RMarkdown - print() 命令导致成套 PDF 中的页面边界线越界

Question

如果您将 RMarkdown 文档编织成 PDF，是否有任何方法可以避免超出页面边缘的线条？

插图：

# RMarkdown file
    title: "xyz"
    author: "John Doe"
    date: "23 2 2021"
    output:
      pdf_document: 
        latex_engine: xelatex
          toc: true
          toc_depth: 5
     html_document: default
     mainfont: Times New Roman
     fontsize: 12

text
more text
```{r}
  print("This is a very long line illustrating my question that drives me nuts. It should include more text that is supposed line-break if it goes beyond specified margins.)

  a <- 10
  b <- sqrt(2)
 
  print(paste("This is also a use case that I am looking at right now. I want to print results in the PDF documents of a calcualtion and put it in context.", a, "divided by square root of 2 results in", (a/b))

 ```

如果文本超出范围，有什么方法可以强制换行？我尝试在 Markdown 文件中编辑 YAML 标头，创建前导文件并在 YAML 标头中引用它们，尝试各种乳胶引擎将我的文档编织为 PDF，定义 PDF 文档的边距，手动拆分长 print() 调用以跨越几行在源文件中并遵守最大值。每行的字符数，但到目前为止都失败了。 HTML 输出似乎还不错。

非常感谢任何提示过去已经提供的答案，因为我确信我不是唯一遇到此类问题的人，但不幸的是我无法找到合适的解决我的问题。

Answer 1

一种可能的解决方案是使用“--listings”（根据https://bookdown.org/yihui/rmarkdown-cookbook/text-width.html）更改宽度，例如

在您要编织的目录中创建一个名为“preamble.tex”的文件并包含以下行：

\lstset{
  breaklines=true
}

然后更改 YAML 并编织：

> --- title: "xyz" author: "John Doe" date: "23 2 2021" output:
>     pdf_document:
>         pandoc_args: --listings
>         toc: true
>         toc_depth: 5
>         includes:
>             in_header: preamble.tex
>     html_document: default
>     mainfont: Times New Roman
>     fontsize: 12
> ---
> 
> ```{r setup, include=FALSE}
> knitr::opts_chunk$set(echo = TRUE)
> options(width = 80)
> ```
> 
> text
> more text
> ```{r}
> print("This is a very long line illustrating my
> question that drives me nuts. It should include more text that is
> supposed line-break if it goes beyond specified margins.")
> 
> a <- 10 b <- sqrt(2)   paste("This is also a use case that I am
> looking at right now. I want to print results in the PDF documents of
> a calcualtion and put it in context.", a, "divided by square root of 2
> results in", a/b, sep = " ")
> ```
> 
> ## R Markdown
> 
> This is an R Markdown document. Markdown is a simple formatting syntax
> for authoring HTML, PDF, and MS Word documents. For more details on
> using R Markdown see <http://rmarkdown.rstudio.com>.
> 
> When you click the **Knit** button a document will be generated that
> includes both content as well as the output of any embedded R code
> chunks within the document. You can embed an R code chunk like this:
> 
> ```{r cars}
> summary(cars)
> ```
> 
> ## Including Plots
> 
> You can also embed plots, for example:
> 
> ```{r pressure, echo=FALSE}
> plot(pressure)
> ```
> 
> Note that the `echo = FALSE` parameter was added to the code chunk to
> prevent printing of the R code that generated the plot.

编辑

另一个可能的解决方案（我通常做的）是在 {r setup} 块中使用 options(width = 80) 将 RMarkdown 输出为 html，然后使用 https://wkhtmltopdf.org/ 将 html 转换为 pdf。如果您使用的是 macOS，您可以使用 homebrew (brew install wkhtmltopdf) 安装 wkhtmltopdf。这种方法的优点是它可以维护任何特定于 html 的格式，即您可以使用主题