带 R 的多彩标题

我想添加颜色某些词在我的图表标题中。我已经能够在这里找到一些先例 http://blog.revolutionanalytics.com/2009/01/multicolor-text-in-r.html。具体来说，我希望用撇号括起来的文本（在下面的输出中）与各自条形图的颜色相对应。

以下是我在将 PDF 导出到 Adob​​e Illustrator 或其他程序之前在 R 中使用标题的情况。

name <- c("Peter", "Gabriel", "Rachel", "Bradley")
age <- c(34, 13, 28, 0.9)
fake_graph <- family[order(family$age, decreasing = F), ]
fake_graph <- within(fake_graph, {
    bar_color = ifelse(fake_graph$name == "Rachel", "blue", "gray")
})

# Plot creation
library(ggplot2)
fake_bar_charts <- ggplot() +
  geom_bar(
    data = fake_graph,
    position = "identity",
    stat = "identity",
    width = 0.75,
    fill = fake_graph$bar_color,
    aes(x = name, y = age)
    ) +
  scale_x_discrete(limits = fake_graph$name) +
  scale_y_continuous(expand = c(0, 0)) +
  coord_flip() +
  theme_minimal()
family <- data.frame(name, age)

# Add title
library(grid)
library(gridExtra)
grid_title <- textGrob(
  label = "I spend more time with 'Rachel' than\nwith 'other family members.'",
  x = unit(0.2, "lines"),
  y = unit(0.1, "lines"),
  hjust = 0, vjust = 0,
  gp = gpar(fontsize = 14, fontface = "bold")
)
gg <- arrangeGrob(fake_bar_charts, top = grid_title)
grid.arrange(gg)

Output:

本示例使用ggplot2创建条形图以及grid and gridExtra对于标题功能，但我愿意使用任何解决方案（最好是ggplot2创建图表本身），它可以为我提供引号中的文本，以匹配它们各自的条形图颜色。

该网站上的任何其他解决方案都无法解决这个难题，但我很乐意从 R 中找到解决方案。

感谢您的任何帮助！

我写标签的方式太诚实了。第一的grob的宽度决定第二个grob的x， 等等。我用了grobTree()将它们分组。因为gTree没有自己的尺寸信息，我给了arrangeGrob()一个论点padding保留gTree的空间。

library(grid); library(gridExtra); library(ggplot2)

df <- data.frame(name = c("Rachel", "Peter", "Gabriel","Bradley"), age = c(23, 35, 12, 3))
fake_bar_charts <- ggplot(df, aes(x=name, y=age)) + 
  geom_bar(stat="identity", fill = c(rep("gray50",3), "red")) + coord_flip()

grobs <- grobTree(
  gp = gpar(fontsize = 14, fontface = "bold"), 
  textGrob(label = "I spend more time with '", name = "title1",
           x = unit(0.2, "lines"), y = unit(1.4, "lines"), 
           hjust = 0, vjust = 0),
  textGrob(label = "Rachel", name = "title2",
           x = grobWidth("title1") + unit(0.2, "lines"), y = unit(1.4, "lines"),
           hjust = 0, vjust = 0, gp = gpar(col = "red")),
  textGrob(label = "' than", name = "title3",
           x = grobWidth("title1") + grobWidth("title2") + unit(0.2, "lines"), y = unit(1.4, "lines"),
           hjust = 0, vjust = 0),
  textGrob(label = "with '", name = "title4",
           x = unit(0.2, "lines"), y = unit(0.1, "lines"),
           hjust = 0, vjust = 0),
  textGrob(label = "other family members", name = "title5",
           x = grobWidth("title4") + unit(0.2, "lines"), y = unit(0.1, "lines"),
           hjust = 0, vjust = 0, gp = gpar(col = "gray50")),
  textGrob(label = "'.", name = "title6",
           x = grobWidth("title4") + grobWidth("title5") + unit(0.2, "lines"), y = unit(0.1, "lines"),
           hjust = 0, vjust = 0)
)

gg <- arrangeGrob(fake_bar_charts, top=grobs, padding = unit(2.6, "line"))
grid.newpage()
grid.draw(gg)