在使用 R markdown 生成的投影仪演示中减少表格和标题之间的距离

Question

如何在使用 R markdown 生成的beamer演示中减少表格与其标题之间的距离？ 理想情况下，如果 output 格式是bookdown::pdf_book使用base_format: rmarkdown::beamer_presentation （参见下面的 MWE），该解决方案也有效。

MWE

---
output:
  bookdown::pdf_book:
    base_format: rmarkdown::beamer_presentation
    latex_engine: xelatex
    toc: false
    slide_level: 2
header-includes:
  - \usepackage{booktabs} 
  - \usepackage{longtable} 
  - \usepackage{array}          
  - \usepackage{multirow}   
  - \usepackage{wrapfig}    
  - \usepackage{float}
  - \usepackage{colortbl}    
  - \usepackage{pdflscape}
  - \usepackage{tabu}
  - \usepackage{threeparttable} 
  - \usepackage{threeparttablex}
  - \usepackage[normalem]{ulem}
  - \usepackage{makecell}
---

## Slide with table

(ref:footnote-a) Text for footnote a
(ref:footnote-b) Text for footnote b

\renewcommand{\arraystretch}{1.3} <!-- increase line spacing for the table -->
```{r table-wLatex, echo=FALSE, fig.align="center", message=FALSE, warning=FALSE, out.width='30%'}
library(kableExtra)
library(dplyr)

# table with manually added footnotes within table
df <- data.frame(
  col1 = c("Category 1", "Category 2"),
  col2 = c(
    "foo and \\emph{special foo}$^{a}$", 
    "bar and \n $\\boldsymbol{\\cdot}$ \\emph{random bar}$^{a}$\n $\\boldsymbol{\\cdot}$ \\emph{special bar}$^{b}$")
)

# header: add column names
names(df) <- c("Categories", "Description")

df %>%
  mutate_all(linebreak) %>% # required for linebreaks to work
  kable(
    "latex",
    escape = FALSE, # needed to be able to include latex commands
    booktabs=TRUE,
    align = "l",
    caption = "Caption Table with LaTex" # short caption for LoT
  ) %>%
  kableExtra::footnote(
    alphabet = c(
      "(ref:footnote-a)",
      "(ref:footnote-b)"
      ),
    threeparttable = TRUE, # important! Else footnote runs beyond the table
    footnote_as_chunk = TRUE, title_format = c("italic", "underline")
  ) %>% 
  column_spec(1, width = "3cm") %>% # fix width column 1
  column_spec(2, width = "5cm") # fix width column 2
```
\renewcommand{\arraystretch}{1} <!-- reset row height/line spacing -->

在 MWE 中添加一个简单的LaTex标题而不是上面的bookdown方法会引发以下错误：

# ... table as above
\captionof{table-wLatex}{Table caption}
\label{table-wLatex}

: Package 字幕错误。 未定义浮点类型“tablewLatex”。

Answer 1

如果要为表格添加\captionof ，则应使用table作为标题类型，而不是table-wLatex 。

如果生成的标题仍然很高（这可能是因为 rmarkdown 会自动加载caption package，这对于 beamer 来说是不必要的......），您可以使用\vspace{-0.2cm}或类似方法对其进行一些调整。

---
output:
  bookdown::pdf_book:
    base_format: rmarkdown::beamer_presentation
    latex_engine: xelatex
    keep_tex: true
    toc: false
    slide_level: 2
header-includes:
  - \usepackage{booktabs} 
  - \usepackage{longtable} 
  - \usepackage{array}          
  - \usepackage{multirow}   
  - \usepackage{wrapfig}    
  - \usepackage{float}
  - \usepackage{colortbl}    
  - \usepackage{pdflscape}
  - \usepackage{tabu}
  - \usepackage{threeparttable} 
  - \usepackage{threeparttablex}
  - \usepackage[normalem]{ulem}
  - \usepackage{makecell}
---

## Slide with table

(ref:footnote-a) Text for footnote a
(ref:footnote-b) Text for footnote b

\renewcommand{\arraystretch}{1.3} <!-- increase line spacing for the table -->
\captionof{table}{Table caption}
\label{table-wLatex}
\vspace{-0.2cm}
```{r table-wLatex, echo=FALSE, fig.align="center", message=FALSE, warning=FALSE, out.width='30%'}
library(kableExtra)
library(dplyr)

# table with manually added footnotes within table
df <- data.frame(
  col1 = c("Category 1", "Category 2"),
  col2 = c(
    "foo and \\emph{special foo}$^{a}$", 
    "bar and \n $\\boldsymbol{\\cdot}$ \\emph{random bar}$^{a}$\n $\\boldsymbol{\\cdot}$ \\emph{special bar}$^{b}$")
)

# header: add column names
names(df) <- c("Categories", "Description")

df %>%
  mutate_all(linebreak) %>% # required for linebreaks to work
  kable(
    "latex",
    escape = FALSE, # needed to be able to include latex commands
    booktabs=TRUE,
    align = "l",
  ) %>%
  kableExtra::footnote(
    alphabet = c(
      "(ref:footnote-a)",
      "(ref:footnote-b)"
      ),
    threeparttable = TRUE, # important! Else footnote runs beyond the table
    footnote_as_chunk = TRUE, title_format = c("italic", "underline")
  ) %>% 
  column_spec(1, width = "3cm") %>% # fix width column 1
  column_spec(2, width = "5cm") # fix width column 2
```

\renewcommand{\arraystretch}{1} <!-- reset row height/line spacing -->