在R Markdown中為代碼塊添加換行符

Question

我正在使用帶有R Markdown的knitr包來創建HTML報告。 使用'+'時，我在將代碼保持在單獨的行上時遇到了一些麻煩。

例如，

```{r}
ggplot2(mydata, aes(x, y)) +
   geom_point()
```

將返回以下HTML文檔

ggplot2(mydata, aes(x, y)) + geom_point()

通常情況下這很好，但是一旦我開始添加額外的行就會出現問題，我希望將其分開以使代碼更容易理解。 運行以下內容：

```{r}
ggplot2(mydata, aes(x, y)) +
   geom_point() +
   geom_line() +
   opts(panel.background = theme_rect(fill = "lightsteelblue2"),
        panel.border = theme_rect(col = "grey"),
        panel.grid.major = theme_line(col = "grey90"),
        axis.ticks = theme_blank(),
        axis.text.x  = theme_text (size = 14, vjust = 0),
        axis.text.y  = theme_text (size = 14, hjust = 1.3))
```

將導致所有代碼出現在一行中，使得更難以遵循：

ggplot2(mydata, aes(x, y)) + geom_point() + geom_line() + opts(panel.background = theme_rect(fill = "lightsteelblue2"), panel.border = theme_rect(col = "grey"), panel.grid.major = theme_line(col = "grey90"), axis.ticks = theme_blank(), axis.text.x  = theme_text (size = 14, vjust = 0), axis.text.y  = theme_text (size = 14, hjust = 1.3))

任何幫助解決這個問題將不勝感激！

Answer 1

try chunk option tidy = FALSE ：

```{r tidy=FALSE}
ggplot2(mydata, aes(x, y)) +
  geom_point() +
  geom_line() +
  opts(panel.background = theme_rect(fill = "lightsteelblue2"),
       panel.border = theme_rect(col = "grey"),
       panel.grid.major = theme_line(col = "grey90"),
       axis.ticks = theme_blank(),
       axis.text.x  = theme_text (size = 14, vjust = 0),
       axis.text.y  = theme_text (size = 14, hjust = 1.3))
```

Answer 2

我發現將塊的“整潔”設置更改為false的一種方法是添加一個中間命令注釋 。 這似乎使整個塊處理為非整潔，從而尊重您在代碼中擁有（或沒有）的換行符。 不幸的是，這不會在特定位置（對於特定行）添加換行符。

示例：將下面的原始文本復制到Rmd文件中並使用knitr進行處理。

整理（即默認）

輸入

```{r eval=FALSE}
# Line comments do not seem to change tidiness.
list(
    sublist=list( 
        suba=10, subb=20 ),
    a=1,
    b=2 ) # End of line comment does not seem to change tidiness.

list(
    sublist=list( 
        suba=10, subb=20 ),
    a=1,
    b=2 )

```

產量

# Line comments do not seem to change tidiness.
list(sublist = list(suba = 10, subb = 20), a = 1, b = 2) # End of line comment does not seem to change tidiness.

list(sublist = list(suba = 10, subb = 20), a = 1, b = 2)

Untidied

輸入

```{r eval=FALSE}
list(
    sublist=list( 
        suba=10, subb=20 ),
    a=1, # Mid-command comment seems to "untidy" the chunk.
    b=2 )

list(
    sublist=list( 
        suba=10, subb=20 ),
    a=1,
    b=2 )

```

產量

list(
    sublist=list(
        suba=10, subb=20 ),
    a=1, # Mid-command comment seems to "untidy" the chunk.
    b=2 )

list(
    sublist=list(
        suba=10, subb=20 ),
    a=1,
    b=2 )