r - 设置xtable生成的longtable的列对齐方式和宽度

请考虑以下MWE

library(xtable)
DF <- as.data.frame(UCBAdmissions)
print(xtable(DF, align="p{0.4\textwidth}|p{0.15\textwidth} p{0.15\textwidth} p{0.15\textwidth}"), sanitize.text.function = function(x){x},
      table.placement="!htp", include.rownames=FALSE,
      tabular.environment='longtable',floating=FALSE)

我想像这样设置longtable的对齐方式

\begin{longtable}{p{0.4\textwidth}|p{0.15\textwidth} p{0.15\textwidth} p{0.15\textwidth}}

仍然当我尝试将参数传递给xtable对象时，我得到了

Warning message:
In .alignStringToVector(value) : Nonstandard alignments in align string
Error in print(xtable(DF, align = "p{0.4\textwidth}|p{0.15\textwidth} p{0.15\textwidth} p{0.15\textwidth}"),  :
  error in evaluating the argument 'x' in selecting a method for function 'print': Error in `align<-.xtable`(`*tmp*`, value = "p{0.4\textwidth}|p{0.15\textwidth} p{0.15\textwidth} p{0.15\textwidth}") :
  "align" must have length equal to 5 ( ncol(x) + 1 )

我知道我应该为第5列添加对齐方式（如何？），但我也不了解错误消息。我应该对琴弦进行消毒吗？

最佳答案

我无法对此进行测试，但是我认为您需要对字符串中的反斜杠应用标准R转义，删除多余的“ \”并添加缺少的“竖线”（|）。然后align<-成功，但仅显示警告：

xtb <- xtable(DF,
       table.placement="!htp", include.rownames=FALSE,
       tabular.environment='longtable',floating=FALSE)
align(xtb) <- "p{0.4\\textwidth}|p{0.15\\textwidth}|p{0.15\\textwidth}| p{0.15\\textwidth}"
#Warning message:
#In .alignStringToVector(value) : Nonstandard alignments in align string
 print(xtb)

要么：

xtb <- xtable(DF, type="latex",
      table.placement="!htp", include.rownames=FALSE,
      tabular.environment='longtable',floating=FALSE, align= c("p{0.15\\textwidth}",
"p{0.4\\textwidth}", "p{0.15\\textwidth}|", "p{0.15\\textwidth}", "p{0.15\\textwidth}"
))