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Accepted
Bogaso
Asked: 2024-08-03 15:22:43 +0800 CST

在 ggplot 中的直方图中放置标签

  • 772

我有以下 histogra 沉思 ggplot

library(ggplot2)
n = 1000
mean = 0
sd = 1
binwidth = 0.3 # passed to geom_histogram and stat_function
set.seed(1)
df <- data.frame(x = rnorm(n, mean, sd))

myplot = ggplot(df, aes(x = x, mean = mean, sd = sd, binwidth = binwidth, n = n)) +
    theme_bw() +
    geom_histogram(binwidth = binwidth, 
        colour = "white", fill = "cornflowerblue", size = 0.1)

现在我想在顶部中间区域添加一个自定义标签，但标签顶部应该留出一些边距，比如说 10 点。我尝试了以下方法

myplot+
geom_label(aes(x = mean((df$x)), y = 100), label = 'Plot with y', label.padding = unit(.7, 'lines'), fill = '#000000', color = '#ffffff', alpha = 0.2)

有没有什么方法可以动态地（仅基于数据而不进行任何硬编码）设置y = 100将标签保持在顶部并以 10 点的边距？

1 个回答

  1. Best Answer

    将标签放置在绘图区域顶部并留出一些边距的一种方法是使用annotation_custom需要通过 grob 添加标签的方法。对于后者，我使用gridtext::richtext_grob（因为grid不提供labelGrob而ggplot2没有导出它）：

    library(ggplot2)
library(gridtext)
library(grid)

myplot +
  annotation_custom(
    grob = gridtext::richtext_grob(
      text = "Plot with y",
      # Place at the top with margin of 5mm
      y = unit(1, "npc") - unit(5, "mm"),
      # Padding around label
      padding = unit(.7, "lines"),
      gp = grid::gpar(col = "#ffffff"),
      box_gp = grid::gpar(fill = "#000000", alpha = .6),
      vjust = 1
    ),
    xmin = mean(df$x),
    xmax = mean(df$x)
  )

    编辑如果你不能安装任何非标准包（例如）一个选项是使用gridtext非导出labelGrob的：ggplot2:::

    myplot +
  annotation_custom(
    grob = ggplot2:::labelGrob(
      label = "Plot with y",
      # Place at the top with margin of 5mm
      y = unit(1, "npc") - unit(5, "mm"),
      # Padding around label
      padding = unit(rep(.7, 4), "lines"),
      text.gp = grid::gpar(col = "#ffffff"),
      rect.gp = grid::gpar(fill = "black", alpha = .6),
      just = "top"
    ),
    xmin = mean(df$x),
    xmax = mean(df$x)
  )

    • 1

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