这是另一种基于函数近似核密度的
ggplot2
变体:
approxdens <- function(x) {
dens <- density(x)
f <- with(dens, approxfun(x, y))
f(x)
}
![](https://i.imgur.com/7viN5xc.png)
使用原始数据(而不是生成具有密度估计的x和y值的新数据框)的好处在于,它还适用于分面图,其中分位数值取决于按哪个变量对数据进行分组:
![](https://i.imgur.com/aJNBG0f.png)
所使用的代码
library(tidyverse)
library(RColorBrewer)
set.seed(1)
n <- 1e2
dt <- tibble(value = rnorm(n)^2)
approxdens <- function(x) {
dens <- density(x)
f <- with(dens, approxfun(x, y))
f(x)
}
probs <- c(0.75, 0.95)
dt <- dt %>%
mutate(dy = approxdens(value),
p = percent_rank(value),
pcat = as.factor(cut(p, breaks = probs,
include.lowest = TRUE)))
ggplot(dt, aes(value, dy)) +
geom_ribbon(aes(ymin = 0, ymax = dy, fill = pcat)) +
geom_line() +
scale_fill_brewer(guide = "none") +
theme_bw()
dt2 <- tibble(category = c(rep("A", n), rep("B", n)),
value = c(rnorm(n)^2, rnorm(n, mean = 2)))
dt2 <- dt2 %>%
group_by(category) %>%
mutate(dy = approxdens(value),
p = percent_rank(value),
pcat = as.factor(cut(p, breaks = probs,
include.lowest = TRUE)))
ggplot(dt2, aes(value, dy)) +
geom_ribbon(aes(ymin = 0, ymax = dy, fill = pcat)) +
geom_line() +
facet_wrap(~ category, nrow = 2, scales = "fixed") +
scale_fill_brewer(guide = "none") +
theme_bw()
此内容由reprex包 (v0.2.0)于2018年7月13日创建。