问题
Is is possible to hide some comments in code when kniting using knitr / R markdown? Example:
---
title: "SOSO"
author: "SO"
date: '2017-06-06'
output: pdf_document
---
```{r}
# Generate some data
rnorm(2)
## But keep this comment
```
When kniting I would like the first comment to disapear, but keep the second one somehow.
回答1:
Here is a quick example of modifying the hook to change knitr behavior.
---
title: "SOSO"
author: "SO"
date: 2017-06-06
output: pdf_document
---
```{r setup-hook, echo=FALSE}
hook_in <- function(x, options) {
x <- x[!grepl("^#\\s+", x)]
paste0("```r\n",
paste0(x, collapse="\n"),
"\n```")
}
knitr::knit_hooks$set(source = hook_in)
```
```{r}
# Generate some data
# Lines that starts with `# ` will be removed from the rendered documents
rnorm(2)
## But keep this comment
## But lines that starts with `## ` will be kept
```
produces this
回答2:
In fact, you can choose to show any lines of R code by passing numeric indices to the chunk option echo, e.g.
---
title: "SOSO"
author: "SO"
date: '2017-06-06'
output: pdf_document
---
```{r echo=4:7}
# Generate some data
rnorm(2)
## But keep this comment
```
See knitr documentation for more information.
来源：https://stackoverflow.com/questions/44399048/hide-comments-in-r-markdown