R生成表格无法并排显示问题咨询（需支持PDF导出）

我正在制作一份可通过knit导出为PDF的报告，遇到格式问题：尝试让两个表格并排显示，但它们始终自动换行。以下是相关代码：

{r OWNER TABLE, echo = F}
owner_probs <- data.frame(In = c(0.56, 0.24), 
                          Out = c(0.14, 0.06))
row.names(owner_probs) <- c("In", "Out")

owner_dse <- owner_probs * 350000

owner_probs <- owner_probs %>%
  kable(longtable = T,
        booktabs = T, 
        align = "c", 
        caption = "Probability Table") %>%
  kable_styling(bootstrap_options = "bordered",
                position = "float_left") %>% 
  column_spec (1:3,
               border_left = T, 
               border_right = T)

owner_dse <- owner_dse %>%
  kable(longtable = T,
        booktabs = T, 
        align = "c", 
        caption = "DSE Table") %>%
  kable_styling(bootstrap_options = "bordered",
                position = "float_right") %>% 
  column_spec (1:3,
               border_left = T,
               border_right = T)

owner_probs
owner_dse

补充：生成的表格TeX代码如下：

\subsection{Owner (On a Population of
350,000)}\label{owner-on-a-population-of-350000}

\begin{longtabu} to \linewidth {|>{}l||>{}c||>{}c|}
\caption{\label{tab:OWNER TABLE}Probability Table}\\
\toprule
 & In & Out\\
\midrule
In & 0.56 & 0.14\\
Out & 0.24 & 0.06\\
\bottomrule
\end{longtabu}

\begin{longtabu} to \linewidth {|>{}l||>{}c||>{}c|}
\caption{\label{tab:OWNER TABLE}DSE Table}\\
\toprule
 & In & Out\\
\midrule
In & 196000 & 49000\\
Out & 84000 & 21000\\
\bottomrule
\end{longtabu}

问题根源 #

1. 长表格不支持并排：你给kable()设置了longtable = T，生成的是longtabu环境的长表格，这类表格专为跨页设计，默认占满整行宽度，无法实现并排。
2. 宽度设置过满：生成的TeX代码中两个表格都用了to \linewidth，直接占满页面宽度，自然无法放在同一行。

修正步骤 #

方案一：用kableExtra直接调整 #

去掉长表格设置，给每个表格指定宽度，配合浮动位置实现并排：

{r OWNER TABLE, echo = F}
library(kableExtra)
library(dplyr)

owner_probs <- data.frame(In = c(0.56, 0.24), 
                          Out = c(0.14, 0.06))
row.names(owner_probs) <- c("In", "Out")

owner_dse <- owner_probs * 350000

# 第一个表格：取消longtable，设置宽度为页面45%，左浮动
owner_probs <- owner_probs %>%
  kable(booktabs = T, 
        align = "c", 
        caption = "Probability Table") %>%
  kable_styling(bootstrap_options = "bordered",
                position = "float_left",
                width = "45%") %>% 
  column_spec(1:3, border_left = T, border_right = T)

# 第二个表格：取消longtable，设置宽度为页面45%，右浮动
owner_dse <- owner_dse %>%
  kable(booktabs = T, 
        align = "c", 
        caption = "DSE Table") %>%
  kable_styling(bootstrap_options = "bordered",
                position = "float_right",
                width = "45%") %>% 
  column_spec(1:3, border_left = T, border_right = T)

# 输出表格
owner_probs
owner_dse
# 手动添加垂直间距，避免后续内容与浮动表格重叠
cat("\\vspace{1em}")

方案二：用TeX minipage环境精细控制 #

如果需要更灵活的排版，可直接生成TeX代码并用minipage包裹：

{r OWNER TABLE, echo = F, results='asis'}
library(kableExtra)
library(dplyr)

owner_probs <- data.frame(In = c(0.56, 0.24), 
                          Out = c(0.14, 0.06))
row.names(owner_probs) <- c("In", "Out")

owner_dse <- owner_probs * 350000

# 生成不带自动环境的表格TeX代码
tab1 <- owner_probs %>%
  kable(booktabs = T, 
        align = "c", 
        caption = "Probability Table",
        format = "latex") %>%
  kable_styling(bootstrap_options = "bordered") %>% 
  column_spec(1:3, border_left = T, border_right = T)

tab2 <- owner_dse %>%
  kable(booktabs = T, 
        align = "c", 
        caption = "DSE Table",
        format = "latex") %>%
  kable_styling(bootstrap_options = "bordered") %>% 
  column_spec(1:3, border_left = T, border_right = T)

# 用minipage将两个表格放在同一行，中间留空隙
cat("\\begin{minipage}{0.45\\linewidth}")
cat(tab1)
cat("\\end{minipage}")
cat("\\hfill") # 表格间自动填充空隙
cat("\\begin{minipage}{0.45\\linewidth}")
cat(tab2)
cat("\\end{minipage}")

注意事项 #

• 不需要跨页的表格别用longtable，这是并排失败的核心原因。
• 两个表格的总宽度要小于页面宽度，比如各占45%，留10%空隙避免拥挤。
• 使用浮动位置时，记得在表格后添加\\vspace{1em}这类命令，防止后续内容与表格重叠。

内容的提问来源于stack exchange，提问作者Miller25