在R markdown中隐藏评论

Question

使用knitr / R markdown编织时，是否可以在代码中隐藏一些注释？例如：

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


---

```{r}

# Generate some data

rnorm(2)

## But keep this comment

```

在编织时，我希望第一个评论消失，但保留第二个不知何故。

Answer 1

这是一个修改钩子以改变编织者行为的快速示例。

---
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

```

生成此

Answer 2

实际上，您可以通过将数字索引传递给块选项echo来选择显示任何R代码行，例如

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

```{r echo=4:7}

# Generate some data

rnorm(2)

## But keep this comment

```

有关详细信息，请参阅knitr documentation。