Question

我正在使用ggplot2来绘制患者BMI的箱线图，我在x轴上遇到了问题。我想把BMI的单位（kg / m2）包括在内，我希望“2”能够上标。当我像这样制作图表时：

require(plyr)
require(ggplot2)

Weights <- data.frame(SubjectID = 1:500,
                      Weight = rnorm(500, 28, 7))
Weights$Cat <- cut(Weights$Weight, breaks = c(0, 18.5, 25, 30, 40, Inf),
                   right = FALSE)
Weights$BMIcat <- revalue(Weights$Cat, 
                           c("[0,18.5)" = "Underweight\n(<18.5 kg/m2)",
                             "[18.5,25)" = "Normal weight\n(18.5 to 24.9\nkg/m2)",
                             "[25,30)" = "Overweight\n(25 to 29.9\nkg/m2)",
                             "[30,40)" = "Obese\n(30 to 39.9\nkg/m2)",
                             "[40,Inf)" = "Severely obese\n(>40 kg/m2)"))

ggplot(Weights, aes(x = BMIcat, y = Weight)) +
      geom_boxplot() +
      xlab("BMI category") + ylab("Weight (kg)")

除了2都不是上标之外，一切看起来都很美。我正在尝试使用expression来完成这项工作，这是我提出的最好的选择：

ggplot(Weights, aes(x = Cat, y = Weight)) +
      geom_boxplot() +
      scale_x_discrete(breaks=c("[0,18.5)", "[18.5,25)", "[25,30)",
                                "[30,40)", "[40,Inf)"),
                       labels=c(
                             expression("Underweight\n(<18.5 kg/m"^2*")"),
                             expression("Normal weight\n(18.5 to 24.9\nkg/m"^2*")"),
                             expression("Overweight\n(25 to 29.9\nkg/m"^2*")"),
                             expression("Obese\n(30 to 39.9\nkg/m"^2*")"),
                             expression("Severely obese\n(>40 kg/m"^2*")"))) +
      xlab("BMI category") + ylab("Weight (kg)")

现在，我的2s是上标的，但其他一切看起来都很糟糕。它看起来像是突然离开或者可能是完全对齐而不是居中，2有时真的远离m，轴文本与图形重叠！有什么建议吗？

Answer 1

您可以使用{1.0}}

中的Unicode上标两个字符

Weights$BMIcat <- revalue(Weights$Cat, 
                           c("[0,18.5)" = "Underweight\n(<18.5 kg/m²)",
                             "[18.5,25)" = "Normal weight\n(18.5 to 24.9\nkg/m²)",
                             "[25,30)" = "Overweight\n(25 to 29.9\nkg/m²)",
                             "[30,40)" = "Obese\n(30 to 39.9\nkg/m²)",
                             "[40,Inf)" = "Severely obese\n(>40 kg/m²)"))
ggplot(Weights, aes(x = BMIcat, y = Weight)) +
      geom_boxplot() +
      xlab("BMI category") + ylab("Weight (kg)")

Latin-1 block

使用“表达式”在ggplot2轴文本

1 个答案: