如何在 R Markdown pdf 文档中多次更改列数？

Question

我正在使用 R Markdown 创建一个 .pdf。我想要一段两列格式的文本，然后用一个占据整个页面宽度的图表（或表格、照片等），然后返回两列文本。我是 Markdown / LaTex / Pandoc 的新手，我不知道该怎么做。

@AlisonShelton 的This answer 似乎是我想要的，但是当我运行它时，我在 RStudo R Markdown 控制台中收到此错误：

！未定义的控制序列。
l.87 \btwocol
pandoc.exe：生成 PDF 时出错
错误：pandoc 文档转换失败，错误 43

我已经成功使用@scoa 的this method 制作了一个两列的.pdf，但我不知道如何使用它在一列和两列之间来回切换。

这是一些用于测试目的的示例代码

    ---
    title: "Test"
    output: pdf_document
    ---

    ```{r setup, include=FALSE}
    knitr::opts_chunk$set(echo = TRUE)
    ```

    ## Two columns of text

    This seciton should be in two column format.
    Here are a bunch of ? to make it longer: ???????????????????????????????????????????????????????????????????????????????
    ????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????
    ??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????
    ??????????????????????????????????????????????????????????????????????????????????????????????????????????????????

## Once column section. 
This part should be the whole page width
```{r plot}
plot(rnorm(20),rnorm(20))
```

## Now 2 columns again
This section should go back to two columns  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer 1

首先，您可以做的是，如您所说，将pandoc_args: ... 添加到您的 YAML 标头中。其次，有一些 LaTeX 解决方案（如 this 或 this one）不适用于 RMarkdown。到目前为止，我发现的唯一方法是使用 \onyecolumn / \twocolumn - 只是有分页符的缺点。但也许你可以忍受它，直到有更好的解决方案。

---
title: "Test"
output:
  pdf_document: 
    pandoc_args: [
      "-V", "classoption=twocolumn"
    ]
  html_document: default
header-includes:
- \usepackage{lipsum}  # just used for producing example text in document
---
```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```

## Two columns of text
\lipsum[1-7]
\onecolumn

## Once column section. 
This part should be the whole page width
```{r plot}
plot(rnorm(20),rnorm(20))
```
\lipsum[1]
\twocolumn

## Now 2 columns again
This section should go back to two columns
\lipsum

\begin{table*}
This is nice, but won't work with R chunks or headers. And you'll have to format with LaTeX code (e.g. \textbf{Foo blaah}).
\lipsum[1]
\end{table*}
\lipsum