Xtable两列使用longtable自定义

Question

这是我之前发布的question的延续。我在RStudio中有一个code.Rnw文件，我使用code.tex命令编译成knit("code.Rnw")文件。

我有一个使用xtable命令打印的数据框。在下面的示例中，它是20行。但是，为了节省空间，我将其打印为两列，每列有10行。

以下是我的代码：

\documentclass[11pt, a4paper]{article}
\usepackage[margin=3cm]{geometry}
\usepackage{longtable}

\begin{document}

<<echo=FALSE,results='asis'>>=
library(xtable)
set.seed(1)

spaceCol =  rep("     ",10)
df1 = data.frame(student = letters[1:10], vals=runif(10, 1, 10))
df2 = data.frame(student = letters[11:20], vals=runif(10, 1, 10))
dfFull = data.frame(df1,spaceCol,df2)
names(dfFull) = c(" ","% Correct","     "," ", "% Correct")
row.names(dfFull) = NULL

x.big <- xtable(dfFull, label ='tabtwo',caption ='Caption for table with student scores')
print(x.big, tabular.environment ='longtable', floating = FALSE, include.rownames=FALSE)
@

\end{document}

这是输出的样子：

我喜欢这种输出的美学，特别是因为在longtable格式中，如果需要，此输出将自动分页。但是，我正在努力改进的是，更容易想象这个输出实际上是两个不同的列。

为此，我想在两列之间添加一个空格，因此输出看起来更像如下：

但是，如果证明这是不可能的，那么我可以考虑添加一条垂直线来区分两列，如下所示：

鉴于我使用xtable的限制，这怎么可能？

Answer 1

\documentclass[11pt, a4paper]{article}

\usepackage{subfig}

\begin{document}

<<echo = FALSE>>=
library(xtable)

opts_chunk$set(
  echo = FALSE,
  results = 'asis'
)

set.seed(1)

mynames <- c("", "% Correct")

df1 = data.frame(letters[1:10], runif(10, 1, 10))
df2 = data.frame(student = letters[11:20], vals=runif(10, 1, 10))

colnames(df1) <- mynames
colnames(df2) <- mynames
@

\begin{table}\centering
\subfloat{
<<>>=
print(xtable(df1), floating = FALSE, include.rownames = FALSE)
@
} \hspace{2cm}
\subfloat{
<<>>=
print(xtable(df2), floating = FALSE, include.rownames = FALSE)
@
}
\caption{Caption for table with student scores} \label{tabtwo}
\end{table}
\end{document}

唯一的缺点是，您不能使用longtable这种方法。

更新：以下是使用longtable的替代方法。诀窍是只对表的xtable使用contents并手动构建标题，这样你就可以完全控制所有行等。我决定使用空列来表示空间，因为制作第2列更宽会使水平线看起来很丑。

\documentclass{article}

\usepackage{longtable}

\begin{document}
\thispagestyle{empty}

<<echo = FALSE>>=
library(xtable)

opts_chunk$set(
  echo = FALSE,
  results = 'asis'
)

set.seed(1)

df1 = data.frame(letters[1:10], runif(10, 1, 10))
df2 = data.frame(student = letters[11:20], vals=runif(10, 1, 10))

dfFull <- cbind(df1, NA, df2)
@

\begin{longtable}{lrl@{\hskip 2cm}lr} \cline{1-2} \cline{4-5}
 & \% Correct & & & \% Correct \\ \cline{1-2} \cline{4-5}
<<>>=
print(xtable(dfFull), only.contents = TRUE, include.rownames = FALSE, include.colnames = FALSE, hline.after = NULL)
@
\cline{1-2} \cline{4-5}
\caption{Caption for table with studen scores} \label{tabtwo}
\end{longtable}
\end{document}

UPDATE2 ：最后，使用longtable的解决方案并不涉及创建表的一半＆＃34;手动＆＃34;。诀窍是删除所有水平线（hline.after = NULL），然后使用\clines（受this question启发）在需要时添加add.to.row。

\documentclass{article}

\usepackage{longtable}

\begin{document}
\thispagestyle{empty}

<<echo = FALSE, results = 'asis'>>=
library(xtable)

set.seed(1)


df1 = data.frame(letters[1:10], runif(10, 1, 10))
df2 = data.frame(letters[11:20], runif(10, 1, 10))

dfFull <- cbind(df1, NA, df2)

# To test "longtable", rbind data several times:
multiply <- 5
dfFull <- do.call("rbind", replicate(multiply, dfFull, simplify = FALSE))

colnames(dfFull) <- c("", "% Correct", "", "", "% Correct")

print(xtable(dfFull,
             caption = "Caption for table with student scores",
             label = "tabtwo",
             align = c("l",  # ignored (would apply to colnames)
                       "l", "r",
                       "l@{\\hskip 2cm}", # space between blocks
                       "l", "r")),
      include.rownames = FALSE,
      include.colnames = TRUE,
      hline.after = NULL, # Remove all default lines. A line after the very last row remains, which is automatically added when using "longtable".
      tabular.environment = "longtable",
      floating = FALSE,
      add.to.row = list(
        pos = list(-1, 0),
        command = rep("\\cline{1-2} \\cline{4-5}", 2))
      )
@
\end{document}