r - 如何在 R Markdown 中将每列的最小值加粗每个单元格

Question

我想将我的一个数据框的最小值加粗，并将其合并为一个。我希望每列中的最小值加粗。

下面的 R 代码显示了我的最低工作示例 (MWE)。该表由五 (5) 列从正态分布中随机生成的值组成。前三 (3) 个显示 std dev =1 时，后三 (3) 个显示 std dev =2 时。每列根据其生成种子及其std dev而有所不同。

---
title: "Min Value to be Bolded"
output:  pdf_document
---

```{r}
set.seed(1)
df1 <- data.frame(
  seed1 = rnorm(5, mean = 0, sd = 1),
  seed2 = rnorm(5, mean = 0, sd = 1),
  seed3 = rnorm(5, mean = 0, sd = 1)
)
set.seed(1)
df2 <- data.frame(
  seed1 = rnorm(5, mean = 0, sd = 2),
  seed2 = rnorm(5, mean = 0, sd = 2),
  seed3 = rnorm(5, mean = 0, sd = 2)
)
df <- cbind(df1, df2)
df |>
  knitr::kable(format = "html", table.attr = "style='width:100%;'", digits = 2, align = 'c', caption = "5 Random Numbers from the Normal Dist at diff set and std dev") |>
  kableExtra::kable_styling(bootstrap_options = 'bordered') |>
  kableExtra::add_header_above(c('$sd = 1$' = 3, '$sd$ = 2' = 3)) |>
  row_spec(3, bold=T, hline_after = TRUE)
```

输出

而不是我来获取最小值粗体。我把第三行全部加粗了。我可以像这样获取 R 上的值:

lapply(df1, 2, FUN = min)

但我需要有关如何使用 kable 或 kableExtral 将单元格加粗的帮助。

请注意，我并不是要对整个数据框执行此操作，我只需要 df1 或 df2。

Answer 1

您可以添加库(formattable)，然后

df |> 
  lapply(\(x){ifelse(x == min(x), cell_spec(round(x,2), bold = TRUE), round(x,2))}) |>
  knitr::kable(format = "html", table.attr = "style='width:100%;'", digits = 2, align = 'c', 
                caption = "5 Random Numbers from the Normal Dist at diff set and std dev", 
                escape = FALSE) |>
  kableExtra::kable_styling(bootstrap_options = 'bordered') |>
  kableExtra::add_header_above(c('$sd = 1$' = 3, '$sd$ = 2' = 3))

或者，如果您只想要df1，您可以从

开始

df1 |> lapply(\(x){ifelse(x == min(x), cell_spec(round(x, 2), bold = TRUE), round(x, 2))}) |> cbind(df2) |> 

对于df2

df1 |> cbind(df2 |> lapply(\(x){ifelse(x == min(x), cell_spec(round(x, 2), bold = TRUE), round(x, 2))})) |>

备注:在我的解决方案中，数据帧的名称全部变为 x。您可以在 lapply 之后添加 as.data.frame 来获取原始名称，但在这种情况下，它们会发生变化，因为 df 具有名称重复，这不是一个合适的做法。相反，使用 col.names 您可以编写所需的名称，例如

df |> 
  lapply(\(x){ifelse(x == min(x), cell_spec(round(x,2), bold = TRUE), round(x,2))}) |>
  as.data.frame() |>
  knitr::kable(format = "html", table.attr = "style='width:100%;'", digits = 2, align = 'c', 
               caption = "5 Random Numbers from the Normal Dist at diff set and std dev", 
               escape = FALSE, col.names = rep(c("seed1", "seed2", "seed3"), 2)) |>
  kableExtra::kable_styling(bootstrap_options = 'bordered') |>
  kableExtra::add_header_above(c('$sd = 1$' = 3, '$sd$ = 2' = 3)) 

另请注意，作为评论@phiver，我必须将 output: pdf_document 修改为 output: html_document，否则代码将无法工作。要获得 pdf，代码的最后几行应如下所示(然后它就可以工作):

  knitr::kable(format = "latex",  digits = 2, align = 'c', 
               caption = "5 Random Numbers from the Normal Dist at diff set and std dev", 
               escape = FALSE, col.names = rep(c("seed1", "seed2", "seed3"), 2)) |>
  kableExtra::kable_styling(bootstrap_options = 'bordered', full_width = TRUE) |>
  kableExtra::add_header_above(c('$sd = 1$' = 3, '$sd$ = 2' = 3))