r - 将百分位线添加到密度图

Question

我有一些数据dt = data.table(x=c(1:200),y=rnorm(200))，我从密度图开始使用ggplot2：

plot = ggplot(dt,aes(y)) + geom_density(aes(y=..density..))

有没有办法可以添加类似于此的百分位线？

如果进一步我可以对类似于此的图形段（由百分位线创建）进行着色，那就太好了！

Answer 1

以下是受此答案启发的可能性：

dt <- data.table(x=c(1:200),y=rnorm(200))
dens <- density(dt$y)
df <- data.frame(x=dens$x, y=dens$y)
probs <- c(0.1, 0.25, 0.5, 0.75, 0.9)
quantiles <- quantile(dt$y, prob=probs)
df$quant <- factor(findInterval(df$x,quantiles))
ggplot(df, aes(x,y)) + geom_line() + geom_ribbon(aes(ymin=0, ymax=y, fill=quant)) + scale_x_continuous(breaks=quantiles) + scale_fill_brewer(guide="none")

Answer 2

myd = data.frame(xvar=rnorm(2000),yvar=rnorm(2000))

    xd <- data.frame(density(myd$xvar)[c("x", "y")])
    p <- ggplot(xd, aes(x, y)) + 

      geom_area(data = subset(xd, x < -1), fill = "pink") +
      geom_area(data = subset(xd, x < -1.96), fill = "red") +
      geom_area(data = subset(xd, x > 1), fill = "lightgreen") +
      geom_area(data = subset(xd, x > 1.96), fill = "green") +

      geom_line()

    p