如何将ggboxplot箱线图标签移离线条，提升可见性？

首先还原你的数据与绘图代码：

TEST1 <- data.frame(
    Number = c(46.68, 46.45, 48.35, 44.63, 45.65, 46.46, 45.14, 45.69, 47.10),
    House.Height= c("LOW", "LOW", "LOW", "MODERATE", "MODERATE", "MODERATE", "HIGH", "HIGH", "HIGH"))

原绘图代码：

ggboxplot(TEST1, x = "House.Height", y = "Number", fill = "House.Height", 
          palette = c("#009E73", "#D55E00", "#CC79A7"), order = c("LOW", "MODERATE", "HIGH"), 
          sort.by.groups = TRUE, label = TRUE, label.pos = "out", lab.vjust = -2) +
    scale_x_discrete(labels = c("low", "moderate", "high")) +
    xlab("House Height")+ ylab("Number") + 
    labs(fill = "House") + 
    scale_y_continuous(breaks = seq(44,50)) +
    coord_cartesian(ylim = c(44, 50)) 

针对你遇到的标签压线、点看不清的问题，提供两种可行方案：

方案1：调整标签垂直位置并优化y轴范围 #

• 将lab.vjust设为正值（正值会让标签向下偏移，负值为向上偏移），比如lab.vjust = 1.5，让标签移到点的下方，避免与箱线或点重叠。
• 移除coord_cartesian(ylim = c(44, 50))，改用scale_y_continuous的limits参数扩展y轴底部范围，给下方标签留出显示空间，同时保留原有刻度设置：

修改后的代码：

ggboxplot(TEST1, x = "House.Height", y = "Number", fill = "House.Height", 
          palette = c("#009E73", "#D55E00", "#CC79A7"), order = c("LOW", "MODERATE", "HIGH"), 
          sort.by.groups = TRUE, label = TRUE, label.pos = "out", lab.vjust = 1.5) +
    scale_x_discrete(labels = c("low", "moderate", "high")) +
    xlab("House Height")+ ylab("Number") + 
    labs(fill = "House") + 
    scale_y_continuous(breaks = seq(43.5,50), limits = c(43.5, 50))

方案2：手动添加标签（更灵活的控制） #

如果内置标签参数不够灵活，可以放弃label = TRUE，改用geom_text自定义标签位置，甚至可以根据点的y值动态调整偏移：

ggboxplot(TEST1, x = "House.Height", y = "Number", fill = "House.Height", 
          palette = c("#009E73", "#D55E00", "#CC79A7"), order = c("LOW", "MODERATE", "HIGH"), 
          sort.by.groups = TRUE) +
    geom_text(aes(label = Number), vjust = 1.5, size = 3.5) + # 手动添加标签并向下偏移
    scale_x_discrete(labels = c("low", "moderate", "high")) +
    xlab("House Height")+ ylab("Number") + 
    labs(fill = "House") + 
    scale_y_continuous(breaks = seq(43.5,50), limits = c(43.5, 50))

如果需要针对不同位置的点设置不同偏移，可以用ifelse判断y值：

geom_text(aes(label = Number, vjust = ifelse(Number < 45, 1.5, -1)), size = 3.5)

这样y值小于45的点标签向下移，大于等于45的向上移，彻底避免重叠。

内容的提问来源于stack exchange，提问作者lizzy