(),
axis.title.x=element_blank(),
axis.title.y=element_blank(),
legend.position="none",
panel.background=element_blank(),
panel.border=element_blank(),
panel.grid.major=element_blank(),
panel.grid.minor=element_blank(),
panel.grid.major.x = element_line( size=.1, color="grey" ),
panel.grid.minor.x = element_line( size=.1, color="grey" ),
plot.title=element_text(size=25, hjust=0.5, face="bold", colour="grey", vjust=-1),
plot.subtitle=element_text(size=18, hjust=0.5, face="italic", color="grey"),
plot.caption =element_text(size=8, hjust=0.5, face="italic", color="grey"),
plot.background=element_blank(),
plot.margin = margin(2,2, 2, 4, "cm")) +
labs(title = 'MCI Vietnam : {closest_state}',
subtitle = "Number of students") +
view_follow(fixed_x = TRUE) +
enter_fade() +
exit_shrink() +
ease_aes('sine-in-out') -> anim
# gif
animate(anim, nframes = length(unique(df$date)),
detail = 5,
fps = 5,
# duration = 20,
renderer = gifski_renderer("file.gif"))
Last plot in gif file here:
Thanks all for read & support me.

Answer 1

Since the y position of the bars is tweened in the animation (cum_2 in your data frame), and the label position and text are based on cum_2, it will also get tweened and the result is that you have numbers with lots of decimal places appearing as a result.
Luckily, the fix is pretty easy: just force your label to be evaluated as.character(). Change your geom_text line to read as follows, and that fixes the issue:
geom_text(aes(y = cum_2, label = as.character(round(cum_2,0)),
hjust = 0, size = 12))
Here's the result (saved with duration=5):
*FYI: your code was missing the colors you used, so here I defined fill=c('red','blue','green','orange').