将第 1/3 个四分位数和第 90 个百分位数添加到 R 中的折线图

Question

The title says it all. What I would like to do is plotting the median, but also displaying the two quartiles as well as the 90th percentile at each timepoint.

Answer 1

First, here's a small sample dataset with observations y for 3 timepoints time (100 observations for each timepoint).

dd <- data.frame(y=c(rnorm(100, 10, 2), rnorm(100, 15, 2), rnorm(100, 20,2)), time=rep(c(1,2,3), each=100))

Next, summarizing you data according to what you want (here only median and first quantile, but the principle is the same to obtain other quantiles)

dd1 <- ddply(dd, "time", summarise, med=median(y), firstquart=quantile(y, probs=.01))

Finally, plotting your lines with ggplot - first quantile is in red.

ggplot(dd1, aes(x=time, y=med)) + geom_line()+geom_line(aes(x=time, y=firstquart), colour="red")