Question

使用 Rstudio 编辑 Rmarkdown 文件，我使用HTML注释标记出我不想处理或输出的大块。这在Rstudio中工作得很好，它忽略了注释中的所有内容。但是，当我要求Rstudio编织文档时， knitr 正在评论中执行 R 代码块。

这是一个MWE .Rmd文件：

# Important stuff I want to see
This is what I want to see:
```{r}
pi # I like pi
```
<!---
**This section commented out, as not ready to be knit yet**
This is what I do not want to see:
```{r}
cake # I also like cake, but it's undefined
```
-->

这导致knitr失败并显示Error in eval(expr, envir, enclos) : object 'cake' not found ... Execution halted

是否有一种简单的方法可以注释掉整个Rmarkdown文件，以防止knitr在评论中执行R代码块？

我查看了global comment option for R markdown in knitr和Comments in Markdown以及https://yihui.name/knitr/，但没有找到解决方案。

Answer 1

考虑到jburkhardt使用eval=F的想法，这可以作为一种方法来执行块注释，其中knitr不执行R代码块：

Stuff I want to see...
```{r}
pi
```

<!--
This is added at the beginning of the comment:
```{r, include=FALSE}
knitr::opts_chunk$set(eval= FALSE)
```

Stuff I have commented out:

```{r}
cake
```

This is added to the end of the comment:
```{r, include=FALSE, eval=TRUE}
knitr::opts_chunk$set(eval= TRUE)
```
-->

More stuff I want to see:
```{r}
2*pi
```

它有点笨重，而且肯定不是防弹的（例如，knitr仍会运行它使用显式eval=true找到的任何代码块），但它适用于我的情况。

Answer 2

选择{r}代码块之前和之后的行，并使用Control / Shift-C（pc）注释掉。你会得到这种语法;它不会编织，也不会出错。

<!-- **This section commented out, as not ready to be knit yet** -->
<!-- This is what I do not want to see: -->
<!-- ```{r} -->
<!-- cake # I also like cake, but it's undefined -->
<!-- ``` -->

Answer 3

在第二段代码垃圾中，您可以设置eval=F，直到完成此部分代码。

<!--
**This section commented out, as not ready to be knit yet**
This is what I do not want to see:
```{r eval=F}
cake # I also like cake, but it's undefined
```
-->

knitr在HTML风格的评论中执行R代码块

3 个答案: