Komputasi gagal dalam `stat_flow ()`:
ggplot(df_data_Aluv,
aes(x = month,
stratum = Job,
alluvium = Employee,
y = freq,
fill = Job,
label = Job)) +
scale_x_discrete(expand = c(.1, .1)) +
geom_flow(stat = "alluvium",
lode.guidance = "frontback",
color = "darkgray") +
geom_stratum(alpha = .5) +
geom_text(stat = "stratum", size = 3) +
theme(legend.position = "bottom") +
ggtitle("Project month responses at three points in time")
MF