R stacked bar plots

melted <- melt(beitraege, id.vars=c("Droge"))

melted$Droge <- factor(
  melted$Droge,
  levels=rev(sort(unique(melted$Droge))),
  ordered=TRUE
)

melted2 <- melted[order(melted$value),]

melted2 <- within(melted2, {
  Droge <- factor(Droge, levels = names(sort(tapply(value, Droge, sum))))
})

ggplot(melted2, aes(x= Droge, y = value, fill = variable, order = variable)) +
  geom_bar(stat = "identity") +
  coord_flip()