將兩條命令添加到xtable中的add.to.row參數

Question

我已經使用了以下兩個答案向xtable中的交替行添加顏色或向長表添加頁腳，但是我需要弄清楚如何執行都。

（1）How to only show table caption once in "list of table" for a table split onto multiple pages和

（2） R, knitr, xtable, alternating row colors

是否有同時使用這兩種方式？

Answer 1

從你列出的答案看來，你用LaTeX作爲輸出。您可以通過爲每個命令分配一個位置來組合兩個或多個add.to.row命令。命令必須是模式爲character的矢量，並且位置必須在列表中。在下面，我創建一個清單addtorow <- list()，然後分配職位：addtorow$pos <- as.list(c(rowIndexForFirstCommands, rowIndexForSecondCommands))及其相應的命令addtorow$command <- as.vector(c(firstCommands, secondCommands),mode="character")。這是一個最小的工作示例：

\documentclass{article} 
\usepackage[utf8]{inputenc} 
\usepackage[T1]{fontenc} 
\usepackage[english]{babel} 
\usepackage{longtable} 
\usepackage[table]{xcolor} 
\begin{document} 

<<yoman,echo=FALSE,results='asis'>>= 
library(xtable) 
#define a data frame 
mydf <- data.frame(id = make.unique(rep(letters, length.out = 100), sep=''), 
        var1 = rnorm(100), 
        var2 = runif(100), 
        var3=rexp(100), 
        var4=rpois(100,1.4)) 

#define row indexes to be highlighted (each two), 
#and repeat rowcolor command correspondingly 
rws <- seq(1, (nrow(mydf)), by = 2) 
col <- rep("\\rowcolor[gray]{0.95}", length(rws)) 

#create a list that will receive the instructions 
#for add.to.row and add the two instructions 
addtorow <- list() 

#assign a position argument to addtorow 
#rws are the row indexes for the row to be colored, 
#0 is the row index for longtable argument 
addtorow$pos <- as.list(c(
         rws, #positions for first commands(highlighting rows) 
         0 #position for second command (longtable argument) 
         )) 

#assign corresponding commands to addtorow 
addtorow$command <- as.vector(c(col, #first command (highlighting rows) 
           paste("\\hline \n", 
             "\\endhead \n", 
             "\\hline \n", 
             "{\\footnotesize Continued on next page} \n", 
             "\\endfoot \n", 
             "\\endlastfoot \n", 
             sep="")), #second command (longtable) 
           mode="character") 
print(xtable(mydf, 
      caption = "My caption "), 
      tabular.environment = "longtable", 
      floating = FALSE, 
      include.colnames = TRUE, 
      include.rownames = TRUE, 
      add.to.row = addtorow,  
      hline.after=c(-1),  # addtorow substitute default hline for first row 
      caption.placement="top") 

@ 

\end{document}