您可以将数字添加到图例中。
library(ggplot2)
critters <- structure(list(Zoo = "Omaha", Animals = 50, Bears = 10, PolarBears = 3), .Names = c("Zoo", "Animals", "Bears", "PolarBears"), row.names = c(NA, -1L), class = "data.frame")
d <- data.frame(animal=factor(c(rep("Animals", critters$Animals),
rep("Bears", critters$Bears), rep("PolarBears", critters$PolarBears)),
levels = c("PolarBears", "Bears", "Animals"), ordered= TRUE))
levels(d$animal) <- apply(data.frame(table(d$animal)), 1, paste, collapse = ": ")
ggplot(d, aes(x = factor(1), fill = factor(animal))) + geom_bar() +
coord_polar() + labs(x = NULL, fill = NULL) +
scale_fill_manual(values = c("firebrick2", "yellow2", "green3")) +
opts(title = paste("Animals, Bears and Polar Bears:\nOmaha Zoo", sep=""))