在knitr输出中进行文本换行长字符串（RStudio）

I have a long vector string (DNA sequence) of up to a couple of thousand sequential characters that I want to add to my knitr report output. RStudio handles the text wrapping perfectly in the console but when I generate the knitr html output I can see only one line of text and it just runs off the page.

我有一个长的矢量字符串(DNA序列),我想要添加到我的knitr报告输出中的几千个连续字符。 RStudio在控制台中完美地处理文本包装,但是当我生成knitr html输出时,我只能看到一行文本,它只是在页面上运行。

RStudio output

knitr output

Any way of adjusting knitr output to wrap text?

有没有什么方法可以调整knitr输出来换行文字?

Thanks.

1 个解决方案

#1

I recommend you to try the R Markdown v2. The default HTML template does text wrapping for you. This is achieved by the CSS definitions for the HTML tags pre/code, e.g. word-wrap: break-word; word-break: break-all;. These definitions are actually from Bootstrap (currently rmarkdown uses Bootstrap 2.3.2).

我建议你试试R Markdown v2。默认的HTML模板为您进行文本换行。这是通过HTML标签pre / code的CSS定义来实现的,例如自动换行:break-word;分手:打破一切;这些定义实际上来自Bootstrap(目前rmarkdown使用Bootstrap 2.3.2)。

You were still using the first version of R Markdown, namely the markdown package. You can certainly achieve the same goal using some custom CSS definitions, and it just requires you to learn more about HTML/CSS.

您仍在使用R Markdown的第一个版本,即降价包。您当然可以使用一些自定义CSS定义来实现相同的目标,它只需要您了解有关HTML / CSS的更多信息。

Another solution is to manually break the long string using the function str_break() I wrote below:

另一个解决方案是使用我在下面写的函数str_break()手动中断长字符串:

A helper function `str_break()`:

```{r setup}
str_break = function(x, width = 80L) {
  n = nchar(x)
  if (n <= width) return(x)
  n1 = seq(1L, n, by = width)
  n2 = seq(width, n, by = width)
  if (n %% width != 0) n2 = c(n2, n)
  substring(x, n1, n2)
}
```

See if it works:

```{r test}
x = paste(sample(c('A', 'C', 'T', 'G'), 1000, replace = TRUE), collapse = '')
str_break(x)
cat(str_break(x), sep = '\n')
```