在x方向上扩展ggplot`geom_ribbon（）`

Question

library(tidyverse)
mQ <- quantile(mtcars$wt, c(0.025, 0.975))
mtcarsQ <- data.frame(x = c(min(as.numeric(diamonds$cut)), 
                            max(as.numeric(diamonds$cut))), 
                      ymin = rep(mQ[1], 2), 
                      ymax = rep(mQ[2], 2))

ggplot() + 
  geom_blank(data = diamonds, aes(x = cut, y = y)) +
  geom_ribbon(data = mtcarsQ, aes(x = x, ymin = ymin, ymax = ymax), alpha=0.2) +
  geom_boxplot(data = diamonds, aes(x = cut, y = y, fill = cut, group = cut)) +
  coord_cartesian(ylim = c(0, 12)) + 
  theme_bw()

我想将我的geom_ribbon()从上面的代码块沿x轴的任一方向扩展。类似于下面的图片。我偏爱的geom_ribbon()将完全吸引到蓝色虚线框中。

我该怎么做？

Answer 1

您可以从mtcarsQ$x减去/加0.5

mtcarsQ <- data.frame(x = c(min(as.numeric(diamonds$cut)) - 0.5,
                            max(as.numeric(diamonds$cut)) + 0.5),
                      ymin = rep(mQ[1], 2),
                      ymax = rep(mQ[2], 2))

ggplot() +
  geom_blank(data = diamonds, aes(x = cut, y = y)) +
  geom_ribbon(data = mtcarsQ, aes(x = x, ymin = ymin, ymax = ymax), alpha=0.2) +
  geom_boxplot(data = diamonds, aes(x = cut, y = y, fill = cut, group = cut)) +
  coord_cartesian(ylim = c(0, 12)) +
  theme_bw()

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更新

为回应您的评论，这是一个示例

mtcars %>%
    mutate(cyl = factor(cyl)) %>%
    ggplot() +
    geom_col(aes(cyl, mpg)) +
    geom_rect(
        data = data.frame(
            xmin = min(as.integer(as.factor(mtcars$cyl))) - 0.5,
            xmax = max(as.integer(as.factor(mtcars$cyl))) + 0.5,
            ymin = 20,
            ymax = 120),
        aes(xmin = xmin, xmax = xmax, ymin = ymin, ymax = ymax),
        alpha = 0.2, fill = "green")