在R markdown中隱藏評論

Question

當使用knitr/R markdown進行鍼織時，可以在代碼中隱藏一些註釋嗎？例如：

--- 
title: "SOSO" 
author: "SO" 
date: '2017-06-06' 
output: pdf_document 


--- 

```{r} 

# Generate some data 

rnorm(2) 

## But keep this comment 

``` 

編織時，我想第一個評論放棄，但保持第二個莫名其妙。

Answer 1

下面是一個修改掛鉤以改變knitr行爲的快速示例。

--- 
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 

``` 

產生此

Answer 2

事實上，可以選擇通過傳遞數字索引到塊選項echo，例如以顯示R代碼裏面的任何行

--- 
title: "SOSO" 
author: "SO" 
date: '2017-06-06' 
output: pdf_document 
--- 

```{r echo=4:7} 

# Generate some data 

rnorm(2) 

## But keep this comment 

``` 

更多信息請參見knitr documentation。