ggplot2 标签

ggplot2是一种用于数据可视化的R语言包。在使用ggplot2进行可视化时，可以使用geom_text函数在图外添加数据点标签和注释。以下是几种在ggplot2中添加标签的方法：

方法1：

library(ggplot2)
library(grid)

df <- data.frame(y = c("cat1", "cat2", "cat3"), x = c(12, 10, 14), n = c(5, 15, 20))

p <- ggplot(df, aes(x, y)) +
  geom_point() +
  theme(plot.margin = unit(c(1, 3, 1, 1), "lines"))

for (i in 1:length(df$n)) {
  p <- p +
    annotation_custom(
      grob = textGrob(label = df$n[i], hjust = 0, gp = gpar(cex = 1.5)),
      ymin = df$y[i],
      ymax = df$y[i],
      xmin = 14.3,
      xmax = 14.3
    )
}

gt <- ggplot_gtable(ggplot_build(p))
gt$layout$clip[gt$layout$name == "panel"] <- "off"
grid.draw(gt)

方法2：

df <- data.frame(y = c("cat1", "cat2", "cat3"), x = c(12, 10, 14), n = c(5, 15, 20))

ggplot(df, aes(x = x, y = y, label = n)) +
  geom_point() +
  geom_text(x = 14.25, hjust = 0, size = 8) +
  coord_cartesian(xlim = c(10, 14), clip = 'off') +
  theme(plot.margin = unit(c(1,3, 1, 1), "lines"))

方法3：

df <- data.frame(y = c("cat1", "cat2", "cat3"), x = c(12, 10, 14), n = c(5, 15, 20))

ggplot(df, aes(x = x, y = y, label = n)) +
  geom_point() +
  geom_text(size = 8, hjust = -0.5)

以上是三种在ggplot2中添加标签的方法。你可以根据需要选择适合你的情况的方法。