在保留其大小的同时将表达式更改为ggplot2中的粗体

Indrajeet帕蒂

我想在ggplot2绘图轴上显示一个表达式，在此我想同时更改size和face测试轴：

使用ggplot2::element_text，我可以更改size，但不能更改face。

ggplot(mtcars, aes(cyl, mpg)) + geom_point() +
  scale_x_continuous(
    labels = parse(text = "widehat(mu)=='6'"),
    breaks = 6
  ) +
  ggplot2::theme(axis.text.x = ggplot2::element_text(face = "bold", size = 12))

作为建议在这里，我可以换的表达bold，这部分工作（注意，仅6是大胆的，而不是斜体亩），但是文本size不会改变：

ggplot(mtcars, aes(cyl, mpg)) + geom_point() +
  scale_x_continuous(
    labels = parse(text = "bold(widehat(mu)=='6')"),
    breaks = 6
  ) +
  ggplot2::theme(axis.text.x = ggplot2::element_text(face = "bold", size = 12))

^{由reprex软件包（v1.0.0）创建于2021-02-12}

有没有办法做到这一点ggplot2呢？或将不得不使用类似的东西ggtext？

瑞·巴拉达斯（Rui Barradas）

Here is a way to make the font size vary as requested.
The .top in the second plot's theme seems to be a typo, remove it and the font becomes bigger.
And instead of parse, use expression for plotmath.

library(ggplot2)

ggplot(mtcars, aes(cyl, mpg)) + geom_point() +
  scale_x_continuous(
    labels = expression(bold(widehat(mu) == '6')),
    breaks = 6
  ) +
  theme(axis.text.x = element_text(face = "bold", size = 12))

Here is another one, with the axis label even bigger.

ggplot(mtcars, aes(cyl, mpg)) + geom_point() +
  scale_x_continuous(
    labels = expression(bold(widehat(mu) == '6')),
    breaks = 6
  ) +
  theme(axis.text.x = element_text(face = "bold", size = 24))