如何在gt表格中自定义行组标签（含上下标、换行）及样式调整

问题分析 #

行组标签的HTML未解析、行组列未垂直居中、标签未加粗，核心原因是gt默认将行组标签视为纯文本，且未配置对应样式。

修正方案（两种实现方式） #

方式一：使用Markdown语法（推荐，更简洁） #

修正后的完整代码：

library(gt)
library(dplyr)

# 生成第一组数据
a <- rnorm(21, mean = 112, sd = 12)
colour <- rep(c("Blue", "Red", "Green"), 7)

data <- data.frame(colour, a) %>% 
  group_by(colour) %>% 
  summarise(mean = mean(a), sd = sd(a), n = n()) %>%
  mutate(grp = "[H~2~O]") %>%  # Markdown下标语法
  rename(cat = colour)

# 生成第二组数据（修正原代码中误用mean(a)的错误）
b <- rnorm(21, mean = 60, sd = 12)
day <- rep(c("2", "4", "6"), 7)

data2 <- data.frame(day, b) %>% 
  group_by(day) %>% 
  summarise(mean = mean(b), sd = sd(b), n = n()) %>%
  mutate(grp = "[H~2~O] Addition  \n(Days)") %>%  # Markdown换行（两个空格+回车）
  rename(cat = day)

# 构建带样式的gt表格
bind_rows(data, data2) %>% 
  gt(rowname_col = "cat") %>%
  # 将行组转为单独列
  tab_options(row_group.as_column = TRUE) %>%
  # 解析行组标签为Markdown，同时添加加粗效果
  opt_row_groups(
    label_fn = function(x) md(paste0("**", x, "**"))
  ) %>%
  # 设置行组标签垂直居中
  tab_style(
    style = cell_text(align = "center", v_align = "middle"),
    locations = cells_row_groups()
  ) %>%
  # 可选：设置行组列标题居中
  tab_style(
    style = cell_text(align = "center"),
    locations = cells_column_labels(columns = "row_group")
  )

方式二：使用HTML语法 #

如果偏好HTML标签，可采用以下代码：

library(gt)
library(dplyr)

# 生成第一组数据
a <- rnorm(21, mean = 112, sd = 12)
colour <- rep(c("Blue", "Red", "Green"), 7)

data <- data.frame(colour, a) %>% 
  group_by(colour) %>% 
  summarise(mean = mean(a), sd = sd(a), n = n()) %>%
  mutate(grp = "<strong>[H<sub>2</sub>O]</strong>") %>%  # HTML加粗+下标
  rename(cat = colour)

# 生成第二组数据（修正原代码错误）
b <- rnorm(21, mean = 60, sd = 12)
day <- rep(c("2", "4", "6"), 7)

data2 <- data.frame(day, b) %>% 
  group_by(day) %>% 
  summarise(mean = mean(b), sd = sd(b), n = n()) %>%
  mutate(grp = "<strong>[H<sub>2</sub>O] Addition <br> (Days)</strong>") %>%  # HTML换行+加粗
  rename(cat = day)

# 构建表格
bind_rows(data, data2) %>% 
  gt(rowname_col = "cat") %>%
  tab_options(row_group.as_column = TRUE) %>%
  # 解析行组标签中的HTML
  opt_row_groups(label_fn = html) %>%
  # 设置行组标签垂直居中
  tab_style(
    style = cell_text(align = "center", v_align = "middle"),
    locations = cells_row_groups()
  )

关键要点 #

• HTML/Markdown解析：gt默认不解析行组标签的标记语言，必须通过opt_row_groups(label_fn = html)或label_fn = md指定解析函数。
• 标签加粗：可直接在标签文本中加入Markdown的**或HTML的<strong>，配合解析函数生效。
• 垂直居中：通过tab_style()选中cells_row_groups()，设置v_align = "middle"实现行组标签垂直居中。

内容的提问来源于stack exchange，提问作者MM1