将 data.frame 从 R 转置为没有“rownumber”（和 booktabs）的 Latex

Question

我想在 R 中转置（即向量作为列）一个 data.frame 并将其导出到没有行号但有列的 Latex。我想要这样的输出：

但是

df <- data.frame(qwertz=c("a","b","c","d","e","f"), asdfg=c("a","b"))

即

    qwertz asdfg
1      a     a
2      b     b
3      c     a
4      d     b
5      e     a
6      f     b

当我使用 xtable 和 booktabs 时

library(xtable)
print(xtable(t(df)), include.colnames=FALSE, booktabs=TRUE)

乳胶输出是

即

print(xtable(t(df)), include.colnames=FALSE, booktabs=TRUE)
% latex table generated in R 3.0.2 by xtable 1.7-1 package
\begin{table}[ht]
    \centering
    \begin{tabular}{rllllll}
      \toprule
      \midrule
        qwertz & a & b & c & d & e & f \\ 
         asdfg & a & b & a & b & a & b \\ 
      \bottomrule
    \end{tabular}
\end{table}

问题：我怎样才能在两行之间直接使用\midrule？

我也尝试使用来自ENmisc 的toLatex() 和来自Hmisc 的Latex()，并且在阅读了这两个问题之后：

https://tex.stackexchange.com/q/25575/36408

https://tex.stackexchange.com/q/75793/36408

Answer 1

你可以使用add.to.row参数

library(xtable)
df <- data.frame(qwertz=c("a","b","c","d","e","f"), asdfg=c("a","b"))
df <- t(df)
n <- nrow(df)

print(xtable(df), hline.after = NULL,
      include.colnames = FALSE,
      add.to.row = list(pos = list(0, 1, n),
      command = c('\\toprule[1.5pt]\n', '\\midrule[1pt]\n', '\\bottomrule[1.5pt]\n')))
## % latex table generated in R 3.0.2 by xtable 1.7-1 package
## % Sat Jan 25 14:32:34 2014
## \begin{table}[ht]
## \centering
## \begin{tabular}{rllllll}
##   \toprule[1.5pt]
##  qwertz & a & b & c & d & e & f \\ 
##    \midrule[1pt]
## asdfg & a & b & a & b & a & b \\ 
##    \bottomrule[1.5pt]
## \end{tabular}
## \end{table}

要在longtable LaTeX 环境中使用它，你可以这样做

print(xtable(df),
      tabular.environment = "longtable",
      floating = FALSE,
      hline.after = NULL,
      include.colnames = FALSE,
      booktabs = TRUE,
      add.to.row = list(pos = list(0, 1, n),
      command = c('\\toprule[1.5pt]\n', '\\midrule[1pt]\n', '\\bottomrule[1.5pt]\n')))
## % latex table generated in R 3.0.2 by xtable 1.7-1 package
## % Mon Jan 27 13:00:01 2014
## \begin{longtable}{rllllll}
##    \toprule[1.5pt]
## qwertz & a & b & c & d & e & f \\ 
##    \midrule[1pt]
## asdfg & a & b & a & b & a & b \\ 
##    \bottomrule[1.5pt]
## \end{longtable}