# Assume 'g' is the previous plot object saved under a variable
newdat <- layer_data(g)
newdat <- newdat[newdat$side == "start", ]
split <- split(newdat, interaction(newdat$stratum, newdat$x))
split <- lapply(split, function(dat) {
dat$label <- dat$label / sum(dat$label)
dat
})
newdat <- do.call(rbind, split)
ggplot(vaccinations,
aes(x = survey, stratum = response, alluvium = subject,
y = freq,
fill = response, label = freq)) +
scale_x_discrete(expand = c(.1, .1)) +
geom_flow() +
geom_stratum(alpha = .5) +
geom_text(stat = "stratum", size = 3) +
geom_text(data = newdat, aes(x = xmin + 0.4, y = y, label = format(label, digits = 1)),
inherit.aes = FALSE) +
theme(legend.position = "bottom") +
ggtitle("vaccination survey responses at three points in time")